gcc-4.4.0/libstdc++-v3/doc/html/ext/lwg-defects.html - toolchain/gcc - Git at Google

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 <td align="left">Doc. no.</td>
 <td align="left">N2728=08-0238</td>
 </tr>
 <tr>
 <td align="left">Date:</td>
 <td align="left">2008-08-24</td>
 </tr>
 <tr>
 <td align="left">Project:</td>
 <td align="left">Programming Language C++</td>
 </tr>
 <tr>
 <td align="left">Reply to:</td>
 <td align="left">Howard Hinnant &lt;<a href="mailto:howard.hinnant@gmail.com">howard.hinnant@gmail.com</a>&gt;</td>
 </tr>
 </tbody></table>
 <h1>C++ Standard Library Defect Report List (Revision R59)</h1>

   <p>Reference ISO/IEC IS 14882:1998(E)</p>
   <p>Also see:</p>
     <ul>
       <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-toc.html">Table of Contents</a> for all library issues.</li>
       <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html">Index by Section</a> for all library issues.</li>
       <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html">Index by Status</a> for all library issues.</li>
       <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html">Library Active Issues List</a></li>
       <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html">Library Closed Issues List</a></li>
     </ul>
   <p>This document contains only library issues which have been closed
   by the Library Working Group (LWG) after being found to be defects
   in the standard.  That is, issues which have a status of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>,
   <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>, or <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#RR">RR</a>. See the
   <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html">Library Closed Issues List</a> for issues closed as non-defects.  See the
   <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html">Library Active Issues List</a> for active issues and more information.  The
   introductory material in that document also applies to this
   document.</p>

 <h2>Revision History</h2>
 <ul>
 <li>R59:
 2008-08-22 pre-San Francisco mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>192 open issues, up by 9.</li>
 <li>686 closed issues, up by 0.</li>
 <li>878 issues total, up by 9.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#870">870</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#871">871</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#872">872</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#873">873</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#874">874</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#875">875</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#876">876</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#877">877</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#878">878</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R58:
 2008-07-28 mid-term mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>183 open issues, up by 12.</li>
 <li>686 closed issues, down by 4.</li>
 <li>869 issues total, up by 8.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#862">862</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#863">863</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#864">864</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#865">865</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#866">866</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#867">867</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#868">868</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#869">869</a>.</li>
 <li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#393">393</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>.</li>
 <li>Changed the following issues from Pending WP to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#644">644</a>.</li>
 <li>Changed the following issues from WP to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#629">629</a>.</li>
 <li>Changed the following issues from Pending NAD Editorial to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#709">709</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R57:
 2008-06-27 post-Sophia Antipolis mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>171 open issues, down by 20.</li>
 <li>690 closed issues, up by 43.</li>
 <li>861 issues total, up by 23.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#840">840</a>.</li>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#841">841</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#843">843</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#845">845</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#846">846</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#847">847</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#849">849</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#853">853</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#854">854</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#855">855</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#856">856</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#857">857</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#858">858</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#859">859</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#860">860</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#861">861</a>.</li>
 <li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#839">839</a>.</li>
 <li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#842">842</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#844">844</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#848">848</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#850">850</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#852">852</a>.</li>
 <li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#851">851</a>.</li>
 <li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#826">826</a>.</li>
 <li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#570">570</a>.</li>
 <li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#786">786</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#831">831</a>.</li>
 <li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>.</li>
 <li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#723">723</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#726">726</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#794">794</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#815">815</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#833">833</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>.</li>
 <li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>.</li>
 <li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#711">711</a>.</li>
 <li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#713">713</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#714">714</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#769">769</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#772">772</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#779">779</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#787">787</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#805">805</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#806">806</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#807">807</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#808">808</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#809">809</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#813">813</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#824">824</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#829">829</a>.</li>
 <li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#396">396</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#522">522</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#762">762</a>.</li>
 <li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#691">691</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#776">776</a>.</li>
 <li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#692">692</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#698">698</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#804">804</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#823">823</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#828">828</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#832">832</a>.</li>
 <li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#23">23</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#803">803</a>.</li>
 <li>Changed the following issues from Ready to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#758">758</a>.</li>
 <li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#595">595</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#789">789</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#792">792</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#798">798</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R56:
 2008-05-16 pre-Sophia Antipolis mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>191 open issues, up by 24.</li>
 <li>647 closed issues, up by 1.</li>
 <li>838 issues total, up by 25.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#814">814</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#815">815</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#816">816</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#818">818</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#819">819</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#820">820</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#821">821</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#823">823</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#824">824</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#826">826</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#827">827</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#828">828</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#829">829</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#831">831</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#832">832</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#833">833</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#836">836</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#837">837</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#838">838</a>.</li>
 <li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#802">802</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R55:
 2008-03-14 post-Bellevue mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>167 open issues, down by 39.</li>
 <li>646 closed issues, up by 65.</li>
 <li>813 issues total, up by 26.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following Dup issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#795">795</a>.</li>
 <li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#790">790</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#791">791</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#796">796</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#797">797</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#799">799</a>.</li>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#788">788</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#794">794</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#802">802</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#804">804</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#805">805</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#806">806</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#807">807</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#808">808</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#809">809</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#810">810</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#811">811</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#812">812</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#813">813</a>.</li>
 <li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#793">793</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#800">800</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#801">801</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#803">803</a>.</li>
 <li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#789">789</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#792">792</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#798">798</a>.</li>
 <li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#116">116</a>.</li>
 <li>Changed the following issues from NAD Future to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#188">188</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>.</li>
 <li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#729">729</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#730">730</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#731">731</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#733">733</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#735">735</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#736">736</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#737">737</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#739">739</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#741">741</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#745">745</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#748">748</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#763">763</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#764">764</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#773">773</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#784">784</a>.</li>
 <li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#462">462</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#579">579</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>.</li>
 <li>Changed the following issues from NAD Future to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>.</li>
 <li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#626">626</a>.</li>
 <li>Changed the following issues from Review to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>.</li>
 <li>Changed the following issues from NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#128">128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#190">190</a>.</li>
 <li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#617">617</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#718">718</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#719">719</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#732">732</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#747">747</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#750">750</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#753">753</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#760">760</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#762">762</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a>.</li>
 <li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#688">688</a>.</li>
 <li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#709">709</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#717">717</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#725">725</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#738">738</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>.</li>
 <li>Changed the following issues from Open to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#625">625</a>.</li>
 <li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>.</li>
 <li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>.</li>
 <li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>.</li>
 <li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#776">776</a>.</li>
 <li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>.</li>
 <li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#561">561</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#562">562</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#563">563</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>.</li>
 <li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R54:
 2008-02-01 pre-Bellevue mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>206 open issues, up by 23.</li>
 <li>581 closed issues, up by 0.</li>
 <li>787 issues total, up by 23.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#765">765</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#769">769</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#772">772</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#773">773</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#776">776</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#779">779</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#780">780</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#784">784</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#785">785</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#786">786</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#787">787</a>.</li>
 <li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#105">105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#348">348</a>.</li>
 <li>Changed the following issues from NAD Future to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#353">353</a>.</li>
 <li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#697">697</a>.</li>
 <li>Changed the following issues from NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>.</li>
 <li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R53:
 2007-12-09 mid-term mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>183 open issues, up by 11.</li>
 <li>581 closed issues, down by 1.</li>
 <li>764 issues total, up by 10.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#760">760</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#762">762</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#763">763</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#764">764</a>.</li>
 <li>Changed the following issues from NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#463">463</a>.</li>
 <li>Changed the following issues from Pending WP to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#607">607</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#608">608</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R52:
 2007-10-19 post-Kona mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>172 open issues, up by 4.</li>
 <li>582 closed issues, up by 27.</li>
 <li>754 issues total, up by 31.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#725">725</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#726">726</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#729">729</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#730">730</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#731">731</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#732">732</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#733">733</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#735">735</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#736">736</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#737">737</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#738">738</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#739">739</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#741">741</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#745">745</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#747">747</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#748">748</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#750">750</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#751">751</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#753">753</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>.</li>
 <li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#77">77</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>.</li>
 <li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#639">639</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#657">657</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#663">663</a>.</li>
 <li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#548">548</a>.</li>
 <li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#546">546</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#564">564</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#565">565</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#573">573</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#585">585</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#588">588</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#632">632</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#635">635</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#669">669</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#670">670</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#708">708</a>.</li>
 <li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#393">393</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>.</li>
 <li>Changed the following issues from New to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#607">607</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#608">608</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>.</li>
 <li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#561">561</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#562">562</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#563">563</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#595">595</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>.</li>
 <li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>.</li>
 <li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#691">691</a>.</li>
 <li>Changed the following issues from New to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#552">552</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#634">634</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#650">650</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#651">651</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#652">652</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#678">678</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#681">681</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#699">699</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#712">712</a>.</li>
 <li>Changed the following issues from Open to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#401">401</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#524">524</a>.</li>
 <li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#577">577</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R51:
 2007-09-09 pre-Kona mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>168 open issues, up by 15.</li>
 <li>555 closed issues, up by 0.</li>
 <li>723 issues total, up by 15.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#709">709</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#712">712</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#713">713</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#714">714</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#716">716</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#717">717</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#718">718</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#719">719</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#721">721</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#723">723</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R50:
 2007-08-05 post-Toronto mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>153 open issues, down by 5.</li>
 <li>555 closed issues, up by 17.</li>
 <li>708 issues total, up by 12.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#697">697</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#698">698</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#699">699</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#701">701</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#702">702</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#708">708</a>.</li>
 <li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#583">583</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#584">584</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#662">662</a>.</li>
 <li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#528">528</a>.</li>
 <li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#637">637</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#647">647</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#658">658</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#690">690</a>.</li>
 <li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#525">525</a>.</li>
 <li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
 <li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#579">579</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>.</li>
 <li>Changed the following issues from Pending WP to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>.</li>
 <li>Changed the following issues from Ready to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#644">644</a>.</li>
 <li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#577">577</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>.</li>
 <li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>.</li>
 <li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>.</li>
 <li>Changed the following issues from Ready to TRDec: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a>.</li>
 <li>Changed the following issues from DR to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#453">453</a>.</li>
 <li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R49:
 2007-06-23 pre-Toronto mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>158 open issues, up by 13.</li>
 <li>538 closed issues, up by 7.</li>
 <li>696 issues total, up by 20.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#678">678</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#681">681</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#690">690</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#691">691</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#692">692</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#696">696</a>.</li>
 <li>Added the following Pending NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#683">683</a>.</li>
 <li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#587">587</a>.</li>
 <li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#590">590</a>.</li>
 <li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R48:
 2007-05-06 post-Oxford mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>145 open issues, down by 33.</li>
 <li>531 closed issues, up by 53.</li>
 <li>676 issues total, up by 20.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#657">657</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#658">658</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#662">662</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#663">663</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#669">669</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#670">670</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>.</li>
 <li>Changed the following issues from Tentatively Ready to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>.</li>
 <li>Changed the following issues from Tentatively Ready to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#385">385</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#463">463</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#470">470</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#547">547</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#560">560</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>.</li>
 <li>Changed the following issues from NAD to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#351">351</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#357">357</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#368">368</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#499">499</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#555">555</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#558">558</a>.</li>
 <li>Changed the following issues from Tentatively Ready to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#482">482</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#615">615</a>.</li>
 <li>Changed the following issues from NAD_Future to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#77">77</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#105">105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#116">116</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#128">128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#149">149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#188">188</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#190">190</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#219">219</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#348">348</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#353">353</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>.</li>
 <li>Changed the following issues from Tentatively Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>.</li>
 <li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
 <li>Changed the following issues from Tentatively Ready to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#594">594</a>.</li>
 <li>Changed the following issues from Tentatively Ready to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>.</li>
 <li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>.</li>
 <li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a>.</li>
 <li>Changed the following issues from Ready to TRDec: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#598">598</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#599">599</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#600">600</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#601">601</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#602">602</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#603">603</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#605">605</a>.</li>
 <li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>.</li>
 <li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#201">201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#206">206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#416">416</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#422">422</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#456">456</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#576">576</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#578">578</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#586">586</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#589">589</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#611">611</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#613">613</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#616">616</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R47:
 2007-03-09 pre-Oxford mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>178 open issues, up by 37.</li>
 <li>478 closed issues, up by 0.</li>
 <li>656 issues total, up by 37.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#632">632</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#634">634</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#635">635</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#637">637</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#639">639</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#647">647</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#650">650</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#651">651</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#652">652</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
 <li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#625">625</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#626">626</a>.</li>
 <li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#570">570</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#580">580</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#582">582</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#590">590</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#614">614</a>.</li>
 <li>Changed the following issues from New to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#547">547</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#560">560</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#576">576</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#578">578</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#586">586</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#589">589</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#594">594</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#611">611</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#613">613</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#615">615</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#616">616</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
 <li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#201">201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#206">206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#385">385</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#416">416</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#422">422</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#456">456</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#463">463</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#470">470</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#482">482</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>.</li>
 <li>Changed the following issues from Review to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R46:
 2007-01-12 mid-term mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>141 open issues, up by 11.</li>
 <li>478 closed issues, down by 1.</li>
 <li>619 issues total, up by 10.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R45:
 2006-11-03 post-Portland mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>130 open issues, up by 0.</li>
 <li>479 closed issues, up by 17.</li>
 <li>609 issues total, up by 17.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#520">520</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#521">521</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a> to WP.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#554">554</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#555">555</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#558">558</a> to NAD.</li>
 <li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a> to Dup.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#523">523</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#524">524</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#597">597</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#606">606</a> to Open.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#598">598</a> - <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#603">603</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#605">605</a> to Ready.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a> to Review.</li>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R44:
 2006-09-08 pre-Portland mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>130 open issues, up by 6.</li>
 <li>462 closed issues, down by 1.</li>
 <li>592 issues total, up by 5.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#583">583</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R43:
 2006-06-23 mid-term mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>124 open issues, up by 14.</li>
 <li>463 closed issues, down by 1.</li>
 <li>587 issues total, up by 13.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#582">582</a>.</li>
 <li>Reopened <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#255">255</a>.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#520">520</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a> to Tentatively Ready.</li>
 </ul></li>
 </ul>
 </li>
 <li>R42:
 2006-04-21 post-Berlin mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>110 open issues, down by 16.</li>
 <li>464 closed issues, up by 24.</li>
 <li>574 issues total, up by 8.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#499">499</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#501">501</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#506">506</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#509">509</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#511">511</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#517">517</a> to NAD.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#502">502</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#503">503</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#522">522</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#525">525</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#548">548</a> to Open.</li>
 <li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#521">521</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a> to Ready.</li>
 <li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#247">247</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#294">294</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#369">369</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#376">376</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#384">384</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#475">475</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#495">495</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#497">497</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#505">505</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#507">507</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#508">508</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#519">519</a> to WP.</li>
 <li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a> to Review.</li>
 </ul></li>
 </ul>
 </li>
 <li>R41:
 2006-02-24 pre-Berlin mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>126 open issues, up by 31.</li>
 <li>440 closed issues, up by 0.</li>
 <li>566 issues total, up by 31.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>.</li>
 <li>Moved <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#342">342</a> from Ready to Open.</li>
 <li>Reopened <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#309">309</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R40:
 2005-12-16 mid-term mailing.
 <ul>
 <li><b>Summary:</b><ul>
 <li>95 open issues.</li>
 <li>440 closed issues.</li>
 <li>535 issues total.</li>
 </ul></li>
 <li><b>Details:</b><ul>
 <li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>.</li>
 </ul></li>
 </ul>
 </li>
 <li>R39:
 2005-10-14 post-Mont Tremblant mailing.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#528">528</a>.
 Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#280">280</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#461">461</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#464">464</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#465">465</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#467">467</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#468">468</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#474">474</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#496">496</a> from Ready to WP as per the vote from Mont Tremblant.
 Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#247">247</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#294">294</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#342">342</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#369">369</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#376">376</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#384">384</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#475">475</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#495">495</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#497">497</a> from Review to Ready.
 Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#498">498</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#506">506</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#509">509</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#510">510</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#511">511</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a> from New to Open.
 Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#505">505</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#507">507</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#508">508</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#519">519</a> from New to Ready.
 Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#500">500</a> from New to NAD.
 Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a> from New to Review.
 </li>
 <li>R38:
 2005-07-03 pre-Mont Tremblant mailing.
 Merged open TR1 issues in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#522">522</a>.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#523">523</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#523">523</a>
 </li>
 <li>R37:
 2005-06 mid-term mailing.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#498">498</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#503">503</a>.
 </li>
 <li>R36:
 2005-04 post-Lillehammer mailing. All issues in "ready" status except
 for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#454">454</a> were moved to "DR" status, and all issues
 previously in "DR" status were moved to "WP".
 </li>
 <li>R35:
 2005-03 pre-Lillehammer mailing.
 </li>
 <li>R34:
 2005-01 mid-term mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#494">494</a>.
 </li>
 <li>R33:
 2004-11 post-Redmond mailing. Reflects actions taken in Redmond.
 </li>
 <li>R32:
 2004-09 pre-Redmond mailing: reflects new proposed resolutions and
 new issues received after the 2004-07 mailing.  Added
 new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#481">481</a>.
 </li>
 <li>R31:
 2004-07 mid-term mailing: reflects new proposed resolutions and
 new issues received after the post-Sydney mailing.  Added
 new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#463">463</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>.
 </li>
 <li>R30:
 Post-Sydney mailing: reflects decisions made at the Sydney meeting.
 Voted all "Ready" issues from R29 into the working paper.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#460">460</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#462">462</a>.
 </li>
 <li>R29:
 Pre-Sydney mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#441">441</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#457">457</a>.
 </li>
 <li>R28:
 Post-Kona mailing: reflects decisions made at the Kona meeting.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#432">432</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#440">440</a>.
 </li>
 <li>R27:
 Pre-Kona mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#404">404</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#431">431</a>.
 </li>
 <li>R26:
 Post-Oxford mailing: reflects decisions made at the Oxford meeting.
 All issues in Ready status were voted into DR status.  All issues in
 DR status were voted into WP status.
 </li>
 <li>R25:
 Pre-Oxford mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#402">402</a>.
 </li>
 <li>R24:
 Post-Santa Cruz mailing: reflects decisions made at the Santa Cruz
 meeting.  All Ready issues from R23 with the exception of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, which has been given a new proposed resolution, were
 moved to DR status.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#383">383</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#389">389</a>.  (Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#387">387</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#389">389</a> were discussed
 at the meeting.)  Made progress on issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a>: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a> have been moved to Ready status, and the only remaining
 concerns with <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a> involve wording.
 </li>
 <li>R23:
 Pre-Santa Cruz mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#367">367</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#382">382</a>.
 Moved issues in the TC to TC status.
 </li>
 <li>R22:
 Post-Curaçao mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#366">366</a>.
 </li>
 <li>R21:
 Pre-Curaçao mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#351">351</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#361">361</a>.
 </li>
 <li>R20:
 Post-Redmond mailing; reflects actions taken in Redmond.  Added
 new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#336">336</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>, of which issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#347">347</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a> were added since Redmond, hence
 not discussed at the meeting.

 All Ready issues were moved to DR status, with the exception of issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#284">284</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">241</a>, and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>.

 Noteworthy issues discussed at Redmond include
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#120">120</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#202">202</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#270">270</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>.
 </li>
 <li>R19:
 Pre-Redmond mailing.  Added new issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#335">335</a>.
 </li>
 <li>R18:
 Post-Copenhagen mailing; reflects actions taken in Copenhagen.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#312">312</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#317">317</a>, and discussed
 new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#271">271</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#314">314</a>.

 Changed status of issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#118">118</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#136">136</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#153">153</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#165">165</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#171">171</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#183">183</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#184">184</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#185">185</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#186">186</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#214">214</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#221">221</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#234">234</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#237">237</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#243">243</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#248">248</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#251">251</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#252">252</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#256">256</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#260">260</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#261">261</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#262">262</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#263">263</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#265">265</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#268">268</a>
 to DR.

 Changed status of issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#49">49</a>  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#117">117</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#182">182</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#230">230</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#232">232</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#238">238</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">241</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#242">242</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#259">259</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#264">264</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#266">266</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#271">271</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#272">272</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#273">273</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#275">275</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#281">281</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#284">284</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#285">285</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#286">286</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#288">288</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#292">292</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#295">295</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#297">297</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#298">298</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#301">301</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#303">303</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#306">306</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#307">307</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#308">308</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#312">312</a>
 to Ready.

 Closed issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#277">277</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#279">279</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#287">287</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#289">289</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#293">293</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#302">302</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#313">313</a>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#314">314</a>
 as NAD.

 </li>
 <li>R17:
 Pre-Copenhagen mailing.  Converted issues list to XML.  Added proposed
 resolutions for issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#49">49</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#76">76</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#91">91</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>.
 Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#278">278</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#311">311</a>.
 </li>
 <li>R16:
 post-Toronto mailing; reflects actions taken in Toronto. Added new
 issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#265">265</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#277">277</a>.  Changed status of issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#3">3</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#8">8</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#9">9</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#19">19</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#26">26</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#31">31</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#61">61</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#63">63</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#86">86</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#108">108</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#114">114</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#115">115</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#122">122</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#127">127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#129">129</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#134">134</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#137">137</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#142">142</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#144">144</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#146">146</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#147">147</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#159">159</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#164">164</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#170">170</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#181">181</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#199">199</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#208">208</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#209">209</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#210">210</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#211">211</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#212">212</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#217">217</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#220">220</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#222">222</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#223">223</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#224">224</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a> to "DR".  Reopened issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#23">23</a>. Reopened
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#187">187</a>. Changed issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#2">2</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> to NAD. Fixed a typo in issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#17">17</a>. Fixed
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#70">70</a>: signature should be changed both places it
 appears. Fixed issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#160">160</a>: previous version didn't fix
 the bug in enough places.
 </li>
 <li>R15:
 pre-Toronto mailing. Added issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#264">264</a>. Some small HTML formatting
 changes so that we pass Weblint tests.
 </li>
 <li>R14:
 post-Tokyo II mailing; reflects committee actions taken in
 Tokyo. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#232">232</a>. (00-0019R1/N1242)
 </li>
 <li>R13:
 pre-Tokyo II updated: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#212">212</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a>.
 </li>
 <li>R12:
 pre-Tokyo II mailing: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#199">199</a> to
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#211">211</a>. Added "and paragraph 5" to the proposed resolution
 of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#29">29</a>.  Add further rationale to issue
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#178">178</a>.
 </li>
 <li>R11:
 post-Kona mailing: Updated to reflect LWG and full committee actions
 in Kona (99-0048/N1224). Note changed resolution of issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#38">38</a>. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#196">196</a>
 to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#198">198</a>. Closed issues list split into "defects" and
 "closed" documents.  Changed the proposed resolution of issue
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> to NAD, and changed the wording of proposed resolution
 of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#38">38</a>.
 </li>
 <li>R10:
 pre-Kona updated.  Added proposed resolutions <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#83">83</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#86">86</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#91">91</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#92">92</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a>. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#190">190</a> to
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#195">195</a>. (99-0033/D1209, 14 Oct 99)
 </li>
 <li>R9:
 pre-Kona mailing.  Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a> to
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#189">189</a>. Issues list split into separate "active" and
 "closed" documents. (99-0030/N1206, 25 Aug 99)
 </li>
 <li>R8:
 post-Dublin mailing. Updated to reflect LWG and full committee actions
 in Dublin. (99-0016/N1193, 21 Apr 99)
 </li>
 <li>R7:
 pre-Dublin updated: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#130">130</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#131">131</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#132">132</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#133">133</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#134">134</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#135">135</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#136">136</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#137">137</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#139">139</a> (31 Mar 99)
 </li>
 <li>R6:
 pre-Dublin mailing. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#127">127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#128">128</a>,
 and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#129">129</a>.  (99-0007/N1194, 22 Feb 99)
 </li>
 <li>R5:
 update issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>; added issues
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#114">114</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#126">126</a>. Format revisions to prepare
 for making list public. (30 Dec 98)
 </li>
 <li>R4:
 post-Santa Cruz II updated: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#110">110</a>,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#113">113</a> added, several
 issues corrected. (22 Oct 98)
 </li>
 <li>R3:
 post-Santa Cruz II: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#94">94</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a>
 added, many issues updated to reflect LWG consensus (12 Oct 98)
 </li>
 <li>R2:
 pre-Santa Cruz II: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#73">73</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#93">93</a> added,
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#17">17</a> updated. (29 Sep 98)
 </li>
 <li>R1:
 Correction to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#55">55</a> resolution, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#60">60</a> code
 format, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#64">64</a> title. (17 Sep 98)
 </li>
 </ul>

 <h2>Defect Reports</h2>
 <hr>
 <h3><a name="1"></a>1. C library linkage editing oversight</h3>
 <p><b>Section:</b> 17.4.2.2 [using.linkage] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 1997-11-16</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The change specified in the proposed resolution below did not make
 it into the Standard. This change was accepted in principle at the
 London meeting, and the exact wording below was accepted at the
 Morristown meeting.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 17.4.2.2 [using.linkage] paragraph 2
 from:</p>

 <blockquote>
   <p>It is unspecified whether a name from the Standard C library
   declared with external linkage has either extern "C" or
   extern "C++" linkage.</p>
 </blockquote>

 <p>to:</p>

 <blockquote>
   <p>Whether a name from the Standard C library declared with external
   linkage has extern "C" or extern "C++" linkage
   is implementation defined. It is recommended that an implementation
   use extern "C++" linkage for this purpose.</p>
 </blockquote>


 <hr>
 <h3><a name="3"></a>3. Atexit registration during atexit() call is not described</h3>
 <p><b>Section:</b> 18.4 [support.start.term] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 1997-12-12</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>We appear not to have covered all the possibilities of
  exit processing with respect to
 atexit registration. <br>
 <br>
 Example 1: (C and C++)</p>

 <pre>    #include &lt;stdlib.h&gt;
     void f1() { }
     void f2() { atexit(f1); }

     int main()
     {
         atexit(f2); // the only use of f2
         return 0; // for C compatibility
     }</pre>

 <p>At program exit, f2 gets called due to its registration in
 main. Running f2 causes f1 to be newly registered during the exit
 processing. Is this a valid program? If so, what are its
 semantics?</p>

 <p>
 Interestingly, neither the C standard, nor the C++ draft standard nor
 the forthcoming C9X Committee Draft says directly whether you can
 register a function with atexit during exit processing.</p>

 <p>
 All 3 standards say that functions are run in reverse order of their
 registration. Since f1 is registered last, it ought to be run first,
 but by the time it is registered, it is too late to be first.</p>

 <p>If the program is valid, the standards are self-contradictory about
 its semantics.</p>

 <p>Example 2: (C++ only)</p>

 <pre>
     void F() { static T t; } // type T has a destructor

     int main()
     {
         atexit(F); // the only use of F
     }
 </pre>

 <p>Function F registered with atexit has a local static variable t,
 and F is called for the first time during exit processing. A local
 static object is initialized the first time control flow passes
 through its definition, and all static objects are destroyed during
 exit processing. Is the code valid? If so, what are its semantics?</p>

 <p>
 Section 18.3 "Start and termination" says that if a function
 F is registered with atexit before a static object t is initialized, F
 will not be called until after t's destructor completes.</p>

 <p>
 In example 2, function F is registered with atexit before its local
 static object O could possibly be initialized. On that basis, it must
 not be called by exit processing until after O's destructor
 completes. But the destructor cannot be run until after F is called,
 since otherwise the object could not be constructed in the first
 place.</p>

 <p>If the program is valid, the standard is self-contradictory about
 its semantics.</p>

 <p>I plan to submit Example 1 as a public comment on the C9X CD, with
 a recommendation that the results be undefined. (Alternative: make it
 unspecified. I don't think it is worthwhile to specify the case where
 f1 itself registers additional functions, each of which registers
 still more functions.)</p>

 <p>I think we should resolve the situation in the whatever way the C
 committee decides. </p>

 <p>For Example 2, I recommend we declare the results undefined.</p>

 <p><i>[See reflector message lib-6500 for further discussion.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change section 18.3/8 from:</p>
 <blockquote><p>
   First, objects with static storage duration are destroyed and
   functions registered by calling atexit are called. Objects with
   static storage duration are destroyed in the reverse order of the
   completion of their constructor.  (Automatic objects are not
   destroyed as a result of calling exit().) Functions registered with
   atexit are called in the reverse order of their registration.  A
   function registered with atexit before an object obj1 of static
   storage duration is initialized will not be called until obj1's
   destruction has completed. A function registered with atexit after
   an object obj2 of static storage duration is initialized will be
   called before obj2's destruction starts.
 </p></blockquote>
 <p>to:</p>
 <blockquote><p>
   First, objects with static storage duration are destroyed and
   functions registered by calling atexit are called. Non-local objects
   with static storage duration are destroyed in the reverse order of
   the completion of their constructor. (Automatic objects are not
   destroyed as a result of calling exit().) Functions registered with
   atexit are called in the reverse order of their registration, except
   that a function is called after any previously registered functions
   that had already been called at the time it was registered. A
   function registered with atexit before a non-local object obj1 of
   static storage duration is initialized will not be called until
   obj1's destruction has completed. A function registered with atexit
   after a non-local object obj2 of static storage duration is
   initialized will be called before obj2's destruction starts. A local
   static object obj3 is destroyed at the same time it would be if a
   function calling the obj3 destructor were registered with atexit at
   the completion of the obj3 constructor.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>See 99-0039/N1215, October 22, 1999, by Stephen D. Clamage for the analysis
 supporting to the proposed resolution.</p>


 <hr>
 <h3><a name="5"></a>5. String::compare specification questionable</h3>
 <p><b>Section:</b> 21.3.6.8 [string::swap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Jack Reeves <b>Date:</b> 1997-12-11</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::swap">issues</a> in [string::swap].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#87">87</a></p>
 <p><b>Discussion:</b></p>
 <p>At the very end of the basic_string class definition is the signature: int
 compare(size_type pos1, size_type n1, const charT* s, size_type n2 = npos) const; In the
 following text this is defined as: returns
 basic_string&lt;charT,traits,Allocator&gt;(*this,pos1,n1).compare(
 basic_string&lt;charT,traits,Allocator&gt;(s,n2); </p>

 <p>Since the constructor basic_string(const charT* s, size_type n, const Allocator&amp; a
 = Allocator()) clearly requires that s != NULL and n &lt; npos and further states that it
 throws length_error if n == npos, it appears the compare() signature above should always
 throw length error if invoked like so: str.compare(1, str.size()-1, s); where 's' is some
 null terminated character array. </p>

 <p>This appears to be a typo since the obvious intent is to allow either the call above or
 something like: str.compare(1, str.size()-1, s, strlen(s)-1); </p>

 <p>This would imply that what was really intended was two signatures int compare(size_type
 pos1, size_type n1, const charT* s) const int compare(size_type pos1, size_type n1, const
 charT* s, size_type n2) const; each defined in terms of the corresponding constructor. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the compare signature in 21.3 [basic.string]
 (at the very end of the basic_string synopsis) which reads:</p>

 <blockquote>
   <p><tt>int compare(size_type pos1, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const charT* s,
   size_type n2 = npos) const;</tt></p>
 </blockquote>

 <p>with:</p>

 <blockquote>
   <p><tt>int compare(size_type pos1, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const charT* s) const;<br>
   int compare(size_type pos1, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const charT* s,
   size_type n2) const;</tt></p>
 </blockquote>

 <p>Replace the portion of 21.3.6.8 [string::swap]
 paragraphs 5 and 6 which read:</p>

 <blockquote>
   <p><tt>int compare(size_type pos, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; charT * s, size_type n2
   = npos) const;<br>
   </tt>Returns:<tt><br>
   basic_string&lt;charT,traits,Allocator&gt;(*this, pos, n1).compare(<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   basic_string&lt;charT,traits,Allocator&gt;( s, n2))</tt></p>
 </blockquote>

 <p>with:</p>

 <blockquote>
   <p><tt>int compare(size_type pos, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const charT * s) const;<br>
   </tt>Returns:<tt><br>
   basic_string&lt;charT,traits,Allocator&gt;(*this, pos, n1).compare(<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   basic_string&lt;charT,traits,Allocator&gt;( s ))<br>
   <br>
   int compare(size_type pos, size_type n1,<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const charT * s,
   size_type n2) const;<br>
   </tt>Returns:<tt><br>
   basic_string&lt;charT,traits,Allocator&gt;(*this, pos, n1).compare(<br>
   &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
   basic_string&lt;charT,traits,Allocator&gt;( s, n2))</tt></p>
 </blockquote>

 <p>Editors please note that in addition to splitting the signature, the third argument
 becomes const, matching the existing synopsis.</p>


 <p><b>Rationale:</b></p>
 <p>While the LWG dislikes adding signatures, this is a clear defect in
 the Standard which must be fixed.&nbsp; The same problem was also
 identified in issues 7 (item 5) and 87.</p>


 <hr>
 <h3><a name="7"></a>7. String clause minor problems</h3>
 <p><b>Section:</b> 21 [strings] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1997-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#strings">issues</a> in [strings].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>(1) In 21.3.6.4 [string::insert], the description of template
 &lt;class InputIterator&gt; insert(iterator, InputIterator,
 InputIterator) makes no sense. It refers to a member function that
 doesn't exist. It also talks about the return value of a void
 function. </p>

 <p>(2) Several versions of basic_string::replace don't appear in the
 class synopsis. </p>

 <p>(3) basic_string::push_back appears in the synopsis, but is never
 described elsewhere.  In the synopsis its argument is const charT,
 which doesn't makes much sense; it should probably be charT, or
 possible const charT&amp;. </p>

 <p>(4) basic_string::pop_back is missing. </p>

 <p>(5) int compare(size_type pos, size_type n1, charT* s, size_type n2
 = npos) make no sense. First, it's const charT* in the synopsis and
 charT* in the description. Second, given what it says in RETURNS,
 leaving out the final argument will always result in an exception
 getting thrown. This is paragraphs 5 and 6 of
 21.3.6.8 [string::swap]</p>

 <p>(6) In table 37, in section 21.1.1 [char.traits.require],
 there's a note for X::move(s, p, n). It says "Copies correctly
 even where p is in [s, s+n)". This is correct as far as it goes,
 but it doesn't go far enough; it should also guarantee that the copy
 is correct even where s in in [p, p+n). These are two orthogonal
 guarantees, and neither one follows from the other. Both guarantees
 are necessary if X::move is supposed to have the same sort of
 semantics as memmove (which was clearly the intent), and both
 guarantees are necessary if X::move is actually supposed to be
 useful. </p>


 <p><b>Proposed resolution:</b></p>
 <p>ITEM 1: In 21.3.5.4 [lib.string::insert], change paragraph 16 to <br>
 <br>
 &nbsp;&nbsp;&nbsp; EFFECTS: Equivalent to insert(p - begin(), basic_string(first, last)).<br>
 <br>
 ITEM 2:&nbsp; Not a defect; the Standard is clear.. There are ten versions of replace() in
 the synopsis, and ten versions in 21.3.5.6 [lib.string::replace].<br>
 <br>
 ITEM 3: Change the declaration of push_back in the string synopsis (21.3,
 [lib.basic.string]) from:</p>

 <p>&nbsp;&nbsp;&nbsp;&nbsp; void push_back(const charT)<br>
 <br>
 to<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; void push_back(charT)<br>
 <br>
 Add the following text immediately after 21.3.5.2 [lib.string::append], paragraph 10.<br>
 <br>
 &nbsp;&nbsp;&nbsp; void basic_string::push_back(charT c);<br>
 &nbsp;&nbsp;&nbsp; EFFECTS: Equivalent to append(static_cast&lt;size_type&gt;(1), c);<br>
 <br>
 ITEM 4: Not a defect. The omission appears to have been deliberate.<br>
 <br>
 ITEM 5: Duplicate; see issue 5 (and 87).<br>
 <br>
 ITEM 6: In table 37, Replace:<br>
 <br>
 &nbsp;&nbsp;&nbsp; "Copies correctly even where p is in [s, s+n)."<br>
 <br>
 with:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; "Copies correctly even where the ranges [p, p+n) and [s,
 s+n) overlap."</p>


 <hr>
 <h3><a name="8"></a>8. Locale::global lacks guarantee</h3>
 <p><b>Section:</b> 22.1.1.5 [locale.statics] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1997-12-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>It appears there's an important guarantee missing from clause
 22. We're told that invoking locale::global(L) sets the C locale if L
 has a name. However, we're not told whether or not invoking
 setlocale(s) sets the global C++ locale. </p>

 <p>The intent, I think, is that it should not, but I can't find any
 such words anywhere. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add a sentence at the end of 22.1.1.5 [locale.statics],
 paragraph 2:&nbsp; </p>

 <blockquote>
   <p>No library function other than <tt>locale::global()</tt> shall affect
   the value returned by <tt>locale()</tt>. </p>

 </blockquote>


 <hr>
 <h3><a name="9"></a>9. Operator new(0) calls should not yield the same pointer</h3>
 <p><b>Section:</b> 18.5.1 [new.delete] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 1998-01-04</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Scott Meyers, in a comp.std.c++ posting: I just noticed that
 section 3.7.3.1 of CD2 seems to allow for the possibility that all
 calls to operator new(0) yield the same pointer, an implementation
 technique specifically prohibited by ARM 5.3.3.Was this prohibition
 really lifted? Does the FDIS agree with CD2 in the regard? [Issues
 list maintainer's note: the IS is the same.]</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the last paragraph of 3.7.3 from:</p>
 <blockquote>
   <p>Any allocation and/or deallocation functions defined in a C++ program shall
   conform to the semantics specified in 3.7.3.1 and 3.7.3.2.</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>Any allocation and/or deallocation functions defined in a C++ program,
   including the default versions in the library, shall conform to the semantics
   specified in 3.7.3.1 and 3.7.3.2.</p>
 </blockquote>
 <p>Change 3.7.3.1/2, next-to-last sentence, from :</p>
 <blockquote>
   <p>If the size of the space requested is zero, the value returned shall not be
   a null pointer value (4.10).</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>Even if the size of the space requested is zero, the request can fail. If
   the request succeeds, the value returned shall be a non-null pointer value
   (4.10) p0 different from any previously returned value p1, unless that value
   p1 was since passed to an operator delete.</p>
 </blockquote>
 <p>5.3.4/7 currently reads:</p>
 <blockquote>
   <p>When the value of the expression in a direct-new-declarator is zero, the
   allocation function is called to allocate an array with no elements. The
   pointer returned by the new-expression is non-null. [Note: If the library
   allocation function is called, the pointer returned is distinct from the
   pointer to any other object.]</p>
 </blockquote>
 <p>Retain the first sentence, and delete the remainder.</p>
 <p>18.5.1 currently has no text. Add the following:</p>
 <blockquote>
   <p>Except where otherwise specified, the provisions of 3.7.3 apply to the
   library versions of operator new and operator delete.</p>
 </blockquote>
 <p>To 18.5.1.3, add the following text:</p>
 <blockquote>
   <p>The provisions of 3.7.3 do not apply to these reserved placement forms of
   operator new and operator delete.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>See 99-0040/N1216, October 22, 1999, by Stephen D. Clamage for the analysis
 supporting to the proposed resolution.</p>


 <hr>
 <h3><a name="11"></a>11. Bitset minor problems</h3>
 <p><b>Section:</b> 23.3.5 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-01-22</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>(1) bitset&lt;&gt;::operator[] is mentioned in the class synopsis (23.3.5), but it is
 not documented in 23.3.5.2. </p>

 <p>(2) The class synopsis only gives a single signature for bitset&lt;&gt;::operator[],
 reference operator[](size_t pos). This doesn't make much sense. It ought to be overloaded
 on const. reference operator[](size_t pos); bool operator[](size_t pos) const. </p>

 <p>(3) Bitset's stream input function (23.3.5.3) ought to skip all whitespace before
 trying to extract 0s and 1s. The standard doesn't explicitly say that, though. This should
 go in the Effects clause.</p>


 <p><b>Proposed resolution:</b></p>
 <p>ITEMS 1 AND 2:<br>
 <br>
 In the bitset synopsis (23.3.5 [template.bitset]),
 replace the member function <br>
 <br>
 <tt>&nbsp;&nbsp;&nbsp; reference operator[](size_t pos);<br>
 </tt><br>
 with the two member functions<br>
 <br>
 <tt>&nbsp;&nbsp;&nbsp; bool operator[](size_t pos) const; <br>
 &nbsp;&nbsp;&nbsp; reference operator[](size_t pos); <br>
 </tt><br>
 Add the following text at the end of 23.3.5.2 [bitset.members],
 immediately after paragraph 45:</p>

 <blockquote>
   <p><tt>bool operator[](size_t pos) const;</tt><br>
   Requires: pos is valid<br>
   Throws: nothing<br>
   Returns: <tt>test(pos)</tt><br>
   <br>
   <tt>bitset&lt;N&gt;::reference operator[](size_t pos);</tt> <br>
   Requires: pos is valid<br>
   Throws: nothing<br>
   Returns: An object of type <tt>bitset&lt;N&gt;::reference</tt> such that <tt>(*this)[pos]
   == this-&gt;test(pos)</tt>, and such that <tt>(*this)[pos] = val</tt> is equivalent to <tt>this-&gt;set(pos,
   val);</tt></p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG believes Item 3 is not a defect. "Formatted
 input" implies the desired semantics. See 27.6.1.2 [istream.formatted].
 </p>


 <hr>
 <h3><a name="13"></a>13. Eos refuses to die</h3>
 <p><b>Section:</b> 27.6.1.2.3 [istream::extractors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> William M. Miller <b>Date:</b> 1998-03-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::extractors">issues</a> in [istream::extractors].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 27.6.1.2.3, there is a reference to "eos", which is
 the only one in the whole draft (at least using Acrobat search), so
 it's undefined. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.1.2.3 [istream::extractors], replace "eos" with
 "charT()"</p>


 <hr>
 <h3><a name="14"></a>14. Locale::combine should be const</h3>
 <p><b>Section:</b> 22.1.1.3 [locale.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.members">issues</a> in [locale.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>locale::combine is the only member function of locale (other than constructors and
 destructor) that is not const. There is no reason for it not to be const, and good reasons
 why it should have been const. Furthermore, leaving it non-const conflicts with 22.1.1
 paragraph 6: "An instance of a locale is immutable." </p>

 <p>History: this member function originally was a constructor. it happened that the
 interface it specified had no corresponding language syntax, so it was changed to a member
 function. As constructors are never const, there was no "const" in the interface
 which was transformed into member "combine". It should have been added at that
 time, but the omission was not noticed. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1 [locale] and also in 22.1.1.3 [locale.members], add
 "const" to the declaration of member combine: </p>
 <blockquote>
   <pre>template &lt;class Facet&gt; locale combine(const locale&amp; other) const; </pre>
 </blockquote>


 <hr>
 <h3><a name="15"></a>15. Locale::name requirement inconsistent</h3>
 <p><b>Section:</b> 22.1.1.3 [locale.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.members">issues</a> in [locale.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>locale::name() is described as returning a string that can be passed to a locale
 constructor, but there is no matching constructor. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1.3 [locale.members], paragraph 5, replace
 "<tt>locale(name())</tt>" with
 "<tt>locale(name().c_str())</tt>".
 </p>


 <hr>
 <h3><a name="16"></a>16. Bad ctype_byname&lt;char&gt; decl</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The new virtual members ctype_byname&lt;char&gt;::do_widen and do_narrow did not get
 edited in properly. Instead, the member do_widen appears four times, with wrong argument
 lists. </p>


 <p><b>Proposed resolution:</b></p>
 <p>The correct declarations for the overloaded members
 <tt>do_narrow</tt> and <tt>do_widen</tt> should be copied
 from 22.2.1.3 [facet.ctype.special].</p>


 <hr>
 <h3><a name="17"></a>17. Bad bool parsing</h3>
 <p><b>Section:</b> 22.2.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>This section describes the process of parsing a text boolean value from the input
 stream. It does not say it recognizes either of the sequences "true" or
 "false" and returns the corresponding bool value; instead, it says it recognizes
 only one of those sequences, and chooses which according to the received value of a
 reference argument intended for returning the result, and reports an error if the other
 sequence is found. (!) Furthermore, it claims to get the names from the ctype&lt;&gt;
 facet rather than the numpunct&lt;&gt; facet, and it examines the "boolalpha"
 flag wrongly; it doesn't define the value "loc"; and finally, it computes
 wrongly whether to use numeric or "alpha" parsing.<br>
 <br>
 I believe the correct algorithm is "as if": </p>

 <pre>  // in, err, val, and str are arguments.
   err = 0;
   const numpunct&lt;charT&gt;&amp; np = use_facet&lt;numpunct&lt;charT&gt; &gt;(str.getloc());
   const string_type t = np.truename(), f = np.falsename();
   bool tm = true, fm = true;
   size_t pos = 0;
   while (tm &amp;&amp; pos &lt; t.size() || fm &amp;&amp; pos &lt; f.size()) {
     if (in == end) { err = str.eofbit; }
     bool matched = false;
     if (tm &amp;&amp; pos &lt; t.size()) {
       if (!err &amp;&amp; t[pos] == *in) matched = true;
       else tm = false;
     }
     if (fm &amp;&amp; pos &lt; f.size()) {
       if (!err &amp;&amp; f[pos] == *in) matched = true;
       else fm = false;
     }
     if (matched) { ++in; ++pos; }
     if (pos &gt; t.size()) tm = false;
     if (pos &gt; f.size()) fm = false;
   }
   if (tm == fm || pos == 0) { err |= str.failbit; }
   else                      { val = tm; }
   return in;</pre>

 <p>Notice this works reasonably when the candidate strings are both empty, or equal, or
 when one is a substring of the other. The proposed text below captures the logic of the
 code above.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.1.2 [facet.num.get.virtuals], in the first line of paragraph 14,
 change "&amp;&amp;" to "&amp;".</p>

 <p>Then, replace paragraphs 15 and 16 as follows:</p>

 <blockquote>

   <p>Otherwise target sequences are determined "as if" by
   calling the members <tt>falsename()</tt> and
   <tt>truename()</tt> of the facet obtained by
   <tt>use_facet&lt;numpunct&lt;charT&gt;&nbsp;&gt;(str.getloc())</tt>.
   Successive characters in the range <tt>[in,end)</tt> (see
   [lib.sequence.reqmts]) are obtained and matched against
   corresponding positions in the target sequences only as necessary to
   identify a unique match. The input iterator <tt>in</tt> is
   compared to <tt>end</tt> only when necessary to obtain a
   character. If and only if a target sequence is uniquely matched,
   <tt>val</tt> is set to the corresponding value.</p>

 </blockquote>

 <blockquote>
   <p>The <tt>in</tt> iterator is always left pointing one position beyond the last character
   successfully matched. If <tt>val</tt> is set, then err is set to <tt>str.goodbit</tt>; or to
   <tt>str.eofbit</tt> if, when seeking another character to match, it is found that
   <tt>(in==end)</tt>. If <tt>val</tt> is not set, then <i>err</i> is set to <tt>str.failbit</tt>; or to
   <tt>(str.failbit|str.eofbit)</tt>if
   the reason for the failure was that <tt>(in==end)</tt>. [Example: for targets
   <tt>true</tt>:"a" and <tt>false</tt>:"abb", the input sequence "a" yields
   <tt>val==true</tt> and <tt>err==str.eofbit</tt>; the input sequence "abc" yields
   <tt>err=str.failbit</tt>, with <tt>in</tt> ending at the 'c' element. For targets
   <tt>true</tt>:"1"
   and <tt>false</tt>:"0", the input sequence "1" yields <tt>val==true</tt>
   and <tt>err=str.goodbit</tt>. For empty targets (""), any input sequence yields
   <tt>err==str.failbit</tt>. --end example]</p>
 </blockquote>


 <hr>
 <h3><a name="18"></a>18. Get(...bool&amp;) omitted</h3>
 <p><b>Section:</b> 22.2.2.1.1 [facet.num.get.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.members">issues</a> in [facet.num.get.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In the list of num_get&lt;&gt; non-virtual members on page 22-23, the member
 that parses bool values was omitted from the list of definitions of non-virtual
 members, though it is listed in the class definition and the corresponding
 virtual is listed everywhere appropriate. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add at the beginning of 22.2.2.1.1 [facet.num.get.members]
 another get member for bool&amp;, copied from the entry in
 22.2.2.1 [locale.num.get].</p>


 <hr>
 <h3><a name="19"></a>19. "Noconv" definition too vague</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#10">10</a></p>
 <p><b>Discussion:</b></p>
 <p>
 In the definitions of codecvt&lt;&gt;::do_out and do_in, they are
 specified to return noconv if "no conversion is
 needed". This definition is too vague, and does not say
 normatively what is done with the buffers.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the entry for noconv in the table under paragraph 4 in section
 22.2.1.4.2 [locale.codecvt.virtuals] to read:
 </p>
 <blockquote>
   <p><tt>noconv</tt>: <tt>internT</tt> and <tt>externT</tt> are the same type,
   and input sequence is identical to converted sequence.</p>
 </blockquote>
 <p>Change the Note in paragraph 2 to normative text as follows:</p>
 <blockquote>
   <p>If returns <tt>noconv</tt>, <tt>internT</tt> and <tt>externT</tt> are the
   same type and the converted sequence is identical to the input sequence <tt>[from,from_next)</tt>.
   <tt>to_next</tt> is set equal to <tt>to</tt>, the value of <tt>state</tt> is
   unchanged, and there are no changes to the values in <tt>[to, to_limit)</tt>.</p>
 </blockquote>


 <hr>
 <h3><a name="20"></a>20. Thousands_sep returns wrong type</h3>
 <p><b>Section:</b> 22.2.3.1.2 [facet.numpunct.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The synopsis for numpunct&lt;&gt;::do_thousands_sep, and the
 definition of numpunct&lt;&gt;::thousands_sep which calls it, specify
 that it returns a value of type char_type. Here it is erroneously
 described as returning a "string_type". </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.3.1.2 [facet.numpunct.virtuals], above paragraph 2, change
 "string_type" to "char_type". </p>


 <hr>
 <h3><a name="21"></a>21. Codecvt_byname&lt;&gt; instantiations</h3>
 <p><b>Section:</b> 22.1.1.1.1 [locale.category] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.category">issues</a> in [locale.category].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In the second table in the section, captioned "Required
 instantiations", the instantiations for codecvt_byname&lt;&gt;
 have been omitted. These are necessary to allow users to construct a
 locale by name from facets. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add in 22.1.1.1.1 [locale.category] to the table captioned
 "Required instantiations", in the category "ctype"
 the lines </p>

 <blockquote>
   <pre>codecvt_byname&lt;char,char,mbstate_t&gt;,
 codecvt_byname&lt;wchar_t,char,mbstate_t&gt; </pre>
 </blockquote>


 <hr>
 <h3><a name="22"></a>22. Member open vs. flags</h3>
 <p><b>Section:</b> 27.8.1.9 [ifstream.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ifstream.members">issues</a> in [ifstream.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description of basic_istream&lt;&gt;::open leaves unanswered questions about how it
 responds to or changes flags in the error status for the stream. A strict reading
 indicates that it ignores the bits and does not change them, which confuses users who do
 not expect eofbit and failbit to remain set after a successful open. There are three
 reasonable resolutions: 1) status quo 2) fail if fail(), ignore eofbit 3) clear failbit
 and eofbit on call to open(). </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.8.1.9 [ifstream.members] paragraph 3, <i>and</i> in 27.8.1.13 [ofstream.members] paragraph 3, under open() effects, add a footnote:
 </p>

 <blockquote>
   <p>A successful open does not change the error state.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>This may seem surprising to some users, but it's just an instance
 of a general rule: error flags are never cleared by the
 implementation. The only way error flags are are ever cleared is if
 the user explicitly clears them by hand.</p>

 <p>The LWG believed that preserving this general rule was
 important enough so that an exception shouldn't be made just for this
 one case.  The resolution of this issue clarifies what the LWG
 believes to have been the original intent.</p>


 <hr>
 <h3><a name="24"></a>24. "do_convert" doesn't exist</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#72">72</a></p>
 <p><b>Discussion:</b></p>
 <p>The description of codecvt&lt;&gt;::do_out and do_in mentions a
 symbol "do_convert" which is not defined in the
 standard. This is a leftover from an edit, and should be "do_in
 and do_out". </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.1.4 [locale.codecvt], paragraph 3, change
 "do_convert" to "do_in or do_out". Also, in 22.2.1.4.2 [locale.codecvt.virtuals], change "do_convert()" to "do_in
 or do_out". </p>


 <hr>
 <h3><a name="25"></a>25. String operator&lt;&lt; uses width() value wrong</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#67">67</a></p>
 <p><b>Discussion:</b></p>
 <p>In the description of operator&lt;&lt; applied to strings, the standard says that uses
 the smaller of os.width() and str.size(), to pad "as described in stage 3"
 elsewhere; but this is inconsistent, as this allows no possibility of space for padding. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 21.3.8.9 [string.io]  paragraph 4 from:<br>
 <br>
 &nbsp;&nbsp;&nbsp; "... where <tt>n</tt> is the smaller of <tt>os.width()</tt> and <tt>str.size()</tt>;
 ..."<br>
 <br>
 to: <br>
 <br>
 &nbsp;&nbsp;&nbsp; "... where <tt>n</tt> is the larger of <tt>os.width()</tt> and <tt>str.size()</tt>;
 ..."</p>


 <hr>
 <h3><a name="26"></a>26. Bad sentry example</h3>
 <p><b>Section:</b> 27.6.1.1.3 [istream::sentry] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::sentry">issues</a> in [istream::sentry].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In paragraph 6, the code in the example: </p>

 <pre>  template &lt;class charT, class traits = char_traits&lt;charT&gt; &gt;
   basic_istream&lt;charT,traits&gt;::sentry(
            basic_istream&lt;charT,traits&gt;&amp; is, bool noskipws = false) {
       ...
       int_type c;
       typedef ctype&lt;charT&gt; ctype_type;
       const ctype_type&amp; ctype = use_facet&lt;ctype_type&gt;(is.getloc());
       while ((c = is.rdbuf()-&gt;snextc()) != traits::eof()) {
         if (ctype.is(ctype.space,c)==0) {
           is.rdbuf()-&gt;sputbackc (c);
           break;
         }
       }
       ...
    }</pre>

 <p>fails to demonstrate correct use of the facilities described. In
 particular, it fails to use traits operators, and specifies incorrect
 semantics. (E.g. it specifies skipping over the first character in the
 sequence without examining it.) </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the example above from 27.6.1.1.3 [istream::sentry]
 paragraph 6.</p>


 <p><b>Rationale:</b></p>
 <p>The originally proposed replacement code for the example was not
 correct. The LWG tried in Kona and again in Tokyo to correct it
 without success. In Tokyo, an implementor reported that actual working
 code ran over one page in length and was quite complicated. The LWG
 decided that it would be counter-productive to include such a lengthy
 example, which might well still contain errors.</p>


 <hr>
 <h3><a name="27"></a>27. String::erase(range) yields wrong iterator</h3>
 <p><b>Section:</b> 21.3.6.5 [string::erase] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::erase">issues</a> in [string::erase].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The string::erase(iterator first, iterator last) is specified to return an element one
 place beyond the next element after the last one erased. E.g. for the string
 "abcde", erasing the range ['b'..'d') would yield an iterator for element 'e',
 while 'd' has not been erased. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 21.3.6.5 [string::erase], paragraph 10, change: </p>

 <blockquote>
   <p>Returns: an iterator which points to the element immediately following _last_ prior to
   the element being erased. </p>
 </blockquote>

 <p>to read </p>

 <blockquote>
   <p>Returns: an iterator which points to the element pointed to by _last_ prior to the
   other elements being erased. </p>
 </blockquote>


 <hr>
 <h3><a name="28"></a>28. Ctype&lt;char&gt;is ambiguous</h3>
 <p><b>Section:</b> 22.2.1.3.2 [facet.ctype.char.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.ctype.char.members">issues</a> in [facet.ctype.char.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#236">236</a></p>
 <p><b>Discussion:</b></p>
 <p>The description of the vector form of ctype&lt;char&gt;::is can be interpreted to mean
 something very different from what was intended. Paragraph 4 says </p>

 <blockquote>
   <p>Effects: The second form, for all *p in the range [low, high), assigns vec[p-low] to
   table()[(unsigned char)*p]. </p>
 </blockquote>

 <p>This is intended to copy the value indexed from table()[] into the place identified in
 vec[]. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 22.2.1.3.2 [facet.ctype.char.members], paragraph 4, to read </p>

 <blockquote>
   <p>Effects: The second form, for all *p in the range [low, high), assigns into vec[p-low]
   the value table()[(unsigned char)*p]. </p>
 </blockquote>


 <hr>
 <h3><a name="29"></a>29. Ios_base::init doesn't exist</h3>
 <p><b>Section:</b> 27.3.1 [narrow.stream.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#narrow.stream.objects">issues</a> in [narrow.stream.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Sections 27.3.1 [narrow.stream.objects] and 27.3.2 [wide.stream.objects] mention
 a function ios_base::init, which is not defined. Probably they mean
 basic_ios&lt;&gt;::init, defined in 27.4.4.1 [basic.ios.cons],
 paragraph 3. </p>


 <p><b>Proposed resolution:</b></p>
 <p>[R12: modified to include paragraph 5.]</p>

 <p>In 27.3.1 [narrow.stream.objects] paragraph 2 and 5, change </p>

 <blockquote>
   <p>ios_base::init </p>
 </blockquote>

 <p>to </p>

 <blockquote>
   <p>basic_ios&lt;char&gt;::init </p>
 </blockquote>

 <p>Also, make a similar change in 27.3.2 [wide.stream.objects] except it
 should read </p>

 <blockquote>
   <p>basic_ios&lt;wchar_t&gt;::init </p>
 </blockquote>


 <hr>
 <h3><a name="30"></a>30. Wrong header for LC_*</h3>
 <p><b>Section:</b> 22.1.1.1.1 [locale.category] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.category">issues</a> in [locale.category].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 2 implies that the C macros LC_CTYPE etc. are defined in &lt;cctype&gt;,
 where they are in fact defined elsewhere to appear in &lt;clocale&gt;. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1.1.1 [locale.category], paragraph 2, change
 "&lt;cctype&gt;" to read "&lt;clocale&gt;". </p>


 <hr>
 <h3><a name="31"></a>31. Immutable locale values</h3>
 <p><b>Section:</b> 22.1.1 [locale] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale">issues</a> in [locale].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#378">378</a></p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 6, says "An instance of <tt>locale</tt> is
 <i>immutable</i>; once a facet reference is obtained from it,
 ...". This has caused some confusion, because locale variables
 are manifestly assignable. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1 [locale] replace paragraph 6</p>

 <blockquote>
   <p>An instance of <tt>locale</tt> is immutable; once a facet
   reference is obtained from it, that reference remains usable as long
   as the locale value itself exists.</p>
 </blockquote>

 <p>with</p>

 <blockquote>
   <p>Once a facet reference is obtained from a locale object by
   calling use_facet&lt;&gt;, that reference remains usable, and the
   results from member functions of it may be cached and re-used, as
   long as some locale object refers to that facet.</p>
 </blockquote>


 <hr>
 <h3><a name="32"></a>32. Pbackfail description inconsistent</h3>
 <p><b>Section:</b> 27.5.2.4.4 [streambuf.virt.pback] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description of the required state before calling virtual member
 basic_streambuf&lt;&gt;::pbackfail requirements is inconsistent with the conditions
 described in 27.5.2.2.4 [lib.streambuf.pub.pback] where member sputbackc calls it.
 Specifically, the latter says it calls pbackfail if: </p>

 <p>&nbsp;&nbsp;&nbsp; traits::eq(c,gptr()[-1]) is false </p>

 <p>where pbackfail claims to require: </p>

 <p>&nbsp;&nbsp;&nbsp; traits::eq(*gptr(),traits::to_char_type(c)) returns false </p>

 <p>It appears that the pbackfail description is wrong. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.5.2.4.4 [streambuf.virt.pback], paragraph 1, change:</p>

 <blockquote>
   <p>"<tt>traits::eq(*gptr(),traits::to_char_type( c))</tt>"</p>
 </blockquote>

 <p>to </p>

 <blockquote>
   <p>"<tt>traits::eq(traits::to_char_type(c),gptr()[-1])</tt>"
   </p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Note deliberate reordering of arguments for clarity in addition to the correction of
 the argument value.</p>


 <hr>
 <h3><a name="33"></a>33. Codecvt&lt;&gt; mentions from_type</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#43">43</a></p>
 <p><b>Discussion:</b></p>
 <p>In the table defining the results from do_out and do_in, the specification for the
 result <i>error</i> says </p>

 <blockquote>
   <p>encountered a from_type character it could not convert </p>
 </blockquote>

 <p>but from_type is not defined. This clearly is intended to be an externT for do_in, or
 an internT for do_out. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.1.4.2 [locale.codecvt.virtuals] paragraph 4, replace the definition
 in the table for the case of _error_ with </p>

 <blockquote>
   <p>encountered a character in <tt>[from,from_end)</tt> that it could not convert. </p>
 </blockquote>


 <hr>
 <h3><a name="34"></a>34. True/falsename() not in ctype&lt;&gt;</h3>
 <p><b>Section:</b> 22.2.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.put.virtuals">issues</a> in [facet.num.put.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In paragraph 19, Effects:, members truename() and falsename are used from facet
 ctype&lt;charT&gt;, but it has no such members. Note that this is also a problem in
 22.2.2.1.2, addressed in (4). </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.2.2 [facet.num.put.virtuals], paragraph 19, in the Effects:
 clause for member put(...., bool), replace the initialization of the
 string_type value s as follows: </p>

 <blockquote>
   <pre>const numpunct&amp; np = use_facet&lt;numpunct&lt;charT&gt; &gt;(loc);
 string_type s = val ? np.truename() : np.falsename(); </pre>
 </blockquote>


 <hr>
 <h3><a name="35"></a>35. No manipulator unitbuf in synopsis</h3>
 <p><b>Section:</b> 27.4 [iostreams.base] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 27.4.5.1 [fmtflags.manip], we have a definition for a manipulator
 named "unitbuf". Unlike other manipulators, it's not listed
 in synopsis. Similarly for "nounitbuf". </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to the synopsis for &lt;ios&gt; in 27.4 [iostreams.base], after
 the entry for "nouppercase", the prototypes: </p>

 <blockquote>
   <pre>ios_base&amp; unitbuf(ios_base&amp; str);
 ios_base&amp; nounitbuf(ios_base&amp; str); </pre>
 </blockquote>


 <hr>
 <h3><a name="36"></a>36. Iword &amp; pword storage lifetime omitted</h3>
 <p><b>Section:</b> 27.4.2.5 [ios.base.storage] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base.storage">issues</a> in [ios.base.storage].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In the definitions for ios_base::iword and pword, the lifetime of the storage is
 specified badly, so that an implementation which only keeps the last value stored appears
 to conform. In particular, it says: </p>

 <p>The reference returned may become invalid after another call to the object's iword
 member with a different index ... </p>

 <p>This is not idle speculation; at least one implementation was done this way. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add in 27.4.2.5 [ios.base.storage], in both paragraph 2 and also in
 paragraph 4, replace the sentence: </p>

 <blockquote>
   <p>The reference returned may become invalid after another call to the object's iword
   [pword] member with a different index, after a call to its copyfmt member, or when the
   object is destroyed. </p>
 </blockquote>

 <p>with: </p>

 <blockquote>
   <p>The reference returned is invalid after any other operations on the object. However,
   the value of the storage referred to is retained, so that until the next call to copyfmt,
   calling iword [pword] with the same index yields another reference to the same value. </p>
 </blockquote>

 <p>substituting "iword" or "pword" as appropriate. </p>


 <hr>
 <h3><a name="37"></a>37. Leftover "global" reference</h3>
 <p><b>Section:</b> 22.1.1 [locale] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale">issues</a> in [locale].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In the overview of locale semantics, paragraph 4, is the sentence </p>

 <blockquote>
   <p>If Facet is not present in a locale (or, failing that, in the global locale), it throws
   the standard exception bad_cast. </p>
 </blockquote>

 <p>This is not supported by the definition of use_facet&lt;&gt;, and represents semantics
 from an old draft. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1 [locale], paragraph 4, delete the parenthesized
 expression </p>

 <blockquote>
   <p>(or, failing that, in the global locale) </p>
 </blockquote>


 <hr>
 <h3><a name="38"></a>38. Facet definition incomplete</h3>
 <p><b>Section:</b> 22.1.2 [locale.global.templates] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>It has been noticed by Esa Pulkkinen that the definition of
 "facet" is incomplete. In particular, a class derived from
 another facet, but which does not define a member <i>id</i>, cannot
 safely serve as the argument <i>F</i> to use_facet&lt;F&gt;(loc),
 because there is no guarantee that a reference to the facet instance
 stored in <i>loc</i> is safely convertible to <i>F</i>. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In the definition of std::use_facet&lt;&gt;(), replace the text in paragraph 1 which
 reads: </p>

 <blockquote>
   <p>Get a reference to a facet of a locale. </p>
 </blockquote>

 <p>with: </p>

 <blockquote>
   <p>Requires: <tt>Facet</tt> is a facet class whose definition
   contains the public static member <tt>id</tt> as defined in 22.1.1.1.2 [locale.facet]. </p>
 </blockquote>

 <p><i>[
 Kona: strike as overspecification the text "(not inherits)"
 from the original resolution, which read "... whose definition
 contains (not inherits) the public static member
 <tt>id</tt>..."
 ]</i></p>


 <hr>
 <h3><a name="39"></a>39. istreambuf_iterator&lt;&gt;::operator++(int) definition garbled</h3>
 <p><b>Section:</b> 24.5.3.4 [istreambuf.iterator::op++] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Following the definition of istreambuf_iterator&lt;&gt;::operator++(int) in paragraph
 3, the standard contains three lines of garbage text left over from a previous edit. </p>

 <blockquote>
   <pre>istreambuf_iterator&lt;charT,traits&gt; tmp = *this;
 sbuf_-&gt;sbumpc();
 return(tmp); </pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>In 24.5.3.4 [istreambuf.iterator::op++], delete the three lines of code at the
 end of paragraph 3. </p>


 <hr>
 <h3><a name="40"></a>40. Meaningless normative paragraph in examples</h3>
 <p><b>Section:</b> 22.2.8 [facets.examples] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facets.examples">issues</a> in [facets.examples].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 3 of the locale examples is a description of part of an
 implementation technique that has lost its referent, and doesn't mean
 anything. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Delete 22.2.8 [facets.examples] paragraph 3 which begins "This
 initialization/identification system depends...", or (at the
 editor's option) replace it with a place-holder to keep the paragraph
 numbering the same. </p>


 <hr>
 <h3><a name="41"></a>41. Ios_base needs clear(), exceptions()</h3>
 <p><b>Section:</b> 27.4.2 [ios.base] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base">issues</a> in [ios.base].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#157">157</a></p>
 <p><b>Discussion:</b></p>
 <p>The description of ios_base::iword() and pword() in 27.4.2.4 [ios.members.static], say that if they fail, they "set badbit,
 which may throw an exception". However, ios_base offers no
 interface to set or to test badbit; those interfaces are defined in
 basic_ios&lt;&gt;. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the description in 27.4.2.5 [ios.base.storage] in
 paragraph 2, and also in paragraph 4, as follows. Replace</p>

 <blockquote>
   <p>If the function fails it sets badbit, which may throw an exception.</p>
 </blockquote>

 <p>with</p>

 <blockquote>
   <p>If the function fails, and <tt>*this</tt> is a base sub-object of
   a <tt>basic_ios&lt;&gt;</tt> object or sub-object, the effect is
   equivalent to calling <tt>basic_ios&lt;&gt;::setstate(badbit)</tt>
   on the derived object (which may throw <tt>failure</tt>).</p>
 </blockquote>

 <p><i>[Kona: LWG reviewed wording; setstate(failbit) changed to
 setstate(badbit).]</i></p>


 <hr>
 <h3><a name="42"></a>42. String ctors specify wrong default allocator</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The basic_string&lt;&gt; copy constructor: </p>

 <pre>basic_string(const basic_string&amp; str, size_type pos = 0,
              size_type n = npos, const Allocator&amp; a = Allocator()); </pre>

 <p>specifies an Allocator argument default value that is
 counter-intuitive. The natural choice for a the allocator to copy from
 is str.get_allocator(). Though this cannot be expressed in
 default-argument notation, overloading suffices. </p>

 <p>Alternatively, the other containers in Clause 23 (deque, list,
 vector) do not have this form of constructor, so it is inconsistent,
 and an evident source of confusion, for basic_string&lt;&gt; to have
 it, so it might better be removed. </p>


 <p><b>Proposed resolution:</b></p>
 <p> In 21.3 [basic.string], replace the declaration of the copy
 constructor as follows: </p>

 <blockquote>
   <pre>basic_string(const basic_string&amp; str);
 basic_string(const basic_string&amp; str, size_type pos, size_type n = npos,
              const Allocator&amp; a = Allocator());</pre>
 </blockquote>

 <p>In 21.3.1 [string.require], replace the copy constructor declaration
 as above. Add to paragraph 5, Effects:</p>

 <blockquote>
   <p>In the first form, the Allocator value used is copied from
   <tt>str.get_allocator()</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG believes the constructor is actually broken, rather than
 just an unfortunate design choice.</p>

 <p>The LWG considered two other possible resolutions:</p>

 <p>A. In 21.3 [basic.string], replace the declaration of the copy
 constructor as follows:</p>

 <blockquote>
   <pre>basic_string(const basic_string&amp; str, size_type pos = 0,
              size_type n = npos);
 basic_string(const basic_string&amp; str, size_type pos,
              size_type n, const Allocator&amp; a); </pre>
 </blockquote>

 <p>In 21.3.1 [string.require], replace the copy constructor declaration
 as above. Add to paragraph 5, Effects: </p>

 <blockquote>
   <p>When no <tt>Allocator</tt> argument is provided, the string is constructed using the
   value <tt>str.get_allocator()</tt>. </p>
 </blockquote>

 <p>B. In 21.3 [basic.string], and also in 21.3.1 [string.require], replace
 the declaration of the copy constructor as follows: </p>

 <blockquote>
   <pre>basic_string(const basic_string&amp; str, size_type pos = 0,
              size_type n = npos); </pre>
 </blockquote>

 <p>The proposed resolution reflects the original intent of the LWG. It
 was also noted by Pete Becker that this fix "will cause
 a small amount of existing code to now work correctly."</p>

 <p><i>[
 Kona: issue editing snafu fixed - the proposed resolution now correctly
 reflects the LWG consensus.
 ]</i></p>


 <hr>
 <h3><a name="44"></a>44. Iostreams use operator== on int_type values</h3>
 <p><b>Section:</b> 27 [input.output] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.output">issues</a> in [input.output].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Many of the specifications for iostreams specify that character
 values or their int_type equivalents are compared using operators ==
 or !=, though in other places traits::eq() or traits::eq_int_type is
 specified to be used throughout. This is an inconsistency; we should
 change uses of == and != to use the traits members instead. </p>


 <p><b>Proposed resolution:</b></p>

 <p><i>[Pre-Kona: Dietmar supplied wording]</i></p>


 <p>List of changes to clause 27:</p>
 <ol>
 <li>
    In lib.basic.ios.members paragraph 13 (postcondition clause for
    'fill(cT)') change

 <blockquote><pre>     fillch == fill()
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(fillch, fill())
 </pre></blockquote>


 </li>
 <li>
    In lib.istream.unformatted paragraph 7 (effects clause for
    'get(cT,streamsize,cT)'), third bullet, change

 <blockquote><pre>     c == delim for the next available input character c
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(c, delim) for the next available input character c
 </pre></blockquote>

 </li>
 <li>
    In lib.istream.unformatted paragraph 12 (effects clause for
    'get(basic_streambuf&lt;cT,Tr&gt;&amp;,cT)'), third bullet, change

 <blockquote><pre>     c == delim for the next available input character c
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(c, delim) for the next available input character c
 </pre></blockquote>

 </li>
 <li>
    In lib.istream.unformatted paragraph 17 (effects clause for
    'getline(cT,streamsize,cT)'), second bullet, change

 <blockquote><pre>     c == delim for the next available input character c
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(c, delim) for the next available input character c
   </pre></blockquote>

 </li>
 <li>
    In lib.istream.unformatted paragraph 24 (effects clause for
    'ignore(int,int_type)'), second bullet, change

 <blockquote><pre>     c == delim for the next available input character c
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq_int_type(c, delim) for the next available input
      character c
 </pre></blockquote>

 </li>
 <li>
    In lib.istream.unformatted paragraph 25 (notes clause for
    'ignore(int,int_type)'), second bullet, change

 <blockquote><pre>     The last condition will never occur if delim == traits::eof()
 </pre></blockquote>

    to

 <blockquote><pre>     The last condition will never occur if
      traits::eq_int_type(delim, traits::eof()).
 </pre></blockquote>

 </li>
 <li>
    In lib.istream.sentry paragraph 6 (example implementation for the
    sentry constructor) change

 <blockquote><pre>     while ((c = is.rdbuf()-&gt;snextc()) != traits::eof()) {
 </pre></blockquote>

    to

 <blockquote><pre>     while (!traits::eq_int_type(c = is.rdbuf()-&gt;snextc(), traits::eof())) {
 </pre></blockquote>

 </li>
 </ol>

 <p>List of changes to Chapter 21:</p>

 <ol>
 <li>
    In lib.string::find paragraph 1 (effects clause for find()),
    second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>

 </li>
 <li>
    In lib.string::rfind paragraph 1 (effects clause for rfind()),
    second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>

 </li>
 <li>
    In lib.string::find.first.of paragraph 1 (effects clause for
    find_first_of()), second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>

 </li>
 <li>
    In lib.string::find.last.of paragraph 1 (effects clause for
    find_last_of()), second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>

 </li>
 <li>
    In lib.string::find.first.not.of paragraph 1 (effects clause for
    find_first_not_of()), second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>
 </li>

 <li>
    In lib.string::find.last.not.of paragraph 1 (effects clause for
    find_last_not_of()), second bullet, change

 <blockquote><pre>     at(xpos+I) == str.at(I) for all elements ...
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(at(xpos+I), str.at(I)) for all elements ...
 </pre></blockquote>
 </li>

 <li>
    In lib.string.ios paragraph 5 (effects clause for getline()),
    second bullet, change

 <blockquote><pre>     c == delim for the next available input character c
 </pre></blockquote>

    to

 <blockquote><pre>     traits::eq(c, delim) for the next available input character c
 </pre></blockquote>
 </li>

 </ol>

 <p>Notes:</p>
 <ul>
 <li>
   Fixing this issue highlights another sloppyness in
   lib.istream.unformatted paragraph 24: this clause mentions a "character"
   which is then compared to an 'int_type' (see item 5. in the list
   below). It is not clear whether this requires explicit words and
   if so what these words are supposed to be. A similar issue exists,
   BTW, for operator*() of istreambuf_iterator which returns the result
   of sgetc() as a character type (see lib.istreambuf.iterator::op*
   paragraph 1), and for operator++() of istreambuf_iterator which
   passes the result of sbumpc() to a constructor taking a char_type
   (see lib.istreambuf.iterator::operator++ paragraph 3). Similarily, the
   assignment operator ostreambuf_iterator passes a char_type to a function
   taking an int_type (see lib.ostreambuf.iter.ops paragraph 1).
 </li>
 <li>
   It is inconsistent to use comparisons using the traits functions in
   Chapter 27 while not using them in Chapter 21, especially as some
   of the inconsistent uses actually involve streams (eg. getline() on
   streams). To avoid leaving this issue open still longer due to this
   inconsistency (it is open since 1998), a list of changes to Chapter
   21 is below.
 </li>
 <li>
   In Chapter 24 there are several places with statements like "the end
   of stream is reached (streambuf_type::sgetc() returns traits::eof())"
   (lib.istreambuf.iterator paragraph 1, lib.ostreambuf.iter.ops
   paragraph 5). It is unclear whether these should be clarified to use
   traits::eq_int_type() for detecting traits::eof().
 </li>
 </ul>


 <hr>
 <h3><a name="46"></a>46. Minor Annex D errors</h3>
 <p><b>Section:</b> D.7 [depr.str.strstreams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Brendan Kehoe <b>Date:</b> 1998-06-01</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p><p>See lib-6522 and edit-814.</p>

 <p><b>Proposed resolution:</b></p>
 <p>Change D.7.1 [depr.strstreambuf] (since streambuf is a typedef of
 basic_streambuf&lt;char&gt;) from:</p>

 <pre>         virtual streambuf&lt;char&gt;* setbuf(char* s, streamsize n);</pre>

 <p>to:</p>

 <pre>         virtual streambuf* setbuf(char* s, streamsize n);</pre>

 <p>In D.7.4 [depr.strstream] insert the semicolon now missing after
 int_type:</p>

 <pre>     namespace std {
        class strstream
          : public basic_iostream&lt;char&gt; {
        public:
          // Types
          typedef char                                char_type;
          typedef typename char_traits&lt;char&gt;::int_type int_type
          typedef typename char_traits&lt;char&gt;::pos_type pos_type;</pre>


 <hr>
 <h3><a name="47"></a>47. Imbue() and getloc() Returns clauses swapped</h3>
 <p><b>Section:</b> 27.4.2.3 [ios.base.locales] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base.locales">issues</a> in [ios.base.locales].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 27.4.2.3 specifies how imbue() and getloc() work. That
 section has two RETURNS clauses, and they make no sense as
 stated. They make perfect sense, though, if you swap them. Am I
 correct in thinking that paragraphs 2 and 4 just got mixed up by
 accident?</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.4.2.3 [ios.base.locales] swap paragraphs 2 and 4.</p>


 <hr>
 <h3><a name="48"></a>48. Use of non-existent exception constructor</h3>
 <p><b>Section:</b> 27.4.2.1.1 [ios::failure] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios::failure">issues</a> in [ios::failure].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.4.2.1.1, paragraph 2, says that class failure initializes the
 base class, exception, with exception(msg). Class exception (see
 18.6.1) has no such constructor.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace 27.4.2.1.1 [ios::failure], paragraph 2, with</p>

 <blockquote>
   <p>EFFECTS: Constructs an object of class <tt>failure</tt>.</p>
 </blockquote>


 <hr>
 <h3><a name="49"></a>49. Underspecification of ios_base::sync_with_stdio</h3>
 <p><b>Section:</b> 27.4.2.4 [ios.members.static] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-21</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Two problems</p>

 <p>(1) 27.4.2.4 doesn't say what ios_base::sync_with_stdio(f)
 returns. Does it return f, or does it return the previous
 synchronization state? My guess is the latter, but the standard
 doesn't say so.</p>

 <p>(2) 27.4.2.4 doesn't say what it means for streams to be
 synchronized with stdio.  Again, of course, I can make some
 guesses. (And I'm unhappy about the performance implications of those
 guesses, but that's another matter.)</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the following sentence in 27.4.2.4 [ios.members.static]
 returns clause from:</p>

 <blockquote>
   <p><tt>true</tt> if the standard iostream objects (27.3) are
   synchronized and otherwise returns <tt>false</tt>.</p>
 </blockquote>

 <p>to:</p>

 <blockquote>
   <p><tt>true</tt> if the previous state of the standard iostream
   objects (27.3) was synchronized and otherwise returns
   <tt>false</tt>.</p>
 </blockquote>

 <p>Add the following immediately after 27.4.2.4 [ios.members.static],
 paragraph 2:</p>

 <blockquote>
 <p>When a standard iostream object str is <i>synchronized</i> with a
 standard stdio stream f, the effect of inserting a character c by</p>
 <pre>  fputc(f, c);
 </pre>

 <p>is the same as the effect of</p>
 <pre>  str.rdbuf()-&gt;sputc(c);
 </pre>

 <p>for any sequence of characters; the effect of extracting a
 character c by</p>
 <pre>  c = fgetc(f);
 </pre>

 <p>is the same as the effect of:</p>
 <pre>  c = str.rdbuf()-&gt;sbumpc(c);
 </pre>

 <p>for any sequences of characters; and the effect of pushing
 back a character c by</p>
 <pre>  ungetc(c, f);
 </pre>

 <p>is the same as the effect of</p>
 <pre>  str.rdbuf()-&gt;sputbackc(c);
 </pre>

 <p>for any sequence of characters.  [<i>Footnote</i>: This implies
 that operations on a standard iostream object can be mixed arbitrarily
 with operations on the corresponding stdio stream.  In practical
 terms, synchronization usually means that a standard iostream object
 and a standard stdio object share a buffer. <i>--End Footnote</i>]</p>
 </blockquote>

 <p><i>[pre-Copenhagen: PJP and Matt contributed the definition
 of "synchronization"]</i></p>


 <p><i>[post-Copenhagen: proposed resolution was revised slightly:
 text was added in the non-normative footnote to say that operations
 on the two streams can be mixed arbitrarily.]</i></p>


 <hr>
 <h3><a name="50"></a>50. Copy constructor and assignment operator of ios_base</h3>
 <p><b>Section:</b> 27.4.2 [ios.base] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base">issues</a> in [ios.base].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>As written, ios_base has a copy constructor and an assignment
 operator. (Nothing in the standard says it doesn't have one, and all
 classes have copy constructors and assignment operators unless you
 take specific steps to avoid them.) However, nothing in 27.4.2 says
 what the copy constructor and assignment operator do. </p>

 <p>My guess is that this was an oversight, that ios_base is, like
 basic_ios, not supposed to have a copy constructor or an assignment
 operator.</p>

 <p>
 Jerry Schwarz comments: Yes, its an oversight, but in the opposite
 sense to what you're suggesting. At one point there was a definite
 intention that you could copy ios_base. It's an easy way to save the
 entire state of a stream for future use. As you note, to carry out
 that intention would have required a explicit description of the
 semantics (e.g. what happens to the iarray and parray stuff).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.4.2 [ios.base], class ios_base, specify the copy
 constructor and operator= members as being private.</p>


 <p><b>Rationale:</b></p>
 <p>The LWG believes the difficulty of specifying correct semantics
 outweighs any benefit of allowing ios_base objects to be copyable.</p>


 <hr>
 <h3><a name="51"></a>51. Requirement to not invalidate iterators missing</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> David Vandevoorde <b>Date:</b> 1998-06-23</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The std::sort algorithm can in general only sort a given sequence
 by moving around values. The list&lt;&gt;::sort() member on the other
 hand could move around values or just update internal pointers. Either
 method can leave iterators into the list&lt;&gt; dereferencable, but
 they would point to different things. </p>

 <p>Does the FDIS mandate anywhere which method should be used for
 list&lt;&gt;::sort()?</p>

 <p>Matt Austern comments:</p>

 <p>I think you've found an omission in the standard. </p>

 <p>The library working group discussed this point, and there was
 supposed to be a general requirement saying that list, set, map,
 multiset, and multimap may not invalidate iterators, or change the
 values that iterators point to, except when an operation does it
 explicitly. So, for example, insert() doesn't invalidate any iterators
 and erase() and remove() only invalidate iterators pointing to the
 elements that are being erased. </p>

 <p>I looked for that general requirement in the FDIS, and, while I
 found a limited form of it for the sorted associative containers, I
 didn't find it for list. It looks like it just got omitted. </p>

 <p>The intention, though, is that list&lt;&gt;::sort does not
 invalidate any iterators and does not change the values that any
 iterator points to. There would be no reason to have the member
 function otherwise.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add a new paragraph at the end of 23.1:</p>

 <blockquote>
   <p>Unless otherwise specified (either explicitly or by defining a function in terms of
   other functions), invoking a container member function or passing a container as an
   argument to a library function shall not invalidate iterators to, or change the values of,
   objects within that container. </p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>This was US issue CD2-23-011; it was accepted in London but the
 change was not made due to an editing oversight. The wording in the
 proposed resolution below is somewhat updated from CD2-23-011,
 particularly the addition of the phrase "or change the values
 of"</p>


 <hr>
 <h3><a name="52"></a>52. Small I/O problems</h3>
 <p><b>Section:</b> 27.4.3.2 [fpos.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>First, 27.4.4.1 [basic.ios.cons], table 89. This is pretty obvious:
 it should be titled "basic_ios&lt;&gt;() effects", not
 "ios_base() effects". </p>

 <p>[The second item is a duplicate; see issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#6">6</a> for
 resolution.]</p>

 <p>Second, 27.4.3.2 [fpos.operations] table 88 . There are a couple
 different things wrong with it, some of which I've already discussed
 with Jerry, but the most obvious mechanical sort of error is that it
 uses expressions like P(i) and p(i), without ever defining what sort
 of thing "i" is.
 </p>

 <p>(The other problem is that it requires support for streampos
 arithmetic. This is impossible on some systems, i.e. ones where file
 position is a complicated structure rather than just a number. Jerry
 tells me that the intention was to require syntactic support for
 streampos arithmetic, but that it wasn't actually supposed to do
 anything meaningful except on platforms, like Unix, where genuine
 arithmetic is possible.) </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.4.4.1 [basic.ios.cons] table 89 title from
 "ios_base() effects" to "basic_ios&lt;&gt;()
 effects". </p>


 <hr>
 <h3><a name="53"></a>53. Basic_ios destructor unspecified</h3>
 <p><b>Section:</b> 27.4.4.1 [basic.ios.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.cons">issues</a> in [basic.ios.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>There's nothing in 27.4.4 saying what basic_ios's destructor does.
 The important question is whether basic_ios::~basic_ios() destroys
 rdbuf().</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add after 27.4.4.1 [basic.ios.cons] paragraph 2:</p>

 <blockquote>
   <p><tt>virtual ~basic_ios();</tt></p>
   <p><b>Notes</b>: The destructor does not destroy <tt>rdbuf()</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG reviewed the additional question of whether or not
 <tt>rdbuf(0)</tt> may set <tt>badbit</tt>.  The answer is
 clearly yes; it may be set via <tt>clear()</tt>.  See 27.4.4.2 [basic.ios.members], paragraph 6.  This issue was reviewed at length
 by the LWG, which removed from the original proposed resolution a
 footnote which incorrectly said "<tt>rdbuf(0)</tt> does not set
 <tt>badbit</tt>".</p>


 <hr>
 <h3><a name="54"></a>54. Basic_streambuf's destructor</h3>
 <p><b>Section:</b> 27.5.2.1 [streambuf.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#streambuf.cons">issues</a> in [streambuf.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The class synopsis for basic_streambuf shows a (virtual)
 destructor, but the standard doesn't say what that destructor does. My
 assumption is that it does nothing, but the standard should say so
 explicitly. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add after 27.5.2.1 [streambuf.cons] paragraph 2:</p>

 <blockquote>
   <p><tt>virtual&nbsp; ~basic_streambuf();</tt></p>
   <p><b>Effects</b>: None.</p>
 </blockquote>


 <hr>
 <h3><a name="55"></a>55. Invalid stream position is undefined</h3>
 <p><b>Section:</b> 27 [input.output] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.output">issues</a> in [input.output].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Several member functions in clause 27 are defined in certain
 circumstances to return an "invalid stream position", a term
 that is defined nowhere in the standard. Two places (27.5.2.4.2,
 paragraph 4, and 27.8.1.4, paragraph 15) contain a cross-reference to
 a definition in _lib.iostreams.definitions_, a nonexistent
 section. </p>

 <p>I suspect that the invalid stream position is just supposed to be
 pos_type(-1).  Probably best to say explicitly in (for example)
 27.5.2.4.2 that the return value is pos_type(-1), rather than to use
 the term "invalid stream position", define that term
 somewhere, and then put in a cross-reference. </p>

 <p>The phrase "invalid stream position" appears ten times in
 the C++ Standard.  In seven places it refers to a return value, and it
 should be changed. In three places it refers to an argument, and it
 should not be changed. Here are the three places where "invalid
 stream position" should not be changed:</p>

 <blockquote>
   <p>27.7.1.4 [stringbuf.virtuals], paragraph 14<br>
   27.8.1.5 [filebuf.virtuals], paragraph 14<br>
   D.7.1.3 [depr.strstreambuf.virtuals], paragraph 17
   </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.5.2.4.2 [streambuf.virt.buffer], paragraph 4, change "Returns an
 object of class pos_type that stores an invalid stream position
 (_lib.iostreams.definitions_)" to "Returns
 <tt>pos_type(off_type(-1))</tt>".
 </p>

 <p>In 27.5.2.4.2 [streambuf.virt.buffer], paragraph 6, change "Returns
 an object of class pos_type that stores an invalid stream
 position" to "Returns <tt>pos_type(off_type(-1))</tt>".</p>

 <p>In 27.7.1.4 [stringbuf.virtuals], paragraph 13, change "the object
 stores an invalid stream position" to "the return value is
 <tt>pos_type(off_type(-1))</tt>". </p>

 <p>In 27.8.1.5 [filebuf.virtuals], paragraph 13, change "returns an
 invalid stream position (27.4.3)" to "returns
 <tt>pos_type(off_type(-1))</tt>" </p>

 <p>In 27.8.1.5 [filebuf.virtuals], paragraph 15, change "Otherwise
 returns an invalid stream position (_lib.iostreams.definitions_)"
 to "Otherwise returns <tt>pos_type(off_type(-1))</tt>"
 </p>

 <p>In D.7.1.3 [depr.strstreambuf.virtuals], paragraph 15, change "the object
 stores an invalid stream position" to "the return value is
 <tt>pos_type(off_type(-1))</tt>" </p>

 <p>In D.7.1.3 [depr.strstreambuf.virtuals], paragraph 18, change "the object
 stores an invalid stream position" to "the return value is
 <tt>pos_type(off_type(-1))</tt>"</p>


 <hr>
 <h3><a name="56"></a>56. Showmanyc's return type</h3>
 <p><b>Section:</b> 27.5.2 [streambuf] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-06-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#streambuf">issues</a> in [streambuf].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The class summary for basic_streambuf&lt;&gt;, in 27.5.2, says that
 showmanyc has return type int. However, 27.5.2.4.3 says that its
 return type is streamsize. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change <tt>showmanyc</tt>'s return type in the
 27.5.2 [streambuf] class summary to <tt>streamsize</tt>.</p>


 <hr>
 <h3><a name="57"></a>57. Mistake in char_traits</h3>
 <p><b>Section:</b> 21.1.3.4 [char.traits.specializations.wchar.t] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-07-01</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>21.1.3.2, paragraph 3, says "The types streampos and
 wstreampos may be different if the implementation supports no shift
 encoding in narrow-oriented iostreams but supports one or more shift
 encodings in wide-oriented streams". </p>

 <p>That's wrong: the two are the same type. The &lt;iosfwd&gt; summary
 in 27.2 says that streampos and wstreampos are, respectively, synonyms
 for fpos&lt;char_traits&lt;char&gt;::state_type&gt; and
 fpos&lt;char_traits&lt;wchar_t&gt;::state_type&gt;, and, flipping back
 to clause 21, we see in 21.1.3.1 and 21.1.3.2 that
 char_traits&lt;char&gt;::state_type and
 char_traits&lt;wchar_t&gt;::state_type must both be mbstate_t. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the sentence in 21.1.3.4 [char.traits.specializations.wchar.t] paragraph 3 which
 begins "The types streampos and wstreampos may be
 different..." . </p>


 <hr>
 <h3><a name="59"></a>59. Ambiguity in specification of gbump</h3>
 <p><b>Section:</b> 27.5.2.3.2 [streambuf.get.area] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-07-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.5.2.3.1 says that basic_streambuf::gbump() "Advances the
 next pointer for the input sequence by n." </p>

 <p>The straightforward interpretation is that it is just gptr() +=
 n. An alternative interpretation, though, is that it behaves as if it
 calls sbumpc n times. (The issue, of course, is whether it might ever
 call underflow.) There is a similar ambiguity in the case of
 pbump. </p>

 <p>(The "classic" AT&amp;T implementation used the
 former interpretation.)</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.5.2.3.2 [streambuf.get.area] paragraph 4 gbump effects from:</p>

 <blockquote>
   <p>Effects: Advances the next pointer for the input sequence by n.</p>
 </blockquote>

 <p>to:</p>

 <blockquote>
   <p>Effects: Adds <tt>n</tt> to the next pointer for the input sequence.</p>
 </blockquote>

 <p>Make the same change to 27.5.2.3.3 [streambuf.put.area] paragraph 4 pbump
 effects.</p>


 <hr>
 <h3><a name="60"></a>60. What is a formatted input function?</h3>
 <p><b>Section:</b> 27.6.1.2.1 [istream.formatted.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.formatted.reqmts">issues</a> in [istream.formatted.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#162">162</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#163">163</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#166">166</a></p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 1 of 27.6.1.2.1 contains general requirements for all
 formatted input functions. Some of the functions defined in section
 27.6.1.2 explicitly say that those requirements apply ("Behaves
 like a formatted input member (as described in 27.6.1.2.1)"), but
 others don't. The question: is 27.6.1.2.1 supposed to apply to
 everything in 27.6.1.2, or only to those member functions that
 explicitly say "behaves like a formatted input member"? Or
 to put it differently: are we to assume that everything that appears
 in a section called "Formatted input functions" really is a
 formatted input function? I assume that 27.6.1.2.1 is intended to
 apply to the arithmetic extractors (27.6.1.2.2), but I assume that it
 is not intended to apply to extractors like </p>

 <pre>    basic_istream&amp; operator&gt;&gt;(basic_istream&amp; (*pf)(basic_istream&amp;));</pre>

 <p>and </p>

 <pre>    basic_istream&amp; operator&gt;&gt;(basic_streammbuf*);</pre>

 <p>There is a similar ambiguity for unformatted input, formatted output, and unformatted
 output. </p>

 <p>Comments from Judy Ward: It seems like the problem is that the
 basic_istream and basic_ostream operator &lt;&lt;()'s that are used
 for the manipulators and streambuf* are in the wrong section and
 should have their own separate section or be modified to make it clear
 that the "Common requirements" listed in section 27.6.1.2.1
 (for basic_istream) and section 27.6.2.5.1 (for basic_ostream) do not
 apply to them. </p>

 <p>Additional comments from Dietmar Kühl: It appears to be somewhat
 nonsensical to consider the functions defined in 27.6.1.2.3
 [istream::extractors] paragraphs 1 to 5 to be "Formatted input
 function" but since these functions are defined in a section
 labeled "Formatted input functions" it is unclear to me
 whether these operators are considered formatted input functions which
 have to conform to the "common requirements" from 27.6.1.2.1
 [istream.formatted.reqmts]: If this is the case, all manipulators, not
 just <tt>ws</tt>, would skip whitespace unless <tt>noskipws</tt> is
 set (... but setting <tt>noskipws</tt> using the manipulator syntax
 would also skip whitespace :-)</p> <p>It is not clear which functions
 are to be considered unformatted input functions. As written, it seems
 that all functions in 27.6.1.3 [istream.unformatted] are unformatted input
 functions. However, it does not really make much sense to construct a
 sentry object for <tt>gcount()</tt>, <tt>sync()</tt>, ... Also it is
 unclear what happens to the <tt>gcount()</tt> if
 eg. <tt>gcount()</tt>, <tt>putback()</tt>, <tt>unget()</tt>, or
 <tt>sync()</tt> is called: These functions don't extract characters,
 some of them even "unextract" a character. Should this still
 be reflected in <tt>gcount()</tt>? Of course, it could be read as if
 after a call to <tt>gcount()</tt> <tt>gcount()</tt> return <tt>0</tt>
 (the last unformatted input function, <tt>gcount()</tt>, didn't
 extract any character) and after a call to <tt>putback()</tt>
 <tt>gcount()</tt> returns <tt>-1</tt> (the last unformatted input
 function <tt>putback()</tt> did "extract" back into the
 stream). Correspondingly for <tt>unget()</tt>. Is this what is
 intended?  If so, this should be clarified. Otherwise, a corresponding
 clarification should be used.</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.6.1.2.2 [lib.istream.formatted.arithmetic], paragraph 1.
 Change the beginning of the second sentence from "The conversion
 occurs" to "These extractors behave as formatted input functions (as
 described in 27.6.1.2.1).  After a sentry object is constructed,
 the conversion occurs"
 </p>

 <p>
 In 27.6.1.2.3, [lib.istream::extractors], before paragraph 1.
 Add an effects clause.  "Effects: None.  This extractor does
 not behave as a formatted input function (as described in
 27.6.1.2.1).
 </p>

 <p>
 In 27.6.1.2.3, [lib.istream::extractors], paragraph 2.  Change the
 effects clause to "Effects: Calls pf(*this).  This extractor does not
 behave as a formatted input function (as described in 27.6.1.2.1).
 </p>

 <p>
 In 27.6.1.2.3, [lib.istream::extractors], paragraph 4.  Change the
 effects clause to "Effects: Calls pf(*this).  This extractor does not
 behave as a formatted input function (as described in 27.6.1.2.1).
 </p>

 <p>
 In 27.6.1.2.3, [lib.istream::extractors], paragraph 12.  Change the
 first two sentences from "If sb is null, calls setstate(failbit),
 which may throw ios_base::failure (27.4.4.3).  Extracts characters
 from *this..." to "Behaves as a formatted input function (as described
 in 27.6.1.2.1).  If sb is null, calls setstate(failbit), which may
 throw ios_base::failure (27.4.4.3).  After a sentry object is
 constructed, extracts characters from *this...".
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], before paragraph 2.  Add an
 effects clause.  "Effects: none. This member function does not behave
 as an unformatted input function (as described in 27.6.1.3, paragraph 1)."
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 3.  Change the
 beginning of the first sentence of the effects clause from "Extracts a
 character" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts a
 character"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 5.  Change the
 beginning of the first sentence of the effects clause from "Extracts a
 character" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts a
 character"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 7.  Change the
 beginning of the first sentence of the effects clause from "Extracts
 characters" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts
 characters"
 </p>

 <p>
 [No change needed in paragraph 10, because it refers to paragraph 7.]
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 12.  Change the
 beginning of the first sentence of the effects clause from "Extracts
 characters" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts
 characters"
 </p>

 <p>
 [No change needed in paragraph 15.]
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 17.  Change the
 beginning of the first sentence of the effects clause from "Extracts
 characters" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts
 characters"
 </p>

 <p>
 [No change needed in paragraph 23.]
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 24.  Change the
 beginning of the first sentence of the effects clause from "Extracts
 characters" to "Behaves as an unformatted input function (as described
 in 27.6.1.3, paragraph 1).  After constructing a sentry object, extracts
 characters"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], before paragraph 27.  Add an
 Effects clause: "Effects: Behaves as an unformatted input function (as
 described in 27.6.1.3, paragraph 1).  After constructing a sentry
 object, reads but does not extract the current input character."
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 28.  Change the
 first sentence of the Effects clause from "If !good() calls" to
 Behaves as an unformatted input function (as described in 27.6.1.3,
 paragraph 1).  After constructing a sentry object, if !good() calls"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 30.  Change the
 first sentence of the Effects clause from "If !good() calls" to
 "Behaves as an unformatted input function (as described in 27.6.1.3,
 paragraph 1).  After constructing a sentry object, if !good() calls"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 32.  Change the
 first sentence of the Effects clause from "If !good() calls..." to
 "Behaves as an unformatted input function (as described in 27.6.1.3,
 paragraph 1).  After constructing a sentry object, if !good()
 calls..."  Add a new sentence to the end of the Effects clause:
 "[Note: this function extracts no characters, so the value returned
 by the next call to gcount() is 0.]"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 34.  Change the
 first sentence of the Effects clause from "If !good() calls" to
 "Behaves as an unformatted input function (as described in 27.6.1.3,
 paragraph 1).  After constructing a sentry object, if !good() calls".
 Add a new sentence to the end of the Effects clause: "[Note: this
 function extracts no characters, so the value returned by the next
 call to gcount() is 0.]"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 36.  Change the
 first sentence of the Effects clause from "If !rdbuf() is" to "Behaves
 as an unformatted input function (as described in 27.6.1.3, paragraph
 1), except that it does not count the number of characters extracted
 and does not affect the value returned by subsequent calls to
 gcount().  After constructing a sentry object, if rdbuf() is"
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], before paragraph 37.  Add an
 Effects clause: "Effects: Behaves as an unformatted input function (as
 described in 27.6.1.3, paragraph 1), except that it does not count the
 number of characters extracted and does not affect the value returned
 by subsequent calls to gcount()."  Change the first sentence of
 paragraph 37 from "if fail()" to "after constructing a sentry object,
 if fail()".
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 38.  Change the
 first sentence of the Effects clause from "If fail()" to "Behaves
 as an unformatted input function (as described in 27.6.1.3, paragraph
 1), except that it does not count the number of characters extracted
 and does not affect the value returned by subsequent calls to
 gcount().  After constructing a sentry object, if fail()
 </p>

 <p>
 In 27.6.1.3, [lib.istream.unformatted], paragraph 40.  Change the
 first sentence of the Effects clause from "If fail()" to "Behaves
 as an unformatted input function (as described in 27.6.1.3, paragraph
 1), except that it does not count the number of characters extracted
 and does not affect the value returned by subsequent calls to
 gcount().  After constructing a sentry object, if fail()
 </p>

 <p>
 In 27.6.2.5.2 [lib.ostream.inserters.arithmetic], paragraph 1.  Change
 the beginning of the third sentence from "The formatting conversion"
 to "These extractors behave as formatted output functions (as
 described in 27.6.2.5.1).  After the sentry object is constructed, the
 conversion occurs".
 </p>

 <p>
 In 27.6.2.5.3 [lib.ostream.inserters], before paragraph 1.  Add an
 effects clause: "Effects: None. Does not behave as a formatted output
 function (as described in 27.6.2.5.1).".
 </p>

 <p>
 In 27.6.2.5.3 [lib.ostream.inserters], paragraph 2.  Change the
 effects clause to "Effects: calls pf(*this).  This extractor does not
 behave as a formatted output function (as described in 27.6.2.5.1).".
 </p>

 <p>
 In 27.6.2.5.3 [lib.ostream.inserters], paragraph 4.  Change the
 effects clause to "Effects: calls pf(*this).  This extractor does not
 behave as a formatted output function (as described in 27.6.2.5.1).".
 </p>

 <p>
 In 27.6.2.5.3 [lib.ostream.inserters], paragraph 6.  Change the first
 sentence from "If sb" to "Behaves as a formatted output function (as
 described in 27.6.2.5.1).  After the sentry object is constructed, if
 sb".
 </p>

 <p>
 In 27.6.2.6 [lib.ostream.unformatted], paragraph 2.  Change the first
 sentence from "Inserts the character" to "Behaves as an unformatted
 output function (as described in 27.6.2.6, paragraph 1).  After
 constructing a sentry object, inserts the character".
 </p>

 <p>
 In 27.6.2.6 [lib.ostream.unformatted], paragraph 5.  Change the first
 sentence from "Obtains characters" to "Behaves as an unformatted
 output function (as described in 27.6.2.6, paragraph 1).  After
 constructing a sentry object, obtains characters".
 </p>

 <p>
 In 27.6.2.6 [lib.ostream.unformatted], paragraph 7.  Add a new
 sentence at the end of the paragraph: "Does not behave as an
 unformatted output function (as described in 27.6.2.6, paragraph 1)."
 </p>


 <p><b>Rationale:</b></p>
 <p>See J16/99-0043==WG21/N1219, Proposed Resolution to Library Issue 60,
 by Judy Ward and Matt Austern.  This proposed resolution is section
 VI of that paper.</p>


 <hr>
 <h3><a name="61"></a>61. Ambiguity in iostreams exception policy</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The introduction to the section on unformatted input (27.6.1.3)
 says that every unformatted input function catches all exceptions that
 were thrown during input, sets badbit, and then conditionally rethrows
 the exception. That seems clear enough. Several of the specific
 functions, however, such as get() and read(), are documented in some
 circumstances as setting eofbit and/or failbit. (The standard notes,
 correctly, that setting eofbit or failbit can sometimes result in an
 exception being thrown.) The question: if one of these functions
 throws an exception triggered by setting failbit, is this an exception
 "thrown during input" and hence covered by 27.6.1.3, or does
 27.6.1.3 only refer to a limited class of exceptions? Just to make
 this concrete, suppose you have the following snippet. </p>

 <pre>
   char buffer[N];
   istream is;
   ...
   is.exceptions(istream::failbit); // Throw on failbit but not on badbit.
   is.read(buffer, N);</pre>

 <p>Now suppose we reach EOF before we've read N characters. What
 iostate bits can we expect to be set, and what exception (if any) will
 be thrown? </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.6.1.3, paragraph 1, after the sentence that begins
 "If an exception is thrown...", add the following
 parenthetical comment: "(Exceptions thrown from
 <tt>basic_ios&lt;&gt;::clear()</tt> are not caught or rethrown.)"
 </p>


 <p><b>Rationale:</b></p>
 <p>The LWG looked to two alternative wordings, and choose the proposed
 resolution as better standardese.</p>


 <hr>
 <h3><a name="62"></a>62. <tt>Sync</tt>'s return value</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The Effects clause for sync() (27.6.1.3, paragraph 36) says that it
 "calls rdbuf()-&gt;pubsync() and, if that function returns -1
 ... returns traits::eof()." </p>

 <p>That looks suspicious, because traits::eof() is of type
 traits::int_type while the return type of sync() is int. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.1.3 [istream.unformatted], paragraph 36, change "returns
 <tt>traits::eof()</tt>" to "returns <tt>-1</tt>".
 </p>


 <hr>
 <h3><a name="63"></a>63. Exception-handling policy for unformatted output</h3>
 <p><b>Section:</b> 27.6.2.7 [ostream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-11</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.unformatted">issues</a> in [ostream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Clause 27 details an exception-handling policy for formatted input,
 unformatted input, and formatted output. It says nothing for
 unformatted output (27.6.2.6). 27.6.2.6 should either include the same
 kind of exception-handling policy as in the other three places, or
 else it should have a footnote saying that the omission is
 deliberate. </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.6.2.6, paragraph 1, replace the last sentence ("In any
 case, the unformatted output function ends by destroying the sentry
 object, then returning the value specified for the formatted output
 function.") with the following text:
 </p>
 <blockquote><p>
 If an exception is thrown during output, then <tt>ios::badbit</tt> is
 turned on [Footnote: without causing an <tt>ios::failure</tt> to be
 thrown.] in <tt>*this</tt>'s error state. If <tt>(exceptions() &amp;
 badbit) != 0</tt> then the exception is rethrown.  In any case, the
 unformatted output function ends by destroying the sentry object,
 then, if no exception was thrown, returning the value specified for
 the formatted output function.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>
 This exception-handling policy is consistent with that of formatted
 input, unformatted input, and formatted output.
 </p>


 <hr>
 <h3><a name="64"></a>64. Exception handling in <tt>basic_istream::operator&gt;&gt;(basic_streambuf*)</tt></h3>
 <p><b>Section:</b> 27.6.1.2.3 [istream::extractors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-11</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::extractors">issues</a> in [istream::extractors].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.6.1.2.3, paragraph 13, is ambiguous. It can be interpreted two
 different ways, depending on whether the second sentence is read as an
 elaboration of the first. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace 27.6.1.2.3 [istream::extractors], paragraph 13, which begins
 "If the function inserts no characters ..." with:</p>

 <blockquote>
   <p>If the function inserts no characters, it calls
   <tt>setstate(failbit)</tt>, which may throw
   <tt>ios_base::failure</tt> (27.4.4.3). If it inserted no characters
   because it caught an exception thrown while extracting characters
   from <tt>sb</tt> and <tt>failbit</tt> is on in <tt>exceptions()</tt>
   (27.4.4.3), then the caught exception is rethrown. </p>
 </blockquote>


 <hr>
 <h3><a name="66"></a>66. Strstreambuf::setbuf</h3>
 <p><b>Section:</b> D.7.1.3 [depr.strstreambuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-08-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.strstreambuf.virtuals">issues</a> in [depr.strstreambuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>D.7.1.3, paragraph 19, says that strstreambuf::setbuf
 "Performs an operation that is defined separately for each class
 derived from strstreambuf". This is obviously an incorrect
 cut-and-paste from basic_streambuf. There are no classes derived from
 strstreambuf. </p>


 <p><b>Proposed resolution:</b></p>
 <p>D.7.1.3 [depr.strstreambuf.virtuals], paragraph 19, replace the setbuf effects
 clause which currently says "Performs an operation that is
 defined separately for each class derived from strstreambuf"
 with:</p>

 <blockquote>
   <p><b>Effects</b>: implementation defined, except that
   <tt>setbuf(0,0)</tt> has no effect.</p>
 </blockquote>


 <hr>
 <h3><a name="68"></a>68. Extractors for char* should store null at end</h3>
 <p><b>Section:</b> 27.6.1.2.3 [istream::extractors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 1998-07-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::extractors">issues</a> in [istream::extractors].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Extractors for char* (27.6.1.2.3) do not store a null character
 after the extracted character sequence whereas the unformatted
 functions like get() do. Why is this?</p>

 <p>Comment from Jerry Schwarz: There is apparently an editing
 glitch. You'll notice that the last item of the list of what stops
 extraction doesn't make any sense. It was supposed to be the line that
 said a null is stored.</p>


 <p><b>Proposed resolution:</b></p>
 <p>27.6.1.2.3 [istream::extractors], paragraph 7, change the last list
 item from:</p>

 <blockquote><p>
   A null byte (<tt>charT()</tt>) in the next position, which may be
   the first position if no characters were extracted.
 </p></blockquote>

 <p>to become a new paragraph which reads:</p>

 <blockquote><p>
   Operator&gt;&gt; then stores a null byte (<tt>charT()</tt>) in the
   next position, which may be the first position if no characters were
   extracted.
 </p></blockquote>


 <hr>
 <h3><a name="69"></a>69. Must elements of a vector be contiguous?</h3>
 <p><b>Section:</b> 23.2.6 [vector] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1998-07-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector">issues</a> in [vector].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The issue is this: Must the elements of a vector be in contiguous memory?</p>

 <p>(Please note that this is entirely separate from the question of
 whether a vector iterator is required to be a pointer; the answer to
 that question is clearly "no," as it would rule out
 debugging implementations)</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following text to the end of 23.2.6 [vector],
 paragraph 1. </p>

 <blockquote>
   <p>The elements of a vector are stored contiguously, meaning that if
   v is a <tt>vector&lt;T, Allocator&gt;</tt> where T is some type
   other than <tt>bool</tt>, then it obeys the identity <tt>&amp;v[n]
   == &amp;v[0] + n</tt> for all <tt>0 &lt;= n &lt; v.size()</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG feels that as a practical matter the answer is clearly
 "yes".  There was considerable discussion as to the best way
 to express the concept of "contiguous", which is not
 directly defined in the standard.  Discussion included:</p>

 <ul>
   <li>An operational definition similar to the above proposed resolution is
     already used for valarray (26.5.2.3 [valarray.access]).</li>
   <li>There is no need to explicitly consider a user-defined operator&amp;
     because elements must be copyconstructible (23.1 [container.requirements] para 3)
     and copyconstructible (20.1.1 [utility.arg.requirements]) specifies
     requirements for operator&amp;.</li>
   <li>There is no issue of one-past-the-end because of language rules.</li>
 </ul>


 <hr>
 <h3><a name="70"></a>70. Uncaught_exception() missing throw() specification</h3>
 <p><b>Section:</b> 18.7 [support.exception], 18.7.4 [uncaught] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 1998-08-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#support.exception">issues</a> in [support.exception].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In article 3E04@pratique.fr, Valentin Bonnard writes: </p>

 <p>uncaught_exception() doesn't have a throw specification.</p>

 <p>It is intentional ? Does it means that one should be prepared to
 handle exceptions thrown from uncaught_exception() ?</p>

 <p>uncaught_exception() is called in exception handling contexts where
 exception safety is very important.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 15.5.3 [except.uncaught], paragraph 1, 18.7 [support.exception],
 and 18.7.4 [uncaught], add "throw()" to uncaught_exception().</p>


 <hr>
 <h3><a name="71"></a>71. Do_get_monthname synopsis missing argument</h3>
 <p><b>Section:</b> 22.2.5.1 [locale.time.get] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-08-13</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The locale facet member <tt>time_get&lt;&gt;::do_get_monthname</tt>
 is described in 22.2.5.1.2 [locale.time.get.virtuals] with five arguments,
 consistent with do_get_weekday and with its specified use by member
 get_monthname. However, in the synopsis, it is specified instead with
 four arguments. The missing argument is the "end" iterator
 value.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.5.1 [locale.time.get], add an "end" argument to
 the declaration of member do_monthname as follows:</p>

 <pre>  virtual iter_type do_get_monthname(iter_type s, iter_type end, ios_base&amp;,
                                      ios_base::iostate&amp; err, tm* t) const;</pre>


 <hr>
 <h3><a name="74"></a>74. Garbled text for <tt>codecvt::do_max_length</tt></h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-09-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The text of <tt>codecvt::do_max_length</tt>'s "Returns"
 clause (22.2.1.5.2, paragraph 11) is garbled. It has unbalanced
 parentheses and a spurious <b>n</b>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace 22.2.1.4.2 [locale.codecvt.virtuals] paragraph 11 with the
 following:</p>

 <blockquote><p>
   <b>Returns</b>: The maximum value that
   <tt>do_length(state, from, from_end, 1)</tt> can return for any
   valid range <tt>[from, from_end)</tt> and <tt>stateT</tt> value
   <tt>state</tt>. The specialization <tt>codecvt&lt;char, char,
   mbstate_t&gt;::do_max_length()</tt> returns 1.
 </p></blockquote>


 <hr>
 <h3><a name="75"></a>75. Contradiction in <tt>codecvt::length</tt>'s argument types</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b>  Matt
 Austern <b>Date:</b> 1998-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The class synopses for classes <tt>codecvt&lt;&gt;</tt> (22.2.1.5)
 and <tt>codecvt_byname&lt;&gt;</tt> (22.2.1.6) say that the first
 parameter of the member functions <tt>length</tt> and
 <tt>do_length</tt> is of type <tt>const stateT&amp;</tt>. The member
 function descriptions, however (22.2.1.5.1, paragraph 6; 22.2.1.5.2,
 paragraph 9) say that the type is <tt>stateT&amp;</tt>.  Either the
 synopsis or the summary must be changed. </p>

 <p>If (as I believe) the member function descriptions are correct,
 then we must also add text saying how <tt>do_length</tt> changes its
 <tt>stateT</tt> argument. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.1.4 [locale.codecvt], and also in 22.2.1.5 [locale.codecvt.byname],
 change the <tt>stateT</tt> argument type on both member
 <tt>length()</tt> and member <tt>do_length()</tt> from </p>

 <blockquote>
   <p><tt>const stateT&amp;</tt></p>
 </blockquote>

 <p>to</p>

 <blockquote>
   <p><tt>stateT&amp;</tt></p>
 </blockquote>

 <p>In 22.2.1.4.2 [locale.codecvt.virtuals], add to the definition for member
 <tt>do_length</tt> a paragraph:</p>

 <blockquote>
   <p>Effects: The effect on the <tt>state</tt> argument is ``as if''
   it called <tt>do_in(state, from, from_end, from, to, to+max,
   to)</tt> for <tt>to</tt> pointing to a buffer of at least
   <tt>max</tt> elements.</p>
 </blockquote>


 <hr>
 <h3><a name="76"></a>76. Can a <tt>codecvt</tt> facet always convert one internal character at a time?</h3>
 <p><b>Section:</b> 22.2.1.4 [locale.codecvt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-09-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt">issues</a> in [locale.codecvt].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>This issue concerns the requirements on classes derived from
 <tt>codecvt</tt>, including user-defined classes. What are the
 restrictions on the conversion from external characters
 (e.g. <tt>char</tt>) to internal characters (e.g. <tt>wchar_t</tt>)?
 Or, alternatively, what assumptions about <tt>codecvt</tt> facets can
 the I/O library make? </p>

 <p>The question is whether it's possible to convert from internal
 characters to external characters one internal character at a time,
 and whether, given a valid sequence of external characters, it's
 possible to pick off internal characters one at a time. Or, to put it
 differently: given a sequence of external characters and the
 corresponding sequence of internal characters, does a position in the
 internal sequence correspond to some position in the external
 sequence? </p>

 <p>To make this concrete, suppose that <tt>[first, last)</tt> is a
 sequence of <i>M</i> external characters and that <tt>[ifirst,
 ilast)</tt> is the corresponding sequence of <i>N</i> internal
 characters, where <i>N &gt; 1</i>. That is, <tt>my_encoding.in()</tt>,
 applied to <tt>[first, last)</tt>, yields <tt>[ifirst,
 ilast)</tt>. Now the question: does there necessarily exist a
 subsequence of external characters, <tt>[first, last_1)</tt>, such
 that the corresponding sequence of internal characters is the single
 character <tt>*ifirst</tt>?
 </p>

 <p>(What a "no" answer would mean is that
 <tt>my_encoding</tt> translates sequences only as blocks. There's a
 sequence of <i>M</i> external characters that maps to a sequence of
 <i>N</i> internal characters, but that external sequence has no
 subsequence that maps to <i>N-1</i> internal characters.) </p>

 <p>Some of the wording in the standard, such as the description of
 <tt>codecvt::do_max_length</tt> (22.2.1.4.2 [locale.codecvt.virtuals],
 paragraph 11) and <tt>basic_filebuf::underflow</tt> (27.8.1.5 [filebuf.virtuals], paragraph 3) suggests that it must always be
 possible to pick off internal characters one at a time from a sequence
 of external characters. However, this is never explicitly stated one
 way or the other. </p>

 <p>This issue seems (and is) quite technical, but it is important if
 we expect users to provide their own encoding facets. This is an area
 where the standard library calls user-supplied code, so a well-defined
 set of requirements for the user-supplied code is crucial. Users must
 be aware of the assumptions that the library makes. This issue affects
 positioning operations on <tt>basic_filebuf</tt>, unbuffered input,
 and several of <tt>codecvt</tt>'s member functions. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following text as a new paragraph, following 22.2.1.4.2 [locale.codecvt.virtuals] paragraph 2:</p>

 <blockquote>
 <p>A <tt>codecvt</tt> facet that is used by <tt>basic_filebuf</tt>
 (27.8 [file.streams]) must have the property that if</p>
 <pre>    do_out(state, from, from_end, from_next, to, to_lim, to_next)
 </pre>
 <p>would return <tt>ok</tt>, where <tt>from != from_end</tt>, then </p>
 <pre>    do_out(state, from, from + 1, from_next, to, to_end, to_next)
 </pre>
 <p>must also return <tt>ok</tt>, and that if</p>
 <pre>    do_in(state, from, from_end, from_next, to, to_lim, to_next)
 </pre>
 <p>would return <tt>ok</tt>, where <tt>to != to_lim</tt>, then</p>
 <pre>    do_in(state, from, from_end, from_next, to, to + 1, to_next)
 </pre>
 <p>must also return <tt>ok</tt>.  [<i>Footnote:</i> Informally, this
 means that <tt>basic_filebuf</tt> assumes that the mapping from
 internal to external characters is 1 to N: a <tt>codecvt</tt> that is
 used by <tt>basic_filebuf</tt> must be able to translate characters
 one internal character at a time.  <i>--End Footnote</i>]</p>
 </blockquote>

 <p><i>[Redmond: Minor change in proposed resolution.  Original
 proposed resolution talked about "success", with a parenthetical
 comment that success meant returning <tt>ok</tt>.  New wording
 removes all talk about "success", and just talks about the
 return value.]</i></p>


 <p><b>Rationale:</b></p>

   <p>The proposed resoluion says that conversions can be performed one
   internal character at a time.  This rules out some encodings that
   would otherwise be legal.  The alternative answer would mean there
   would be some internal positions that do not correspond to any
   external file position.</p>
   <p>
   An example of an encoding that this rules out is one where the
   <tt>internT</tt> and <tt>externT</tt> are of the same type, and
   where the internal sequence <tt>c1 c2</tt> corresponds to the
   external sequence <tt>c2 c1</tt>.
   </p>
   <p>It was generally agreed that <tt>basic_filebuf</tt> relies
   on this property: it was designed under the assumption that
   the external-to-internal mapping is N-to-1, and it is not clear
   that <tt>basic_filebuf</tt> is implementable without that
   restriction.
   </p>
   <p>
   The proposed resolution is expressed as a restriction on
   <tt>codecvt</tt> when used by <tt>basic_filebuf</tt>, rather
   than a blanket restriction on all <tt>codecvt</tt> facets,
   because <tt>basic_filebuf</tt> is the only other part of the
   library that uses <tt>codecvt</tt>.  If a user wants to define
   a <tt>codecvt</tt> facet that implements a more general N-to-M
   mapping, there is no reason to prohibit it, so long as the user
   does not expect <tt>basic_filebuf</tt> to be able to use it.
   </p>


 <hr>
 <h3><a name="78"></a>78. Typo: event_call_back</h3>
 <p><b>Section:</b> 27.4.2 [ios.base] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base">issues</a> in [ios.base].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>typo: event_call_back should be event_callback &nbsp; </p>


 <p><b>Proposed resolution:</b></p>
 <p>In the 27.4.2 [ios.base] synopsis change
 "event_call_back" to "event_callback". </p>


 <hr>
 <h3><a name="79"></a>79. Inconsistent declaration of polar()</h3>
 <p><b>Section:</b> 26.3.1 [complex.synopsis], 26.3.7 [complex.value.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.synopsis">issues</a> in [complex.synopsis].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 26.3.1 [complex.synopsis] polar is declared as follows:</p>
 <pre>   template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp;, const T&amp;); </pre>

 <p>In 26.3.7 [complex.value.ops] it is declared as follows:</p>
 <pre>   template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp; rho, const T&amp; theta = 0); </pre>

 <p>Thus whether the second parameter is optional is not clear. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 26.3.1 [complex.synopsis] change:</p>
 <pre>   template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp;, const T&amp;);</pre>

 <p>to:</p>
 <pre>   template&lt;class T&gt; complex&lt;T&gt; polar(const T&amp; rho, const T&amp; theta = 0); </pre>


 <hr>
 <h3><a name="80"></a>80. Global Operators of complex declared twice</h3>
 <p><b>Section:</b> 26.3.1 [complex.synopsis], 26.3.2 [complex] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.synopsis">issues</a> in [complex.synopsis].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Both 26.2.1 and 26.2.2 contain declarations of global operators for
 class complex. This redundancy should be removed.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Reduce redundancy according to the general style of the standard. </p>


 <hr>
 <h3><a name="83"></a>83. String::npos vs. string::max_size()</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#89">89</a></p>
 <p><b>Discussion:</b></p>
 <p>Many string member functions throw if size is getting or exceeding
 npos. However, I wonder why they don't throw if size is getting or
 exceeding max_size() instead of npos.  May be npos is known at compile
 time, while max_size() is known at runtime. However, what happens if
 size exceeds max_size() but not npos, then? It seems the standard
 lacks some clarifications here.</p>


 <p><b>Proposed resolution:</b></p>
 <p>After 21.3 [basic.string] paragraph 4 ("The functions
 described in this clause...") add a new paragraph:</p>

 <blockquote>
   <p>For any string operation, if as a result of the operation, <tt> size()</tt> would exceed
   <tt> max_size()</tt> then
   the operation throws <tt>length_error</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG believes length_error is the correct exception to throw.</p>


 <hr>
 <h3><a name="86"></a>86. String constructors don't describe exceptions</h3>
 <p><b>Section:</b> 21.3.1 [string.require] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.require">issues</a> in [string.require].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The constructor from a range:</p>

 <pre>template&lt;class InputIterator&gt;
          basic_string(InputIterator begin, InputIterator end,
                       const Allocator&amp; a = Allocator());</pre>

 <p>lacks a throws clause. However, I would expect that it throws
 according to the other constructors if the numbers of characters in
 the range equals npos (or exceeds max_size(), see above). </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 21.3.1 [string.require], Strike throws paragraphs for
 constructors which say "Throws: length_error if n ==
 npos."</p>


 <p><b>Rationale:</b></p>
 <p>Throws clauses for length_error if n == npos are no longer needed
 because they are subsumed by the general wording added by the
 resolution for issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#83">83</a>.</p>


 <hr>
 <h3><a name="90"></a>90. Incorrect description of operator &gt;&gt; for strings</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The effect of operator &gt;&gt; for strings contain the following item:</p>

 <p>&nbsp;&nbsp;&nbsp; <tt>isspace(c,getloc())</tt> is true for the next available input
 character c.</p>

 <p>Here <tt>getloc()</tt> has to be replaced by <tt>is.getloc()</tt>. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 21.3.8.9 [string.io] paragraph 1 Effects clause replace:</p>

 <blockquote>
   <p><tt>isspace(c,getloc())</tt> is true for the next available input character c.</p>
 </blockquote>

 <p>with:</p>

 <blockquote>
   <p><tt>isspace(c,is.getloc())</tt> is true for the next available input character c.</p>
 </blockquote>


 <hr>
 <h3><a name="91"></a>91. Description of operator&gt;&gt; and getline() for string&lt;&gt; might cause endless loop</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Operator &gt;&gt; and getline() for strings read until eof()
 in the input stream is true. However, this might never happen, if the
 stream can't read anymore without reaching EOF. So shouldn't it be
 changed into that it reads until !good() ? </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 21.3.8.9 [string.io], paragraph 1, replace:</p>
 <blockquote><p>
 Effects: Begins by constructing a sentry object k as if k were
 constructed by typename basic_istream&lt;charT,traits&gt;::sentry k( is). If
 bool( k) is true, it calls str.erase() and then extracts characters
 from is and appends them to str as if by calling str.append(1, c). If
 is.width() is greater than zero, the maximum number n of characters
 appended is is.width(); otherwise n is str.max_size(). Characters are
 extracted and appended until any of the following occurs:
 </p></blockquote>
 <p>with:</p>
 <blockquote><p>
 Effects: Behaves as a formatted input function (27.6.1.2.1
 [istream.formatted.reqmts]). After constructing a sentry object, if the
 sentry converts to true, calls str.erase() and then extracts
 characters from is and appends them to str as if by calling
 str.append(1,c). If is.width() is greater than zero, the maximum
 number n of characters appended is is.width(); otherwise n is
 str.max_size(). Characters are extracted and appended until any of the
 following occurs:
 </p></blockquote>

 <p>In 21.3.8.9 [string.io], paragraph 6, replace</p>
 <blockquote><p>
 Effects: Begins by constructing a sentry object k as if by typename
 basic_istream&lt;charT,traits&gt;::sentry k( is, true). If bool( k) is true,
 it calls str.erase() and then extracts characters from is and appends
 them to str as if by calling str.append(1, c) until any of the
 following occurs:
 </p></blockquote>
 <p>with:</p>
 <blockquote><p>Effects: Behaves as an unformatted input function
 (27.6.1.3 [istream.unformatted]), except that it does not affect the
 value returned
 by subsequent calls to basic_istream&lt;&gt;::gcount(). After
 constructing a sentry object, if the sentry converts to true, calls
 str.erase() and then extracts characters from is and appends them to
 str as if by calling str.append(1,c) until any of the following
 occurs:
 </p></blockquote>

 <p><i>[Redmond: Made changes in proposed resolution.  <tt>operator&gt;&gt;</tt>
 should be a formatted input function, not an unformatted input function.
 <tt>getline</tt> should not be required to set <tt>gcount</tt>, since
 there is no mechanism for <tt>gcount</tt> to be set except by one of
 <tt>basic_istream</tt>'s member functions.]</i></p>


 <p><i>[Curaçao: Nico agrees with proposed resolution.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The real issue here is whether or not these string input functions
 get their characters from a streambuf, rather than by calling an
 istream's member functions, a streambuf signals failure either by
 returning eof or by throwing an exception; there are no other
 possibilities.  The proposed resolution makes it clear that these two
 functions do get characters from a streambuf.</p>


 <hr>
 <h3><a name="92"></a>92. Incomplete Algorithm Requirements</h3>
 <p><b>Section:</b> 25 [algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 1998-09-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#algorithms">issues</a> in [algorithms].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The standard does not state, how often a function object is copied,
 called, or the order of calls inside an algorithm. This may lead to
 surprising/buggy behavior. Consider the following example: </p>

 <pre>class Nth {    // function object that returns true for the nth element
   private:
     int nth;     // element to return true for
     int count;   // element counter
   public:
     Nth (int n) : nth(n), count(0) {
     }
     bool operator() (int) {
         return ++count == nth;
     }
 };
 ....
 // remove third element
     list&lt;int&gt;::iterator pos;
     pos = remove_if(coll.begin(),coll.end(),  // range
                     Nth(3)),                  // remove criterion
     coll.erase(pos,coll.end()); </pre>

 <p>This call, in fact removes the 3rd <b>AND the 6th</b> element. This
 happens because the usual implementation of the algorithm copies the
 function object internally: </p>

 <pre>template &lt;class ForwIter, class Predicate&gt;
 ForwIter std::remove_if(ForwIter beg, ForwIter end, Predicate op)
 {
     beg = find_if(beg, end, op);
     if (beg == end) {
         return beg;
     }
     else {
         ForwIter next = beg;
         return remove_copy_if(++next, end, beg, op);
     }
 } </pre>

 <p>The algorithm uses find_if() to find the first element that should
 be removed. However, it then uses a copy of the passed function object
 to process the resulting elements (if any). Here, Nth is used again
 and removes also the sixth element. This behavior compromises the
 advantage of function objects being able to have a state. Without any
 cost it could be avoided (just implement it directly instead of
 calling find_if()). </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add a new paragraph following 25 [algorithms] paragraph 8:</p>
 <blockquote><p>
 [Note: Unless otherwise specified, algorithms that take function
 objects as arguments are permitted to copy those function objects
 freely.  Programmers for whom object identity is important should
 consider using a wrapper class that points to a noncopied
 implementation object, or some equivalent solution.]
 </p></blockquote>

 <p><i>[Dublin: Pete Becker felt that this may not be a defect,
 but rather something that programmers need to be educated about.
 There was discussion of adding wording to the effect that the number
 and order of calls to function objects, including predicates, not
 affect the behavior of the function object.]</i></p>


 <p><i>[Pre-Kona: Nico comments: It seems the problem is that we don't
 have a clear statement of "predicate" in the
 standard. People including me seemed to think "a function
 returning a Boolean value and being able to be called by an STL
 algorithm or be used as sorting criterion or ... is a
 predicate". But a predicate has more requirements: It should
 never change its behavior due to a call or being copied. IMHO we have
 to state this in the standard. If you like, see section 8.1.4 of my
 library book for a detailed discussion.]</i></p>


 <p><i>[Kona: Nico will provide wording to the effect that "unless
 otherwise specified, the number of copies of and calls to function
 objects by algorithms is unspecified".&nbsp; Consider placing in
 25 [algorithms] after paragraph 9.]</i></p>


 <p><i>[Santa Cruz: The standard doesn't currently guarantee that
   functions object won't be copied, and what isn't forbidden is
   allowed.  It is believed (especially since implementations that were
   written in concert with the standard do make copies of function
   objects) that this was intentional.  Thus, no normative change is
   needed.  What we should put in is a non-normative note suggesting to
   programmers that if they want to guarantee the lack of copying they
   should use something like the <tt>ref</tt> wrapper.]</i></p>


 <p><i>[Oxford: Matt provided wording.]</i></p>


 <hr>
 <h3><a name="98"></a>98. Input iterator requirements are badly written</h3>
 <p><b>Section:</b> 24.1.1 [input.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> AFNOR <b>Date:</b> 1998-10-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.iterators">issues</a> in [input.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Table 72 in 24.1.1 [input.iterators] specifies semantics for
 <tt>*r++</tt> of:</p>

 <p>&nbsp;&nbsp; <tt>{ T tmp = *r; ++r; return tmp; }</tt></p>

 <p>There are two problems with this.  First, the return type is
 specified to be "T", as opposed to something like "convertible to T".
 This is too specific: we want to allow *r++ to return an lvalue.</p>

 <p>Second, writing the semantics in terms of code misleadingly
 suggests that the effects *r++ should precisely replicate the behavior
 of this code, including side effects.  (Does this mean that *r++
 should invoke the copy constructor exactly as many times as the sample
 code above would?) See issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#334">334</a> for a similar
 problem.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In Table 72 in 24.1.1 [input.iterators], change the return type
 for <tt>*r++</tt> from <tt>T</tt> to "convertible to T".</p>


 <p><b>Rationale:</b></p>
 <p>This issue has two parts: the return type, and the number of times
   the copy constructor is invoked.</p>

 <p>The LWG believes the the first part is a real issue.  It's
   inappropriate for the return type to be specified so much more
   precisely for *r++ than it is for *r.  In particular, if r is of
   (say) type <tt>int*</tt>, then *r++ isn't <tt>int</tt>,
   but <tt>int&amp;</tt>.</p>

 <p>The LWG does not believe that the number of times the copy
   constructor is invoked is a real issue.  This can vary in any case,
   because of language rules on copy constructor elision.  That's too
   much to read into these semantics clauses.</p>

 <p>Additionally, as Dave Abrahams pointed out (c++std-lib-13703): since
    we're told (24.1/3) that forward iterators satisfy all the requirements
    of input iterators, we can't impose any requirements in the Input
    Iterator requirements table that forward iterators don't satisfy.</p>


 <hr>
 <h3><a name="103"></a>103. set::iterator is required to be modifiable, but this allows modification of keys</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> AFNOR <b>Date:</b> 1998-10-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Set::iterator is described as implementation-defined with a
 reference to the container requirement; the container requirement says
 that const_iterator is an iterator pointing to const T and iterator an
 iterator pointing to T.</p>

 <p>23.1.2 paragraph 2 implies that the keys should not be modified to
 break the ordering of elements. But that is not clearly
 specified. Especially considering that the current standard requires
 that iterator for associative containers be different from
 const_iterator. Set, for example, has the following: </p>

 <p><tt>typedef implementation defined iterator;<br>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; // See _lib.container.requirements_</tt></p>

 <p>23.1 [container.requirements] actually requires that iterator type pointing
 to T (table 65). Disallowing user modification of keys by changing the
 standard to require an iterator for associative container to be the
 same as const_iterator would be overkill since that will unnecessarily
 significantly restrict the usage of associative container. A class to
 be used as elements of set, for example, can no longer be modified
 easily without either redesigning the class (using mutable on fields
 that have nothing to do with ordering), or using const_cast, which
 defeats requiring iterator to be const_iterator. The proposed solution
 goes in line with trusting user knows what he is doing. </p>

 <p><b>Other Options Evaluated:</b> </p>

 <p>Option A.&nbsp;&nbsp; In 23.1.4 [associative.reqmts], paragraph 2, after
 first sentence, and before "In addition,...", add one line:
 </p>

 <blockquote>
   <p>Modification of keys shall not change their strict weak ordering. </p>
 </blockquote>

 <p>Option B.&nbsp;Add three new sentences to 23.1.4 [associative.reqmts]:</p>

 <blockquote>
   <p>At the end of paragraph 5: "Keys in an associative container
   are immutable." At the end of paragraph 6: "For
   associative containers where the value type is the same as the key
   type, both <tt>iterator</tt> and <tt>const_iterator</tt> are
   constant iterators. It is unspecified whether or not
   <tt>iterator</tt> and <tt>const_iterator</tt> are the same
   type."</p>
 </blockquote>

 <p>Option C.&nbsp;To 23.1.4 [associative.reqmts], paragraph 3, which
 currently reads:</p>

 <blockquote>
   <p>The phrase ``equivalence of keys'' means the equivalence relation imposed by the
   comparison and not the operator== on keys. That is, two keys k1 and k2 in the same
   container are considered to be equivalent if for the comparison object comp, comp(k1, k2)
   == false &amp;&amp; comp(k2, k1) == false.</p>
 </blockquote>

 <p>&nbsp; add the following:</p>

 <blockquote>
   <p>For any two keys k1 and k2 in the same container, comp(k1, k2) shall return the same
   value whenever it is evaluated. [Note: If k2 is removed from the container and later
   reinserted, comp(k1, k2) must still return a consistent value but this value may be
   different than it was the first time k1 and k2 were in the same container. This is
   intended to allow usage like a string key that contains a filename, where comp compares
   file contents; if k2 is removed, the file is changed, and the same k2 (filename) is
   reinserted, comp(k1, k2) must again return a consistent value but this value may be
   different than it was the previous time k2 was in the container.]</p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following to 23.1.4 [associative.reqmts] at
 the indicated location:</p>

 <blockquote>
   <p>At the end of paragraph 3: "For any two keys k1 and k2 in the same container,
   calling comp(k1, k2) shall always return the same
   value."</p>
   <p>At the end of paragraph 5: "Keys in an associative container are immutable."</p>
   <p>At the end of paragraph 6: "For associative containers where the value type is the
   same as the key type, both <tt>iterator</tt> and <tt>const_iterator</tt> are constant
   iterators. It is unspecified whether or not <tt>iterator</tt> and <tt>const_iterator</tt>
   are the same type."</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Several arguments were advanced for and against allowing set elements to be
 mutable as long as the ordering was not effected. The argument which swayed the
 LWG was one of safety; if elements were mutable, there would be no compile-time
 way to detect of a simple user oversight which caused ordering to be
 modified.  There was a report that this had actually happened in practice,
 and had been painful to diagnose.  If users need to modify elements,
 it is possible to use mutable members or const_cast.</p>

 <p>Simply requiring that keys be immutable is not sufficient, because the comparison
 object may indirectly (via pointers) operate on values outside of the keys.</p>

 <p>
 The types <tt>iterator</tt> and <tt>const_iterator</tt> are permitted
 to be different types to allow for potential future work in which some
 member functions might be overloaded between the two types.  No such
 member functions exist now, and the LWG believes that user functionality
 will not be impaired by permitting the two types to be the same.  A
 function that operates on both iterator types can be defined for
 <tt>const_iterator</tt> alone, and can rely on the automatic
 conversion from <tt>iterator</tt> to <tt>const_iterator</tt>.
 </p>

 <p><i>[Tokyo: The LWG crafted the proposed resolution and rationale.]</i></p>


 <hr>
 <h3><a name="106"></a>106. Numeric library private members are implementation defined</h3>
 <p><b>Section:</b> 26.5.5 [template.slice.array] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> AFNOR <b>Date:</b> 1998-10-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.slice.array">issues</a> in [template.slice.array].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>This is the only place in the whole standard where the implementation has to document
 something private.</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Remove the comment which says "// remainder implementation defined" from:
 </p>

 <ul>
   <li>26.5.5 [template.slice.array]</li>
   <li>26.5.7 [template.gslice.array]</li>
   <li>26.5.8 [template.mask.array]</li>
   <li>26.5.9 [template.indirect.array]</li>
 </ul>


 <hr>
 <h3><a name="108"></a>108. Lifetime of exception::what() return unspecified</h3>
 <p><b>Section:</b> 18.6.1 [type.info] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> AFNOR <b>Date:</b> 1998-10-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#type.info">issues</a> in [type.info].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 18.6.1, paragraphs 8-9, the lifetime of the return value of
 exception::what() is left unspecified. This issue has implications
 with exception safety of exception handling: some exceptions should
 not throw bad_alloc.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to 18.6.1 [type.info] paragraph 9 (exception::what notes
 clause) the sentence:</p>

 <blockquote>
   <p>The return value remains valid until the exception object from which it is obtained is
   destroyed or a non-const member function of the exception object is called.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>If an exception object has non-const members, they may be used
 to set internal state that should affect the contents of the string
 returned by <tt>what()</tt>.
 </p>


 <hr>
 <h3><a name="109"></a>109. Missing binders for non-const sequence elements</h3>
 <p><b>Section:</b> D.8 [depr.lib.binders] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bjarne Stroustrup <b>Date:</b> 1998-10-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.lib.binders">issues</a> in [depr.lib.binders].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>There are no versions of binders that apply to non-const elements
 of a sequence. This makes examples like for_each() using bind2nd() on
 page 521 of "The C++ Programming Language (3rd)"
 non-conforming. Suitable versions of the binders need to be added.</p>

 <p>Further discussion from Nico:</p>

 <p>What is probably meant here is shown in the following example:</p>

 <pre>class Elem {
   public:
     void print (int i) const { }
     void modify (int i) { }
 }; </pre>
 <pre>int main()
 {
     vector&lt;Elem&gt; coll(2);
     for_each (coll.begin(), coll.end(), bind2nd(mem_fun_ref(&amp;Elem::print),42));    // OK
     for_each (coll.begin(), coll.end(), bind2nd(mem_fun_ref(&amp;Elem::modify),42));   // ERROR
 }</pre>

 <p>The error results from the fact that bind2nd() passes its first
 argument (the argument of the sequence) as constant reference. See the
 following typical implementation:</p>

 <blockquote>
   <pre>template &lt;class Operation&gt;
 class binder2nd
   : public unary_function&lt;typename Operation::first_argument_type,
                           typename Operation::result_type&gt; {
 protected:
   Operation op;
   typename Operation::second_argument_type value;
 public:
   binder2nd(const Operation&amp; o,
             const typename Operation::second_argument_type&amp; v)
       : op(o), value(v) {} </pre>
   <pre> typename Operation::result_type
   operator()(const typename Operation::first_argument_type&amp; x) const {
     return op(x, value);
   }
 };</pre>
 </blockquote>

 <p>The solution is to overload operator () of bind2nd for non-constant arguments:</p>

 <blockquote>
   <pre>template &lt;class Operation&gt;
 class binder2nd
   : public unary_function&lt;typename Operation::first_argument_type,
                           typename Operation::result_type&gt; {
 protected:
   Operation op;
   typename Operation::second_argument_type value;
 public:
   binder2nd(const Operation&amp; o,
             const typename Operation::second_argument_type&amp; v)
       : op(o), value(v) {} </pre>
   <pre> typename Operation::result_type
   operator()(const typename Operation::first_argument_type&amp; x) const {
     return op(x, value);
   }
   typename Operation::result_type
   operator()(typename Operation::first_argument_type&amp; x) const {
     return op(x, value);
   }
 };</pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>

 <p><b>Howard believes there is a flaw</b> in this resolution.
 See c++std-lib-9127.  We may need to reopen this issue.</p>

 <p>In D.8 [depr.lib.binders] in the declaration of binder1st after:</p>
 <blockquote>
   <p><tt>typename Operation::result_type<br>
   &nbsp;operator()(const typename Operation::second_argument_type&amp; x) const;</tt></p>
 </blockquote>
 <p>insert:</p>
 <blockquote>
   <p><tt>typename Operation::result_type<br>
   &nbsp;operator()(typename Operation::second_argument_type&amp; x) const;</tt></p>
 </blockquote>
 <p>In D.8 [depr.lib.binders] in the declaration of binder2nd after:</p>
 <blockquote>
   <p><tt>typename Operation::result_type<br>
   &nbsp;operator()(const typename Operation::first_argument_type&amp; x) const;</tt></p>
 </blockquote>
 <p>insert:</p>
 <blockquote>
   <p><tt>typename Operation::result_type<br>
   &nbsp;operator()(typename Operation::first_argument_type&amp; x) const;</tt></p>
 </blockquote>

 <p><i>[Kona: The LWG discussed this at some length.It was agreed that
 this is a mistake in the design, but there was no consensus on whether
 it was a defect in the Standard.  Straw vote: NAD - 5.  Accept
 proposed resolution - 3.  Leave open - 6.]</i></p>


 <p><i>[Copenhagen: It was generally agreed that this was a defect.
 Strap poll: NAD - 0.  Accept proposed resolution - 10.
 Leave open - 1.]</i></p>


 <hr>
 <h3><a name="110"></a>110. istreambuf_iterator::equal not const</h3>
 <p><b>Section:</b> 24.5.3 [istreambuf.iterator], 24.5.3.5 [istreambuf.iterator::equal] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 1998-10-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istreambuf.iterator">issues</a> in [istreambuf.iterator].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Member istreambuf_iterator&lt;&gt;::equal is not declared
 "const", yet 24.5.3.6 [istreambuf.iterator::op==] says that operator==,
 which is const, calls it. This is contradictory. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 24.5.3 [istreambuf.iterator] and also in 24.5.3.5 [istreambuf.iterator::equal],
 replace:</p>

 <blockquote>
   <pre>bool equal(istreambuf_iterator&amp; b);</pre>
 </blockquote>

 <p>with:</p>

 <blockquote>
   <pre>bool equal(const istreambuf_iterator&amp; b) const;</pre>
 </blockquote>


 <hr>
 <h3><a name="112"></a>112. Minor typo in <tt>ostreambuf_iterator</tt> constructor</h3>
 <p><b>Section:</b> 24.5.4.1 [ostreambuf.iter.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-10-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The <b>requires</b> clause for <tt>ostreambuf_iterator</tt>'s
 constructor from an <tt>ostream_type</tt> (24.5.4.1, paragraph 1)
 reads "<i>s</i> is not null". However, <i>s</i> is a
 reference, and references can't be null. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 24.5.4.1 [ostreambuf.iter.cons]:</p>

 <p>Move the current paragraph 1, which reads "Requires: s is not
 null.", from the first constructor to the second constructor.</p>

 <p>Insert a new paragraph 1 Requires clause for the first constructor
 reading:</p>

 <blockquote>
   <p><b>Requires</b>: <tt>s.rdbuf()</tt> is not null.</p>
 </blockquote>


 <hr>
 <h3><a name="114"></a>114. Placement forms example in error twice</h3>
 <p><b>Section:</b> 18.5.1.3 [new.delete.placement] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 1998-10-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#new.delete.placement">issues</a> in [new.delete.placement].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#196">196</a></p>
 <p><b>Discussion:</b></p>
 <p>Section 18.5.1.3 contains the following example: </p>

 <pre>[Example: This can be useful for constructing an object at a known address:
         char place[sizeof(Something)];
         Something* p = new (place) Something();
  -end example]</pre>

 <p>First code line: "place" need not have any special alignment, and the
 following constructor could fail due to misaligned data.</p>

 <p>Second code line: Aren't the parens on Something() incorrect?&nbsp; [Dublin: the LWG
 believes the () are correct.]</p>

 <p>Examples are not normative, but nevertheless should not show code that is invalid or
 likely to fail.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the first line of code in the example in
 18.5.1.3 [new.delete.placement] with:
 </p>

 <blockquote>
   <pre>void* place = operator new(sizeof(Something));</pre>
 </blockquote>


 <hr>
 <h3><a name="115"></a>115. Typo in strstream constructors</h3>
 <p><b>Section:</b> D.7.4.1 [depr.strstream.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 1998-11-02</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>D.7.4.1 strstream constructors paragraph 2 says: </p>

 <blockquote>
   <p>Effects: Constructs an object of class strstream, initializing the base class with
   iostream(&amp; sb) and initializing sb with one of the two constructors: </p>
   <p>- If mode&amp;app==0, then s shall designate the first element of an array of n
   elements. The constructor is strstreambuf(s, n, s). </p>
   <p>- If mode&amp;app==0, then s shall designate the first element of an array of n
   elements that contains an NTBS whose first element is designated by s. The constructor is
   strstreambuf(s, n, s+std::strlen(s)).</p>
 </blockquote>

 <p>Notice the second condition is the same as the first. I think the second condition
 should be "If mode&amp;app==app", or "mode&amp;app!=0", meaning that
 the append bit is set.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In D.7.3.1 [depr.ostrstream.cons] paragraph 2 and D.7.4.1 [depr.strstream.cons]
 paragraph 2, change the first condition to <tt>(mode&amp;app)==0</tt>
 and the second condition to <tt>(mode&amp;app)!=0</tt>.</p>


 <hr>
 <h3><a name="117"></a>117. <tt>basic_ostream</tt> uses nonexistent <tt>num_put</tt> member functions</h3>
 <p><b>Section:</b> 27.6.2.6.2 [ostream.inserters.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-11-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.inserters.arithmetic">issues</a> in [ostream.inserters.arithmetic].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The <b>effects</b> clause for numeric inserters says that
 insertion of a value <tt>x</tt>, whose type is either <tt>bool</tt>,
 <tt>short</tt>, <tt>unsigned short</tt>, <tt>int</tt>, <tt>unsigned
 int</tt>, <tt>long</tt>, <tt>unsigned long</tt>, <tt>float</tt>,
 <tt>double</tt>, <tt>long double</tt>, or <tt>const void*</tt>, is
 delegated to <tt>num_put</tt>, and that insertion is performed as if
 through the following code fragment: </p>

 <pre>bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(), val). failed();</pre>

 <p>This doesn't work, because <tt>num_put&lt;&gt;</tt>::put is only
 overloaded for the types <tt>bool</tt>, <tt>long</tt>, <tt>unsigned
 long</tt>, <tt>double</tt>, <tt>long double</tt>, and <tt>const
 void*</tt>. That is, the code fragment in the standard is incorrect
 (it is diagnosed as ambiguous at compile time) for the types
 <tt>short</tt>, <tt>unsigned short</tt>, <tt>int</tt>, <tt>unsigned
 int</tt>, and <tt>float</tt>. </p>

 <p>We must either add new member functions to <tt>num_put</tt>, or
 else change the description in <tt>ostream</tt> so that it only calls
 functions that are actually there. I prefer the latter. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace 27.6.2.5.2, paragraph 1 with the following: </p>

 <blockquote>
 <p>
 The classes num_get&lt;&gt; and num_put&lt;&gt; handle locale-dependent numeric
 formatting and parsing.  These inserter functions use the imbued
 locale value to perform numeric formatting.  When val is of type bool,
 long, unsigned long, double, long double, or const void*, the
 formatting conversion occurs as if it performed the following code
 fragment:
 </p>

 <pre>bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(), val). failed();
 </pre>

 <p>
 When val is of type short the formatting conversion occurs as if it
 performed the following code fragment:
 </p>

 <pre>ios_base::fmtflags baseflags = ios_base::flags() &amp; ios_base::basefield;
 bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(),
       baseflags == ios_base::oct || baseflags == ios_base::hex
          ? static_cast&lt;long&gt;(static_cast&lt;unsigned short&gt;(val))
          : static_cast&lt;long&gt;(val)). failed();
 </pre>

 <p>
 When val is of type int the formatting conversion occurs as if it performed
 the following code fragment:
 </p>

 <pre>ios_base::fmtflags baseflags = ios_base::flags() &amp; ios_base::basefield;
 bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(),
       baseflags == ios_base::oct || baseflags == ios_base::hex
          ? static_cast&lt;long&gt;(static_cast&lt;unsigned int&gt;(val))
          : static_cast&lt;long&gt;(val)). failed();
 </pre>

 <p>
 When val is of type unsigned short or unsigned int the formatting conversion
 occurs as if it performed the following code fragment:
 </p>

 <pre>bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(), static_cast&lt;unsigned long&gt;(val)).
 failed();
 </pre>

 <p>
 When val is of type float the formatting conversion occurs as if it
 performed the following code fragment:
 </p>

 <pre>bool failed = use_facet&lt;
    num_put&lt;charT,ostreambuf_iterator&lt;charT,traits&gt; &gt;
    &gt;(getloc()).put(*this, *this, fill(), static_cast&lt;double&gt;(val)).
 failed();
 </pre>

 </blockquote>

 <p><i>[post-Toronto: This differs from the previous proposed
 resolution; PJP provided the new wording.  The differences are in
 signed short and int output.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The original proposed resolution was to cast int and short to long,
 unsigned int and unsigned short to unsigned long, and float to double,
 thus ensuring that we don't try to use nonexistent num_put&lt;&gt;
 member functions.  The current proposed resolution is more
 complicated, but gives more expected results for hex and octal output
 of signed short and signed int.  (On a system with 16-bit short, for
 example, printing short(-1) in hex format should yield 0xffff.)</p>


 <hr>
 <h3><a name="118"></a>118. <tt>basic_istream</tt> uses nonexistent <tt>num_get</tt> member functions</h3>
 <p><b>Section:</b> 27.6.1.2.2 [istream.formatted.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1998-11-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.formatted.arithmetic">issues</a> in [istream.formatted.arithmetic].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Formatted input is defined for the types <tt>short</tt>, <tt>unsigned short</tt>, <tt>int</tt>,
 <tt>unsigned int</tt>, <tt>long</tt>, <tt>unsigned long</tt>, <tt>float</tt>, <tt>double</tt>,
 <tt>long double</tt>, <tt>bool</tt>, and <tt>void*</tt>. According to section 27.6.1.2.2,
 formatted input of a value <tt>x</tt> is done as if by the following code fragment: </p>

 <pre>typedef num_get&lt; charT,istreambuf_iterator&lt;charT,traits&gt; &gt; numget;
 iostate err = 0;
 use_facet&lt; numget &gt;(loc).get(*this, 0, *this, err, val);
 setstate(err);</pre>

 <p>According to section 22.2.2.1.1 [facet.num.get.members], however,
 <tt>num_get&lt;&gt;::get()</tt> is only overloaded for the types
 <tt>bool</tt>, <tt>long</tt>, <tt>unsigned short</tt>, <tt>unsigned
 int</tt>, <tt>unsigned long</tt>, <tt>unsigned long</tt>,
 <tt>float</tt>, <tt>double</tt>, <tt>long double</tt>, and
 <tt>void*</tt>. Comparing the lists from the two sections, we find
 that 27.6.1.2.2 is using a nonexistent function for types
 <tt>short</tt> and <tt>int</tt>. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.1.2.2 [istream.formatted.arithmetic] Arithmetic Extractors, remove the
 two lines (1st and 3rd) which read:</p>
 <blockquote>
   <pre>operator&gt;&gt;(short&amp; val);
 ...
 operator&gt;&gt;(int&amp; val);</pre>
 </blockquote>

 <p>And add the following at the end of that section (27.6.1.2.2) :</p>

 <blockquote>
   <pre>operator&gt;&gt;(short&amp; val);</pre>
   <p>The conversion occurs as if performed by the following code fragment (using
   the same notation as for the preceding code fragment):</p>
   <pre>  typedef num_get&lt; charT,istreambuf_iterator&lt;charT,traits&gt; &gt; numget;
   iostate err = 0;
   long lval;
   use_facet&lt; numget &gt;(loc).get(*this, 0, *this, err, lval);
         if (err == 0
                 &amp;&amp; (lval &lt; numeric_limits&lt;short&gt;::min() || numeric_limits&lt;short&gt;::max() &lt; lval))
                 err = ios_base::failbit;
   setstate(err);</pre>
   <pre>operator&gt;&gt;(int&amp; val);</pre>
   <p>The conversion occurs as if performed by the following code fragment (using
   the same notation as for the preceding code fragment):</p>
   <pre>  typedef num_get&lt; charT,istreambuf_iterator&lt;charT,traits&gt; &gt; numget;
   iostate err = 0;
   long lval;
   use_facet&lt; numget &gt;(loc).get(*this, 0, *this, err, lval);
         if (err == 0
                 &amp;&amp; (lval &lt; numeric_limits&lt;int&gt;::min() || numeric_limits&lt;int&gt;::max() &lt; lval))
                 err = ios_base::failbit;
   setstate(err);</pre>
 </blockquote>

 <p><i>[Post-Tokyo: PJP provided the above wording.]</i></p>


 <hr>
 <h3><a name="119"></a>119. Should virtual functions be allowed to strengthen the exception specification?</h3>
 <p><b>Section:</b> 17.4.4.9 [res.on.exception.handling] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#res.on.exception.handling">issues</a> in [res.on.exception.handling].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 17.4.4.9 [res.on.exception.handling] states: </p>

 <p>"An implementation may strengthen the exception-specification
 for a function by removing listed exceptions." </p>

 <p>The problem is that if an implementation is allowed to do this for
 virtual functions, then a library user cannot write a class that
 portably derives from that class. </p>

 <p>For example, this would not compile if ios_base::failure::~failure
 had an empty exception specification: </p>

 <pre>#include &lt;ios&gt;
 #include &lt;string&gt;

 class D : public std::ios_base::failure {
 public:
         D(const std::string&amp;);
         ~D(); // error - exception specification must be compatible with
               // overridden virtual function ios_base::failure::~failure()
 };</pre>


 <p><b>Proposed resolution:</b></p>
 <p>Change Section 17.4.4.9 [res.on.exception.handling] from:</p>

 <p>&nbsp;&nbsp;&nbsp;&nbsp; "may strengthen the
 exception-specification for a function"</p>

 <p>to:</p>

 <p>&nbsp;&nbsp;&nbsp;&nbsp; "may strengthen the
 exception-specification for a non-virtual function". </p>


 <hr>
 <h3><a name="120"></a>120. Can an implementor add specializations?</h3>
 <p><b>Section:</b> 17.4.3.2 [reserved.names] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#reserved.names">issues</a> in [reserved.names].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>The original issue asked whether a library implementor could
 specialize standard library templates for built-in types.  (This was
 an issue because users are permitted to explicitly instantiate
 standard library templates.)</p>

 <p>Specializations are no longer a problem, because of the resolution
 to core issue 259.  Under the proposed resolution, it will be legal
 for a translation unit to contain both a specialization and an
 explicit instantiation of the same template, provided that the
 specialization comes first.  In such a case, the explicit
 instantiation will be ignored.  Further discussion of library issue
 120 assumes that the core 259 resolution will be adopted.</p>

 <p>However, as noted in lib-7047, one piece of this issue still
 remains: what happens if a standard library implementor explicitly
 instantiates a standard library templates?  It's illegal for a program
 to contain two different explicit instantiations of the same template
 for the same type in two different translation units (ODR violation),
 and the core working group doesn't believe it is practical to relax
 that restriction.</p>

 <p>The issue, then, is: are users allowed to explicitly instantiate
 standard library templates for non-user defined types?  The status quo
 answer is 'yes'.  Changing it to 'no' would give library implementors
 more freedom.</p>

 <p>This is an issue because, for performance reasons, library
 implementors often need to explicitly instantiate standard library
 templates.  (for example, std::basic_string&lt;char&gt;)  Does giving
 users freedom to explicitly instantiate standard library templates for
 non-user defined types make it impossible or painfully difficult for
 library implementors to do this?</p>

 <p>John Spicer suggests, in lib-8957, that library implementors have a
 mechanism they can use for explicit instantiations that doesn't
 prevent users from performing their own explicit instantiations: put
 each explicit instantiation in its own object file.  (Different
 solutions might be necessary for Unix DSOs or MS-Windows DLLs.)  On
 some platforms, library implementors might not need to do anything
 special: the "undefined behavior" that results from having two
 different explicit instantiations might be harmless.</p>


 <p><b>Proposed resolution:</b></p>
   <p>Append to 17.4.3.2 [reserved.names] paragraph 1: </p>
   <blockquote><p>
     A program may explicitly instantiate any templates in the standard
     library only if the declaration depends on the name of a user-defined
     type of external linkage and the instantiation meets the standard library
     requirements for the original template.
   </p></blockquote>

 <p><i>[Kona: changed the wording from "a user-defined name" to "the name of
   a user-defined type"]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG considered another possible resolution:</p>
 <blockquote>
   <p>In light of the resolution to core issue 259, no normative changes
   in the library clauses are necessary.  Add the following non-normative
   note to the end of 17.4.3.2 [reserved.names] paragraph 1:</p>
   <blockquote><p>
     [<i>Note:</i> A program may explicitly instantiate standard library
     templates, even when an explicit instantiation does not depend on
     a user-defined name. <i>--end note</i>]
   </p></blockquote>
 </blockquote>

 <p>The LWG rejected this because it was believed that it would make
   it unnecessarily difficult for library implementors to write
   high-quality implementations.  A program may not include an
   explicit instantiation of the same template, for the same template
   arguments, in two different translation units.  If users are
   allowed to provide explicit instantiations of Standard Library
   templates for built-in types, then library implementors aren't,
   at least not without nonportable tricks.</p>

 <p>The most serious problem is a class template that has writeable
   static member variables.  Unfortunately, such class templates are
   important and, in existing Standard Library implementations, are
   often explicitly specialized by library implementors: locale facets,
   which have a writeable static member variable <tt>id</tt>.  If a
   user's explicit instantiation collided with the implementations
   explicit instantiation, iostream initialization could cause locales
   to be constructed in an inconsistent state.</p>

 <p>One proposed implementation technique was for Standard Library
   implementors to provide explicit instantiations in separate object
   files, so that they would not be picked up by the linker when the
   user also provides an explicit instantiation.  However, this
   technique only applies for Standard Library implementations that
   are packaged as static archives.  Most Standard Library
   implementations nowadays are packaged as dynamic libraries, so this
   technique would not apply.</p>

 <p>The Committee is now considering standardization of dynamic
   linking.  If there are such changes in the future, it may be
   appropriate to revisit this issue later.</p>


 <hr>
 <h3><a name="122"></a>122. streambuf/wstreambuf description should not say they are specializations</h3>
 <p><b>Section:</b> 27.5.2 [streambuf] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#streambuf">issues</a> in [streambuf].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 27.5.2 describes the streambuf classes this way: </p>

 <blockquote>

 <p>The class streambuf is a specialization of the template class basic_streambuf
 specialized for the type char. </p>

 <p>The class wstreambuf is a specialization of the template class basic_streambuf
 specialized for the type wchar_t. </p>

 </blockquote>

 <p>This implies that these classes must be template specializations, not typedefs. </p>

 <p>It doesn't seem this was intended, since Section 27.5 has them declared as typedefs. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove 27.5.2 [streambuf] paragraphs 2 and 3 (the above two
 sentences). </p>


 <p><b>Rationale:</b></p>
 <p>The <tt>streambuf</tt>  synopsis already has a declaration for the
 typedefs and that is sufficient. </p>


 <hr>
 <h3><a name="123"></a>123. Should valarray helper arrays fill functions be const?</h3>
 <p><b>Section:</b> 26.5.5.3 [slice.arr.fill], 26.5.7.3 [gslice.array.fill], 26.5.8.3 [mask.array.fill], 26.5.9.3 [indirect.array.fill] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>One of the operator= in the valarray helper arrays is const and one
 is not. For example, look at slice_array. This operator= in Section
 26.5.5.1 [slice.arr.assign] is const: </p>

 <p>&nbsp;&nbsp;&nbsp; <tt>void operator=(const valarray&lt;T&gt;&amp;) const;</tt> </p>

 <p>but this one in Section 26.5.5.3 [slice.arr.fill] is not: </p>

 <p>&nbsp;&nbsp;&nbsp; <tt>void operator=(const T&amp;); </tt></p>

 <p>The description of the semantics for these two functions is similar. </p>


 <p><b>Proposed resolution:</b></p>

 <p>26.5.5 [template.slice.array] Template class slice_array</p>
 <blockquote>

    <p>In the class template definition for slice_array, replace the member
    function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>with</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.5.3 [slice.arr.fill] slice_array fill function</p>
 <blockquote>

    <p>Change the function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>to</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.7 [template.gslice.array] Template class gslice_array</p>
 <blockquote>

    <p>In the class template definition for gslice_array, replace the member
    function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>with</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.7.3 [gslice.array.fill] gslice_array fill function</p>
 <blockquote>

    <p>Change the function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>to</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.8 [template.mask.array] Template class mask_array</p>
 <blockquote>

    <p>In the class template definition for mask_array, replace the member
    function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>with</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.8.3 [mask.array.fill] mask_array fill function</p>
 <blockquote>

    <p>Change the function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>to</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.9 [template.indirect.array] Template class indirect_array</p>
 <blockquote>

    <p>In the class template definition for indirect_array, replace the member
    function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>with</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>

 <p>26.5.9.3 [indirect.array.fill] indirect_array fill function</p>
 <blockquote>

    <p>Change the function declaration</p>
     <pre>      void operator=(const T&amp;);
     </pre>
    <p>to</p>
     <pre>      void operator=(const T&amp;) const;
     </pre>
 </blockquote>


 <p><i>[Redmond: Robert provided wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>There's no good reason for one version of operator= being const and
 another one not.  Because of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, this now
 matters: these functions are now callable in more circumstances.  In
 many existing implementations, both versions are already const.</p>


 <hr>
 <h3><a name="124"></a>124. ctype_byname&lt;charT&gt;::do_scan_is &amp; do_scan_not return type should be const charT*</h3>
 <p><b>Section:</b> 22.2.1.2 [locale.ctype.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.ctype.byname">issues</a> in [locale.ctype.byname].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In Section 22.2.1.2 [locale.ctype.byname]
 ctype_byname&lt;charT&gt;::do_scan_is() and do_scan_not() are declared
 to return a const char* not a const charT*. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change Section 22.2.1.2 [locale.ctype.byname] <tt>do_scan_is()</tt> and
 <tt>do_scan_not()</tt> to return a <tt> const
 charT*</tt>. </p>


 <hr>
 <h3><a name="125"></a>125. valarray&lt;T&gt;::operator!() return type is inconsistent</h3>
 <p><b>Section:</b> 26.5.2 [template.valarray] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.valarray">issues</a> in [template.valarray].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In Section 26.5.2 [template.valarray] valarray&lt;T&gt;::operator!()
 is
 declared to return a valarray&lt;T&gt;, but in Section 26.5.2.5
 [valarray.unary] it is declared to return a valarray&lt;bool&gt;. The
 latter appears to be correct. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change in Section 26.5.2 [template.valarray] the declaration of
 <tt>operator!()</tt> so that the return type is
 <tt>valarray&lt;bool&gt;</tt>. </p>


 <hr>
 <h3><a name="126"></a>126. typos in Effects clause of ctype::do_narrow()</h3>
 <p><b>Section:</b> 22.2.1.1.2 [locale.ctype.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.ctype.virtuals">issues</a> in [locale.ctype.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p><p>Typos in 22.2.1.1.2 need to be fixed.</p>

 <p><b>Proposed resolution:</b></p>
 <p>In Section 22.2.1.1.2 [locale.ctype.virtuals] change: </p>

 <pre>   do_widen(do_narrow(c),0) == c</pre>

 <p>to:</p>

 <pre>   do_widen(do_narrow(c,0)) == c</pre>

 <p>and change:</p>

 <pre>   (is(M,c) || !ctc.is(M, do_narrow(c),dfault) )</pre>

 <p>to:</p>

 <pre>   (is(M,c) || !ctc.is(M, do_narrow(c,dfault)) )</pre>


 <hr>
 <h3><a name="127"></a>127. auto_ptr&lt;&gt; conversion issues</h3>
 <p><b>Section:</b> D.9.1 [auto.ptr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Greg Colvin <b>Date:</b> 1999-02-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#auto.ptr">issues</a> in [auto.ptr].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>There are two problems with the current <tt>auto_ptr</tt> wording
 in the standard: </p>

 <p>First, the <tt>auto_ptr_ref</tt> definition cannot be nested
 because <tt>auto_ptr&lt;Derived&gt;::auto_ptr_ref</tt> is unrelated to
 <tt>auto_ptr&lt;Base&gt;::auto_ptr_ref</tt>.  <i>Also submitted by
 Nathan Myers, with the same proposed resolution.</i></p>

 <p>Second, there is no <tt>auto_ptr</tt> assignment operator taking an
 <tt>auto_ptr_ref</tt> argument. </p>

 <p>I have discussed these problems with my proposal coauthor, Bill
 Gibbons, and with some compiler and library implementors, and we
 believe that these problems are not desired or desirable implications
 of the standard. </p>

 <p>25 Aug 1999: The proposed resolution now reflects changes suggested
 by Dave Abrahams, with Greg Colvin's concurrence; 1) changed
 "assignment operator" to "public assignment
 operator", 2) changed effects to specify use of release(), 3)
 made the conversion to auto_ptr_ref const. </p>

 <p>2 Feb 2000: Lisa Lippincott comments: [The resolution of] this issue
 states that the conversion from auto_ptr to auto_ptr_ref should
 be const.  This is not acceptable, because it would allow
 initialization and assignment from _any_ const auto_ptr!  It also
 introduces an implementation difficulty in writing this conversion
 function -- namely, somewhere along the line, a const_cast will be
 necessary to remove that const so that release() may be called.  This
 may result in undefined behavior [7.1.5.1/4]. The conversion
 operator does not have to be const, because a non-const implicit
 object parameter may be bound to an rvalue [13.3.3.1.4/3]
 [13.3.1/5]. </p>

   <p>Tokyo: The LWG removed the following from the proposed resolution:</p>

   <p>In 20.5.4 [meta.unary], paragraph 2, and 20.5.4.3 [meta.unary.prop],
   paragraph 2, make the conversion to auto_ptr_ref const:</p>
   <blockquote>
     <pre>template&lt;class Y&gt; operator auto_ptr_ref&lt;Y&gt;() const throw();</pre>
   </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>In 20.5.4 [meta.unary], paragraph 2, move
 the <tt>auto_ptr_ref</tt> definition to namespace scope.</p>

 <p>In 20.5.4 [meta.unary], paragraph 2, add
 a public assignment operator to the <tt>auto_ptr</tt> definition: </p>

 <blockquote>
   <pre>auto_ptr&amp; operator=(auto_ptr_ref&lt;X&gt; r) throw();</pre>
 </blockquote>

 <p>Also add the assignment operator to 20.5.4.3 [meta.unary.prop]: </p>

 <blockquote>
   <pre>auto_ptr&amp; operator=(auto_ptr_ref&lt;X&gt; r) throw()</pre>

   <p><b>Effects:</b> Calls <tt>reset(p.release())</tt> for the <tt>auto_ptr
   p</tt> that <tt>r</tt> holds a reference to.<br>
   <b>Returns: </b><tt>*this</tt>.</p>

 </blockquote>


 <hr>
 <h3><a name="129"></a>129. Need error indication from seekp() and seekg()</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted], 27.6.2.5 [ostream.seeks] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 1999-02-22</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Currently, the standard does not specify how seekg() and seekp()
 indicate failure. They are not required to set failbit, and they can't
 return an error indication because they must return *this, i.e. the
 stream. Hence, it is undefined what happens if they fail. And they
 <i>can</i> fail, for instance, when a file stream is disconnected from the
 underlying file (is_open()==false) or when a wide character file
 stream must perform a state-dependent code conversion, etc. </p>

 <p>The stream functions seekg() and seekp() should set failbit in the
 stream state in case of failure.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to the Effects: clause of&nbsp; seekg() in
 27.6.1.3 [istream.unformatted] and to the Effects: clause of seekp() in
 27.6.2.5 [ostream.seeks]: </p>

 <blockquote>
   <p>In case of failure, the function calls <tt>setstate(failbit)</tt> (which may throw <tt>ios_base::failure</tt>).
   </p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Setting failbit is the usual error reporting mechanism for streams</p>


 <hr>
 <h3><a name="130"></a>130. Return type of container::erase(iterator) differs for associative containers</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts], 23.1.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1999-03-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#451">451</a></p>
 <p><b>Discussion:</b></p>
 <p>Table 67 (23.1.1) says that container::erase(iterator) returns an
 iterator. Table 69 (23.1.2) says that in addition to this requirement,
 associative containers also say that container::erase(iterator)
 returns void.  That's not an addition; it's a change to the
 requirements, which has the effect of making associative containers
 fail to meet the requirements for containers.</p>


 <p><b>Proposed resolution:</b></p>

 <p>
 In 23.1.4 [associative.reqmts], in Table 69 Associative container
 requirements, change the return type of <tt>a.erase(q)</tt> from
 <tt>void</tt> to <tt>iterator</tt>.  Change the
 assertion/not/pre/post-condition from "erases the element pointed to
 by <tt>q</tt>" to "erases the element pointed to by <tt>q</tt>.
 Returns an iterator pointing to the element immediately following q
 prior to the element being erased. If no such element exists, a.end()
 is returned."
 </p>

 <p>
 In 23.1.4 [associative.reqmts], in Table 69 Associative container
 requirements, change the return type of <tt>a.erase(q1, q2)</tt>
 from <tt>void</tt> to <tt>iterator</tt>.  Change the
 assertion/not/pre/post-condition from "erases the elements in the
 range <tt>[q1, q2)</tt>" to "erases the elements in the range <tt>[q1,
 q2)</tt>.  Returns q2."
 </p>

 <p>
 In 23.3.1 [map], in the <tt>map</tt> class synopsis; and
 in 23.3.2 [multimap], in the <tt>multimap</tt> class synopsis; and
 in 23.3.3 [set], in the <tt>set</tt> class synopsis; and
 in 23.3.4 [multiset], in the <tt>multiset</tt> class synopsis:
 change the signature of the first <tt>erase</tt> overload to
 </p>
 <pre>   iterator erase(iterator position);
 </pre>
 <p>and change the signature of the third <tt>erase</tt> overload to</p>
 <pre>  iterator erase(iterator first, iterator last);
 </pre>


 <p><i>[Pre-Kona: reopened at the request of Howard Hinnant]</i></p>


 <p><i>[Post-Kona: the LWG agrees the return type should be
 <tt>iterator</tt>, not <tt>void</tt>.  (Alex Stepanov agrees too.)
 Matt provided wording.]</i></p>


 <p><i>[
  Sydney: the proposed wording went in the right direction, but it
  wasn't good enough. We want to return an iterator from the range form
  of erase as well as the single-iterator form. Also, the wording is
  slightly different from the wording we have for sequences; there's no
  good reason for having a difference.  Matt provided new wording,
 (reflected above) which we will review at the next meeting.
 ]</i></p>


 <p><i>[
 Redmond:  formally voted into WP.
 ]</i></p>


 <hr>
 <h3><a name="132"></a>132. list::resize description uses random access iterators</h3>
 <p><b>Section:</b> 23.2.4.2 [list.capacity] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-03-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description reads:</p>

 <p>-1- Effects:</p>

 <pre>         if (sz &gt; size())
            insert(end(), sz-size(), c);
          else if (sz &lt; size())
            erase(begin()+sz, end());
          else
            ;                           //  do nothing</pre>

 <p>Obviously list::resize should not be specified in terms of random access iterators.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 23.2.4.2 [list.capacity] paragraph 1 to:</p>

 <p>Effects:</p>

 <pre>         if (sz &gt; size())
            insert(end(), sz-size(), c);
          else if (sz &lt; size())
          {
            iterator i = begin();
            advance(i, sz);
            erase(i, end());
          }</pre>

 <p><i>[Dublin: The LWG asked Howard to discuss exception safety offline
 with David Abrahams. They had a discussion and believe there is
 no issue of exception safety with the proposed resolution.]</i></p>


 <hr>
 <h3><a name="133"></a>133. map missing get_allocator()</h3>
 <p><b>Section:</b> 23.3.1 [map] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-03-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#map">issues</a> in [map].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p><p>The title says it all.</p>

 <p><b>Proposed resolution:</b></p>
 <p>Insert in 23.3.1 [map], paragraph 2,
 after operator= in the map declaration:</p>

 <pre>    allocator_type get_allocator() const;</pre>


 <hr>
 <h3><a name="134"></a>134. vector constructors over specified</h3>
 <p><b>Section:</b> 23.2.6.1 [vector.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-03-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The complexity description says: "It does at most 2N calls to the copy constructor
 of T and logN reallocations if they are just input iterators ...".</p>

 <p>This appears to be overly restrictive, dictating the precise memory/performance
 tradeoff for the implementor.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 23.2.6.1 [vector.cons], paragraph 1 to:</p>

 <p>-1- Complexity: The constructor template &lt;class
 InputIterator&gt; vector(InputIterator first, InputIterator last)
 makes only N calls to the copy constructor of T (where N is the
 distance between first and last) and no reallocations if iterators
 first and last are of forward, bidirectional, or random access
 categories. It makes order N calls to the copy constructor of T and
 order logN reallocations if they are just input iterators.
 </p>


 <p><b>Rationale:</b></p>
 <p>"at most 2N calls" is correct only if the growth factor
 is greater than or equal to 2.
 </p>


 <hr>
 <h3><a name="136"></a>136. seekp, seekg setting wrong streams?</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-03-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>I may be misunderstanding the intent, but should not seekg set only
 the input stream and seekp set only the output stream? The description
 seems to say that each should set both input and output streams. If
 that's really the intent, I withdraw this proposal.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In section 27.6.1.3 change:</p>

 <pre>basic_istream&lt;charT,traits&gt;&amp; seekg(pos_type pos);
 Effects: If fail() != true, executes rdbuf()-&gt;pubseekpos(pos). </pre>

 <p>To:</p>

 <pre>basic_istream&lt;charT,traits&gt;&amp; seekg(pos_type pos);
 Effects: If fail() != true, executes rdbuf()-&gt;pubseekpos(pos, ios_base::in). </pre>

 <p>In section 27.6.1.3 change:</p>

 <pre>basic_istream&lt;charT,traits&gt;&amp; seekg(off_type&amp; off, ios_base::seekdir dir);
 Effects: If fail() != true, executes rdbuf()-&gt;pubseekoff(off, dir). </pre>

 <p>To:</p>

 <pre>basic_istream&lt;charT,traits&gt;&amp; seekg(off_type&amp; off, ios_base::seekdir dir);
 Effects: If fail() != true, executes rdbuf()-&gt;pubseekoff(off, dir, ios_base::in). </pre>

 <p>In section 27.6.2.4, paragraph 2 change:</p>

 <pre>-2- Effects: If fail() != true, executes rdbuf()-&gt;pubseekpos(pos). </pre>

 <p>To:</p>

 <pre>-2- Effects: If fail() != true, executes rdbuf()-&gt;pubseekpos(pos, ios_base::out). </pre>

 <p>In section 27.6.2.4, paragraph 4 change:</p>

 <pre>-4- Effects: If fail() != true, executes rdbuf()-&gt;pubseekoff(off, dir). </pre>

 <p>To:</p>

 <pre>-4- Effects: If fail() != true, executes rdbuf()-&gt;pubseekoff(off, dir, ios_base::out). </pre>

 <p><i>[Dublin: Dietmar Kühl thinks this is probably correct, but would
 like the opinion of more iostream experts before taking action.]</i></p>


 <p><i>[Tokyo: Reviewed by the LWG. PJP noted that although his docs are
 incorrect, his implementation already implements the Proposed
 Resolution.]</i></p>


 <p><i>[Post-Tokyo: Matt Austern comments:<br>
 Is it a problem with basic_istream and basic_ostream, or is it a problem
 with basic_stringbuf?
 We could resolve the issue either by changing basic_istream and
 basic_ostream, or by changing basic_stringbuf. I prefer the latter
 change (or maybe both changes): I don't see any reason for the standard to
 require that std::stringbuf s(std::string("foo"), std::ios_base::in);
 s.pubseekoff(0, std::ios_base::beg); must fail.<br>
 This requirement is a bit weird. There's no similar requirement
 for basic_streambuf&lt;&gt;::seekpos, or for basic_filebuf&lt;&gt;::seekoff or
 basic_filebuf&lt;&gt;::seekpos.]</i></p>


 <hr>
 <h3><a name="137"></a>137. Do use_facet and has_facet look in the global locale?</h3>
 <p><b>Section:</b> 22.1.1 [locale] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 1999-03-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale">issues</a> in [locale].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 22.1.1 [locale] says:</p>

 <p>-4- In the call to use_facet&lt;Facet&gt;(loc), the type argument
 chooses a facet, making available all members of the named type. If
 Facet is not present in a locale (or, failing that, in the global
 locale), it throws the standard exception bad_cast. A C++ program can
 check if a locale implements a particular facet with the template
 function has_facet&lt;Facet&gt;(). </p>

 <p>This contradicts the specification given in section
 22.1.2 [locale.global.templates]:
 <br><br>
 template &lt;class&nbsp; Facet&gt; const&nbsp; Facet&amp; use_facet(const
 locale&amp;&nbsp; loc); <br>
 <br>
 -1- Get a reference to a facet of a locale. <br>
 -2- Returns: a reference to the corresponding facet of loc, if present. <br>
 -3- Throws: bad_cast if has_facet&lt;Facet&gt;(loc) is false. <br>
 -4- Notes: The reference returned remains valid at least as long as any copy of loc exists
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the phrase "(or, failing that, in the global locale)"
 from section 22.1.1. </p>


 <p><b>Rationale:</b></p>
 <p>Needed for consistency with the way locales are handled elsewhere
 in the standard.</p>


 <hr>
 <h3><a name="139"></a>139. Optional sequence operation table description unclear</h3>
 <p><b>Section:</b> 23.1.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1999-03-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The sentence introducing the Optional sequence operation table
 (23.1.1 paragraph 12) has two problems:</p>

 <p>A. It says ``The operations in table 68 are provided only for the containers for which
 they take constant time.''<br>
 <br>
 That could be interpreted in two ways, one of them being ``Even though table 68 shows
 particular operations as being provided, implementations are free to omit them if they
 cannot implement them in constant time.''<br>
 <br>
 B. That paragraph says nothing about amortized constant time, and it should.&nbsp;</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the wording in 23.1.1 paragraph 12&nbsp; which begins ``The operations in table 68 are provided only..."
 with:</p>

 <blockquote>
   <p>Table 68 lists sequence operations that are provided for some types of sequential
   containers but not others. An implementation shall provide these operations for all
   container types shown in the ``container'' column, and shall implement them so as to take
   amortized constant time.</p>
 </blockquote>


 <hr>
 <h3><a name="141"></a>141. basic_string::find_last_of, find_last_not_of say pos instead of xpos</h3>
 <p><b>Section:</b> 21.3.6.4 [string::insert], 21.3.6.6 [string::replace] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Arch Robison <b>Date:</b> 1999-04-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::insert">issues</a> in [string::insert].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1 surely have misprints where they
 say:<br>
 <br>
 &#8212; <tt>xpos &lt;= pos</tt> and <tt>pos &lt; size();</tt></p>

 <p>Surely the document meant to say ``<tt>xpos &lt; size()</tt>'' in both places.</p>

 <p><i>[Judy Ward also sent in this issue for 21.3.6.4 with the same
 proposed resolution.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1, the line which says:<br>
 <br>
 &#8212; <tt>xpos &lt;= pos</tt> and <tt>pos &lt; size();<br>
 <br>
 </tt>to:<br>
 <tt><br>
 </tt>&#8212; <tt>xpos &lt;= pos</tt> and <tt>xpos &lt; size();</tt></p>


 <hr>
 <h3><a name="142"></a>142. lexicographical_compare complexity wrong</h3>
 <p><b>Section:</b> 25.3.8 [alg.lex.comparison] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-06-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The lexicographical_compare complexity is specified as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; "At most min((last1 - first1), (last2 - first2))
 applications of the corresponding comparison."<br>
 <br>
 The best I can do is twice that expensive.</p>

 <p>Nicolai Josuttis comments in lib-6862: You mean, to check for
 equality you have to check both &lt; and &gt;? Yes, IMO you are
 right! (and Matt states this complexity in his book)</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.3.8 [alg.lex.comparison] complexity to:</p>
     <blockquote><p>
     At most <tt>2*min((last1 - first1), (last2 - first2))</tt>
     applications of the corresponding comparison.
     </p></blockquote>

 <p>Change the example at the end of paragraph 3 to read:</p>
     <blockquote><p>
     [Example:<br>
     <br>
     &nbsp;&nbsp;&nbsp; for ( ; first1 != last1 &amp;&amp; first2 != last2 ;
     ++first1, ++first2) {<br>
     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (*first1 &lt; *first2) return true;<br>
     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if (*first2 &lt; *first1) return false;<br>
     &nbsp;&nbsp;&nbsp; }<br>
     &nbsp;&nbsp;&nbsp; return first1 == last1 &amp;&amp; first2 != last2;<br>
     &nbsp;&nbsp;&nbsp;<br>
     --end example]
     </p></blockquote>


 <hr>
 <h3><a name="144"></a>144. Deque constructor complexity wrong </h3>
 <p><b>Section:</b> 23.2.2.1 [deque.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Herb Sutter <b>Date:</b> 1999-05-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#deque.cons">issues</a> in [deque.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 23.2.2.1 [deque.cons] paragraph 6, the deque ctor that takes an iterator range appears
 to have complexity requirements which are incorrect, and which contradict the
 complexity requirements for insert(). I suspect that the text in question,
 below, was taken from vector:</p>
 <blockquote>
   <p>Complexity: If the iterators first and last are forward iterators,
   bidirectional iterators, or random access iterators the constructor makes only
   N calls to the copy constructor, and performs no reallocations, where N is
   last - first.</p>
 </blockquote>
 <p>The word "reallocations" does not really apply to deque. Further,
 all of the following appears to be spurious:</p>
 <blockquote>
   <p>It makes at most 2N calls to the copy constructor of T and log N
   reallocations if they are input iterators.1)</p>
   <p>1) The complexity is greater in the case of input iterators because each
   element must be added individually: it is impossible to determine the distance
   between first abd last before doing the copying.</p>
 </blockquote>
 <p>This makes perfect sense for vector, but not for deque. Why should deque gain
 an efficiency advantage from knowing in advance the number of elements to
 insert?</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.2.2.1 [deque.cons] paragraph 6, replace the Complexity description, including the
 footnote, with the following text (which also corrects the "abd"
 typo):</p>
 <blockquote>
   <p>Complexity: Makes last - first calls to the copy constructor of T.</p>
 </blockquote>


 <hr>
 <h3><a name="146"></a>146. complex&lt;T&gt; Inserter and Extractor need sentries</h3>
 <p><b>Section:</b> 26.3.6 [complex.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 1999-05-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.ops">issues</a> in [complex.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The extractor for complex numbers is specified as:&nbsp;</p>

 <blockquote>

 <p>     template&lt;class T, class charT, class traits&gt;&nbsp;<br>
      basic_istream&lt;charT, traits&gt;&amp;&nbsp;<br>
      operator&gt;&gt;(basic_istream&lt;charT, traits&gt;&amp;  is, complex&lt;T&gt;&amp;  x);<br>
 &nbsp;<br>
 Effects: Extracts a complex number x of the form: u, (u), or (u,v),
 where u is the real part and v is the imaginary part
 (lib.istream.formatted).&nbsp;<br>
 Requires: The input values be convertible to T. If bad input is
 encountered, calls is.setstate(ios::failbit) (which may throw
 ios::failure (lib.iostate.flags).&nbsp;<br>
 Returns: is .</p>

 </blockquote>
 <p>Is it intended that the extractor for complex numbers does not skip
 whitespace, unlike all other extractors in the standard library do?
 Shouldn't a sentry be used?&nbsp;<br>
 <br>
 The inserter for complex numbers is specified as:</p>

 <blockquote>

 <p>     template&lt;class T, class charT, class traits&gt;&nbsp;<br>
      basic_ostream&lt;charT, traits&gt;&amp;&nbsp;<br>
      operator&lt;&lt;(basic_ostream&lt;charT, traits&gt;&amp;  o, const complex&lt;T&gt;&amp;  x);<br>
 <br>
 Effects: inserts the complex number x onto the stream o as if it were implemented as follows:<br>
 <br>
      template&lt;class T, class charT, class traits&gt;&nbsp;<br>
      basic_ostream&lt;charT, traits&gt;&amp;&nbsp;<br>
      operator&lt;&lt;(basic_ostream&lt;charT, traits&gt;&amp; o, const complex&lt;T&gt;&amp; x)&nbsp;<br>
      {&nbsp;<br>
              basic_ostringstream&lt;charT, traits&gt; s;&nbsp;<br>
              s.flags(o.flags());&nbsp;<br>
              s.imbue(o.getloc());&nbsp;<br>
              s.precision(o.precision());&nbsp;<br>
              s &lt;&lt; '(' &lt;&lt; x.real() &lt;&lt; "," &lt;&lt; x.imag() &lt;&lt; ')';&nbsp;<br>
              return o &lt;&lt; s.str();&nbsp;<br>
      }</p>

 </blockquote>

 <p>Is it intended that the inserter for complex numbers ignores the
 field width and does not do any padding? If, with the suggested
 implementation above, the field width were set in the stream then the
 opening parentheses would be adjusted, but the rest not, because the
 field width is reset to zero after each insertion.</p>

 <p>I think that both operations should use sentries, for sake of
 consistency with the other inserters and extractors in the
 library. Regarding the issue of padding in the inserter, I don't know
 what the intent was.&nbsp;</p>


 <p><b>Proposed resolution:</b></p>
 <p>After 26.3.6 [complex.ops] paragraph 14 (operator&gt;&gt;), add a
 Notes clause:</p>

 <blockquote>

 <p>Notes: This extraction is performed as a series of simpler
 extractions. Therefore, the skipping of whitespace is specified to be the
 same for each of the simpler extractions.</p>

 </blockquote>


 <p><b>Rationale:</b></p>
 <p>For extractors, the note is added to make it clear that skipping whitespace
 follows an "all-or-none" rule.</p>

 <p>For inserters, the LWG believes there is no defect; the standard is correct
 as written.</p>


 <hr>
 <h3><a name="147"></a>147. Library Intro refers to global functions that aren't global</h3>
 <p><b>Section:</b> 17.4.4.3 [global.functions] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Lois Goldthwaite <b>Date:</b> 1999-06-04</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#global.functions">issues</a> in [global.functions].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The library had many global functions until 17.4.1.1 [lib.contents]
 paragraph 2 was added: </p>

 <blockquote>

 <p>All library entities except macros, operator new and operator
 delete are defined within the namespace std or namespaces nested
 within namespace std. </p>

 </blockquote>

 <p>It appears "global function" was never updated in the following: </p>

 <blockquote>

 <p>17.4.4.3 - Global functions [lib.global.functions]<br>
 <br>
 -1- It is unspecified whether any global functions in the C++ Standard
 Library are defined as inline (dcl.fct.spec).<br>
 <br>
 -2- A call to a global function signature described in Clauses
 lib.language.support through lib.input.output behaves the same as if
 the implementation declares no additional global function
 signatures.*<br>
 <br>
     [Footnote: A valid C++ program always calls the expected library
     global function. An implementation may also define additional
     global functions that would otherwise not be called by a valid C++
     program. --- end footnote]<br>
 <br>
 -3- A global function cannot be declared by the implementation as
 taking additional default arguments.&nbsp;<br>
 <br>
 17.4.4.4 - Member functions [lib.member.functions]<br>
 <br>
 -2- An implementation can declare additional non-virtual member
 function signatures within a class: </p>

   <blockquote>

 <p>-- by adding arguments with default values to a member function
 signature; The same latitude does not extend to the implementation of
 virtual or global functions, however. </p>

   </blockquote>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>     Change "global" to "global or non-member" in:</p>
 <blockquote>
   <p>17.4.4.3 [lib.global.functions] section title,<br>
   17.4.4.3 [lib.global.functions] para 1,<br>
   17.4.4.3 [lib.global.functions] para 2 in 2 places plus 2
            places in the footnote,<br>
   17.4.4.3 [lib.global.functions] para 3,<br>
   17.4.4.4 [lib.member.functions] para 2</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>
 Because operator new and delete are global, the proposed resolution
 was changed from "non-member" to "global or non-member.
 </p>


 <hr>
 <h3><a name="148"></a>148. Functions in the example facet BoolNames should be const</h3>
 <p><b>Section:</b> 22.2.8 [facets.examples] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Jeremy Siek <b>Date:</b> 1999-06-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facets.examples">issues</a> in [facets.examples].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 22.2.8 [facets.examples] paragraph 13, the do_truename() and
 do_falsename() functions in the example facet BoolNames should be
 const. The functions they are overriding in
 numpunct_byname&lt;char&gt; are const. </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.8 [facets.examples] paragraph 13, insert "const" in
 two places:</p>
 <blockquote>
   <p><tt>string do_truename() const { return "Oui Oui!"; }<br>
   string do_falsename() const { return "Mais Non!"; }</tt></p>
 </blockquote>


 <hr>
 <h3><a name="150"></a>150. Find_first_of says integer instead of iterator </h3>
 <p><b>Section:</b> 25.1.7 [alg.find.first.of] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt McClure <b>Date:</b> 1999-06-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.find.first.of">issues</a> in [alg.find.first.of].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.1.7 [alg.find.first.of] paragraph 2 from:</p>

 <blockquote>
 <p>Returns: The first iterator i in the range [first1, last1) such
 that for some integer j in the range [first2, last2) ...</p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>Returns: The first iterator i in the range [first1, last1) such
 that for some iterator j in the range [first2, last2) ...</p>
 </blockquote>


 <hr>
 <h3><a name="151"></a>151. Can't currently clear() empty container</h3>
 <p><b>Section:</b> 23.1.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Ed Brey <b>Date:</b> 1999-06-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>For both sequences and associative containers, a.clear() has the
 semantics of erase(a.begin(),a.end()), which is undefined for an empty
 container since erase(q1,q2) requires that q1 be dereferenceable
 (23.1.1,3 and 23.1.2,7).  When the container is empty, a.begin() is
 not dereferenceable.<br>
 <br>
 The requirement that q1 be unconditionally dereferenceable causes many
 operations to be intuitively undefined, of which clearing an empty
 container is probably the most dire.<br>
 <br>
 Since q1 and q2 are only referenced in the range [q1, q2), and [q1,
 q2) is required to be a valid range, stating that q1 and q2 must be
 iterators or certain kinds of iterators is unnecessary.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.1.1, paragraph 3, change:</p>
 <blockquote>
   <p>p and q2 denote valid iterators to a, q and q1 denote valid dereferenceable iterators to a, [q1, q2) denotes a valid range</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>p denotes a valid iterator to a, q denotes a valid dereferenceable iterator to a, [q1, q2) denotes a valid range
   in a</p>
 </blockquote>
 <p>In 23.1.2, paragraph 7, change:</p>
 <blockquote>
   <p>p and q2 are valid iterators to a, q and q1 are valid dereferenceable
   iterators to a, [q1, q2) is a valid range</p>
 </blockquote>
 <p>to</p>
 <blockquote>
   <p>p is a valid iterator to a, q is a valid dereferenceable iterator to a, [q1, q2) is a valid range
   into a</p>
 </blockquote>


 <hr>
 <h3><a name="152"></a>152. Typo in <tt>scan_is()</tt> semantics</h3>
 <p><b>Section:</b> 22.2.1.1.2 [locale.ctype.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.ctype.virtuals">issues</a> in [locale.ctype.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The semantics of <tt>scan_is()</tt> (paragraphs 4 and 6) is not exactly described
 because there is no function <tt>is()</tt> which only takes a character as
 argument. Also, in the effects clause (paragraph 3), the semantic is also kept
 vague.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.1.1.2 [locale.ctype.virtuals] paragraphs 4 and 6, change the returns
 clause from:</p>
 <blockquote>
   <p>"... such that <tt>is(*p)</tt>
 would..."</p>
 </blockquote>
 <p>to:&nbsp; "... such that <tt>is(m, *p)</tt>
  would...."</p>


 <hr>
 <h3><a name="153"></a>153. Typo in <tt>narrow()</tt> semantics</h3>
 <p><b>Section:</b> 22.2.1.3.2 [facet.ctype.char.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.ctype.char.members">issues</a> in [facet.ctype.char.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#207">207</a></p>
 <p><b>Discussion:</b></p>
 <p>The description of the array version of <tt>narrow()</tt> (in
 paragraph 11) is flawed: There is no member <tt>do_narrow()</tt> which
 takes only three arguments because in addition to the range a default
 character is needed.</p>

 <p>Additionally, for both <tt>widen</tt> and <tt>narrow</tt> we have
 two signatures followed by a <b>Returns</b> clause that only addresses
 one of them.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the returns clause in 22.2.1.3.2 [facet.ctype.char.members]
 paragraph 10 from:</p>
 <p>&nbsp;&nbsp;&nbsp; Returns: do_widen(low, high, to).</p>

 <p>to:</p>
 <p>&nbsp;&nbsp;&nbsp; Returns: do_widen(c) or do_widen(low, high, to),
 respectively.</p>

 <p>Change 22.2.1.3.2 [facet.ctype.char.members] paragraph 10 and 11 from:</p>
 <pre>        char        narrow(char c, char /*dfault*/) const;
         const char* narrow(const char* low, const char* high,
                            char /*dfault*/, char* to) const;</pre>
 <pre>        Returns: do_narrow(low, high, to).</pre>
 <p>to:</p>
 <pre>        char        narrow(char c, char dfault) const;
         const char* narrow(const char* low, const char* high,
                            char dfault, char* to) const;</pre>
 <pre>        Returns: do_narrow(c, dfault) or
                  do_narrow(low, high, dfault, to), respectively.</pre>

 <p><i>[Kona: 1) the problem occurs in additional places, 2) a user
 defined version could be different.]</i></p>


 <p><i>[Post-Tokyo: Dietmar provided the above wording at the request of
 the LWG. He could find no other places the problem occurred. He
 asks for clarification of the Kona "a user defined
 version..." comment above.  Perhaps it was a circuitous way of
 saying "dfault" needed to be uncommented?]</i></p>


 <p><i>[Post-Toronto: the issues list maintainer has merged in the
 proposed resolution from issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#207">207</a>, which addresses the
 same paragraphs.]</i></p>


 <hr>
 <h3><a name="154"></a>154. Missing <tt>double</tt> specifier for <tt>do_get()</tt></h3>
 <p><b>Section:</b> 22.2.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The table in paragraph 7 for the length modifier does not list the length
 modifier <tt>l</tt> to be applied if the type is <tt>double</tt>. Thus, the
 standard asks the implementation to do undefined things when using <tt>scanf()</tt>
 (the missing length modifier for <tt>scanf()</tt> when scanning <tt>double</tt>s
 is actually a problem I found quite often in production code, too).</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.1.2 [facet.num.get.virtuals], paragraph 7, add a row in the Length
 Modifier table to say that for <tt>double</tt> a length modifier
 <tt>l</tt> is to be used.</p>


 <p><b>Rationale:</b></p>
 <p>The standard makes an embarrassing beginner's mistake.</p>


 <hr>
 <h3><a name="155"></a>155. Typo in naming the class defining the class <tt>Init</tt></h3>
 <p><b>Section:</b> 27.3 [iostream.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostream.objects">issues</a> in [iostream.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>There are conflicting statements about where the class
 <tt>Init</tt> is defined. According to 27.3 [iostream.objects] paragraph 2
 it is defined as <tt>basic_ios::Init</tt>, according to 27.4.2 [ios.base] it is defined as <tt>ios_base::Init</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.3 [iostream.objects] paragraph 2 from
 "<tt>basic_ios::Init"</tt> to
 "<tt>ios_base::Init"</tt>.</p>


 <p><b>Rationale:</b></p>
 <p>Although not strictly wrong, the standard was misleading enough to warrant
 the change.</p>


 <hr>
 <h3><a name="156"></a>156. Typo in <tt>imbue()</tt> description</h3>
 <p><b>Section:</b> 27.4.2.3 [ios.base.locales] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios.base.locales">issues</a> in [ios.base.locales].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>There is a small discrepancy between the declarations of
 <tt>imbue()</tt>: in 27.4.2 [ios.base] the argument is passed as
 <tt>locale const&amp;</tt> (correct), in 27.4.2.3 [ios.base.locales] it
 is passed as <tt>locale const</tt> (wrong).</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.4.2.3 [ios.base.locales] change the <tt>imbue</tt> argument
 from "<tt>locale const" to "locale
 const&amp;".</tt></p>


 <hr>
 <h3><a name="158"></a>158. Underspecified semantics for <tt>setbuf()</tt></h3>
 <p><b>Section:</b> 27.5.2.4.2 [streambuf.virt.buffer] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#streambuf.virt.buffer">issues</a> in [streambuf.virt.buffer].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The default behavior of <tt>setbuf()</tt> is described only for the
 situation that <tt>gptr() != 0 &amp;&amp; gptr() != egptr()</tt>:
 namely to do nothing.  What has to be done in other situations&nbsp;
 is not described although there is actually only one reasonable
 approach, namely to do nothing, too.</p>

 <p>Since changing the buffer would almost certainly mess up most
 buffer management of derived classes unless these classes do it
 themselves, the default behavior of <tt>setbuf()</tt> should always be
 to do nothing.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.5.2.4.2 [streambuf.virt.buffer], paragraph 3, Default behavior,
 to: "Default behavior: Does nothing. Returns this."</p>


 <hr>
 <h3><a name="159"></a>159. Strange use of <tt>underflow()</tt></h3>
 <p><b>Section:</b> 27.5.2.4.3 [streambuf.virt.get] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description of the meaning of the result of
 <tt>showmanyc()</tt> seems to be rather strange: It uses calls to
 <tt>underflow()</tt>. Using <tt>underflow()</tt> is strange because
 this function only reads the current character but does not extract
 it, <tt>uflow()</tt> would extract the current character. This should
 be fixed to use <tt>sbumpc()</tt> instead.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.5.2.4.3 [streambuf.virt.get] paragraph 1,
 <tt>showmanyc()</tt>returns clause, by replacing the word
 "supplied" with the words "extracted from the
 stream".</p>


 <hr>
 <h3><a name="160"></a>160. Typo: Use of non-existing function <tt>exception()</tt></h3>
 <p><b>Section:</b> 27.6.1.1 [istream] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream">issues</a> in [istream].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The paragraph 4 refers to the function <tt>exception()</tt> which
 is not defined. Probably, the referred function is
 <tt>basic_ios&lt;&gt;::exceptions()</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.1.1 [istream], 27.6.1.3 [istream.unformatted], paragraph 1,
 27.6.2.1 [ostream], paragraph 3, and 27.6.2.6.1 [ostream.formatted.reqmts],
 paragraph 1, change "<tt>exception()" to
 "exceptions()"</tt>.</p>

 <p><i>[Note to Editor: "exceptions" with an "s"
 is the correct spelling.]</i></p>


 <hr>
 <h3><a name="161"></a>161. Typo: <tt>istream_iterator</tt> vs. <tt>istreambuf_iterator</tt></h3>
 <p><b>Section:</b> 27.6.1.2.2 [istream.formatted.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.formatted.arithmetic">issues</a> in [istream.formatted.arithmetic].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The note in the second paragraph pretends that the first argument
 is an object of type <tt>istream_iterator</tt>. This is wrong: It is
 an object of type <tt>istreambuf_iterator</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.6.1.2.2 [istream.formatted.arithmetic] from:</p>
 <blockquote>
   <p>The first argument provides an object of the istream_iterator class...</p>
 </blockquote>
 <p>to</p>
 <blockquote>
   <p>The first argument provides an object of the istreambuf_iterator class...</p>
 </blockquote>


 <hr>
 <h3><a name="164"></a>164. do_put() has apparently unused fill argument</h3>
 <p><b>Section:</b> 22.2.5.3.2 [locale.time.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 1999-07-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 22.2.5.3.2 [locale.time.put.virtuals] the do_put() function is specified
 as taking a fill character as an argument, but the description of the
 function does not say whether the character is used at all and, if so,
 in which way. The same holds for any format control parameters that
 are accessible through the ios_base&amp; argument, such as the
 adjustment or the field width. Is strftime() supposed to use the fill
 character in any way? In any case, the specification of
 time_put.do_put() looks inconsistent to me.<br> <br> Is the
 signature of do_put() wrong, or is the effects clause incomplete?</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following note after 22.2.5.3.2 [locale.time.put.virtuals]
 paragraph 2:</p>
 <blockquote>
   <p>  [Note: the <tt>fill</tt> argument may be used in the implementation-defined  formats, or by derivations.  A space character is a reasonable default
   for this argument. --end Note]</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG felt that while the normative text was correct,
 users need some guidance on what to pass for the <tt>fill</tt>
 argument since the standard doesn't say how it's used.</p>


 <hr>
 <h3><a name="165"></a>165. <tt>xsputn()</tt>, <tt>pubsync()</tt> never called by <tt>basic_ostream</tt> members?</h3>
 <p><b>Section:</b> 27.6.2.1 [ostream] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream">issues</a> in [ostream].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 2 explicitly states that none of the <tt>basic_ostream</tt>
 functions falling into one of the groups "formatted output functions"
 and "unformatted output functions" calls any stream buffer function
 which might call a virtual function other than <tt>overflow()</tt>. Basically
 this is fine but this implies that <tt>sputn()</tt> (this function would call
 the virtual function <tt>xsputn()</tt>) is never called by any of the standard
 output functions. Is this really intended? At minimum it would be convenient to
 call <tt>xsputn()</tt> for strings... Also, the statement that <tt>overflow()</tt>
 is the only virtual member of <tt>basic_streambuf</tt> called is in conflict
 with the definition of <tt>flush()</tt> which calls <tt>rdbuf()-&gt;pubsync()</tt>
 and thereby the virtual function <tt>sync()</tt> (<tt>flush()</tt> is listed
 under "unformatted output functions").</p>
 <p>In addition, I guess that the sentence starting with "They may use other
 public members of <tt>basic_ostream</tt> ..." probably was intended to
 start with "They may use other public members of <tt>basic_streamuf</tt>..."
 although the problem with the virtual members exists in both cases.</p>
 <p>I see two obvious resolutions:</p>
 <ol>
   <li>state in a footnote that this means that <tt>xsputn()</tt> will never be
     called by any ostream member and that this is intended.</li>
   <li>relax the restriction and allow calling <tt>overflow()</tt> and <tt>xsputn()</tt>.
     Of course, the problem with <tt>flush()</tt> has to be resolved in some way.</li>
 </ol>


 <p><b>Proposed resolution:</b></p>
 <p>Change the last sentence of 27.6.2.1 (lib.ostream) paragraph 2 from:</p>
 <blockquote>
   <p>They may use other public members of basic_ostream except that they do not
   invoke any virtual members of rdbuf() except overflow().</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>They may use other public members of basic_ostream except that they shall
   not invoke any virtual members of rdbuf() except overflow(), xsputn(), and
   sync().</p>
 </blockquote>

 <p><i>[Kona: the LWG believes this is a problem. Wish to ask Jerry or
 PJP why the standard is written this way.]</i></p>


 <p><i>[Post-Tokyo: Dietmar supplied wording at the request of the
 LWG. He comments: The rules can be made a little bit more specific if
 necessary be explicitly spelling out what virtuals are allowed to be
 called from what functions and eg to state specifically that flush()
 is allowed to call sync() while other functions are not.]</i></p>


 <hr>
 <h3><a name="167"></a>167. Improper use of <tt>traits_type::length()</tt></h3>
 <p><b>Section:</b> 27.6.2.6.4 [ostream.inserters.character] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.inserters.character">issues</a> in [ostream.inserters.character].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 4 states that the length is determined using
 <tt>traits::length(s)</tt>.  Unfortunately, this function is not
 defined for example if the character type is <tt>wchar_t</tt> and the
 type of <tt>s</tt> is <tt>char const*</tt>. Similar problems exist if
 the character type is <tt>char</tt> and the type of <tt>s</tt> is
 either <tt>signed char const*</tt> or <tt>unsigned char
 const*</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 27.6.2.6.4 [ostream.inserters.character] paragraph 4 from:</p>
 <blockquote>
   <p>Effects: Behaves like an formatted inserter (as described in
   lib.ostream.formatted.reqmts) of out. After a sentry object is
   constructed it inserts characters. The number of characters starting
   at s to be inserted is traits::length(s). Padding is determined as
   described in lib.facet.num.put.virtuals. The traits::length(s)
   characters starting at s are widened using out.widen
   (lib.basic.ios.members). The widened characters and any required
   padding are inserted into out. Calls width(0).</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>Effects: Behaves like a formatted inserter (as described in
   lib.ostream.formatted.reqmts) of out. After a sentry object is
   constructed it inserts <i>n</i> characters starting at <i>s</i>,
   where <i>n</i> is the number that would be computed as if by:</p>
   <ul>
   <li>traits::length(s) for the overload where the first argument is of
     type basic_ostream&lt;charT, traits&gt;&amp; and the second is
     of type const charT*, and also for the overload where the first
     argument is of type basic_ostream&lt;char, traits&gt;&amp; and
     the second is of type const char*.</li>
   <li>std::char_traits&lt;char&gt;::length(s)
     for the overload where the first argument is of type
     basic_ostream&lt;charT, traits&gt;&amp; and the second is of type
     const char*.</li>
   <li>traits::length(reinterpret_cast&lt;const char*&gt;(s))
     for the other two overloads.</li>
   </ul>
   <p>Padding is determined as described in
   lib.facet.num.put.virtuals. The <i>n</i> characters starting at
   <i>s</i> are widened using out.widen (lib.basic.ios.members).  The
   widened characters and any required padding are inserted into
   out. Calls width(0).</p>
 </blockquote>

 <p><i>[Santa Cruz: Matt supplied new wording]</i></p>


 <p><i>[Kona: changed "where <i>n</i> is" to " where <i>n</i> is the
   number that would be computed as if by"]</i></p>


 <p><b>Rationale:</b></p>
 <p>We have five separate cases.  In two of them we can use the
 user-supplied traits class without any fuss.  In the other three we
 try to use something as close to that user-supplied class as possible.
 In two cases we've got a traits class that's appropriate for
 char and what we've got is a const signed char* or a const
 unsigned char*; that's close enough so we can just use a reinterpret
 cast, and continue to use the user-supplied traits class.  Finally,
 there's one case where we just have to give up: where we've got a
 traits class for some arbitrary charT type, and we somehow have to
 deal with a const char*.  There's nothing better to do but fall back
 to char_traits&lt;char&gt;</p>


 <hr>
 <h3><a name="168"></a>168. Typo: formatted vs. unformatted</h3>
 <p><b>Section:</b> 27.6.2.7 [ostream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.unformatted">issues</a> in [ostream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The first paragraph begins with a descriptions what has to be done
 in <i>formatted</i> output functions. Probably this is a typo and the
 paragraph really want to describe unformatted output functions...</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.2.7 [ostream.unformatted] paragraph 1, the first and last
 sentences, change the word "formatted" to
 "unformatted":</p>
 <blockquote>
   <p>"Each <b>unformatted </b> output function begins ..."<br>
   "... value specified for the <b>unformatted </b>  output
   function."</p>
 </blockquote>


 <hr>
 <h3><a name="169"></a>169. Bad efficiency of <tt>overflow()</tt> mandated</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 8, Notes, of this section seems to mandate an extremely
 inefficient way of buffer handling for <tt>basic_stringbuf</tt>,
 especially in view of the restriction that <tt>basic_ostream</tt>
 member functions are not allowed to use <tt>xsputn()</tt> (see 27.6.2.1 [ostream]): For each character to be inserted, a new buffer
 is to be created.</p>
 <p>Of course, the resolution below requires some handling of
 simultaneous input and output since it is no longer possible to update
 <tt>egptr()</tt> whenever <tt>epptr()</tt> is changed. A possible
 solution is to handle this in <tt>underflow()</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.7.1.4 [stringbuf.virtuals] paragraph 8, Notes, insert the words
 "at least" as in the following:</p>
 <blockquote>
   <p>To make a write position available, the function reallocates (or initially
   allocates) an array object with a sufficient number of elements to hold the
   current array object (if any), plus <b>at least</b> one additional write
   position.</p>
 </blockquote>


 <hr>
 <h3><a name="170"></a>170. Inconsistent definition of <tt>traits_type</tt></h3>
 <p><b>Section:</b> 27.7.4 [stringstream] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The classes <tt>basic_stringstream</tt> (27.7.4 [stringstream]),
 <tt>basic_istringstream</tt> (27.7.2 [istringstream]), and
 <tt>basic_ostringstream</tt> (27.7.3 [ostringstream]) are inconsistent
 in their definition of the type <tt>traits_type</tt>: For
 <tt>istringstream</tt>, this type is defined, for the other two it is
 not. This should be consistent.</p>


 <p><b>Proposed resolution:</b></p>
 <p><b>Proposed resolution:</b></p> <p>To the declarations of
 <tt>basic_ostringstream</tt> (27.7.3 [ostringstream]) and
 <tt>basic_stringstream</tt> (27.7.4 [stringstream]) add:</p>
 <blockquote>
 <pre>typedef traits traits_type;</pre>
 </blockquote>


 <hr>
 <h3><a name="171"></a>171. Strange <tt>seekpos()</tt> semantics due to joint position</h3>
 <p><b>Section:</b> 27.8.1.5 [filebuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#filebuf.virtuals">issues</a> in [filebuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Overridden virtual functions, seekpos()</p> <p>In 27.8.1.1 [filebuf] paragraph 3, it is stated that a joint input and
 output position is maintained by <tt>basic_filebuf</tt>. Still, the
 description of <tt>seekpos()</tt> seems to talk about different file
 positions. In particular, it is unclear (at least to me) what is
 supposed to happen to the output buffer (if there is one) if only the
 input position is changed. The standard seems to mandate that the
 output buffer is kept and processed as if there was no positioning of
 the output position (by changing the input position). Of course, this
 can be exactly what you want if the flag <tt>ios_base::ate</tt> is
 set. However, I think, the standard should say something like
 this:</p>
 <ul>
   <li>If <tt>(which &amp; mode) == 0</tt> neither read nor write position is
     changed and the call fails. Otherwise, the joint read and write position is
     altered to correspond to <tt>sp</tt>.</li>
   <li>If there is an output buffer, the output sequences is updated and any
     unshift sequence is written before the position is altered.</li>
   <li>If there is an input buffer, the input sequence is updated after the
     position is altered.</li>
 </ul>
 <p>Plus the appropriate error handling, that is...</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the unnumbered paragraph in 27.8.1.4 (lib.filebuf.virtuals) before
 paragraph 14 from:</p>
 <blockquote>
   <p>pos_type seekpos(pos_type sp, ios_base::openmode = ios_base::in |
   ios_base::out);</p>
   <p>Alters the file position, if possible, to correspond to the position stored
   in sp (as described below).</p>
   <p>- if (which&amp;ios_base::in)!=0, set the file position to sp, then update
   the input sequence</p>
   <p>- if (which&amp;ios_base::out)!=0, then update the output sequence, write
   any unshift sequence, and set the file position to sp.</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>pos_type seekpos(pos_type sp, ios_base::openmode = ios_base::in |
   ios_base::out);</p>
   <p>Alters the file position, if possible, to correspond to the position stored
   in sp (as described below). Altering the file position performs as follows:</p>
   <p>1. if (om &amp; ios_base::out)!=0, then update the output sequence and
   write any unshift sequence;</p>
   <p>2. set the file position to sp;</p>
   <p>3. if (om &amp; ios_base::in)!=0, then update the input sequence;</p>
   <p>where om is the open mode passed to the last call to open(). The operation
   fails if is_open() returns false.</p>
 </blockquote>

 <p><i>[Kona: Dietmar is working on a proposed resolution.]</i></p>

 <p><i>[Post-Tokyo: Dietmar supplied the above wording.]</i></p>


 <hr>
 <h3><a name="172"></a>172. Inconsistent types for <tt>basic_istream::ignore()</tt></h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Greg Comeau, Dietmar Kühl <b>Date:</b> 1999-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 27.6.1.1 [istream] the function
 <tt>ignore()</tt> gets an object of type <tt>streamsize</tt> as first
 argument. However, in 27.6.1.3 [istream.unformatted]
 paragraph 23 the first argument is of type <tt>int.</tt></p>

 <p>As far as I can see this is not really a contradiction because
 everything is consistent if <tt>streamsize</tt> is typedef to be
 <tt>int</tt>. However, this is almost certainly not what was
 intended. The same thing happened to <tt>basic_filebuf::setbuf()</tt>,
 as described in issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#173">173</a>.</p>

 <p>Darin Adler also
 submitted this issue, commenting: Either 27.6.1.1 should be modified
 to show a first parameter of type int, or 27.6.1.3 should be modified
 to show a first parameter of type streamsize and use
 numeric_limits&lt;streamsize&gt;::max.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.6.1.3 [istream.unformatted] paragraph 23 and 24, change both uses
 of <tt>int</tt> in the description of <tt>ignore()</tt> to
 <tt>streamsize</tt>.</p>


 <hr>
 <h3><a name="173"></a>173. Inconsistent types for <tt>basic_filebuf::setbuf()</tt></h3>
 <p><b>Section:</b> 27.8.1.5 [filebuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Greg Comeau, Dietmar Kühl <b>Date:</b> 1999-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#filebuf.virtuals">issues</a> in [filebuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 In 27.8.1.1 [filebuf] the function <tt>setbuf()</tt> gets an
 object of type <tt>streamsize</tt> as second argument. However, in
 27.8.1.5 [filebuf.virtuals] paragraph 9 the second argument is of type
 <tt>int</tt>.
 </p>

 <p>
 As far as I can see this is not really a contradiction because
 everything is consistent if <tt>streamsize</tt> is typedef to be
 <tt>int</tt>. However, this is almost certainly not what was
 intended. The same thing happened to <tt>basic_istream::ignore()</tt>,
 as described in issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#172">172</a>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.8.1.5 [filebuf.virtuals] paragraph 9, change all uses of
 <tt>int</tt> in the description of <tt>setbuf()</tt> to
 <tt>streamsize</tt>.</p>


 <hr>
 <h3><a name="174"></a>174. Typo: <tt>OFF_T</tt> vs. <tt>POS_T</tt></h3>
 <p><b>Section:</b> D.6 [depr.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.ios.members">issues</a> in [depr.ios.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>According to paragraph 1 of this section, <tt>streampos</tt> is the
 type <tt>OFF_T</tt>, the same type as <tt>streamoff</tt>. However, in
 paragraph 6 the <tt>streampos</tt> gets the type <tt>POS_T</tt></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change D.6 [depr.ios.members] paragraph 1 from "<tt>typedef
 OFF_T streampos;</tt>" to "<tt>typedef POS_T
 streampos;</tt>"</p>


 <hr>
 <h3><a name="175"></a>175. Ambiguity for <tt>basic_streambuf::pubseekpos()</tt> and a few other functions.</h3>
 <p><b>Section:</b> D.6 [depr.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.ios.members">issues</a> in [depr.ios.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>According to paragraph 8 of this section, the methods
 <tt>basic_streambuf::pubseekpos()</tt>,
 <tt>basic_ifstream::open()</tt>, and <tt>basic_ofstream::open</tt>
 "may" be overloaded by a version of this function taking the
 type <tt>ios_base::open_mode</tt> as last argument argument instead of
 <tt>ios_base::openmode</tt> (<tt>ios_base::open_mode</tt> is defined
 in this section to be an alias for one of the integral types). The
 clause specifies, that the last argument has a default argument in
 three cases.  However, this generates an ambiguity with the overloaded
 version because now the arguments are absolutely identical if the last
 argument is not specified.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In D.6 [depr.ios.members] paragraph 8, remove the default arguments for
 <tt>basic_streambuf::pubseekpos()</tt>,
 <tt>basic_ifstream::open()</tt>, and
 <tt>basic_ofstream::open().</tt></p>


 <hr>
 <h3><a name="176"></a>176. <tt>exceptions()</tt> in <tt>ios_base</tt>...?</h3>
 <p><b>Section:</b> D.6 [depr.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 1999-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.ios.members">issues</a> in [depr.ios.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The "overload" for the function <tt>exceptions()</tt> in
 paragraph 8 gives the impression that there is another function of
 this function defined in class <tt>ios_base</tt>. However, this is not
 the case. Thus, it is hard to tell how the semantics (paragraph 9) can
 be implemented: "Call the corresponding member function specified
 in clause 27 [input.output]."</p>


 <p><b>Proposed resolution:</b></p>
 <p>In D.6 [depr.ios.members] paragraph 8, move the declaration of the
 function <tt>exceptions()</tt>into class <tt>basic_ios</tt>.</p>


 <hr>
 <h3><a name="179"></a>179. Comparison of const_iterators to iterators doesn't work</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 1998-07-02</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Currently the following will not compile on two well-known standard
 library implementations:</p>

 <blockquote>
   <pre>#include &lt;set&gt;
 using namespace std;

 void f(const set&lt;int&gt; &amp;s)
 {
   set&lt;int&gt;::iterator i;
   if (i==s.end()); // s.end() returns a const_iterator
 }</pre>
 </blockquote>

 <p>
 The reason this doesn't compile is because operator== was implemented
 as a member function of the nested classes set:iterator and
 set::const_iterator, and there is no conversion from const_iterator to
 iterator. Surprisingly, (s.end() == i) does work, though, because of
 the conversion from iterator to const_iterator.
 </p>

 <p>
 I don't see a requirement anywhere in the standard that this must
 work. Should there be one?  If so, I think the requirement would need
 to be added to the tables in section 24.1.1. I'm not sure about the
 wording.  If this requirement existed in the standard, I would think
 that implementors would have to make the comparison operators
 non-member functions.</p>

 <p>This issues was also raised on comp.std.c++ by Darin
 Adler.&nbsp; The example given was:</p>

 <blockquote>
   <pre>bool check_equal(std::deque&lt;int&gt;::iterator i,
 std::deque&lt;int&gt;::const_iterator ci)
 {
 return i == ci;
 }</pre>
 </blockquote>

 <p>Comment from John Potter:</p>
 <blockquote>
     <p>
     In case nobody has noticed, accepting it will break reverse_iterator.
     </p>

     <p>
     The fix is to make the comparison operators templated on two types.
     </p>

     <pre>    template &lt;class Iterator1, class Iterator2&gt;
     bool operator== (reverse_iterator&lt;Iterator1&gt; const&amp; x,
                      reverse_iterator&lt;Iterator2&gt; const&amp; y);
     </pre>

     <p>
     Obviously:  return x.base() == y.base();
     </p>

     <p>
     Currently, no reverse_iterator to const_reverse_iterator compares are
     valid.
     </p>

     <p>
     BTW, I think the issue is in support of bad code.  Compares should be
     between two iterators of the same type.  All std::algorithms require
     the begin and end iterators to be of the same type.
     </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Insert this paragraph after 23.1 [container.requirements] paragraph 7:</p>
 <blockquote>
   <p>In the expressions</p>
   <pre>    i == j
     i != j
     i &lt; j
     i &lt;= j
     i &gt;= j
     i &gt; j
     i - j
   </pre>
   <p>Where i and j denote objects of a container's iterator type,
   either or both may be replaced by an object of the container's
   const_iterator type referring to the same element with no
   change in semantics.</p>
 </blockquote>

 <p><i>[post-Toronto: Judy supplied a proposed resolution saying that
 <tt>iterator</tt> and <tt>const_iterator</tt> could be freely mixed in
 iterator comparison and difference operations.]</i></p>


 <p><i>[Redmond: Dave and Howard supplied a new proposed resolution which
 explicitly listed expressions; there was concern that the previous
 proposed resolution was too informal.]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 The LWG believes it is clear that the above wording applies only to
 the nested types <tt>X::iterator</tt> and <tt>X::const_iterator</tt>,
 where <tt>X</tt> is a container.  There is no requirement that
 <tt>X::reverse_iterator</tt> and <tt>X::const_reverse_iterator</tt>
 can be mixed.  If mixing them is considered important, that's a
 separate issue.  (Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#280">280</a>.)
 </p>


 <hr>
 <h3><a name="181"></a>181. make_pair() unintended behavior</h3>
 <p><b>Section:</b> 20.2.3 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1999-08-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The claim has surfaced in Usenet that expressions such as<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <tt>make_pair("abc", 3)</tt><br>
 <br>
 are illegal, notwithstanding their use in examples, because template instantiation tries to bind the first template
 parameter to <tt> const char (&amp;)[4]</tt>, which type is uncopyable.<br>
 <br>
 I doubt anyone intended that behavior...
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 20.2 [utility], paragraph 1 change the following
 declaration of make_pair():</p>
 <blockquote>
   <pre>template &lt;class T1, class T2&gt; pair&lt;T1,T2&gt; make_pair(const T1&amp;, const T2&amp;);</pre>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <pre>template &lt;class T1, class T2&gt; pair&lt;T1,T2&gt; make_pair(T1, T2);</pre>
 </blockquote>
 <p>  In 20.2.3 [pairs] paragraph 7 and the line before, change:</p>
 <blockquote>
 <pre>template &lt;class T1, class T2&gt;
 pair&lt;T1, T2&gt; make_pair(const T1&amp; x, const T2&amp; y);</pre>
 </blockquote>
 <p>to:</p>
 <blockquote>
 <pre>template &lt;class T1, class T2&gt;
 pair&lt;T1, T2&gt; make_pair(T1 x, T2 y);</pre>
 </blockquote>
 <p>and add the following footnote to the effects clause:</p>
 <blockquote>
   <p> According to 12.8 [class.copy], an implementation is permitted
   to not perform a copy of an argument, thus avoiding unnecessary
   copies.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Two potential fixes were suggested by Matt Austern and Dietmar
 Kühl, respectively, 1) overloading with array arguments, and 2) use of
 a reference_traits class with a specialization for arrays.  Andy
 Koenig suggested changing to pass by value. In discussion, it appeared
 that this was a much smaller change to the standard that the other two
 suggestions, and any efficiency concerns were more than offset by the
 advantages of the solution. Two implementors reported that the
 proposed resolution passed their test suites.</p>


 <hr>
 <h3><a name="182"></a>182. Ambiguous references to size_t</h3>
 <p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Al Stevens <b>Date:</b> 1999-08-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Many references to <tt> size_t</tt> throughout the document
 omit the <tt> std::</tt> namespace qualification.</p> <p>For
 example, 17.4.3.5 [replacement.functions] paragraph 2:</p>
 <blockquote>
 <pre> operator new(size_t)
  operator new(size_t, const std::nothrow_t&amp;)
  operator new[](size_t)
  operator new[](size_t, const std::nothrow_t&amp;)</pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>   In 17.4.3.5 [replacement.functions] paragraph 2: replace:</p>
 <blockquote>
 <p><tt>     - operator new(size_t)<br>
      - operator new(size_t, const std::nothrow_t&amp;)<br>
      - operator new[](size_t)<br>
      - operator new[](size_t, const std::nothrow_t&amp;)</tt></p>
 </blockquote>
 <p>    by:</p>
 <blockquote>
 <pre>- operator new(std::size_t)
 - operator new(std::size_t, const std::nothrow_t&amp;)
 - operator new[](std::size_t)
 - operator new[](std::size_t, const std::nothrow_t&amp;)</pre>
 </blockquote>
 <p>In [lib.allocator.requirements] 20.1.5, paragraph 4: replace:</p>
 <blockquote>
   <p>The typedef members pointer, const_pointer, size_type, and difference_type
   are required to be T*, T const*, size_t, and ptrdiff_t, respectively.</p>
 </blockquote>
 <p>&nbsp;by:</p>
 <blockquote>
   <p>The typedef members pointer, const_pointer, size_type, and difference_type
   are required to be T*, T const*, std::size_t, and std::ptrdiff_t,
   respectively.</p>
 </blockquote>
 <p>In [lib.allocator.members] 20.4.1.1, paragraphs 3 and 6: replace:</p>
 <blockquote>
   <p>3 Notes: Uses ::operator new(size_t) (18.4.1).</p>
   <p>6 Note: the storage is obtained by calling ::operator new(size_t), but it
   is unspecified when or how often this function is called. The use of hint is
   unspecified, but intended as an aid to locality if an implementation so
   desires.</p>
 </blockquote>
 <p>by:</p>
 <blockquote>
   <p>3 Notes: Uses ::operator new(std::size_t) (18.4.1).</p>
   <p>6 Note: the storage is obtained by calling ::operator new(std::size_t), but
   it is unspecified when or how often this function is called. The use of hint
   is unspecified, but intended as an aid to locality if an implementation so
   desires.</p>
 </blockquote>
 <p>In [lib.char.traits.require] 21.1.1, paragraph 1: replace:</p>
 <blockquote>
   <p>In Table 37, X denotes a Traits class defining types and functions for the
   character container type CharT; c and d denote values of type CharT; p and q
   denote values of type const CharT*; s denotes a value of type CharT*; n, i and
   j denote values of type size_t; e and f denote values of type X::int_type; pos
   denotes a value of type X::pos_type; and state denotes a value of type X::state_type.</p>
 </blockquote>
 <p>by:</p>
 <blockquote>
   <p>In Table 37, X denotes a Traits class defining types and functions for the
   character container type CharT; c and d denote values of type CharT; p and q
   denote values of type const CharT*; s denotes a value of type CharT*; n, i and
   j denote values of type std::size_t; e and f denote values of type X::int_type;
   pos denotes a value of type X::pos_type; and state denotes a value of type X::state_type.</p>
 </blockquote>
 <p>In [lib.char.traits.require] 21.1.1, table 37: replace the return type of
 X::length(p): "size_t" by "std::size_t".</p>
 <p>   In [lib.std.iterator.tags] 24.3.3, paragraph 2:    replace:<br>
 &nbsp;&nbsp;&nbsp; typedef ptrdiff_t difference_type;<br>
     by:<br>
 &nbsp;&nbsp;&nbsp; typedef std::ptrdiff_t difference_type;</p>
 <p> In [lib.locale.ctype] 22.2.1.1 put namespace std { ...} around the
 declaration of template &lt;class charT&gt; class ctype.<br>
 <br>
    In [lib.iterator.traits] 24.3.1, paragraph 2    put namespace std { ...} around the declaration of:<br>
 <br>
 &nbsp;&nbsp;&nbsp; template&lt;class Iterator&gt; struct iterator_traits<br>
 &nbsp;&nbsp;&nbsp; template&lt;class T&gt; struct iterator_traits&lt;T*&gt;<br>
 &nbsp;&nbsp;&nbsp; template&lt;class T&gt; struct iterator_traits&lt;const T*&gt;</p>


 <p><b>Rationale:</b></p>
 <p>The LWG believes correcting names like <tt>size_t</tt> and
 <tt>ptrdiff_t</tt> to <tt>std::size_t</tt> and <tt>std::ptrdiff_t</tt>
 to be essentially editorial.  There there can't be another size_t or
 ptrdiff_t meant anyway because, according to 17.4.3.2.4 [extern.types],</p>

 <blockquote><p>
 For each type T from the Standard C library, the types ::T and std::T
 are reserved to the implementation and, when defined, ::T shall be
 identical to std::T.
 </p></blockquote>

 <p>The issue is treated as a Defect Report to make explicit the Project
 Editor's authority to make this change.</p>

 <p><i>[Post-Tokyo: Nico Josuttis provided the above wording at the
 request of the LWG.]</i></p>


 <p><i>[Toronto: This is tangentially related to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a>, but only tangentially: the intent of this issue is to
 address use of the name <tt>size_t</tt> in contexts outside of
 namespace std, such as in the description of <tt>::operator new</tt>.
 The proposed changes should be reviewed to make sure they are
 correct.]</i></p>


 <p><i>[pre-Copenhagen: Nico has reviewed the changes and believes
 them to be correct.]</i></p>


 <hr>
 <h3><a name="183"></a>183. I/O stream manipulators don't work for wide character streams</h3>
 <p><b>Section:</b> 27.6.3 [std.manip] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andy Sawyer <b>Date:</b> 1999-07-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#std.manip">issues</a> in [std.manip].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.6.3 [std.manip] paragraph 3 says (clause numbering added for
 exposition):</p>
 <blockquote>
 <p>Returns: An object s of unspecified type such that if [1] out is an (instance
 of) basic_ostream then the expression out&lt;&lt;s behaves as if f(s) were
 called, and if [2] in is an (instance of) basic_istream then the expression
 in&gt;&gt;s behaves as if f(s) were called. Where f can be defined as: ios_base&amp;
 f(ios_base&amp; str, ios_base::fmtflags mask) { // reset specified flags
 str.setf(ios_base::fmtflags(0), mask); return str; } [3] The expression
 out&lt;&lt;s has type ostream&amp; and value out. [4] The expression in&gt;&gt;s
 has type istream&amp; and value in.</p>
 </blockquote>
 <p>Given the definitions [1] and [2] for out and in, surely [3] should read:
 "The expression out &lt;&lt; s has type basic_ostream&amp; ..." and
 [4] should read: "The expression in &gt;&gt; s has type basic_istream&amp;
 ..."</p>
 <p>If the wording in the standard is correct, I can see no way of implementing
 any of the manipulators so that they will work with wide character streams.</p>
 <p>e.g. wcout &lt;&lt; setbase( 16 );</p>
 <p>Must have value 'wcout' (which makes sense) and type 'ostream&amp;' (which
 doesn't).</p>
 <p>The same "cut'n'paste" type also seems to occur in Paras 4,5,7 and
 8. In addition, Para 6 [setfill] has a similar error, but relates only to
 ostreams.</p>
 <p>I'd be happier if there was a better way of saying this, to make it clear
 that the value of the expression is "the same specialization of
 basic_ostream as out"&amp;</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace section 27.6.3 [std.manip] except paragraph 1 with the
 following:</p>
 <blockquote>
 <p>2- The type designated smanip in each of the following function
 descriptions is implementation-specified and may be different for each
 function.<br>
 <br>
 <tt>smanip resetiosflags(ios_base::fmtflags mask);</tt><br>
 <br>
 -3- Returns: An object s of unspecified type such that if out is an
 instance of basic_ostream&lt;charT,traits&gt; then the expression
 out&lt;&lt;s behaves
 as if f(s, mask) were called, or if in is an instance of
 basic_istream&lt;charT,traits&gt; then the expression in&gt;&gt;s
 behaves as if
 f(s, mask) were called. The function f can be defined as:*<br>
 <br>
 [Footnote: The expression cin &gt;&gt; resetiosflags(ios_base::skipws)
 clears ios_base::skipws in the format flags stored in the
 basic_istream&lt;charT,traits&gt; object cin (the same as cin &gt;&gt;
 noskipws), and the expression cout &lt;&lt;
 resetiosflags(ios_base::showbase) clears
 ios_base::showbase in the format flags stored in the
 basic_ostream&lt;charT,traits&gt; object cout (the same as cout
 &lt;&lt;
 noshowbase). --- end footnote]<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; <tt>ios_base&amp; f(ios_base&amp; str, ios_base::fmtflags mask)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  reset specified flags<br>
 &nbsp;&nbsp; str.setf(ios_base::fmtflags(0), mask);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type basic_ostream&lt;charT,traits&gt;&amp; and value out.
 The expression in&gt;&gt;s has type basic_istream&lt;charT,traits&gt;&amp; and value in.<br>
 <br>
 &nbsp;<tt>smanip setiosflags(ios_base::fmtflags mask);</tt><br>
 <br>
 -4- Returns: An object s of unspecified type such that if out is an
 instance of basic_ostream&lt;charT,traits&gt; then the expression
 out&lt;&lt;s behaves
 as if f(s, mask) were called, or if in is an instance of
 basic_istream&lt;charT,traits&gt; then the expression in&gt;&gt;s
 behaves as if f(s,
 mask) were called. The function f can be defined as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; <tt>ios_base&amp; f(ios_base&amp; str, ios_base::fmtflags mask)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  set specified flags<br>
 &nbsp;&nbsp; str.setf(mask);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type basic_ostream&lt;charT,traits&gt;&amp; and value out.
 The expression in&gt;&gt;s has type basic_istream&lt;charT,traits&gt;&amp; and value in.<br>
 <br>
 <tt>smanip setbase(int base);</tt><br>
 <br>
 -5- Returns: An object s of unspecified type such that if out is an
 instance of basic_ostream&lt;charT,traits&gt; then the expression
 out&lt;&lt;s behaves
 as if f(s, base) were called, or if in is an instance of
 basic_istream&lt;charT,traits&gt; then the expression in&gt;&gt;s
 behaves as if f(s,
 base) were called. The function f can be defined as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp; <tt>ios_base&amp; f(ios_base&amp; str, int base)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  set  basefield<br>
 &nbsp;&nbsp; str.setf(base ==  8 ? ios_base::oct :<br>
 &nbsp;&nbsp; base == 10 ? ios_base::dec :<br>
 &nbsp;&nbsp; base == 16 ? ios_base::hex :<br>
 &nbsp;&nbsp; ios_base::fmtflags(0), ios_base::basefield);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type basic_ostream&lt;charT,traits&gt;&amp; and value out.
 The expression in&gt;&gt;s has type basic_istream&lt;charT,traits&gt;&amp; and value in.<br>
 <br>
 <tt>smanip setfill(char_type c);<br>
 </tt><br>
 -6- Returns: An object s of unspecified type such that if out is (or is
 derived from) basic_ostream&lt;charT,traits&gt; and c has type charT
 then the
 expression out&lt;&lt;s behaves as if f(s, c) were called. The function
 f can be
 defined as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <tt>template&lt;class charT, class traits&gt;<br>
 &nbsp;&nbsp; basic_ios&lt;charT,traits&gt;&amp; f(basic_ios&lt;charT,traits&gt;&amp; str, charT c)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  set fill character<br>
 &nbsp;&nbsp; str.fill(c);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type basic_ostream&lt;charT,traits&gt;&amp; and value out.<br>
 <br>
 <tt>smanip setprecision(int n);</tt><br>
 <br>
 -7- Returns: An object s of unspecified type such that if out is an
 instance of basic_ostream&lt;charT,traits&gt; then the expression
 out&lt;&lt;s behaves
 as if f(s, n) were called, or if in is an instance of
 basic_istream&lt;charT,traits&gt; then the expression in&gt;&gt;s
 behaves as if f(s, n)
 were called. The function f can be defined as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <tt>ios_base&amp; f(ios_base&amp; str, int n)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  set precision<br>
 &nbsp;&nbsp; str.precision(n);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type basic_ostream&lt;charT,traits&gt;&amp; and value out.
 The expression in&gt;&gt;s has type basic_istream&lt;charT,traits&gt;&amp; and value in<br>
 .<br>
 <tt>smanip setw(int n);<br>
 </tt><br>
 -8- Returns: An object s of unspecified type such that if out is an
 instance of basic_ostream&lt;charT,traits&gt; then the expression
 out&lt;&lt;s behaves
 as if f(s, n) were called, or if in is an instance of
 basic_istream&lt;charT,traits&gt; then the expression in&gt;&gt;s
 behaves as if f(s, n)
 were called. The function f can be defined as:<br>
 <br>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <tt>ios_base&amp; f(ios_base&amp; str, int n)<br>
 &nbsp;&nbsp; {<br>
 &nbsp;&nbsp; //  set width<br>
 &nbsp;&nbsp; str.width(n);<br>
 &nbsp;&nbsp; return str;<br>
 &nbsp;&nbsp; }<br>
 </tt><br>
 The expression out&lt;&lt;s has type
 basic_ostream&lt;charT,traits&gt;&amp; and value out.  The expression
 in&gt;&gt;s has type basic_istream&lt;charT,traits&gt;&amp; and value
 in.
 </p>
 </blockquote>

 <p><i>[Kona: Andy Sawyer and Beman Dawes will work to improve the wording of
 the proposed resolution.]</i></p>


 <p><i>[Tokyo - The LWG noted that issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#216">216</a> involves
 the same paragraphs.]</i></p>


 <p><i>[Post-Tokyo: The issues list maintainer combined the proposed
 resolution of this issue with the proposed resolution for issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#216">216</a> as they both involved the same paragraphs, and were so
 intertwined that dealing with them separately appear fraught with
 error.  The full text was supplied by Bill Plauger; it was cross
 checked against changes supplied by Andy Sawyer. It should be further
 checked by the LWG.]</i></p>


 <hr>
 <h3><a name="184"></a>184. numeric_limits&lt;bool&gt; wording problems</h3>
 <p><b>Section:</b> 18.2.1.5 [numeric.special] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Gabriel Dos Reis <b>Date:</b> 1999-07-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numeric.special">issues</a> in [numeric.special].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>bools are defined by the standard to be of integer types, as per
 3.9.1 [basic.fundamental] paragraph 7.  However "integer types"
 seems to have a special meaning for the author of 18.2. The net effect
 is an unclear and confusing specification for
 numeric_limits&lt;bool&gt; as evidenced below.</p>

 <p>18.2.1.2/7 says numeric_limits&lt;&gt;::digits is, for built-in integer
 types, the number of non-sign bits in the representation.</p>

 <p>4.5/4 states that a bool promotes to int ; whereas 4.12/1 says any non zero
 arithmetical value converts to true.</p>

 <p>I don't think it makes sense at all to require
 numeric_limits&lt;bool&gt;::digits and numeric_limits&lt;bool&gt;::digits10 to
 be meaningful.</p>

 <p>The standard defines what constitutes a signed (resp. unsigned) integer
 types. It doesn't categorize bool as being signed or unsigned. And the set of
 values of bool type has only two elements.</p>

 <p>I don't think it makes sense to require numeric_limits&lt;bool&gt;::is_signed
 to be meaningful.</p>

 <p>18.2.1.2/18 for numeric_limits&lt;integer_type&gt;::radix&nbsp; says:</p>
 <blockquote>
   <p>For integer types, specifies the base of the representation.186)</p>
 </blockquote>

 <p>This disposition is at best misleading and confusing for the standard
 requires a "pure binary numeration system" for integer types as per
 3.9.1/7</p>

 <p>The footnote 186) says: "Distinguishes types with base other than 2 (e.g
 BCD)."&nbsp; This also erroneous as the standard never defines any integer
 types with base representation other than 2.</p>

 <p>Furthermore, numeric_limits&lt;bool&gt;::is_modulo and
 numeric_limits&lt;bool&gt;::is_signed have similar problems.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Append to the end of 18.2.1.5 [numeric.special]:</p>
 <blockquote>
   <p>The specialization for bool shall be provided as follows:</p>
   <pre>    namespace std {
        template&lt;&gt; class numeric_limits&lt;bool&gt; {
        public:
          static const bool is_specialized = true;
          static bool min() throw() { return false; }
          static bool max() throw() { return true; }

          static const int  digits = 1;
          static const int  digits10 = 0;
          static const bool is_signed = false;
          static const bool is_integer = true;
          static const bool is_exact = true;
          static const int  radix = 2;
          static bool epsilon() throw() { return 0; }
          static bool round_error() throw() { return 0; }

          static const int  min_exponent = 0;
          static const int  min_exponent10 = 0;
          static const int  max_exponent = 0;
          static const int  max_exponent10 = 0;

          static const bool has_infinity = false;
          static const bool has_quiet_NaN = false;
          static const bool has_signaling_NaN = false;
          static const float_denorm_style has_denorm = denorm_absent;
          static const bool has_denorm_loss = false;
          static bool infinity() throw() { return 0; }
          static bool quiet_NaN() throw() { return 0; }
          static bool signaling_NaN() throw() { return 0; }
          static bool denorm_min() throw() { return 0; }

          static const bool is_iec559 = false;
          static const bool is_bounded = true;
          static const bool is_modulo = false;

          static const bool traps = false;
          static const bool tinyness_before = false;
          static const float_round_style round_style = round_toward_zero;
        };
      }</pre>
 </blockquote>

 <p><i>[Tokyo:&nbsp; The LWG desires wording that specifies exact values
 rather than more general wording in the original proposed
 resolution.]</i></p>


 <p><i>[Post-Tokyo:&nbsp; At the request of the LWG in Tokyo, Nico
 Josuttis provided the above wording.]</i></p>


 <hr>
 <h3><a name="185"></a>185. Questionable use of term "inline"</h3>
 <p><b>Section:</b> 20.6 [function.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> UK Panel <b>Date:</b> 1999-07-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#function.objects">issues</a> in [function.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 4 of 20.6 [function.objects] says:</p>
 <blockquote>
   <p>&nbsp;[Example: To negate every element of a: transform(a.begin(), a.end(),
   a.begin(), negate&lt;double&gt;()); The corresponding functions will inline
   the addition and the negation. end example]</p>
 </blockquote>
 <p>(Note: The "addition" referred to in the above is in para 3) we can
 find no other wording, except this (non-normative) example which suggests that
 any "inlining" will take place in this case.</p>
 <p>Indeed both:</p>
 <blockquote>
   <p>17.4.4.3 Global Functions [lib.global.functions] 1 It is
   unspecified whether any global functions in the C++ Standard Library
   are defined as inline (7.1.2).</p>
 </blockquote>
 <p>and</p>
 <blockquote>
   <p>17.4.4.4 Member Functions [lib.member.functions] 1 It is
   unspecified whether any member functions in the C++ Standard Library
   are defined as inline (7.1.2).</p>
 </blockquote>
 <p>take care to state that this may indeed NOT be the case.</p>
 <p>Thus the example "mandates" behavior that is explicitly
 not required elsewhere.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 20.6 [function.objects] paragraph 1, remove the sentence:</p>
 <blockquote>
 <p>They are important for the effective use of the library.</p>
 </blockquote>
 <p>Remove 20.6 [function.objects] paragraph 2, which reads:</p>
 <blockquote>
   <p> Using function objects together with function templates
   increases the expressive power of the library as well as making the
   resulting code much more efficient.</p>
 </blockquote>
 <p>In 20.6 [function.objects] paragraph 4, remove the sentence:</p>
 <blockquote>
   <p>The corresponding functions will inline the addition and the
   negation.</p>
 </blockquote>

 <p><i>[Kona: The LWG agreed there was a defect.]</i></p>

 <p><i>[Tokyo: The LWG crafted the proposed resolution.]</i></p>


 <hr>
 <h3><a name="186"></a>186. bitset::set() second parameter should be bool</h3>
 <p><b>Section:</b> 23.3.5.2 [bitset.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Darin Adler <b>Date:</b> 1999-08-13</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bitset.members">issues</a> in [bitset.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In section 23.3.5.2 [bitset.members], paragraph 13 defines the
 bitset::set operation to take a second parameter of type int. The
 function tests whether this value is non-zero to determine whether to
 set the bit to true or false. The type of this second parameter should
 be bool. For one thing, the intent is to specify a Boolean value. For
 another, the result type from test() is bool. In addition, it's
 possible to slice an integer that's larger than an int. This can't
 happen with bool, since conversion to bool has the semantic of
 translating 0 to false and any non-zero value to true.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.3.5 [template.bitset] Para 1 Replace:</p>
 <blockquote>
 <pre>bitset&lt;N&gt;&amp; set(size_t pos, int val = true ); </pre>
 </blockquote>
 <p>With:</p>
 <blockquote>
   <pre>bitset&lt;N&gt;&amp; set(size_t pos, bool val = true );</pre>
 </blockquote>
 <p>In 23.3.5.2 [bitset.members] Para 12(.5) Replace:</p>
 <blockquote>
   <pre>bitset&lt;N&gt;&amp; set(size_t pos, int val = 1 );</pre>
 </blockquote>
 <p>With:</p>
 <blockquote>
   <pre>bitset&lt;N&gt;&amp; set(size_t pos, bool val = true );</pre>
 </blockquote>

 <p><i>[Kona: The LWG agrees with the description.&nbsp; Andy Sawyer will work
 on better P/R wording.]</i></p>

 <p><i>[Post-Tokyo: Andy provided the above wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p><tt>bool</tt> is a better choice.  It is believed that binary
 compatibility is not an issue, because this member function is
 usually implemented as <tt>inline</tt>, and because it is already
 the case that users cannot rely on the type of a pointer to a
 nonvirtual member of a standard library class.</p>


 <hr>
 <h3><a name="187"></a>187. iter_swap underspecified</h3>
 <p><b>Section:</b> 25.2.3 [alg.swap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1999-08-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.swap">issues</a> in [alg.swap].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description of iter_swap in 25.2.2 paragraph 7,says that it
 ``exchanges the values'' of the objects to which two iterators
 refer.<br> <br> What it doesn't say is whether it does so using swap
 or using the assignment operator and copy constructor.<br> <br> This
 question is an important one to answer, because swap is specialized to
 work efficiently for standard containers.<br> For example:</p>
 <blockquote>
 <pre>vector&lt;int&gt; v1, v2;
 iter_swap(&amp;v1, &amp;v2);</pre>
 </blockquote>
 <p>Is this call to iter_swap equivalent to calling swap(v1, v2)?&nbsp;
 Or is it equivalent to</p>
 <blockquote>
 <pre>{
 vector&lt;int&gt; temp = v1;
 v1 = v2;
 v2 = temp;
 }</pre>
 </blockquote>
 <p>The first alternative is O(1); the second is O(n).</p>
 <p>A LWG member, Dave Abrahams, comments:</p>
 <blockquote>
 <p>Not an objection necessarily, but I want to point out the cost of
 that requirement:</p>
   <blockquote>
 <p><tt>iter_swap(list&lt;T&gt;::iterator, list&lt;T&gt;::iterator)</tt></p>
   </blockquote>
 <p>can currently be specialized to be more efficient than
 iter_swap(T*,T*) for many T (by using splicing). Your proposal would
 make that optimization illegal.&nbsp;</p>
 </blockquote>

 <p><i>[Kona: The LWG notes the original need for iter_swap was proxy iterators
 which are no longer permitted.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the effect clause of iter_swap in 25.2.2 paragraph 7 from:</p>
 <blockquote>
 <p>Exchanges the values pointed to by the two iterators a and b.</p>
 </blockquote>
 <p>to</p>
 <blockquote>
 <p><tt>swap(*a, *b)</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>It's useful to say just what <tt>iter_swap</tt> does.  There may be
   some iterators for which we want to specialize <tt>iter_swap</tt>,
   but the fully general version should have a general specification.</p>

 <p>Note that in the specific case of <tt>list&lt;T&gt;::iterator</tt>,
 iter_swap should not be specialized as suggested above.  That would do
 much more than exchanging the two iterators' values: it would change
 predecessor/successor relationships, possibly moving the iterator from
 one list to another.  That would surely be inappropriate.</p>


 <hr>
 <h3><a name="189"></a>189. setprecision() not specified correctly</h3>
 <p><b>Section:</b> 27.4.2.2 [fmtflags.state] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 1999-08-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#fmtflags.state">issues</a> in [fmtflags.state].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.4.2.2 paragraph 9 claims that setprecision() sets the precision,
 and includes a parenthetical note saying that it is the number of
 digits after the decimal point.<br>
 <br>
 This claim is not strictly correct.  For example, in the default
 floating-point output format, setprecision sets the number of
 significant digits printed, not the number of digits after the decimal
 point.<br>
 <br>
 I would like the committee to look at the definition carefully and
 correct the statement in 27.4.2.2</p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove from 27.4.2.2 [fmtflags.state], paragraph 9, the text
 "(number of digits after the decimal point)".</p>


 <hr>
 <h3><a name="193"></a>193. Heap operations description incorrect</h3>
 <p><b>Section:</b> 25.3.6 [alg.heap.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Markus Mauhart <b>Date:</b> 1999-09-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#216">216</a></p>
 <p><b>Discussion:</b></p>
 <p>25.3.6 [lib.alg.heap.operations] states two key properties of a heap [a,b), the first of them
 is<br>
 <br>
 &nbsp;&nbsp;&nbsp; `"(1) *a is the largest element"<br>
 <br>
 I think this is incorrect and should be changed to the wording in the proposed
 resolution.</p>
 <p>Actually there are two independent changes:</p>
 <blockquote>
   <p>A-"part of largest equivalence class" instead of "largest", cause 25.3
   [lib.alg.sorting] asserts "strict weak ordering" for all its sub clauses.</p>
   <p>B-Take
 'an oldest' from that equivalence class, otherwise the heap functions
 could not be used for a priority queue as explained in 23.2.3.2.2
 [lib.priqueue.members] (where I assume that a "priority queue" respects
 priority AND time).</p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.3.6 [alg.heap.operations] property (1) from:</p>
 <blockquote>
   <p>(1) *a is the largest element</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>(1) There is no element greater than <tt>*a</tt></p>
 </blockquote>


 <hr>
 <h3><a name="195"></a>195. Should <tt>basic_istream::sentry</tt>'s constructor ever set eofbit?</h3>
 <p><b>Section:</b> 27.6.1.1.3 [istream::sentry] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1999-10-13</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::sentry">issues</a> in [istream::sentry].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Suppose that <tt>is.flags() &amp; ios_base::skipws</tt> is nonzero.
 What should <tt>basic_istream&lt;&gt;::sentry</tt>'s constructor do if it
 reaches eof while skipping whitespace?  27.6.1.1.2/5 suggests it
 should set failbit. Should it set eofbit as well?  The standard
 doesn't seem to answer that question.</p>

 <p>On the one hand, nothing in 27.6.1.1.3 [istream::sentry] says that
 <tt>basic_istream&lt;&gt;::sentry</tt> should ever set eofbit.  On the
 other hand, 27.6.1.1 [istream] paragraph 4 says that if
 extraction from a <tt>streambuf</tt> "returns
 <tt>traits::eof()</tt>, then the input function, except as explicitly
 noted otherwise, completes its actions and does
 <tt>setstate(eofbit)"</tt>.  So the question comes down to
 whether <tt>basic_istream&lt;&gt;::sentry</tt>'s constructor is an
 input function.</p>

 <p>Comments from Jerry Schwarz:</p>
 <blockquote>
 <p>It was always my intention that eofbit should be set any time that a
 virtual returned something to indicate eof, no matter what reason
 iostream code had for calling the virtual.</p>
 <p>
 The motivation for this is that I did not want to require streambufs
 to behave consistently if their virtuals are called after they have
 signaled eof.</p>
 <p>
 The classic case is a streambuf reading from a UNIX file.  EOF isn't
 really a state for UNIX file descriptors.  The convention is that a
 read on UNIX returns 0 bytes to indicate "EOF", but the file
 descriptor isn't shut down in any way and future reads do not
 necessarily also return 0 bytes.  In particular, you can read from
 tty's on UNIX even after they have signaled "EOF".  (It
 isn't always understood that a ^D on UNIX is not an EOF indicator, but
 an EOL indicator.  By typing a "line" consisting solely of
 ^D you cause a read to return 0 bytes, and by convention this is
 interpreted as end of file.)</p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Add a sentence to the end of 27.6.1.1.2 paragraph 2:</p>
 <blockquote>
 <p>If <tt>is.rdbuf()-&gt;sbumpc()</tt> or <tt>is.rdbuf()-&gt;sgetc()</tt>
 returns <tt>traits::eof()</tt>, the function calls
 <tt>setstate(failbit | eofbit)</tt> (which may throw
 <tt>ios_base::failure</tt>).
 </p>
 </blockquote>


 <hr>
 <h3><a name="198"></a>198. Validity of pointers and references unspecified after iterator destruction</h3>
 <p><b>Section:</b> 24.1 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 1999-11-03</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Is a pointer or reference obtained from an iterator still valid after
 destruction of the iterator?
 </p>
 <p>
 Is a pointer or reference obtained from an iterator still valid after the value
 of the iterator changes?
 </p>
 <blockquote>
 <pre>#include &lt;iostream&gt;
 #include &lt;vector&gt;
 #include &lt;iterator&gt;

 int main()
 {
     typedef std::vector&lt;int&gt; vec_t;
     vec_t v;
     v.push_back( 1 );

     // Is a pointer or reference obtained from an iterator still
     // valid after destruction of the iterator?
     int * p = &amp;*v.begin();
     std::cout &lt;&lt; *p &lt;&lt; '\n';  // OK?

     // Is a pointer or reference obtained from an iterator still
     // valid after the value of the iterator changes?
     vec_t::iterator iter( v.begin() );
     p = &amp;*iter++;
     std::cout &lt;&lt; *p &lt;&lt; '\n';  // OK?

     return 0;
 }
 </pre>
 </blockquote>

 <p>The standard doesn't appear to directly address these
 questions. The standard needs to be clarified. At least two real-world
 cases have been reported where library implementors wasted
 considerable effort because of the lack of clarity in the
 standard. The question is important because requiring pointers and
 references to remain valid has the effect for practical purposes of
 prohibiting iterators from pointing to cached rather than actual
 elements of containers.</p>

 <p>The standard itself assumes that pointers and references obtained
 from an iterator are still valid after iterator destruction or
 change. The definition of reverse_iterator::operator*(), 24.4.1.3.3 [reverse.iter.conv], which returns a reference, defines
 effects:</p>

 <blockquote>
   <pre>Iterator tmp = current;
 return *--tmp;</pre>
 </blockquote>
 <p>The definition of reverse_iterator::operator-&gt;(), 24.4.1.3.4
 [reverse.iter.op.star], which returns a pointer, defines effects:</p>
 <blockquote>
   <pre>return &amp;(operator*());</pre>
 </blockquote>

 <p>Because the standard itself assumes pointers and references remain
 valid after iterator destruction or change, the standard should say so
 explicitly. This will also reduce the chance of user code breaking
 unexpectedly when porting to a different standard library
 implementation.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add a new paragraph to 24.1 [iterator.requirements]:</p>
 <blockquote><p>
 Destruction of an iterator may invalidate pointers and references
 previously obtained from that iterator.
 </p></blockquote>

 <p>Replace paragraph 1 of 24.4.1.3.3 [reverse.iter.conv] with:</p>

 <blockquote>
 <p><b>Effects:</b></p>
 <pre>  this-&gt;tmp = current;
   --this-&gt;tmp;
   return *this-&gt;tmp;
 </pre>

 <p>
 [<i>Note:</i> This operation must use an auxiliary member variable,
 rather than a temporary variable, to avoid returning a reference that
 persists beyond the lifetime of its associated iterator.  (See
 24.1 [iterator.requirements].)  The name of this member variable is shown for
 exposition only.  <i>--end note</i>]
 </p>
 </blockquote>

 <p><i>[Post-Tokyo: The issue has been reformulated purely
 in terms of iterators.]</i></p>


 <p><i>[Pre-Toronto: Steve Cleary pointed out the no-invalidation
 assumption by reverse_iterator. The issue and proposed resolution was
 reformulated yet again to reflect this reality.]</i></p>


 <p><i>[Copenhagen: Steve Cleary pointed out that reverse_iterator
 assumes its underlying iterator has persistent pointers and
 references.  Andy Koenig pointed out that it is possible to rewrite
 reverse_iterator so that it no longer makes such an assupmption.
 However, this issue is related to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a>.  If we
 decide it is intentional that <tt>p[n]</tt> may return by value
 instead of reference when <tt>p</tt> is a Random Access Iterator,
 other changes in reverse_iterator will be necessary.]</i></p>


 <p><b>Rationale:</b></p>
 <p>This issue has been discussed extensively.  Note that it is
 <i>not</i> an issue about the behavior of predefined iterators.  It is
 asking whether or not user-defined iterators are permitted to have
 transient pointers and references.  Several people presented examples
 of useful user-defined iterators that have such a property; examples
 include a B-tree iterator, and an "iota iterator" that doesn't point
 to memory.  Library implementors already seem to be able to cope with
 such iterators: they take pains to avoid forming references to memory
 that gets iterated past.  The only place where this is a problem is
 <tt>reverse_iterator</tt>, so this issue changes
 <tt>reverse_iterator</tt> to make it work.</p>

 <p>This resolution does not weaken any guarantees provided by
 predefined iterators like <tt>list&lt;int&gt;::iterator</tt>.
 Clause 23 should be reviewed to make sure that guarantees for
 predefined iterators are as strong as users expect.</p>


 <hr>
 <h3><a name="199"></a>199. What does <tt>allocate(0)</tt> return?</h3>
 <p><b>Section:</b> 20.1.2 [allocator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1999-11-19</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#allocator.requirements">active issues</a> in [allocator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.requirements">issues</a> in [allocator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Suppose that <tt>A</tt> is a class that conforms to the
 Allocator requirements of Table 32, and <tt>a</tt> is an
 object of class <tt>A</tt>  What should be the return
 value of <tt>a.allocate(0)</tt>?  Three reasonable
 possibilities: forbid the argument <tt>0</tt>, return
 a null pointer, or require that the return value be a
 unique non-null pointer.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add a note to the <tt>allocate</tt> row of Table 32:
 "[<i>Note:</i> If <tt>n == 0</tt>, the return value is unspecified. <i>--end note</i>]"</p>


 <p><b>Rationale:</b></p>
 <p>A key to understanding this issue is that the ultimate use of
 allocate() is to construct an iterator, and that iterator for zero
 length sequences must be the container's past-the-end
 representation.  Since this already implies special case code, it
 would be over-specification to mandate the return value.
 </p>


 <hr>
 <h3><a name="200"></a>200. Forward iterator requirements don't allow constant iterators</h3>
 <p><b>Section:</b> 24.1.3 [forward.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 1999-11-19</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#forward.iterators">issues</a> in [forward.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In table 74, the return type of the expression <tt>*a</tt> is given
 as <tt>T&amp;</tt>, where <tt>T</tt> is the iterator's value type.
 For constant iterators, however, this is wrong.  ("Value type"
 is never defined very precisely, but it is clear that the value type
 of, say, <tt>std::list&lt;int&gt;::const_iterator</tt> is supposed to be
 <tt>int</tt>, not <tt>const int</tt>.)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In table 74, in the <tt>*a</tt> and <tt>*r++</tt> rows, change the
 return type from "<tt>T&amp;</tt>" to "<tt>T&amp;</tt>
 if <tt>X</tt> is mutable, otherwise <tt>const T&amp;</tt>".
 In the <tt>a-&gt;m</tt> row, change the return type from
 "<tt>U&amp;</tt>" to "<tt>U&amp;</tt> if <tt>X</tt> is mutable,
 otherwise <tt>const U&amp;</tt>".
 </p>

 <p><i>[Tokyo: The LWG believes this is the tip of a larger iceberg;
 there are multiple const problems with the STL portion of the library
 and that these should be addressed as a single package.&nbsp; Note
 that issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#180">180</a> has already been declared NAD Future for
 that very reason.]</i></p>


 <p><i>[Redmond: the LWG thinks this is separable from other constness
 issues.  This issue is just cleanup; it clarifies language that was
 written before we had iterator_traits.  Proposed resolution was
 modified: the original version only discussed *a.  It was pointed out
 that we also need to worry about *r++ and a-&gt;m.]</i></p>


 <hr>
 <h3><a name="201"></a>201. Numeric limits terminology wrong</h3>
 <p><b>Section:</b> 18.2.1 [limits] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Stephen Cleary <b>Date:</b> 1999-12-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#limits">issues</a> in [limits].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In some places in this section, the terms "fundamental types" and
 "scalar types" are used when the term "arithmetic types" is intended.
 The current usage is incorrect because void is a fundamental type and
 pointers are scalar types, neither of which should have
 specializations of numeric_limits.
 </p>
 <p><i>[Lillehammer: it remains true that numeric_limits is using
   imprecise language. However, none of the proposals for changed
   wording are clearer.  A redesign of numeric_limits is needed, but this
   is more a task than an open issue.]</i></p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change 18.2 [support.limits] to:
 </p>

 <blockquote>
 <p>
 -1- The headers <tt>&lt;limits&gt;</tt>, <tt>&lt;climits&gt;</tt>,
 <tt>&lt;cfloat&gt;</tt>, and <tt>&lt;cinttypes&gt;</tt> supply
 characteristics of implementation-dependent <del>fundamental</del>
 <ins>arithmetic</ins> types (3.9.1).
 </p>
 </blockquote>

 <p>
 Change 18.2.1 [limits] to:
 </p>

 <blockquote>
 <p>
 -1- The <tt>numeric_limits</tt> component provides a C++ program with
 information about various properties of the implementation's
 representation of the <del>fundamental</del> <ins>arithmetic</ins>
 types.
 </p>
 <p>
 -2- Specializations shall be provided for each <del>fundamental</del>
 <ins>arithmetic</ins> type, both floating point and integer, including
 <tt>bool</tt>. The member <tt>is_specialized</tt> shall be <tt>true</tt>
 for all such specializations of <tt>numeric_limits</tt>.
 </p>
 <p>
 -4- Non-<del>fundamental</del><ins>arithmetic</ins> standard types, such
 as <tt>complex&lt;T&gt;</tt> (26.3.2), shall not have specializations.
 </p>
 </blockquote>

 <p>
 Change 18.2.1.1 [numeric.limits] to:
 </p>

 <blockquote>
 <p>
 <del>-1- The member <tt>is_specialized</tt> makes it possible to distinguish
 between fundamental types, which have specializations, and non-scalar types,
 which do not.</del>
 </p>
 </blockquote>


 <hr>
 <h3><a name="202"></a>202. unique() effects unclear when predicate not an equivalence relation</h3>
 <p><b>Section:</b> 25.2.9 [alg.unique] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 2000-01-13</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.unique">issues</a> in [alg.unique].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 What should unique() do if you give it a predicate that is not an
 equivalence relation?  There are at least two plausible answers:
 </p>

 <blockquote>

 <p>
    1. You can't, because 25.2.8 says that it it "eliminates all but
    the first element from every consecutive group of equal
    elements..." and it wouldn't make sense to interpret "equal" as
    meaning anything but an equivalence relation.  [It also doesn't
    make sense to interpret "equal" as meaning ==, because then there
    would never be any sense in giving a predicate as an argument at
    all.]
 </p>

 <p>
    2. The word "equal" should be interpreted to mean whatever the
    predicate says, even if it is not an equivalence relation
    (and in particular, even if it is not transitive).
 </p>

 </blockquote>

 <p>
 The example that raised this question is from Usenet:
 </p>

 <blockquote>

 <pre>int f[] = { 1, 3, 7, 1, 2 };
 int* z = unique(f, f+5, greater&lt;int&gt;());</pre>

 </blockquote>

 <p>
 If one blindly applies the definition using the predicate
 greater&lt;int&gt;, and ignore the word "equal", you get:
 </p>

 <blockquote>

 <p>
     Eliminates all but the first element from every consecutive group
     of elements referred to by the iterator i in the range [first, last)
     for which *i &gt; *(i - 1).
 </p>

 </blockquote>

 <p>
 The first surprise is the order of the comparison.  If we wanted to
 allow for the predicate not being an equivalence relation, then we
 should surely compare elements the other way: pred(*(i - 1), *i).  If
 we do that, then the description would seem to say: "Break the
 sequence into subsequences whose elements are in strictly increasing
 order, and keep only the first element of each subsequence".  So the
 result would be 1, 1, 2.  If we take the description at its word, it
 would seem to call for strictly DEcreasing order, in which case the
 result should be 1, 3, 7, 2.<br>
 <br>
 In fact, the SGI implementation of unique() does neither: It yields 1,
 3, 7.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.2.9 [alg.unique] paragraph 1 to:</p>
 <blockquote><p>
 For a nonempty range, eliminates all but the first element from every
 consecutive group of equivalent elements referred to by the iterator
 <tt>i</tt> in the range [first+1, last) for which the following
 conditions hold: <tt>*(i-1) == *i</tt> or <tt>pred(*(i-1), *i) !=
 false</tt>.
 </p></blockquote>

 <p>
 Also insert a new paragraph, paragraph 2a, that reads: "Requires: The
 comparison function must be an equivalence relation."
 </p>

 <p><i>[Redmond: discussed arguments for and against requiring the
 comparison function to be an equivalence relation.  Straw poll:
 14-2-5.  First number is to require that it be an equivalence
 relation, second number is to explicitly not require that it be an
 equivalence relation, third number is people who believe they need
 more time to consider the issue.  A separate issue: Andy Sawyer
 pointed out that "i-1" is incorrect, since "i" can refer to the first
 iterator in the range.  Matt provided wording to address this
 problem.]</i></p>


 <p><i>[Curaçao: The LWG changed "... the range (first,
 last)..." to "...  the range [first+1, last)..." for
 clarity. They considered this change close enough to editorial to not
 require another round of review.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG also considered an alternative resolution: change
 25.2.9 [alg.unique] paragraph 1 to:</p>

 <blockquote><p>
 For a nonempty range, eliminates all but the first element from every
 consecutive group of elements referred to by the iterator
 <tt>i</tt> in the range (first, last) for which the following
 conditions hold: <tt>*(i-1) == *i</tt> or <tt>pred(*(i-1), *i) !=
 false</tt>.
 </p></blockquote>

 <p>
 Also insert a new paragraph, paragraph 1a, that reads: "Notes: The
 comparison function need not be an equivalence relation."
 </p>


 <p>Informally: the proposed resolution imposes an explicit requirement
 that the comparison function be an equivalence relation.  The
 alternative resolution does not, and it gives enough information so
 that the behavior of unique() for a non-equivalence relation is
 specified.  Both resolutions are consistent with the behavior of
 existing implementations.</p>


 <hr>
 <h3><a name="206"></a>206. operator new(size_t, nothrow) may become unlinked to ordinary operator new if ordinary version replaced</h3>
 <p><b>Section:</b> 18.5.1.1 [new.delete.single] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 1999-08-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#new.delete.single">issues</a> in [new.delete.single].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>As specified, the implementation of the nothrow version of operator
 new does not necessarily call the ordinary operator new, but may
 instead simply call the same underlying allocator and return a null
 pointer instead of throwing an exception in case of failure.</p>

 <p>Such an implementation breaks code that replaces the ordinary
 version of new, but not the nothrow version. If the ordinary version
 of new/delete is replaced, and if the replaced delete is not
 compatible with pointers returned from the library versions of new,
 then when the replaced delete receives a pointer allocated by the
 library new(nothrow), crash follows.</p>

 <p>The fix appears to be that the lib version of new(nothrow) must
 call the ordinary new. Thus when the ordinary new gets replaced, the
 lib version will call the replaced ordinary new and things will
 continue to work.</p>

 <p>An alternative would be to have the ordinary new call
 new(nothrow). This seems sub-optimal to me as the ordinary version of
 new is the version most commonly replaced in practice. So one would
 still need to replace both ordinary and nothrow versions if one wanted
 to replace the ordinary version.</p>

 <p>Another alternative is to put in clear text that if one version is
 replaced, then the other must also be replaced to maintain
 compatibility. Then the proposed resolution below would just be a
 quality of implementation issue. There is already such text in
 paragraph 7 (under the new(nothrow) version). But this nuance is
 easily missed if one reads only the paragraphs relating to the
 ordinary new.</p>

 <p>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2158.html">N2158</a>
 has been written explaining the rationale for the proposed resolution below.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 18.5.1.1 [new.delete.single]:
 </p>

 <blockquote>
 <pre>void* operator new(std::size_t <i>size</i>, const std::nothrow_t&amp;) throw();
 </pre>
 <blockquote>
 <p>
 -5- <i>Effects:</i> Same as above, except that it is called by a placement
 version of a <i>new-expression</i> when a C++ program prefers a null pointer result as
 an error indication, instead of a <tt>bad_alloc</tt> exception.
 </p>

 <p>
 -6- <i>Replaceable:</i> a C++ program may define a function with this function
 signature that displaces the default version defined by the C++ Standard
 library.
 </p>

 <p>
 -7- <i>Required behavior:</i> Return a non-null pointer to suitably aligned
 storage (3.7.4), or else return a null pointer. This nothrow version of operator
 new returns a pointer obtained as if acquired from the <ins>(possibly
 replaced)</ins> ordinary version. This requirement is binding on a replacement
 version of this function.
 </p>

 <p>
 -8- <i>Default behavior:</i>
 </p>
 <ul>
 <li><ins>
 Calls <tt>operator new(<i>size</i>)</tt>.
 </ins></li>
 <li><ins>
 If the call to <tt>operator new(<i>size</i>)</tt> returns normally, returns
 the result of that call, else
 </ins></li>
 <li><ins>
 if the call to <tt>operator new(<i>size</i>)</tt> throws an exception, returns
 a null pointer.
 </ins></li>
 <li><del>
 Executes a loop: Within the loop, the function first attempts to allocate the
 requested storage. Whether the attempt involves a call to the Standard C library
 function <tt>malloc</tt> is unspecified.
 </del></li>
 <li><del>
 Returns a pointer to the allocated storage if the attempt is successful.
 Otherwise, if the last argument to <tt>set_new_handler()</tt> was a null
 pointer, return a null pointer.
 </del></li>
 <li><del>
 Otherwise, the function calls the current <i>new_handler</i> (18.5.2.2). If the
 called function returns, the loop repeats.
 </del></li>
 <li><del>
 The loop terminates when an attempt to allocate the requested storage is
 successful or when a called <i>new_handler</i> function does not return. If the
 called <i>new_handler</i> function terminates by throwing a <tt>bad_alloc
 exception</tt>, the function returns a null pointer.
 </del></li>
 </ul>
 <p>
 -9- [<i>Example:</i>
 </p>
 <blockquote><pre>T* p1 = new T;                 <i>// throws bad_alloc if it fails</i>
 T* p2 = new(nothrow) T;        <i>// returns 0 if it fails</i>
 </pre></blockquote>
 <p>
 --<i>end example</i>]
 </p>
 </blockquote>

 <pre>void operator delete(void* <i>ptr</i>) throw();
 <del>void operator delete(void* <i>ptr</i>, const std::nothrow_t&amp;) throw();</del>
 </pre>

 <blockquote>
 <p>
 -10- <i>Effects:</i> The <i>deallocation function</i> (3.7.4.2) called by a
 <i>delete-expression</i> to render the value of <tt><i>ptr</i></tt> invalid.
 </p>
 <p>
 -11- <i>Replaceable:</i> a C++ program may define a function with this function
 signature that displaces the default version defined by the C++ Standard
 library.
 </p>
 <p>
 -12- <i>Requires:</i> the value of <tt><i>ptr</i></tt> is null or the value
 returned by an earlier call to the <del>default</del> <ins>(possibly
 replaced)</ins> <tt>operator new(std::size_t)</tt> or <tt>operator
 new(std::size_t, const std::nothrow_t&amp;)</tt>.
 </p>
 <p>
 -13- <i>Default behavior:</i>
 </p>
 <ul>
 <li>
 For a null value of <tt><i>ptr</i></tt>, do nothing.
 </li>
 <li>
 Any other value of <tt><i>ptr</i></tt> shall be a value returned earlier by a
 call to the default <tt>operator new</tt>, which was not invalidated by an
 intervening call to <tt>operator delete(void*)</tt> (17.4.3.7). For such a
 non-null value of <tt><i>ptr</i></tt>, reclaims storage allocated by the earlier
 call to the default <tt>operator new</tt>.
 </li>
 </ul>
 <p>
 -14- <i>Remarks:</i>  It is unspecified under what conditions part or all of
 such reclaimed storage is allocated by a subsequent call to <tt>operator
 new</tt> or any of <tt>calloc</tt>, <tt>malloc</tt>, or <tt>realloc</tt>,
 declared in <tt>&lt;cstdlib&gt;</tt>.
 </p>
 </blockquote>

 <pre><ins>void operator delete(void* <i>ptr</i>, const std::nothrow_t&amp;) throw();</ins>
 </pre>

 <blockquote>
 <p><ins>
 -15- <i>Effects:</i> Same as above, except that it is called by the
 implementation when an exception propagates from a nothrow placement version
 of the <i>new-expression</i> (i.e. when the constructor throws an exception).
 </ins></p>
 <p><ins>
 -16- <i>Replaceable:</i> a C++ program may define a function with this function
 signature that displaces the default version defined by the C++ Standard
 library.
 </ins></p>
 <p><ins>
 -17- <i>Requires:</i> the value of <tt><i>ptr</i></tt> is null or the
 value returned by an earlier call to the (possibly replaced) <tt>operator
 new(std::size_t)</tt> or <tt>operator new(std::size_t, const
 std::nothrow_t&amp;)</tt>. </ins></p>
 <p><ins>
 -18- <i>Default behavior:</i> Calls <tt>operator delete(<i>ptr</i>)</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 18.5.1.2 [new.delete.array]
 </p>

 <blockquote>
 <pre>void* operator new[](std::size_t <i>size</i>, const std::nothrow_t&amp;) throw();
 </pre>

 <blockquote>
 <p>
 -5- <i>Effects:</i> Same as above, except that it is called by a placement
 version of a <i>new-expression</i> when a C++ program prefers a null pointer result as
 an error indication, instead of a <tt>bad_alloc</tt> exception.
 </p>

 <p>
 -6- <i>Replaceable:</i>  a C++ program can define a function with this function
 signature that displaces the default version defined by the C++ Standard
 library.
 </p>

 <p>
 -7- <i>Required behavior:</i> <del>Same as for operator <tt>new(std::size_t,
 const std::nothrow_t&amp;)</tt>. This nothrow version of operator <tt>new[]</tt>
 returns a pointer obtained as if acquired from the ordinary version.</del>
 <ins>Return a non-null pointer to suitably aligned storage (3.7.4), or else
 return a null pointer. This nothrow version of operator new returns a pointer
 obtained as if acquired from the (possibly replaced) <tt>operator
 new[](std::size_t <i>size</i>)</tt>. This requirement is binding on a
 replacement version of this function.</ins>
 </p>

 <p>
 -8- <i>Default behavior:</i> <del>Returns <tt>operator new(<i>size</i>,
 nothrow)</tt>.</del>
 </p>

 <ul>
 <li><ins>
 Calls <tt>operator new[](<i>size</i>)</tt>.
 </ins></li>
 <li><ins>
 If the call to <tt>operator new[](<i>size</i>)</tt> returns normally, returns
 the result of that call, else
 </ins></li>
 <li><ins>
 if the call to <tt>operator new[](<i>size</i>)</tt> throws an exception, returns
 a null pointer.
 </ins></li>
 </ul>
 </blockquote>

 <pre>void operator delete[](void* <i>ptr</i>) throw();
 void operator delete[](void* <i>ptr</i>, const std::nothrow_t&amp;) throw();
 </pre>

 <blockquote>
 <p>
 -9- <i>Effects:</i> The <i>deallocation function</i> (3.7.4.2) called by the
 array form of a <i>delete-expression</i> to render the value of
 <tt><i>ptr</i></tt> invalid.
 </p>

 <p>
 -10- <i>Replaceable:</i> a C++ program can define a function with this function
 signature that displaces the default version defined by the C++ Standard
 library.
 </p>

 <p>
 -11- <i>Requires:</i> the value of
 <tt><i>ptr</i></tt> is null or the value returned by an earlier call to
 <tt>operator new[](std::size_t)</tt> or <tt>operator new[](std::size_t, const
 std::nothrow_t&amp;)</tt>.
 </p>

 <p>
 -12- <i>Default behavior:</i> Calls <tt>operator delete(<i>ptr</i>)</tt> or
 <tt>operator delete<ins>[]</ins>(<i>ptr</i><del>, std::nothrow</del>)</tt> respectively.
 </p>
 </blockquote>

 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Yes, they may become unlinked, and that is by design. If a user
 replaces one, the user should also replace the other.</p>

 <p><i>[
 Reopened due to a gcc conversation between Howard, Martin and Gaby.  Forwarding
 or not is visible behavior to the client and it would be useful for the client
 to know which behavior it could depend on.
 ]</i></p>


 <p><i>[
 Batavia: Robert voiced serious reservations about backwards compatibility for
 his customers.
 ]</i></p>


 <hr>
 <h3><a name="208"></a>208. Unnecessary restriction on past-the-end iterators</h3>
 <p><b>Section:</b> 24.1 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Stephen Cleary <b>Date:</b> 2000-02-02</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 24.1 paragraph 5, it is stated ". . . Dereferenceable and
 past-the-end values are always non-singular."</p>
 <p>This places an unnecessary restriction on past-the-end iterators for
 containers with forward iterators (for example, a singly-linked list). If the
 past-the-end value on such a container was a well-known singular value, it would
 still satisfy all forward iterator requirements.</p>
 <p>Removing this restriction would allow, for example, a singly-linked list
 without a "footer" node.</p>
 <p>This would have an impact on existing code that expects past-the-end
 iterators obtained from different (generic) containers being not equal.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 24.1 [iterator.requirements] paragraph 5, the last sentence, from:</p>
 <blockquote>
 <p>Dereferenceable and past-the-end values are always non-singular.</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
 <p>Dereferenceable values are always non-singular.&nbsp;</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>For some kinds of containers, including singly linked lists and
 zero-length vectors, null pointers are perfectly reasonable past-the-end
 iterators.  Null pointers are singular.
 </p>


 <hr>
 <h3><a name="209"></a>209. basic_string declarations inconsistent</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Igor Stauder <b>Date:</b> 2000-02-11</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In Section 21.3 [basic.string] the basic_string member function
 declarations use a consistent style except for the following functions:</p>
 <blockquote>
   <pre>void push_back(const charT);
 basic_string&amp; assign(const basic_string&amp;);
 void swap(basic_string&lt;charT,traits,Allocator&gt;&amp;);</pre>
 </blockquote>
 <p>- push_back, assign, swap: missing argument name&nbsp;<br>
 - push_back: use of const with charT (i.e. POD type passed by value
 not by reference - should be charT or const charT&amp; )<br>
 - swap: redundant use of template parameters in argument
 basic_string&lt;charT,traits,Allocator&gt;&amp;</p>


 <p><b>Proposed resolution:</b></p>
 <p>In Section 21.3 [basic.string] change the basic_string member
 function declarations push_back, assign, and swap to:</p>
 <blockquote>
   <pre>void push_back(charT c);

 basic_string&amp; assign(const basic_string&amp; str);
 void swap(basic_string&amp; str);</pre>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Although the standard is in general not consistent in declaration
 style, the basic_string declarations are consistent other than the
 above.  The LWG felt that this was sufficient reason to merit the
 change.
 </p>


 <hr>
 <h3><a name="210"></a>210. distance first and last confused</h3>
 <p><b>Section:</b> 25 [algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Lisa Lippincott <b>Date:</b> 2000-02-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#algorithms">issues</a> in [algorithms].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In paragraph 9 of section 25 [algorithms], it is written:</p>
 <blockquote>
   <p>      In the description of the algorithms operators + and - are used
            for some of the iterator categories for which they do not have to
            be defined. In these cases the semantics of [...] a-b is the same
            as of<br>
   <br>
   &nbsp;&nbsp;&nbsp;&nbsp; <tt>return distance(a, b);</tt></p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>On the last line of paragraph 9 of section 25 [algorithms] change
 <tt>"a-b"</tt> to <tt>"b-a".</tt></p>


 <p><b>Rationale:</b></p>
 <p>There are two ways to fix the defect; change the description to b-a
 or change the return to distance(b,a).  The LWG preferred the
 former for consistency.</p>


 <hr>
 <h3><a name="211"></a>211. operator&gt;&gt;(istream&amp;, string&amp;) doesn't set failbit</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Scott Snyder <b>Date:</b> 2000-02-04</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The description of the stream extraction operator for std::string (section
 21.3.7.9 [lib.string.io]) does not contain a requirement that failbit be set in
 the case that the operator fails to extract any characters from the input
 stream.</p>
 <p>This implies that the typical construction</p>
 <blockquote>
   <pre>std::istream is;
 std::string str;
 ...
 while (is &gt;&gt; str) ... ;</pre>
 </blockquote>
 <p>(which tests failbit) is not required to terminate at EOF.</p>
 <p>Furthermore, this is inconsistent with other extraction operators,
 which do include this requirement. (See sections 27.6.1.2 [istream.formatted] and 27.6.1.3 [istream.unformatted]), where this
 requirement is present, either explicitly or implicitly, for the
 extraction operators. It is also present explicitly in the description
 of getline (istream&amp;, string&amp;, charT) in section 21.3.8.9 [string.io] paragraph 8.)</p>


 <p><b>Proposed resolution:</b></p>
 <p>Insert new paragraph after paragraph 2 in section 21.3.8.9 [string.io]:</p>
 <blockquote>

 <p>If the function extracts no characters, it calls
 is.setstate(ios::failbit) which may throw ios_base::failure
 (27.4.4.3).</p>
 </blockquote>


 <hr>
 <h3><a name="212"></a>212. Empty range behavior unclear for several algorithms</h3>
 <p><b>Section:</b> 25.3.7 [alg.min.max] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Nico Josuttis <b>Date:</b> 2000-02-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.min.max">issues</a> in [alg.min.max].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The standard doesn't specify what min_element() and max_element() shall
 return if the range is empty (first equals last). The usual implementations
 return last. This problem seems also apply to partition(), stable_partition(),
 next_permutation(), and prev_permutation().</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 25.3.7 [alg.min.max] - Minimum and maximum, paragraphs 7 and
 9, append: Returns last if first==last.</p>


 <p><b>Rationale:</b></p>
 <p>The LWG looked in some detail at all of the above mentioned
 algorithms, but believes that except for min_element() and
 max_element() it is already clear that last is returned if first ==
 last.</p>


 <hr>
 <h3><a name="214"></a>214. set::find() missing const overload</h3>
 <p><b>Section:</b> 23.3.3 [set], 23.3.4 [multiset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 2000-02-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#set">issues</a> in [set].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#450">450</a></p>
 <p><b>Discussion:</b></p>
 <p>The specification for the associative container requirements in
 Table 69 state that the find member function should "return
 iterator; const_iterator for constant a". The map and multimap
 container descriptions have two overloaded versions of find, but set
 and multiset do not, all they have is:</p>
 <blockquote>
   <pre>iterator find(const key_type &amp; x) const;</pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Change the prototypes for find(), lower_bound(), upper_bound(), and
 equal_range() in section 23.3.3 [set] and section 23.3.4 [multiset] to each have two overloads:</p>
 <blockquote>
   <pre>iterator find(const key_type &amp; x);
 const_iterator find(const key_type &amp; x) const;</pre>
   <pre>iterator lower_bound(const key_type &amp; x);
 const_iterator lower_bound(const key_type &amp; x) const;</pre>
   <pre>iterator upper_bound(const key_type &amp; x);
 const_iterator upper_bound(const key_type &amp; x) const;</pre>
   <pre>pair&lt;iterator, iterator&gt; equal_range(const key_type &amp; x);
 pair&lt;const_iterator, const_iterator&gt; equal_range(const key_type &amp; x) const;</pre>
 </blockquote>

 <p><i>[Tokyo: At the request of the LWG, Judy Ward provided wording
 extending the proposed resolution to lower_bound, upper_bound, and
 equal_range.]</i></p>


 <hr>
 <h3><a name="217"></a>217. Facets example (Classifying Japanese characters) contains errors</h3>
 <p><b>Section:</b> 22.2.8 [facets.examples] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-02-29</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facets.examples">issues</a> in [facets.examples].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The example in 22.2.8, paragraph 11 contains the following errors:</p>
 <p>1) The member function `My::JCtype::is_kanji()' is non-const; the function
 must be const in order for it to be callable on a const object (a reference to
 which which is what std::use_facet&lt;&gt;() returns).</p>
 <p>2) In file filt.C, the definition of `JCtype::id' must be qualified with the
 name of the namespace `My'.</p>
 <p>3) In the definition of `loc' and subsequently in the call to use_facet&lt;&gt;()
 in main(), the name of the facet is misspelled: it should read `My::JCtype'
 rather than `My::JCType'.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the "Classifying Japanese characters" example in 22.2.8,
 paragraph 11 with the following:</p>
 <pre>#include &lt;locale&gt;</pre>
 <pre>namespace My {
     using namespace std;
     class JCtype : public locale::facet {
     public:
         static locale::id id;     //  required for use as a new locale facet
         bool is_kanji (wchar_t c) const;
         JCtype() {}
     protected:
         ~JCtype() {}
     };
 }</pre>
 <pre>//  file:  filt.C
 #include &lt;iostream&gt;
 #include &lt;locale&gt;
 #include "jctype"                 //  above
 std::locale::id My::JCtype::id;   //  the static  JCtype  member
 declared above.</pre>
 <pre>int main()
 {
     using namespace std;
     typedef ctype&lt;wchar_t&gt; wctype;
     locale loc(locale(""),              //  the user's preferred locale...
                new My::JCtype);         //  and a new feature ...
     wchar_t c = use_facet&lt;wctype&gt;(loc).widen('!');
     if (!use_facet&lt;My::JCtype&gt;(loc).is_kanji(c))
         cout &lt;&lt; "no it isn't!" &lt;&lt; endl;
     return 0;
 }</pre>


 <hr>
 <h3><a name="220"></a>220. ~ios_base() usage valid?</h3>
 <p><b>Section:</b> 27.4.2.7 [ios.base.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Jonathan Schilling, Howard Hinnant <b>Date:</b> 2000-03-13</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The pre-conditions for the ios_base destructor are described in 27.4.2.7
 paragraph 2:</p>
 <blockquote>
   <p>Effects: Destroys an object of class ios_base. Calls each registered
   callback pair (fn,index) (27.4.2.6) as (*fn)(erase_event,*this,index) at such
   time that any ios_base member function called from within fn has well defined
   results.</p>
 </blockquote>
 <p>But what is not clear is: If no callback functions were ever registered, does
 it matter whether the ios_base members were ever initialized?</p>
 <p>For instance, does this program have defined behavior:</p>
 <blockquote>
   <pre>#include &lt;ios&gt;</pre>
   <pre>class D : public std::ios_base { };</pre>
   <pre>int main() { D d; }</pre>
 </blockquote>
 <p>It seems that registration of a callback function would surely affect the
 state of an ios_base. That is, when you register a callback function with an
 ios_base, the ios_base must record that fact somehow.</p>
 <p>But if after construction the ios_base is in an indeterminate state, and that
 state is not made determinate before the destructor is called, then how would
 the destructor know if any callbacks had indeed been registered? And if the
 number of callbacks that had been registered is indeterminate, then is not the
 behavior of the destructor undefined?</p>
 <p>By comparison, the basic_ios class description in 27.4.4.1 paragraph 2 makes
 it explicit that destruction before initialization results in undefined
 behavior.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Modify 27.4.2.7 paragraph 1 from</p>
 <blockquote>
   <p>Effects: Each ios_base member has an indeterminate value after
   construction.</p>
 </blockquote>
 <p>to</p>
 <blockquote>
   <p>Effects: Each ios_base member has an indeterminate
 value after construction. These members must be initialized by calling
 basic_ios::init. If an ios_base object is destroyed before these
 initializations have taken place, the behavior is undefined.</p>
 </blockquote>


 <hr>
 <h3><a name="221"></a>221. num_get&lt;&gt;::do_get stage 2 processing broken</h3>
 <p><b>Section:</b> 22.2.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2000-03-14</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Stage 2 processing of numeric conversion is broken.</p>

 <p>Table 55 in 22.2.2.1.2 says that when basefield is 0 the integral
 conversion specifier is %i. A %i specifier determines a number's base
 by its prefix (0 for octal, 0x for hex), so the intention is clearly
 that a 0x prefix is allowed.  Paragraph 8 in the same section,
 however, describes very precisely how characters are processed. (It
 must be done "as if" by a specified code fragment.) That
 description does not allow a 0x prefix to be recognized.</p>

 <p>Very roughly, stage 2 processing reads a char_type ct. It converts
 ct to a char, not by using narrow but by looking it up in a
 translation table that was created by widening the string literal
 "0123456789abcdefABCDEF+-". The character "x" is
 not found in that table, so it can't be recognized by stage 2
 processing.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.1.2 paragraph 8, replace the line:</p>
 <blockquote>
   <pre>static const char src[] = "0123456789abcdefABCDEF+-";</pre>
 </blockquote>
 <p>with the line:</p>
 <blockquote>
   <pre>static const char src[] = "0123456789abcdefxABCDEFX+-";</pre>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>If we're using the technique of widening a string literal, the
 string literal must contain every character we wish to recognize.
 This technique has the consequence that alternate representations
 of digits will not be recognized.  This design decision was made
 deliberately, with full knowledge of that limitation.</p>


 <hr>
 <h3><a name="222"></a>222. Are throw clauses necessary if a throw is already implied by the effects clause?</h3>
 <p><b>Section:</b> 17.3.1.3 [structure.specifications] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 2000-03-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#structure.specifications">issues</a> in [structure.specifications].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 21.3.6.8 describes the basic_string::compare function this way:</p>
 <blockquote>
   <pre>21.3.6.8 - basic_string::compare [lib.string::compare]

 int compare(size_type pos1, size_type n1,
                 const basic_string&lt;charT,traits,Allocator&gt;&amp;  str ,
                 size_type  pos2 , size_type  n2 ) const;

 -4- Returns:

     basic_string&lt;charT,traits,Allocator&gt;(*this,pos1,n1).compare(
                  basic_string&lt;charT,traits,Allocator&gt;(str,pos2,n2)) .</pre>
 </blockquote>
 <p>and the constructor that's implicitly called by the above is
 defined to throw an out-of-range exception if pos &gt; str.size(). See
 section 21.3.1 [string.require] paragraph 4.</p>

 <p>On the other hand, the compare function descriptions themselves don't have
 "Throws: " clauses and according to 17.3.1.3, paragraph 3, elements
 that do not apply to a function are omitted.</p>
 <p>So it seems there is an inconsistency in the standard -- are the
 "Effects" clauses correct, or are the "Throws" clauses
 missing?</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 17.3.1.3 [structure.specifications] paragraph 3, the footnote 148 attached to
 the sentence "Descriptions of function semantics contain the
 following elements (as appropriate):", insert the word
 "further" so that the foot note reads:</p>
 <blockquote>
   <p>To save space, items that do not apply to a function are
   omitted. For example, if a function does not specify any further
   preconditions, there will be no "Requires" paragraph.</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>The standard is somewhat inconsistent, but a failure to note a
 throw condition in a throws clause does not grant permission not to
 throw.  The inconsistent wording is in a footnote, and thus
 non-normative. The proposed resolution from the LWG clarifies the
 footnote.</p>


 <hr>
 <h3><a name="223"></a>223. reverse algorithm should use iter_swap rather than swap</h3>
 <p><b>Section:</b> 25.2.10 [alg.reverse] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2000-03-21</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Shouldn't the effects say "applies iter_swap to all pairs..."?</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 25.2.10 [alg.reverse], replace:</p>
   <blockquote><p>
   Effects: For each non-negative integer i &lt;= (last - first)/2,
   applies swap to all pairs of iterators first + i, (last - i) - 1.
   </p></blockquote>
 <p>with:</p>
   <blockquote><p>
   Effects: For each non-negative integer i &lt;= (last - first)/2,
   applies iter_swap to all pairs of iterators first + i, (last - i) - 1.
   </p></blockquote>


 <hr>
 <h3><a name="224"></a>224. clear() complexity for associative containers refers to undefined N</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Ed Brey <b>Date:</b> 2000-03-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In the associative container requirements table in 23.1.2 paragraph 7,
 a.clear() has complexity "log(size()) + N". However, the meaning of N
 is not defined.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In the associative container requirements table in 23.1.2 paragraph
 7, the complexity of a.clear(), change "log(size()) + N" to
 "linear in <tt>size()</tt>".</p>


 <p><b>Rationale:</b></p>
 <p>It's the "log(size())", not the "N", that is in
 error: there's no difference between <i>O(N)</i> and <i>O(N +
 log(N))</i>.  The text in the standard is probably an incorrect
 cut-and-paste from the range version of <tt>erase</tt>.</p>


 <hr>
 <h3><a name="225"></a>225. std:: algorithms use of other unqualified algorithms</h3>
 <p><b>Section:</b> 17.4.4.3 [global.functions] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2000-04-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#global.functions">issues</a> in [global.functions].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Are algorithms in std:: allowed to use other algorithms without qualification, so functions in
 user namespaces might be found through Koenig lookup?</p>
 <p>For example, a popular standard library implementation includes this
 implementation of std::unique:</p>
 <blockquote>
 <pre>namespace std {
     template &lt;class _ForwardIter&gt;
     _ForwardIter unique(_ForwardIter __first, _ForwardIter __last) {
       __first = adjacent_find(__first, __last);
       return unique_copy(__first, __last, __first);
     }
     }</pre>
 </blockquote>
 <p>Imagine two users on opposite sides of town, each using unique on his own
 sequences bounded by my_iterators . User1 looks at his standard library
 implementation and says, "I know how to implement a more efficient
 unique_copy for my_iterators", and writes:</p>
 <blockquote>
 <pre>namespace user1 {
     class my_iterator;
     // faster version for my_iterator
     my_iterator unique_copy(my_iterator, my_iterator, my_iterator);
     }</pre>
 </blockquote>
 <p>user1::unique_copy() is selected by Koenig lookup, as he intended.</p>
 <p>User2 has other needs, and writes:</p>
 <blockquote>
 <pre>namespace user2 {
     class my_iterator;
     // Returns true iff *c is a unique copy of *a and *b.
     bool unique_copy(my_iterator a, my_iterator b, my_iterator c);
     }</pre>
 </blockquote>
 <p>User2 is shocked to find later that his fully-qualified use of
 std::unique(user2::my_iterator, user2::my_iterator, user2::my_iterator) fails to
 compile (if he's lucky). Looking in the standard, he sees the following Effects
 clause for unique():</p>
 <blockquote>
   <p>Effects: Eliminates all but the first element from every consecutive group
   of equal elements referred to by the iterator i in the range [first, last) for
   which the following corresponding conditions hold: *i == *(i - 1) or pred(*i,
   *(i - 1)) != false</p>
 </blockquote>
 <p>The standard gives user2 absolutely no reason to think he can interfere with
 std::unique by defining names in namespace user2. His standard library has been
 built with the template export feature, so he is unable to inspect the
 implementation. User1 eventually compiles his code with another compiler, and
 his version of unique_copy silently stops being called. Eventually, he realizes
 that he was depending on an implementation detail of his library and had no
 right to expect his unique_copy() to be called portably.</p>
 <p>On the face of it, and given above scenario, it may seem obvious that the
 implementation of unique() shown is non-conforming because it uses unique_copy()
 rather than ::std::unique_copy(). Most standard library implementations,
 however, seem to disagree with this notion.</p>
 <p> <i>[Tokyo:&nbsp; Steve Adamczyk from
 the core working group indicates that "std::" is sufficient;&nbsp;
 leading "::" qualification is not required because any namespace
 qualification is sufficient to suppress Koenig lookup.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Add a paragraph and a note at the end of
 17.4.4.3 [global.functions]:</p>
 <blockquote>

 <p>Unless otherwise specified, no global or non-member function in the
 standard library shall use a function from another namespace which is
 found through <i>argument-dependent name lookup</i> (3.4.2 [basic.lookup.argdep]).</p>

 <p>[Note: the phrase "unless otherwise specified" is intended to
 allow Koenig lookup in cases like that of ostream_iterators:<br>

 <br>
   Effects:</p>
   <blockquote>
 <p>*out_stream &lt;&lt; value;<br>
       if(delim != 0) *out_stream &lt;&lt; delim;<br>
       return (*this);</p>
     <p>--end note]</p>
   </blockquote>
 </blockquote>

 <p><i>[Tokyo: The LWG agrees that this is a defect in the standard, but
 is as yet unsure if the proposed resolution is the best
 solution. Furthermore, the LWG believes that the same problem of
 unqualified library names applies to wording in the standard itself,
 and has opened issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a> accordingly. Any resolution of
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a> should be coordinated with the resolution of
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a>.]</i></p>


 <p><i>[Toronto: The LWG is not sure if this is a defect in the
 standard.  Most LWG members believe that an implementation of
 <tt>std::unique</tt> like the one quoted in this issue is already
 illegal, since, under certain circumstances, its semantics are not
 those specified in the standard.  The standard's description of
 <tt>unique</tt> does not say that overloading <tt>adjacent_find</tt>
 should have any effect.]</i></p>


 <p><i>[Curaçao: An LWG-subgroup spent an afternoon working on issues
 225, 226, and 229.  Their conclusion was that the issues should be
 separated into an LWG portion (Howard's paper, N1387=02-0045), and a
 EWG portion (Dave will write a proposal). The LWG and EWG had
 (separate) discussions of this plan the next day.  The proposed
 resolution for this issue is in accordance with Howard's paper.]</i></p>


 <p><b>Rationale:</b></p>
 <p>It could be argued that this proposed isn't strictly necessary,
   that the Standard doesn't grant implementors license to write a
   standard function that behaves differently than specified in the
   Standard just because of an unrelated user-defined name in some
   other namespace.  However, this is at worst a clarification.  It is
   surely right that algorithsm shouldn't pick up random names, that
   user-defined names should have no effect unless otherwise specified.
   Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a> deals with the question of when it is
   appropriate for the standard to explicitly specify otherwise.</p>


 <hr>
 <h3><a name="226"></a>226. User supplied specializations or overloads of namespace std function templates</h3>
 <p><b>Section:</b> 17.4.3.2 [reserved.names] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2000-04-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#reserved.names">issues</a> in [reserved.names].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The issues are:&nbsp;</p>
 <p>1. How can a 3rd party library implementor (lib1) write a version of a standard
 algorithm which is specialized to work with his own class template?&nbsp;</p>
 <p>2. How can another library implementor (lib2) write a generic algorithm which
 will take advantage of the specialized algorithm in lib1?</p>
 <p>This appears to be the only viable answer under current language rules:</p>
 <blockquote>
   <pre>namespace lib1
 {
     // arbitrary-precision numbers using T as a basic unit
     template &lt;class T&gt;
     class big_num { //...
     };
     </pre>
   <pre>    // defining this in namespace std is illegal (it would be an
     // overload), so we hope users will rely on Koenig lookup
     template &lt;class T&gt;
     void swap(big_int&lt;T&gt;&amp;, big_int&lt;T&gt;&amp;);
 }</pre>
   <pre>#include &lt;algorithm&gt;
 namespace lib2
 {
     template &lt;class T&gt;
     void generic_sort(T* start, T* end)
     {
             ...
         // using-declaration required so we can work on built-in types
         using std::swap;
         // use Koenig lookup to find specialized algorithm if available
         swap(*x, *y);
     }
 }</pre>
 </blockquote>
 <p>This answer has some drawbacks. First of all, it makes writing lib2 difficult
 and somewhat slippery. The implementor needs to remember to write the
 using-declaration, or generic_sort will fail to compile when T is a built-in
 type. The second drawback is that the use of this style in lib2 effectively
 "reserves" names in any namespace which defines types which may
 eventually be used with lib2. This may seem innocuous at first when applied to
 names like swap, but consider more ambiguous names like unique_copy() instead.
 It is easy to imagine the user wanting to define these names differently in his
 own namespace. A definition with semantics incompatible with the standard
 library could cause serious problems (see issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a>).</p>
 <p>Why, you may ask, can't we just partially specialize std::swap()? It's
 because the language doesn't allow for partial specialization of function
 templates. If you write:</p>
 <blockquote>
   <pre>namespace std
 {
     template &lt;class T&gt;
     void swap(lib1::big_int&lt;T&gt;&amp;, lib1::big_int&lt;T&gt;&amp;);
 }</pre>
 </blockquote>
 <p>You have just overloaded std::swap, which is illegal under the current
 language rules. On the other hand, the following full specialization is legal:</p>
 <blockquote>
   <pre>namespace std
 {
     template &lt;&gt;
     void swap(lib1::other_type&amp;, lib1::other_type&amp;);
 }</pre>
 </blockquote>

 <p>This issue reflects concerns raised by the "Namespace issue
 with specialized swap" thread on comp.lang.c++.moderated. A
 similar set of concerns was earlier raised on the boost.org mailing
 list and the ACCU-general mailing list.  Also see library reflector
 message c++std-lib-7354.</p>

 <p>
 J. C. van Winkel points out (in c++std-lib-9565) another unexpected
 fact: it's impossible to output a container of std::pair's using copy
 and an ostream_iterator, as long as both pair-members are built-in or
 std:: types.  That's because a user-defined operator&lt;&lt; for (for
 example) std::pair&lt;const std::string, int&gt; will not be found:
 lookup for operator&lt;&lt; will be performed only in namespace std.
 Opinions differed on whether or not this was a defect, and, if so,
 whether the defect is that something is wrong with user-defined
 functionality and std, or whether it's that the standard library does
 not provide an operator&lt;&lt; for std::pair&lt;&gt;.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Adopt the wording proposed in Howard Hinnant's paper
   N1523=03-0106, "Proposed Resolution To LWG issues 225, 226, 229".</p>


 <p><i>[Tokyo: Summary, "There is no conforming way to extend
 std::swap for user defined templates."&nbsp; The LWG agrees that
 there is a problem.  Would like more information before
 proceeding. This may be a core issue.  Core issue 229 has been opened
 to discuss the core aspects of this problem. It was also noted that
 submissions regarding this issue have been received from several
 sources, but too late to be integrated into the issues list.
 ]</i></p>


 <p><i>[Post-Tokyo: A paper with several proposed resolutions,
 J16/00-0029==WG21/N1252, "Shades of namespace std functions
 " by Alan Griffiths, is in the Post-Tokyo mailing. It
 should be considered a part of this issue.]</i></p>


 <p><i>[Toronto: Dave Abrahams and Peter Dimov have proposed a
 resolution that involves core changes: it would add partial
 specialization of function template.  The Core Working Group is
 reluctant to add partial specialization of function templates.  It is
 viewed as a large change, CWG believes that proposal presented leaves
 some syntactic issues unanswered; if the CWG does add partial
 specialization of function templates, it wishes to develop its own
 proposal.  The LWG continues to believe that there is a serious
 problem: there is no good way for users to force the library to use
 user specializations of generic standard library functions, and in
 certain cases (e.g. transcendental functions called by
 <tt>valarray</tt> and <tt>complex</tt>) this is important.  Koenig
 lookup isn't adequate, since names within the library must be
 qualified with <tt>std</tt> (see issue 225), specialization doesn't
 work (we don't have partial specialization of function templates), and
 users aren't permitted to add overloads within namespace std.
 ]</i></p>


 <p><i>[Copenhagen: Discussed at length, with no consensus.  Relevant
 papers in the pre-Copenhagen mailing: N1289, N1295, N1296.  Discussion
 focused on four options. (1) Relax restrictions on overloads within
 namespace std. (2) Mandate that the standard library use unqualified
 calls for <tt>swap</tt> and possibly other functions.  (3) Introduce
 helper class templates for <tt>swap</tt> and possibly other functions.
 (4) Introduce partial specialization of function templates.  Every
 option had both support and opposition.  Straw poll (first number is
 support, second is strongly opposed): (1) 6, 4; (2) 6, 7; (3) 3, 8;
 (4) 4, 4.]</i></p>


 <p><i>[Redmond: Discussed, again no consensus.  Herb presented an
 argument that a user who is defining a type <tt>T</tt> with an
 associated <tt>swap</tt> should not be expected to put that
 <tt>swap</tt> in namespace std, either by overloading or by partial
 specialization.  The argument is that <tt>swap</tt> is part of
 <tt>T</tt>'s interface, and thus should to in the same namespace as
 <tt>T</tt> and only in that namespace.  If we accept this argument,
 the consequence is that standard library functions should use
 unqualified call of <tt>swap</tt>.  (And which other functions? Any?)
 A small group (Nathan, Howard, Jeremy, Dave, Matt, Walter, Marc) will
 try to put together a proposal before the next meeting.]</i></p>


 <p><i>[Curaçao: An LWG-subgroup spent an afternoon working on issues
 225, 226, and 229.  Their conclusion was that the issues should be
 separated into an LWG portion (Howard's paper, N1387=02-0045), and a
 EWG portion (Dave will write a proposal). The LWG and EWG had
 (separate) discussions of this plan the next day.  The proposed
 resolution is the one proposed by Howard.]</i></p>


 <p><i>[Santa Cruz: the LWG agreed with the general direction of
   Howard's paper, N1387.  (Roughly: Koenig lookup is disabled unless
   we say otherwise; this issue is about when we do say otherwise.)
   However, there were concerns about wording.  Howard will provide new
   wording.  Bill and Jeremy will review it.]</i></p>


 <p><i>[Kona: Howard proposed the new wording.  The LWG accepted his
   proposed resolution.]</i></p>


 <p><b>Rationale:</b></p>
 <p>Informally: introduce a Swappable concept, and specify that the
   value types of the iterators passed to certain standard algorithms
   (such as iter_swap, swap_ranges, reverse, rotate, and sort) conform
   to that concept.  The Swappable concept will make it clear that
   these algorithms use unqualified lookup for the calls
   to <tt>swap</tt>.  Also, in 26.5.3.3 [valarray.transcend] paragraph 1,
   state that the valarray transcendentals use unqualified lookup.</p>


 <hr>
 <h3><a name="227"></a>227. std::swap() should require CopyConstructible or DefaultConstructible arguments</h3>
 <p><b>Section:</b> 25.2.3 [alg.swap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2000-04-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.swap">issues</a> in [alg.swap].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TC">TC</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>25.2.2 reads:</p>
 <blockquote>
   <p><tt>  template&lt;class T&gt; void swap(T&amp; a, T&amp; b);</tt><br>
   <br>
   Requires:    Type T is Assignable (_lib.container.requirements_).<br>
   Effects:    Exchanges values stored in two locations.</p>
 </blockquote>
 <p>The only reasonable** generic implementation of swap requires construction of a
    new temporary copy of one of its arguments:</p>
 <blockquote>
 <pre>template&lt;class T&gt; void swap(T&amp; a, T&amp; b);
   {
       T tmp(a);
       a = b;
       b = tmp;
   }</pre>
 </blockquote>
 <p>But a type which is only Assignable cannot be swapped by this implementation.</p>
 <p>**Yes, there's also an unreasonable implementation which would require T to be
    DefaultConstructible instead of CopyConstructible. I don't think this is worthy
    of consideration:</p>
 <blockquote>
 <pre>template&lt;class T&gt; void swap(T&amp; a, T&amp; b);
 {
     T tmp;
     tmp = a;
     a = b;
     b = tmp;
 }</pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.2.2 paragraph 1 from:</p>
 <blockquote>
 <p>  Requires: Type T is Assignable (23.1).</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
 <p>  Requires: Type T is CopyConstructible (20.1.3) and Assignable (23.1)</p>
 </blockquote>


 <hr>
 <h3><a name="228"></a>228. Incorrect specification of "..._byname" facets</h3>
 <p><b>Section:</b> 22.2 [locale.categories] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 2000-04-20</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#locale.categories">active issues</a> in [locale.categories].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.categories">issues</a> in [locale.categories].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The sections 22.2.1.2 [locale.ctype.byname], 22.2.1.5
 [locale.codecvt.byname],
 sref ref="22.2.1.6", 22.2.3.2 [locale.numpunct.byname], 22.2.4.2
 [locale.collate.byname], 22.2.5.4 [locale.time.put.byname], 22.2.6.4
 [locale.moneypunct.byname], and 22.2.7.2 [locale.messages.byname]
 overspecify the
 definitions of the "..._byname" classes by listing a bunch
 of virtual functions. At the same time, no semantics of these
 functions are defined. Real implementations do not define these
 functions because the functional part of the facets is actually
 implemented in the corresponding base classes and the constructor of
 the "..._byname" version just provides suitable date used by
 these implementations. For example, the 'numpunct' methods just return
 values from a struct. The base class uses a statically initialized
 struct while the derived version reads the contents of this struct
 from a table. However, no virtual function is defined in
 'numpunct_byname'.</p>

 <p>For most classes this does not impose a problem but specifically
 for 'ctype' it does: The specialization for 'ctype_byname&lt;char&gt;'
 is required because otherwise the semantics would change due to the
 virtual functions defined in the general version for 'ctype_byname':
 In 'ctype&lt;char&gt;' the method 'do_is()' is not virtual but it is
 made virtual in both 'ctype&lt;cT&gt;' and 'ctype_byname&lt;cT&gt;'.
 Thus, a class derived from 'ctype_byname&lt;char&gt;' can tell whether
 this class is specialized or not under the current specification:
 Without the specialization, 'do_is()' is virtual while with
 specialization it is not virtual.</p>


 <p><b>Proposed resolution:</b></p>
 <p>&nbsp; Change section 22.2.1.2 (lib.locale.ctype.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT&gt;
        class ctype_byname : public ctype&lt;charT&gt; {
        public:
          typedef ctype&lt;charT&gt;::mask mask;
          explicit ctype_byname(const char*, size_t refs = 0);
        protected:
         ~ctype_byname();             //  virtual
        };
      }</pre>
 <p>&nbsp; Change section 22.2.1.6 (lib.locale.codecvt.byname) to become:</p>
 <pre>    namespace std {
       template &lt;class internT, class externT, class stateT&gt;
       class codecvt_byname : public codecvt&lt;internT, externT, stateT&gt; {
       public:
        explicit codecvt_byname(const char*, size_t refs = 0);
       protected:
       ~codecvt_byname();             //  virtual
        };
      }
 </pre>
 <p>&nbsp; Change section 22.2.3.2 (lib.locale.numpunct.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT&gt;
        class numpunct_byname : public numpunct&lt;charT&gt; {
      //  this class is specialized for  char  and  wchar_t.
        public:
          typedef charT                char_type;
          typedef basic_string&lt;charT&gt;  string_type;
          explicit numpunct_byname(const char*, size_t refs = 0);
        protected:
         ~numpunct_byname();          //  virtual
        };
      }</pre>
 <p>&nbsp; Change section 22.2.4.2 (lib.locale.collate.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT&gt;
        class collate_byname : public collate&lt;charT&gt; {
        public:
          typedef basic_string&lt;charT&gt; string_type;
          explicit collate_byname(const char*, size_t refs = 0);
        protected:
         ~collate_byname();           //  virtual
        };
      }</pre>
 <p>&nbsp; Change section 22.2.5.2 (lib.locale.time.get.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT, class InputIterator = istreambuf_iterator&lt;charT&gt; &gt;
        class time_get_byname : public time_get&lt;charT, InputIterator&gt; {
        public:
          typedef time_base::dateorder dateorder;
          typedef InputIterator        iter_type</pre>
 <pre>         explicit time_get_byname(const char*, size_t refs = 0);
        protected:
         ~time_get_byname();          //  virtual
        };
      }</pre>
 <p>&nbsp; Change section 22.2.5.4 (lib.locale.time.put.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT, class OutputIterator = ostreambuf_iterator&lt;charT&gt; &gt;
        class time_put_byname : public time_put&lt;charT, OutputIterator&gt;
        {
        public:
          typedef charT          char_type;
          typedef OutputIterator iter_type;</pre>
 <pre>         explicit time_put_byname(const char*, size_t refs = 0);
        protected:
         ~time_put_byname();          //  virtual
        };
      }"</pre>
 <p>&nbsp; Change section 22.2.6.4 (lib.locale.moneypunct.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT, bool Intl = false&gt;
        class moneypunct_byname : public moneypunct&lt;charT, Intl&gt; {
        public:
          typedef money_base::pattern pattern;
          typedef basic_string&lt;charT&gt; string_type;</pre>
 <pre>         explicit moneypunct_byname(const char*, size_t refs = 0);
        protected:
         ~moneypunct_byname();        //  virtual
        };
      }</pre>
 <p>&nbsp; Change section 22.2.7.2 (lib.locale.messages.byname) to become:</p>
 <pre>     namespace std {
        template &lt;class charT&gt;
        class messages_byname : public messages&lt;charT&gt; {
        public:
          typedef messages_base::catalog catalog;
          typedef basic_string&lt;charT&gt;    string_type;</pre>
 <pre>         explicit messages_byname(const char*, size_t refs = 0);
        protected:
         ~messages_byname();          //  virtual
        };
      }</pre>
 <p>Remove section 22.2.1.4 [locale.codecvt] completely (because in
 this case only those members are defined to be virtual which are
 defined to be virtual in 'ctype&lt;cT&gt;'.)</p>

 <p><i>[Post-Tokyo: Dietmar Kühl submitted this issue at the request of
 the LWG to solve the underlying problems raised by issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>.]</i></p>


 <p><i>[Copenhagen: proposed resolution was revised slightly, to remove
 three last virtual functions from <tt>messages_byname</tt>.]</i></p>


 <hr>
 <h3><a name="229"></a>229. Unqualified references of other library entities</h3>
 <p><b>Section:</b> 17.4.1.1 [contents] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 2000-04-19</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Throughout the library chapters, the descriptions of library entities refer
 to other library entities without necessarily qualifying the names.</p>

 <p>For example, section 25.2.2 "Swap" describes the effect of
 swap_ranges in terms of the unqualified name "swap". This section
 could reasonably be interpreted to mean that the library must be implemented so
 as to do a lookup of the unqualified name "swap", allowing users to
 override any ::std::swap function when Koenig lookup applies.</p>

 <p>Although it would have been best to use explicit qualification with
 "::std::" throughout, too many lines in the standard would have to be
 adjusted to make that change in a Technical Corrigendum.</p>

 <p>Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#182">182</a>, which addresses qualification of
 <tt>size_t</tt>, is a special case of this.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>To section 17.4.1.1 "Library contents" Add the following paragraph:</p>
 <blockquote>
   <p>Whenever a name x defined in the standard library is mentioned, the name x
   is assumed to be fully qualified as ::std::x, unless explicitly described
   otherwise. For example, if the Effects section for library function F is
   described as calling library function G, the function ::std::G is meant.</p>
 </blockquote>

 <p><i>[Post-Tokyo: Steve Clamage submitted this issue at the request of
 the LWG to solve a problem in the standard itself similar to the
 problem within implementations of library identified by issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a>.  Any resolution of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a> should be
 coordinated with the resolution of this issue.]</i></p>


 <p><i>[post-Toronto: Howard is undecided about whether it is
 appropriate for all standard library function names referred to in
 other standard library functions to be explicitly qualified by
 <tt>std</tt>: it is common advice that users should define global
 functions that operate on their class in the same namespace as the
 class, and this requires argument-dependent lookup if those functions
 are intended to be called by library code.  Several LWG members are
 concerned that valarray appears to require argument-dependent lookup,
 but that the wording may not be clear enough to fall under
 "unless explicitly described otherwise".]</i></p>


 <p><i>[Curaçao: An LWG-subgroup spent an afternoon working on issues
 225, 226, and 229.  Their conclusion was that the issues should be
 separated into an LWG portion (Howard's paper, N1387=02-0045), and a
 EWG portion (Dave will write a proposal). The LWG and EWG had
 (separate) discussions of this plan the next day.  This paper resolves
 issues 225 and 226.  In light of that resolution, the proposed
 resolution for the current issue makes sense.]</i></p>


 <hr>
 <h3><a name="230"></a>230. Assignable specified without also specifying CopyConstructible</h3>
 <p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2000-04-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a> identified an instance (std::swap) where
 Assignable was specified without also specifying
 CopyConstructible. The LWG asked that the standard be searched to
 determine if the same defect existed elsewhere.</p>

 <p>There are a number of places (see proposed resolution below) where
 Assignable is specified without also specifying
 CopyConstructible. There are also several cases where both are
 specified. For example, 26.4.1 [rand.req].</p>


 <p><b>Proposed resolution:</b></p>
 <p>In  23.1 [container.requirements] table 65 for value_type:
 change "T is Assignable" to "T is CopyConstructible and
 Assignable"
 </p>

 <p>In 23.1.4 [associative.reqmts] table 69 X::key_type; change
 "Key is Assignable" to "Key is
 CopyConstructible and Assignable"<br>
 </p>

 <p>In 24.1.2 [output.iterators] paragraph 1, change:
 </p>
 <blockquote>
 <p> A class or a built-in type X satisfies the requirements of an
 output iterator if X is an Assignable type (23.1) and also the
 following expressions are valid, as shown in Table 73:
 </p>
 </blockquote>
 <p>to:
 </p>
 <blockquote>
 <p> A class or a built-in type X satisfies the requirements of an
 output iterator if X is a CopyConstructible (20.1.3) and Assignable
 type (23.1) and also the following expressions are valid, as shown in
 Table 73:
 </p>
 </blockquote>

 <p><i>[Post-Tokyo: Beman Dawes submitted this issue at the request of
 the LWG.  He asks that the 25.2.5 [alg.replace] and 25.2.6 [alg.fill] changes be studied carefully, as it is not clear that
 CopyConstructible is really a requirement and may be
 overspecification.]</i></p>


 <p><i>[Portions of the resolution for issue 230 have been superceded by
 the resolution of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#276">276</a>.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The original proposed resolution also included changes to input
 iterator, fill, and replace.  The LWG believes that those changes are
 not necessary.  The LWG considered some blanket statement, where an
 Assignable type was also required to be Copy Constructible, but
 decided against this because fill and replace really don't require the
 Copy Constructible property.</p>


 <hr>
 <h3><a name="231"></a>231. Precision in iostream?</h3>
 <p><b>Section:</b> 22.2.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> James Kanze, Stephen Clamage <b>Date:</b> 2000-04-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.put.virtuals">issues</a> in [facet.num.put.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>What is the following program supposed to output?</p>
 <pre>#include &lt;iostream&gt;

     int
     main()
     {
         std::cout.setf( std::ios::scientific , std::ios::floatfield ) ;
         std::cout.precision( 0 ) ;
         std::cout &lt;&lt; 1.00 &lt;&lt; '\n' ;
         return 0 ;
     }</pre>
 <p>From my C experience, I would expect "1e+00"; this is what
 <tt>printf("%.0e" , 1.00 );</tt> does. G++ outputs
 "1.000000e+00".</p>

 <p>The only indication I can find in the standard is 22.2.2.2.2/11,
 where it says "For conversion from a floating-point type, if
 (flags &amp; fixed) != 0 or if str.precision() &gt; 0, then
 str.precision() is specified in the conversion specification."
 This is an obvious error, however, fixed is not a mask for a field,
 but a value that a multi-bit field may take -- the results of and'ing
 fmtflags with ios::fixed are not defined, at least not if
 ios::scientific has been set. G++'s behavior corresponds to what might
 happen if you do use (flags &amp; fixed) != 0 with a typical
 implementation (floatfield == 3 &lt;&lt; something, fixed == 1
 &lt;&lt; something, and scientific == 2 &lt;&lt; something).</p>

 <p>Presumably, the intent is either (flags &amp; floatfield) != 0, or
 (flags &amp; floatfield) == fixed; the first gives something more or
 less like the effect of precision in a printf floating point
 conversion. Only more or less, of course. In order to implement printf
 formatting correctly, you must know whether the precision was
 explicitly set or not. Say by initializing it to -1, instead of 6, and
 stating that for floating point conversions, if precision &lt; -1, 6
 will be used, for fixed point, if precision &lt; -1, 1 will be used,
 etc. Plus, of course, if precision == 0 and flags &amp; floatfield ==
 0, 1 should be = used. But it probably isn't necessary to emulate all
 of the anomalies of printf:-).</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Replace 22.2.2.2.2 [facet.num.put.virtuals], paragraph 11, with the following
 sentence:
 </p>
 <blockquote><p>
 For conversion from a floating-point type,
 <tt><i>str</i>.precision()</tt> is specified in the conversion
 specification.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>The floatfield determines whether numbers are formatted as if
 with %f, %e, or %g.  If the <tt>fixed</tt> bit is set, it's %f,
 if <tt>scientific</tt> it's %e, and if both bits are set, or
 neither, it's %g.</p>
 <p>Turning to the C standard, a precision of 0 is meaningful
 for %f and %e.  For %g, precision 0 is taken to be the same as
 precision 1.</p>
 <p>The proposed resolution has the effect that if neither
 <tt>fixed</tt> nor <tt>scientific</tt> is set we'll be
 specifying a precision of 0, which will be internally
 turned into 1.  There's no need to call it out as a special
 case.</p>
 <p>The output of the above program will be "1e+00".</p>

 <p><i>[Post-Curaçao: Howard provided improved wording covering the case
 where precision is 0 and mode is %g.]</i></p>


 <hr>
 <h3><a name="232"></a>232. "depends" poorly defined in 17.4.3.1</h3>
 <p><b>Section:</b> 17.4.3.2 [reserved.names] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2000-04-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#reserved.names">issues</a> in [reserved.names].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>17.4.3.1/1 uses the term "depends" to limit the set of allowed
 specializations of standard templates to those that "depend on a
 user-defined name of external linkage."</p>
 <p>This term, however, is not adequately defined, making it possible to
 construct a specialization that is, I believe, technically legal according to
 17.4.3.1/1, but that specializes a standard template for a built-in type such as
 'int'.</p>
 <p>The following code demonstrates the problem:</p>
 <blockquote>
   <pre>#include &lt;algorithm&gt;</pre>
   <pre>template&lt;class T&gt; struct X
 {
  typedef T type;
 };</pre>
   <pre>namespace std
 {
  template&lt;&gt; void swap(::X&lt;int&gt;::type&amp; i, ::X&lt;int&gt;::type&amp; j);
 }</pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Change "user-defined name" to "user-defined
 type".</p>


 <p><b>Rationale:</b></p>
 <p>This terminology is used in section 2.5.2 and 4.1.1 of <i>The C++
 Programming Language</i>.  It disallows the example in the issue,
 since the underlying type itself is not user-defined.  The only
 possible problem I can see is for non-type templates, but there's no
 possible way for a user to come up with a specialization for bitset,
 for example, that might not have already been specialized by the
 implementor?</p>

 <p><i>[Toronto: this may be related to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#120">120</a>.]</i></p>


 <p><i>[post-Toronto: Judy provided the above proposed resolution and
 rationale.]</i></p>


 <hr>
 <h3><a name="233"></a>233. Insertion hints in associative containers</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andrew Koenig <b>Date:</b> 2000-04-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#192">192</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#246">246</a></p>
 <p><b>Discussion:</b></p>
 <p>
 If <tt>mm</tt> is a multimap and <tt>p</tt> is an iterator
 into the multimap, then <tt>mm.insert(p, x)</tt> inserts
 <tt>x</tt> into <tt>mm</tt> with <tt>p</tt> as a hint as
 to where it should go.  Table 69 claims that the execution time is
 amortized constant if the insert winds up taking place adjacent to
 <tt>p</tt>, but does not say when, if ever, this is guaranteed to
 happen.  All it says it that <tt>p</tt> is a hint as to where to
 insert.
 </p>
 <p>
 The question is whether there is any guarantee about the relationship
 between <tt>p</tt> and the insertion point, and, if so, what it
 is.
 </p>
 <p>
 I believe the present state is that there is no guarantee: The user
 can supply <tt>p</tt>, and the implementation is allowed to
 disregard it entirely.
 </p>

 <p><b>Additional comments from Nathan:</b><br>

 The vote [in Redmond] was on whether to elaborately specify the use of
 the hint, or to require behavior only if the value could be inserted
 adjacent to the hint.  I would like to ensure that we have a chance to
 vote for a deterministic treatment: "before, if possible, otherwise
 after, otherwise anywhere appropriate", as an alternative to the
 proposed "before or after, if possible, otherwise [...]".
 </p>

 <p><i>[Toronto: there was general agreement that this is a real defect:
 when inserting an element x into a multiset that already contains
 several copies of x, there is no way to know whether the hint will be
 used.  The proposed resolution was that the new element should always
 be inserted as close to the hint as possible.  So, for example, if
 there is a subsequence of equivalent values, then providing a.begin()
 as the hint means that the new element should be inserted before the
 subsequence even if a.begin() is far away.  JC van Winkel supplied
 precise wording for this proposed resolution, and also for an
 alternative resolution in which hints are only used when they are
 adjacent to the insertion point.]</i></p>


 <p><i>[Copenhagen: the LWG agreed to the original proposed resolution,
 in which an insertion hint would be used even when it is far from the
 insertion point.  This was contingent on seeing a example
 implementation showing that it is possible to implement this
 requirement without loss of efficiency.  John Potter provided such a
 example implementation.]</i></p>


 <p><i>[Redmond: The LWG was reluctant to adopt the proposal that
 emerged from Copenhagen: it seemed excessively complicated, and went
 beyond fixing the defect that we identified in Toronto.  PJP provided
 the new wording described in this issue.  Nathan agrees that we
 shouldn't adopt the more detailed semantics, and notes: "we know that
 you can do it efficiently enough with a red-black tree, but there are
 other (perhaps better) balanced tree techniques that might differ
 enough to make the detailed semantics hard to satisfy."]</i></p>


 <p><i>[Curaçao: Nathan should give us the alternative wording he
 suggests so the LWG can decide between the two options.]</i></p>


 <p><i>[Lillehammer: The LWG previously rejected the more detailed
   semantics, because it seemed more loike a new feature than like
   defect fixing.  We're now more sympathetic to it, but we (especially
   Bill) are still worried about performance.  N1780 describes a naive
   algorithm, but it's not clear whether there is a non-naive
   implementation. Is it possible to implement this as efficently as
   the current version of insert?]</i></p>


 <p><i>[Post Lillehammer:
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html">N1780</a>
 updated in post meeting mailing with
 feedback from Lillehammer with more information regarding performance.
 ]</i></p>


 <p><i>[
 Batavia:
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html">1780</a>
 accepted with minor wording changes in the proposed wording (reflected in the
 proposed resolution below).  Concerns about the performance of the algorithm
 were satisfactorily met by
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html">1780</a>.
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a> already handles the stability of equal ranges
 and so that part of the resolution from
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html">1780</a>
 is no longer needed (or reflected in the proposed wording below).
 ]</i></p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change the indicated rows of the "Associative container requirements" Table in
 23.1.4 [associative.reqmts] to:
 </p>

 <p></p><center>
 <table border="1">
 <caption>Associative container requirements</caption>
 <tbody><tr><th>expression</th> <th>return type</th>
 <th>assertion/note<br>pre/post-condition</th>
 <th>complexity</th></tr>
 <tr><td><tt>a_eq.insert(t)</tt></td>
 <td><tt>iterator</tt></td>
 <td>
 inserts <tt>t</tt> and returns the iterator pointing to the newly inserted
 element. <ins>If a range containing elements equivalent to <tt>t</tt> exists in
 <tt>a_eq</tt>, <tt>t</tt> is inserted at the end of that range.</ins>
 </td>
 <td>
 logarithmic
 </td></tr>
 <tr><td><tt>a.insert(p,t)</tt></td>
 <td><tt>iterator</tt></td>
 <td>
 inserts <tt>t</tt> if and only if there is no element with key equivalent to the
 key of <tt>t</tt> in containers with unique keys; always inserts <tt>t</tt> in containers
 with equivalent keys. always returns the iterator pointing to the element with key
 equivalent to the key of <tt>t</tt>. <del>iterator <tt>p</tt> is a hint pointing to where
 the insert should start to search.</del> <ins><tt>t</tt> is inserted as close as possible
 to the position just prior to <tt>p</tt>.</ins>
 </td>
 <td>
 logarithmic in general, but amortized constant if <tt>t</tt> is inserted right <del>after</del>
  <ins>before</ins> <tt>p</tt>.
 </td></tr>
 </tbody></table>
 </center>


 <hr>
 <h3><a name="234"></a>234. Typos in allocator definition</h3>
 <p><b>Section:</b> 20.7.5.1 [allocator.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 2000-04-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.members">issues</a> in [allocator.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In paragraphs 12 and 13 the effects of <tt>construct()</tt> and
 <tt>destruct()</tt> are described as returns but the functions actually
 return <tt>void</tt>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Substitute "Returns" by "Effect".</p>


 <hr>
 <h3><a name="235"></a>235. No specification of default ctor for reverse_iterator</h3>
 <p><b>Section:</b> 24.4.1.1 [reverse.iterator] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 2000-04-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The declaration of <tt>reverse_iterator</tt> lists a default
 constructor.  However, no specification is given what this constructor
 should do.</p>


 <p><b>Proposed resolution:</b></p>
   <p>In section 24.4.1.3.1 [reverse.iter.cons] add the following
   paragraph:</p>
       <blockquote>
       <p><tt>reverse_iterator()</tt></p>

       <p>Default initializes <tt>current</tt>. Iterator operations
       applied to the resulting iterator have defined behavior if and
       only if the corresponding operations are defined on a default
       constructed iterator of type <tt>Iterator</tt>.</p>
       </blockquote>
   <p><i>[pre-Copenhagen: Dietmar provide wording for proposed
   resolution.]</i></p>


 <hr>
 <h3><a name="237"></a>237. Undefined expression in complexity specification</h3>
 <p><b>Section:</b> 23.2.2.1 [deque.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 2000-04-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#deque.cons">issues</a> in [deque.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The complexity specification in paragraph 6 says that the complexity
 is linear in <tt>first - last</tt>. Even if <tt>operator-()</tt> is
 defined on iterators this term is in general undefined because it
 would have to be <tt>last - first</tt>.</p>


 <p><b>Proposed resolution:</b></p>
   <p>Change paragraph 6 from</p>
      <blockquote><p>Linear in <i>first - last</i>.</p></blockquote>
   <p>to become</p>
      <blockquote><p>Linear in <i>distance(first, last)</i>.</p></blockquote>


 <hr>
 <h3><a name="238"></a>238. Contradictory results of stringbuf initialization.</h3>
 <p><b>Section:</b> 27.7.1.1 [stringbuf.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dietmar Kühl <b>Date:</b> 2000-05-11</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 27.7.1.1 paragraph 4 the results of calling the constructor of
 'basic_stringbuf' are said to be <tt>str() == str</tt>. This is fine
 that far but consider this code:</p>

 <pre>  std::basic_stringbuf&lt;char&gt; sbuf("hello, world", std::ios_base::openmode(0));
   std::cout &lt;&lt; "'" &lt;&lt; sbuf.str() &lt;&lt; "'\n";
 </pre>

 <p>Paragraph 3 of 27.7.1.1 basically says that in this case neither
 the output sequence nor the input sequence is initialized and
 paragraph 2 of 27.7.1.2 basically says that <tt>str()</tt> either
 returns the input or the output sequence. None of them is initialized,
 ie. both are empty, in which case the return from <tt>str()</tt> is
 defined to be <tt>basic_string&lt;cT&gt;()</tt>.</p>

 <p>However, probably only test cases in some testsuites will detect this
 "problem"...</p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove 27.7.1.1 paragraph 4.</p>


 <p><b>Rationale:</b></p>
 <p>We could fix 27.7.1.1 paragraph 4, but there would be no point.  If
 we fixed it, it would say just the same thing as text that's already
 in the standard.</p>


 <hr>
 <h3><a name="239"></a>239. Complexity of unique() and/or unique_copy incorrect</h3>
 <p><b>Section:</b> 25.2.9 [alg.unique] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 2000-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.unique">issues</a> in [alg.unique].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The complexity of unique and unique_copy are inconsistent with each
 other and inconsistent with the implementations.&nbsp; The standard
 specifies:</p>

 <p>for unique():</p>

 <blockquote><p>-3- Complexity: If the range (last - first) is not empty, exactly
 (last - first) - 1 applications of the corresponding predicate, otherwise
 no applications of the predicate.</p></blockquote>

 <p>for unique_copy():</p>

 <blockquote><p>-7- Complexity: Exactly last - first applications of the corresponding
 predicate.</p></blockquote>

 <p>
 The implementations do it the other way round: unique() applies the
 predicate last-first times and unique_copy() applies it last-first-1
 times.</p>

 <p>As both algorithms use the predicate for pair-wise comparison of
 sequence elements I don't see a justification for unique_copy()
 applying the predicate last-first times, especially since it is not
 specified to which pair in the sequence the predicate is applied
 twice.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change both complexity sections in 25.2.9 [alg.unique] to:</p>

 <blockquote><p>Complexity: For nonempty ranges, exactly last - first - 1
 applications of the corresponding predicate.</p></blockquote>


 <hr>
 <h3><a name="240"></a>240. Complexity of adjacent_find() is meaningless</h3>
 <p><b>Section:</b> 25.1.8 [alg.adjacent.find] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 2000-05-15</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The complexity section of adjacent_find is defective:</p>

 <blockquote>
 <pre>template &lt;class ForwardIterator&gt;
 ForwardIterator adjacent_find(ForwardIterator first, ForwardIterator last
                               BinaryPredicate pred);
 </pre>

 <p>-1- Returns: The first iterator i such that both i and i + 1 are in
 the range [first, last) for which the following corresponding
 conditions hold: *i == *(i + 1), pred(*i, *(i + 1)) != false. Returns
 last if no such iterator is found.</p>

 <p>-2- Complexity: Exactly find(first, last, value) - first applications
 of the corresponding predicate.
 </p>
 </blockquote>

 <p>In the Complexity section, it is not defined what "value"
 is supposed to mean. My best guess is that "value" means an
 object for which one of the conditions pred(*i,value) or
 pred(value,*i) is true, where i is the iterator defined in the Returns
 section. However, the value type of the input sequence need not be
 equality-comparable and for this reason the term find(first, last,
 value) - first is meaningless.</p>

 <p>A term such as find_if(first, last, bind2nd(pred,*i)) - first or
 find_if(first, last, bind1st(pred,*i)) - first might come closer to
 the intended specification.  Binders can only be applied to function
 objects that have the function call operator declared const, which is
 not required of predicates because they can have non-const data
 members. For this reason, a specification using a binder could only be
 an "as-if" specification.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the complexity section in 25.1.8 [alg.adjacent.find] to:</p>
 <blockquote><p>
 For a nonempty range, exactly <tt>min((<i>i</i> - <i>first</i>) + 1,
 (<i>last</i> - <i>first</i>) - 1)</tt> applications of the
 corresponding predicate, where <i>i</i> is <tt>adjacent_find</tt>'s
 return value.
 </p></blockquote>

 <p><i>[Copenhagen: the original resolution specified an upper
 bound.  The LWG preferred an exact count.]</i></p>


 <hr>
 <h3><a name="241"></a>241. Does unique_copy() require CopyConstructible and Assignable?</h3>
 <p><b>Section:</b> 25.2.9 [alg.unique] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 2000-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.unique">issues</a> in [alg.unique].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>Some popular implementations of unique_copy() create temporary
 copies of values in the input sequence, at least if the input iterator
 is a pointer.  Such an implementation is built on the assumption that
 the value type is CopyConstructible and Assignable.</p>

 <p>It is common practice in the standard that algorithms explicitly
 specify any additional requirements that they impose on any of the
 types used by the algorithm. An example of an algorithm that creates
 temporary copies and correctly specifies the additional requirements
 is accumulate(), 26.4.1 [rand.req].</p>

 <p>Since the specifications of unique() and unique_copy() do not
 require CopyConstructible and Assignable of the InputIterator's value
 type the above mentioned implementations are not standard-compliant. I
 cannot judge whether this is a defect in the standard or a defect in
 the implementations.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 25.2.8 change:</p>

 <blockquote><p>
 -4- Requires: The ranges [first, last) and [result, result+(last-first))
 shall not overlap.
 </p></blockquote>

 <p>to:</p>

 <blockquote>
   <p>-4- Requires: The ranges [first, last) and [result,
   result+(last-first)) shall not overlap. The expression *result =
   *first must be valid. If neither InputIterator nor OutputIterator
   meets the requirements of forward iterator then the value type of
   InputIterator must be copy constructible. Otherwise copy
   constructible is not required. </p>
 </blockquote>

 <p><i>[Redmond: the original proposed resolution didn't impose an
 explicit requirement that the iterator's value type must be copy
 constructible, on the grounds that an input iterator's value type must
 always be copy constructible.  Not everyone in the LWG thought that
 this requirement was clear from table 72.  It has been suggested that
 it might be possible to implement <tt>unique_copy</tt> without
 requiring assignability, although current implementations do impose
 that requirement.  Howard provided new wording.]</i></p>


 <p><i>[
 Curaçao: The LWG changed the PR editorially to specify
 "neither...nor...meet..." as clearer than
 "both...and...do not meet...". Change believed to be so
 minor as not to require re-review.
 ]</i></p>


 <hr>
 <h3><a name="242"></a>242. Side effects of function objects</h3>
 <p><b>Section:</b> 25.2.4 [alg.transform], 26.4 [rand] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Angelika Langer <b>Date:</b> 2000-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.transform">issues</a> in [alg.transform].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The algorithms transform(), accumulate(), inner_product(),
 partial_sum(), and adjacent_difference() require that the function
 object supplied to them shall not have any side effects.</p>

 <p>The standard defines a side effect in 1.9 [intro.execution] as:</p>
 <blockquote><p>-7- Accessing an object designated by a volatile lvalue (basic.lval),
 modifying an object, calling a library I/O function, or calling a function
 that does any of those operations are all side effects, which are changes
 in the state of the execution environment.</p></blockquote>

 <p>As a consequence, the function call operator of a function object supplied
 to any of the algorithms listed above cannot modify data members, cannot
 invoke any function that has a side effect, and cannot even create and
 modify temporary objects.&nbsp; It is difficult to imagine a function object
 that is still useful under these severe limitations. For instance, any
 non-trivial transformator supplied to transform() might involve creation
 and modification of temporaries, which is prohibited according to the current
 wording of the standard.</p>

 <p>On the other hand, popular implementations of these algorithms exhibit
 uniform and predictable behavior when invoked with a side-effect-producing
 function objects. It looks like the strong requirement is not needed for
 efficient implementation of these algorithms.</p>

 <p>The requirement of&nbsp; side-effect-free function objects could be
 replaced by a more relaxed basic requirement (which would hold for all
 function objects supplied to any algorithm in the standard library):</p>
 <blockquote><p>A function objects supplied to an algorithm shall not invalidate
 any iterator or sequence that is used by the algorithm. Invalidation of
 the sequence includes destruction of the sorting order if the algorithm
 relies on the sorting order (see section 25.3 - Sorting and related operations
 [lib.alg.sorting]).</p></blockquote>

 <p>I can't judge whether it is intended that the function objects supplied
 to transform(), accumulate(), inner_product(), partial_sum(), or adjacent_difference()
 shall not modify sequence elements through dereferenced iterators.</p>

 <p>It is debatable whether this issue is a defect or a change request.
 Since the consequences for user-supplied function objects are drastic and
 limit the usefulness of the algorithms significantly I would consider it
 a defect.</p>


 <p><b>Proposed resolution:</b></p>

 <p><i>Things to notice about these changes:</i></p>

 <ol>
 <li> <i>The fully-closed ("[]" as opposed to half-closed "[)" ranges
      are intentional. we want to prevent side-effects from
      invalidating the end iterators.</i></li>

 <li> <i>That has the unintentional side-effect of prohibiting
      modification of the end element as a side-effect. This could
      conceivably be significant in some cases.</i></li>

 <li> <i>The wording also prevents side-effects from modifying elements
      of the output sequence. I can't imagine why anyone would want
      to do this, but it is arguably a restriction that implementors
      don't need to place on users.</i></li>

 <li> <i>Lifting the restrictions imposed in #2 and #3 above is possible
      and simple, but would require more verbiage.</i></li>
 </ol>

 <p>Change 25.2.3/2 from:</p>

 <blockquote><p>
    -2- Requires: op and binary_op shall not have any side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -2- Requires: in the ranges [first1, last1], [first2, first2 +
   (last1 - first1)] and [result, result + (last1- first1)], op and
   binary_op shall neither modify elements nor invalidate iterators or
   subranges.
   [Footnote: The use of fully closed ranges is intentional --end footnote]
 </p></blockquote>


 <p>Change 25.2.3/2 from:</p>

 <blockquote><p>
    -2- Requires: op and binary_op shall not have any side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -2- Requires: op and binary_op shall not invalidate iterators or
    subranges, or modify elements in the ranges [first1, last1],
    [first2, first2 + (last1 - first1)], and [result, result + (last1
    - first1)].
   [Footnote: The use of fully closed ranges is intentional --end footnote]
 </p></blockquote>


 <p>Change 26.4.1/2 from:</p>

 <blockquote><p>
   -2- Requires: T must meet the requirements of CopyConstructible
    (lib.copyconstructible) and Assignable (lib.container.requirements)
    types. binary_op shall not cause side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -2- Requires: T must meet the requirements of CopyConstructible
    (lib.copyconstructible) and Assignable
    (lib.container.requirements) types. In the range [first, last],
    binary_op shall neither modify elements nor invalidate iterators
    or subranges.
   [Footnote: The use of a fully closed range is intentional --end footnote]
 </p></blockquote>

 <p>Change 26.4.2/2 from:</p>

 <blockquote><p>
   -2- Requires: T must meet the requirements of CopyConstructible
    (lib.copyconstructible) and Assignable (lib.container.requirements)
    types. binary_op1 and binary_op2 shall not cause side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -2- Requires: T must meet the requirements of CopyConstructible
    (lib.copyconstructible) and Assignable (lib.container.requirements)
    types. In the ranges [first, last] and [first2, first2 + (last -
    first)], binary_op1 and binary_op2 shall neither modify elements
    nor invalidate iterators or subranges.
   [Footnote: The use of fully closed ranges is intentional --end footnote]
 </p></blockquote>


 <p>Change 26.4.3/4 from:</p>

 <blockquote><p>
   -4- Requires: binary_op is expected not to have any side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -4- Requires: In the ranges [first, last] and [result, result +
    (last - first)], binary_op shall neither modify elements nor
    invalidate iterators or subranges.
   [Footnote: The use of fully closed ranges is intentional --end footnote]
 </p></blockquote>

 <p>Change 26.4.4/2 from:</p>

 <blockquote><p>
   -2- Requires: binary_op shall not have any side effects.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   -2- Requires: In the ranges [first, last] and [result, result +
    (last - first)], binary_op shall neither modify elements nor
    invalidate iterators or subranges.
   [Footnote: The use of fully closed ranges is intentional --end footnote]
 </p></blockquote>

 <p><i>[Toronto: Dave Abrahams supplied wording.]</i></p>


 <p><i>[Copenhagen: Proposed resolution was modified slightly. Matt
 added footnotes pointing out that the use of closed ranges was
 intentional.]</i></p>


 <hr>
 <h3><a name="243"></a>243. <tt>get</tt> and <tt>getline</tt> when sentry reports failure</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>basic_istream&lt;&gt;::get(), and basic_istream&lt;&gt;::getline(),
 are unclear with respect to the behavior and side-effects of the named
 functions in case of an error.</p>

 <p>27.6.1.3, p1 states that "... If the sentry object returns
 true, when converted to a value of type bool, the function endeavors
 to obtain the requested input..." It is not clear from this (or
 the rest of the paragraph) what precisely the behavior should be when
 the sentry ctor exits by throwing an exception or when the sentry
 object returns false.  In particular, what is the number of characters
 extracted that gcount() returns supposed to be?</p>

 <p>27.6.1.3 p8 and p19 say about the effects of get() and getline():
 "...  In any case, it then stores a null character (using
 charT()) into the next successive location of the array." Is not
 clear whether this sentence applies if either of the conditions above
 holds (i.e., when sentry fails).</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to 27.6.1.3, p1 after the sentence</p>

 <blockquote><p>
 "... If the sentry object returns true, when converted to a value of
 type bool, the function endeavors to obtain the requested input."
 </p></blockquote>

 <p>the following</p>


 <blockquote><p>
 "Otherwise, if the sentry constructor exits by throwing an exception or
 if the sentry object returns false, when converted to a value of type
 bool, the function returns without attempting to obtain any input. In
 either case the number of extracted characters is set to 0; unformatted
 input functions taking a character array of non-zero size as an argument
 shall also store a null character (using charT()) in the first location
 of the array."
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>Although the general philosophy of the input functions is that the
 argument should not be modified upon failure, <tt>getline</tt>
 historically added a terminating null unconditionally.  Most
 implementations still do that.  Earlier versions of the draft standard
 had language that made this an unambiguous requirement; those words
 were moved to a place where their context made them less clear.  See
 Jerry Schwarz's message c++std-lib-7618.</p>


 <hr>
 <h3><a name="247"></a>247. <tt>vector</tt>, <tt>deque::insert</tt> complexity</h3>
 <p><b>Section:</b> 23.2.6.4 [vector.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Lisa Lippincott <b>Date:</b> 2000-06-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.modifiers">issues</a> in [vector.modifiers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 2 of 23.2.6.4 [vector.modifiers] describes the complexity
 of <tt>vector::insert</tt>:</p>

    <blockquote><p>
    Complexity: If first and last are forward iterators, bidirectional
    iterators, or random access iterators, the complexity is linear in
    the number of elements in the range [first, last) plus the distance
    to the end of the vector. If they are input iterators, the complexity
    is proportional to the number of elements in the range [first, last)
    times the distance to the end of the vector.
    </p></blockquote>

 <p>First, this fails to address the non-iterator forms of
 <tt>insert</tt>.</p>

 <p>Second, the complexity for input iterators misses an edge case --
 it requires that an arbitrary number of elements can be added at
 the end of a <tt>vector</tt> in constant time.</p>

 <p>I looked to see if <tt>deque</tt> had a similar problem, and was
 surprised to find that <tt>deque</tt> places no requirement on the
 complexity of inserting multiple elements (23.2.2.3 [deque.modifiers],
 paragraph 3):</p>

    <blockquote><p>
    Complexity: In the worst case, inserting a single element into a
    deque takes time linear in the minimum of the distance from the
    insertion point to the beginning of the deque and the distance
    from the insertion point to the end of the deque. Inserting a
    single element either at the beginning or end of a deque always
    takes constant time and causes a single call to the copy constructor
    of T.
    </p></blockquote>


 <p><b>Proposed resolution:</b></p>

 <p>Change Paragraph 2 of 23.2.6.4 [vector.modifiers] to</p>
    <blockquote><p>
    Complexity: The complexity is linear in the number of elements
    inserted plus the distance to the end of the vector.
    </p></blockquote>

    <p><i>[For input iterators, one may achieve this complexity by first
    inserting at the end of the <tt>vector</tt>, and then using
    <tt>rotate</tt>.]</i></p>


 <p>Change 23.2.2.3 [deque.modifiers], paragraph 3, to:</p>

    <blockquote><p>
    Complexity: The complexity is linear in the number of elements
    inserted plus the shorter of the distances to the beginning and
    end of the deque.  Inserting a single element at either the
    beginning or the end of a deque causes a single call to the copy
    constructor of T.
    </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>This is a real defect, and proposed resolution fixes it: some
   complexities aren't specified that should be.  This proposed
   resolution does constrain deque implementations (it rules out the
   most naive possible implementations), but the LWG doesn't see a
   reason to permit that implementation.</p>


 <hr>
 <h3><a name="248"></a>248. time_get fails to set eofbit</h3>
 <p><b>Section:</b> 22.2.5 [category.time] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-06-22</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>There is no requirement that any of time_get member functions set
 ios::eofbit when they reach the end iterator while parsing their input.
 Since members of both the num_get and money_get facets are required to
 do so (22.2.2.1.2, and 22.2.6.1.2, respectively), time_get members
 should follow the same requirement for consistency.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add paragraph 2 to section 22.2.5.1 with the following text:</p>

 <blockquote><p>
 If the end iterator is reached during parsing by any of the get()
 member functions, the member sets ios_base::eofbit in err.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>Two alternative resolutions were proposed.  The LWG chose this one
 because it was more consistent with the way eof is described for other
 input facets.</p>


 <hr>
 <h3><a name="250"></a>250. splicing invalidates iterators</h3>
 <p><b>Section:</b> 23.2.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Brian Parker  <b>Date:</b> 2000-07-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 23.2.4.4 [list.ops] states that
 </p>
 <pre>  void splice(iterator position, list&lt;T, Allocator&gt;&amp; x);
 </pre>
 <p>
 <i>invalidates</i> all iterators and references to list <tt>x</tt>.
 </p>

 <p>
 This is unnecessary and defeats an important feature of splice. In
 fact, the SGI STL guarantees that iterators to <tt>x</tt> remain valid
 after <tt>splice</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add a footnote to 23.2.4.4 [list.ops], paragraph 1:</p>
 <blockquote><p>
 [<i>Footnote:</i> As specified in  [default.con.req], paragraphs
 4-5, the semantics described in this clause applies only to the case
 where allocators compare equal.  --end footnote]
 </p></blockquote>

 <p>In 23.2.4.4 [list.ops], replace paragraph 4 with:</p>
 <blockquote><p>
 Effects: Inserts the contents of x before position and x becomes
 empty.  Pointers and references to the moved elements of x now refer to
 those same elements but as members of *this.  Iterators referring to the
 moved elements will continue to refer to their elements, but they now
 behave as iterators into *this, not into x.
 </p></blockquote>

 <p>In 23.2.4.4 [list.ops], replace paragraph 7 with:</p>
 <blockquote><p>
 Effects: Inserts an element pointed to by i from list x before
 position and removes the element from x. The result is unchanged if
 position == i or position == ++i.  Pointers and references to *i continue
 to refer to this same element but as a member of *this.  Iterators to *i
 (including i itself) continue to refer to the same element, but now
 behave as iterators into *this, not into x.
 </p></blockquote>

 <p>In 23.2.4.4 [list.ops], replace paragraph 12 with:</p>
 <blockquote><p>
 Requires: [first, last) is a valid range in x. The result is
 undefined if position is an iterator in the range [first, last).
 Pointers and references to the moved elements of x now refer to those
 same elements but as members of *this.  Iterators referring to the moved
 elements will continue to refer to their elements, but they now behave as
 iterators into *this, not into x.
 </p></blockquote>

 <p><i>[pre-Copenhagen: Howard provided wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The original proposed resolution said that iterators and references
 would remain "valid".  The new proposed resolution clarifies what that
 means.  Note that this only applies to the case of equal allocators.
 From  [default.con.req] paragraph 4, the behavior of list when
 allocators compare nonequal is outside the scope of the standard.</p>


 <hr>
 <h3><a name="251"></a>251. basic_stringbuf missing allocator_type</h3>
 <p><b>Section:</b> 27.7.1 [stringbuf] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-07-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The synopsis for the template class <tt>basic_stringbuf</tt>
 doesn't list a typedef for the template parameter
 <tt>Allocator</tt>. This makes it impossible to determine the type of
 the allocator at compile time. It's also inconsistent with all other
 template classes in the library that do provide a typedef for the
 <tt>Allocator</tt> parameter.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to the synopses of the class templates basic_stringbuf (27.7.1),
 basic_istringstream (27.7.2), basic_ostringstream (27.7.3), and
 basic_stringstream (27.7.4) the typedef:</p>
 <pre>  typedef Allocator allocator_type;
 </pre>


 <hr>
 <h3><a name="252"></a>252. missing casts/C-style casts used in iostreams</h3>
 <p><b>Section:</b> 27.7 [string.streams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-07-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.streams">issues</a> in [string.streams].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.7.2.2, p1 uses a C-style cast rather than the more appropriate
 const_cast&lt;&gt; in the Returns clause for basic_istringstream&lt;&gt;::rdbuf().
 The same C-style cast is being used in 27.7.3.2, p1, D.7.2.2, p1, and
 D.7.3.2, p1, and perhaps elsewhere. 27.7.6, p1 and D.7.2.2, p1 are missing
 the cast altogether.</p>

 <p>C-style casts have not been deprecated, so the first part of this
 issue is stylistic rather than a matter of correctness.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.7.2.2, p1 replace </p>
 <pre>  -1- Returns: (basic_stringbuf&lt;charT,traits,Allocator&gt;*)&amp;sb.</pre>

 <p>with</p>
 <pre>  -1- Returns: const_cast&lt;basic_stringbuf&lt;charT,traits,Allocator&gt;*&gt;(&amp;sb).</pre>


 <p>In 27.7.3.2, p1 replace</p>
 <pre>  -1- Returns: (basic_stringbuf&lt;charT,traits,Allocator&gt;*)&amp;sb.</pre>

 <p>with</p>
 <pre>  -1- Returns: const_cast&lt;basic_stringbuf&lt;charT,traits,Allocator&gt;*&gt;(&amp;sb).</pre>

 <p>In 27.7.6, p1, replace</p>
 <pre>  -1- Returns: &amp;sb</pre>

 <p>with</p>
 <pre>  -1- Returns: const_cast&lt;basic_stringbuf&lt;charT,traits,Allocator&gt;*&gt;(&amp;sb).</pre>

 <p>In D.7.2.2, p1 replace</p>
 <pre>  -2- Returns: &amp;sb. </pre>

 <p>with</p>
 <pre>  -2- Returns: const_cast&lt;strstreambuf*&gt;(&amp;sb).</pre>


 <hr>
 <h3><a name="253"></a>253. valarray helper functions are almost entirely useless</h3>
 <p><b>Section:</b> 26.5.2.1 [valarray.cons], 26.5.2.2 [valarray.assign] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Robert Klarer <b>Date:</b> 2000-07-31</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#valarray.cons">active issues</a> in [valarray.cons].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#valarray.cons">issues</a> in [valarray.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>This discussion is adapted from message c++std-lib-7056 posted
 November 11, 1999.  I don't think that anyone can reasonably claim
 that the problem described below is NAD.</p>

 <p>These valarray constructors can never be called:</p>

 <pre>   template &lt;class T&gt;
          valarray&lt;T&gt;::valarray(const slice_array&lt;T&gt; &amp;);
    template &lt;class T&gt;
          valarray&lt;T&gt;::valarray(const gslice_array&lt;T&gt; &amp;);
    template &lt;class T&gt;
          valarray&lt;T&gt;::valarray(const mask_array&lt;T&gt; &amp;);
    template &lt;class T&gt;
          valarray&lt;T&gt;::valarray(const indirect_array&lt;T&gt; &amp;);
 </pre>

 <p>Similarly, these valarray assignment operators cannot be
 called:</p>

 <pre>     template &lt;class T&gt;
      valarray&lt;T&gt; valarray&lt;T&gt;::operator=(const slice_array&lt;T&gt; &amp;);
      template &lt;class T&gt;
      valarray&lt;T&gt; valarray&lt;T&gt;::operator=(const gslice_array&lt;T&gt; &amp;);
      template &lt;class T&gt;
      valarray&lt;T&gt; valarray&lt;T&gt;::operator=(const mask_array&lt;T&gt; &amp;);
      template &lt;class T&gt;
      valarray&lt;T&gt; valarray&lt;T&gt;::operator=(const indirect_array&lt;T&gt; &amp;);
 </pre>

 <p>Please consider the following example:</p>

 <pre>   #include &lt;valarray&gt;
    using namespace std;

    int main()
    {
        valarray&lt;double&gt; va1(12);
        valarray&lt;double&gt; va2(va1[slice(1,4,3)]); // line 1
    }
 </pre>


 <p>Since the valarray va1 is non-const, the result of the sub-expression
 va1[slice(1,4,3)] at line 1 is an rvalue of type const
 std::slice_array&lt;double&gt;.  This slice_array rvalue is then used to
 construct va2.  The constructor that is used to construct va2 is
 declared like this:</p>

 <pre>     template &lt;class T&gt;
      valarray&lt;T&gt;::valarray(const slice_array&lt;T&gt; &amp;);
 </pre>

 <p>Notice the constructor's const reference parameter.  When the
 constructor is called, a slice_array must be bound to this reference.
 The rules for binding an rvalue to a const reference are in 8.5.3,
 paragraph 5 (see also 13.3.3.1.4).  Specifically, paragraph 5
 indicates that a second slice_array rvalue is constructed (in this
 case copy-constructed) from the first one; it is this second rvalue
 that is bound to the reference parameter.  Paragraph 5 also requires
 that the constructor that is used for this purpose be callable,
 regardless of whether the second rvalue is elided.  The
 copy-constructor in this case is not callable, however, because it is
 private.  Therefore, the compiler should report an error.</p>

 <p>Since slice_arrays are always rvalues, the valarray constructor that has a
 parameter of type const slice_array&lt;T&gt; &amp; can never be called.  The
 same reasoning applies to the three other constructors and the four
 assignment operators that are listed at the beginning of this post.
 Furthermore, since these functions cannot be called, the valarray helper
 classes are almost entirely useless.</p>


 <p><b>Proposed resolution:</b></p>
 <p>slice_array:</p>
 <ul>
 <li> Make the copy constructor and copy-assignment operator declarations
      public in the slice_array class template definition in 26.5.5 [template.slice.array] </li>
 <li> remove paragraph 3 of 26.5.5 [template.slice.array]</li>
 <li> remove the copy constructor declaration from  [cons.slice.arr]</li>
 <li> change paragraph 1 of  [cons.slice.arr] to read "This constructor is declared
     to be private.  This constructor need not be defined."</li>
 <li> remove the first sentence of paragraph 1 of 26.5.5.1 [slice.arr.assign]</li>
 <li> Change the first three words of the second sentence of paragraph 1 of
     26.5.5.1 [slice.arr.assign] to "These assignment operators have"</li>
 </ul>

 <p>gslice_array:</p>
 <ul>
 <li> Make the copy constructor and copy-assignment operator declarations
     public in the gslice_array class template definition in 26.5.7 [template.gslice.array] </li>
 <li> remove the note in paragraph 3 of 26.5.7 [template.gslice.array]</li>
 <li> remove the copy constructor declaration from  [gslice.array.cons]</li>
 <li> change paragraph 1 of  [gslice.array.cons] to read "This constructor is declared
     to be private.  This constructor need not be defined."</li>
 <li> remove the first sentence of paragraph 1 of 26.5.7.1 [gslice.array.assign]</li>
 <li> Change the first three words of the second sentence of paragraph 1 of
     26.5.7.1 [gslice.array.assign] to "These assignment operators have"</li>
 </ul>

 <p>mask_array:</p>
 <ul>
 <li> Make the copy constructor and copy-assignment operator declarations
     public in the mask_array class template definition in 26.5.8 [template.mask.array] </li>
 <li> remove the note in paragraph 2 of 26.5.8 [template.mask.array]</li>
 <li> remove the copy constructor declaration from  [mask.array.cons]</li>
 <li> change paragraph 1 of  [mask.array.cons] to read "This constructor is declared
     to be private.  This constructor need not be defined."</li>
 <li> remove the first sentence of paragraph 1 of 26.5.8.1 [mask.array.assign]</li>
 <li> Change the first three words of the second sentence of paragraph 1 of
     26.5.8.1 [mask.array.assign] to "These assignment operators have"</li>
 </ul>

 <p>indirect_array:</p>
 <ul>
 <li>Make the copy constructor and copy-assignment operator declarations
     public in the indirect_array class definition in 26.5.9 [template.indirect.array]</li>
 <li> remove the note in paragraph 2 of 26.5.9 [template.indirect.array]</li>
 <li> remove the copy constructor declaration from  [indirect.array.cons]</li>
 <li> change the descriptive text in  [indirect.array.cons] to read "This constructor is
     declared to be private.  This constructor need not be defined."</li>
 <li> remove the first sentence of paragraph 1 of 26.5.9.1 [indirect.array.assign]</li>
 <li> Change the first three words of the second sentence of paragraph 1 of
     26.5.9.1 [indirect.array.assign] to "These assignment operators have"</li>
 </ul>
 <p><i>[Proposed resolution was modified in Santa Cruz: explicitly make
 copy constructor and copy assignment operators public, instead of
 removing them.]</i></p>


 <p><b>Rationale:</b></p>
 <p>Keeping the valarray constructors private is untenable.  Merely
 making valarray a friend of the helper classes isn't good enough,
 because access to the copy constructor is checked in the user's
 environment.</p>

 <p>Making the assignment operator public is not strictly necessary to
 solve this problem.  A majority of the LWG <i>(straw poll: 13-4)</i>
 believed we should make the assignment operators public, in addition
 to the copy constructors, for reasons of symmetry and user
 expectation.</p>


 <hr>
 <h3><a name="254"></a>254. Exception types in clause 19 are constructed from <tt>std::string</tt></h3>
 <p><b>Section:</b> 19.1 [std.exceptions], 27.4.2.1.1 [ios::failure] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2000-08-01</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Many of the standard exception types which implementations are
 required to throw are constructed with a const std::string&amp;
 parameter. For example:
 </p>

 <pre>     19.1.5  Class out_of_range                          [lib.out.of.range]
      namespace std {
        class out_of_range : public logic_error {
        public:
          explicit out_of_range(const string&amp; what_arg);
        };
      }

    1 The class out_of_range defines the type of objects  thrown  as  excep-
      tions to report an argument value not in its expected range.

      out_of_range(const string&amp; what_arg);

      Effects:
        Constructs an object of class out_of_range.
      Postcondition:
        strcmp(what(), what_arg.c_str()) == 0.
 </pre>

 <p>
 There are at least two problems with this:
 </p>
 <ol>
 <li>A program which is low on memory may end up throwing
 std::bad_alloc instead of out_of_range because memory runs out while
 constructing the exception object.</li>
 <li>An obvious implementation which stores a std::string data member
 may end up invoking terminate() during exception unwinding because the
 exception object allocates memory (or rather fails to) as it is being
 copied.</li>
 </ol>

 <p>
 There may be no cure for (1) other than changing the interface to
 out_of_range, though one could reasonably argue that (1) is not a
 defect. Personally I don't care that much if out-of-memory is reported
 when I only have 20 bytes left, in the case when out_of_range would
 have been reported. People who use exception-specifications might care
 a lot, though.
 </p>

 <p>
 There is a cure for (2), but it isn't completely obvious. I think a
 note for implementors should be made in the standard. Avoiding
 possible termination in this case shouldn't be left up to chance.  The
 cure is to use a reference-counted "string" implementation
 in the exception object. I am not necessarily referring to a
 std::string here; any simple reference-counting scheme for a NTBS
 would do.
 </p>

 <p><b>Further discussion, in email:</b></p>

 <p>
 ...I'm not so concerned about (1). After all, a library implementation
 can add const char* constructors as an extension, and users don't
 <i>need</i> to avail themselves of the standard exceptions, though this is
 a lame position to be forced into.  FWIW, std::exception and
 std::bad_alloc don't require a temporary basic_string.
 </p>

 <p>
 ...I don't think the fixed-size buffer is a solution to the problem,
 strictly speaking, because you can't satisfy the postcondition
 <br>
     <tt>&nbsp;&nbsp;strcmp(what(), what_arg.c_str()) == 0</tt>
 <br>
 For all values of what_arg (i.e. very long values). That means that
 the only truly conforming solution requires a dynamic allocation.
 </p>

 <p><b>Further discussion, from Redmond:</b></p>

 <p>The most important progress we made at the Redmond meeting was
 realizing that there are two separable issues here: the const
 string&amp; constructor, and the copy constructor.  If a user writes
 something like <tt>throw std::out_of_range("foo")</tt>, the const
 string&amp; constructor is invoked before anything gets thrown.  The
 copy constructor is potentially invoked during stack unwinding.</p>

 <p>The copy constructor is a more serious problem, becuase failure
 during stack unwinding invokes <tt>terminate</tt>.  The copy
 constructor must be nothrow. <i>Curaçao: Howard thinks this
 requirement may already be present.</i></p>

 <p>The fundamental problem is that it's difficult to get the nothrow
 requirement to work well with the requirement that the exception
 objects store a string of unbounded size, particularly if you also try
 to make the const string&amp; constructor nothrow.  Options discussed
 include:</p>

 <ul>
 <li>Limit the size of a string that exception objects are required to
 throw: change the postconditions of 19.1.2 [domain.error] paragraph 3
 and 19.1.6 [runtime.error] paragraph 3 to something like this:
 "strncmp(what(), what_arg._str(), N) == 0, where N is an
 implementation defined constant no smaller than 256".</li>
 <li>Allow the const string&amp; constructor to throw, but not the
 copy constructor.  It's the implementor's responsibility to get it
 right.  (An implementor might use a simple refcount class.)</li>
 <li>Compromise between the two: an implementation is not allowed to
 throw if the string's length is less than some N, but, if it doesn't
 throw, the string must compare equal to the argument.</li>
 <li>Add a new constructor that takes a const char*</li>
 </ul>

 <p>(Not all of these options are mutually exclusive.)</p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change 19.1.1 [logic.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class logic_error : public exception {
   public:
     explicit logic_error(const string&amp; <i>what_arg</i>);
     <ins>explicit logic_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>logic_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>logic_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.2 [domain.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class domain_error : public logic_error {
   public:
     explicit domain_error(const string&amp; <i>what_arg</i>);
     <ins>explicit domain_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>domain_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>domain_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>

 </blockquote>
 </blockquote>

 <p>
 Change 19.1.3 [invalid.argument]
 </p>

 <blockquote>
 <pre>namespace std {
   class invalid_argument : public logic_error {
   public:
     explicit invalid_argument(const string&amp; <i>what_arg</i>);
     <ins>explicit invalid_argument(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>invalid_argument(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>invalid_argument</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.4 [length.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class length_error : public logic_error {
   public:
     explicit length_error(const string&amp; <i>what_arg</i>);
     <ins>explicit length_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>length_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>length_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.5 [out.of.range]
 </p>

 <blockquote>
 <pre>namespace std {
   class out_of_range : public logic_error {
   public:
     explicit out_of_range(const string&amp; <i>what_arg</i>);
     <ins>explicit out_of_range(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>out_of_range(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>out_of_range</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.6 [runtime.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class runtime_error : public exception {
   public:
     explicit runtime_error(const string&amp; <i>what_arg</i>);
     <ins>explicit runtime_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>runtime_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>runtime_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.7 [range.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class range_error : public runtime_error {
   public:
     explicit range_error(const string&amp; <i>what_arg</i>);
     <ins>explicit range_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>range_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>range_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.8 [overflow.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class overflow_error : public runtime_error {
   public:
     explicit overflow_error(const string&amp; <i>what_arg</i>);
     <ins>explicit overflow_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>overflow_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>overflow_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 19.1.9 [underflow.error]
 </p>

 <blockquote>
 <pre>namespace std {
   class underflow_error : public runtime_error {
   public:
     explicit underflow_error(const string&amp; <i>what_arg</i>);
     <ins>explicit underflow_error(const char* <i>what_arg</i>);</ins>
   };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>underflow_error(const char* <i>what_arg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>underflow_error</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>what_arg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 27.4.2.1.1 [ios::failure]
 </p>

 <blockquote>
 <pre>namespace std {
   class ios_base::failure : public exception {
   public:
     explicit failure(const string&amp; <i>msg</i>);
     <ins>explicit failure(const char* <i>msg</i>);</ins>
     virtual const char* what() const throw();
 };
 }
 </pre>
 <p>...</p>
 <p>
 <ins><tt>failure(const char* <i>msg</i>);</tt></ins>
 </p>
 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Constructs an object of class <tt>failure</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Postcondition:</i> <tt>strcmp(what(), <i>msg</i>) == 0</tt>.
 </ins></p>
 </blockquote>

 </blockquote>


 <p><b>Rationale:</b></p>

 <p>Throwing a bad_alloc while trying to construct a message for another
 exception-derived class is not necessarily a bad thing.  And the
 bad_alloc constructor already has a no throw spec on it (18.4.2.1).</p>

 <p><b>Future:</b></p>

 <p>All involved would like to see const char* constructors added, but
 this should probably be done for C++0X as opposed to a DR.</p>

 <p>I believe the no throw specs currently decorating these functions
 could be improved by some kind of static no throw spec checking
 mechanism (in a future C++ language).  As they stand, the copy
 constructors might fail via a call to unexpected.  I think what is
 intended here is that the copy constructors can't fail.</p>

 <p><i>[Pre-Sydney: reopened at the request of Howard Hinnant.
   Post-Redmond: James Kanze noticed that the copy constructors of
   exception-derived classes do not have nothrow clauses.  Those
   classes have no copy constructors declared, meaning the
   compiler-generated implicit copy constructors are used, and those
   compiler-generated constructors might in principle throw anything.]</i></p>


 <p><i>[
 Batavia:  Merged copy constructor and assignment operator spec into <tt>exception</tt>
 and added <tt>ios::failure</tt> into the proposed resolution.
 ]</i></p>


 <p><i>[
 Oxford:  The proposed resolution simply addresses the issue of constructing
 the exception objects with <tt>const char*</tt> and string literals without
 the need to explicit include or construct a <tt>std::string</tt>.
 ]</i></p>


 <hr>
 <h3><a name="256"></a>256. typo in 27.4.4.2, p17: copy_event does not exist</h3>
 <p><b>Section:</b> 27.4.4.2 [basic.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-08-21</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.ios.members">active issues</a> in [basic.ios.members].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.members">issues</a> in [basic.ios.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 27.4.4.2, p17 says
 </p>

 <blockquote><p>
 -17- Before copying any parts of rhs, calls each registered callback
 pair (fn,index) as (*fn)(erase_event,*this,index). After all parts but
 exceptions() have been replaced, calls each callback pair that was
 copied from rhs as (*fn)(copy_event,*this,index).
 </p></blockquote>

 <p>
 The name copy_event isn't defined anywhere. The intended name was
 copyfmt_event.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace copy_event with copyfmt_event in the named paragraph.</p>


 <hr>
 <h3><a name="258"></a>258. Missing allocator requirement</h3>
 <p><b>Section:</b> 20.1.2 [allocator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2000-08-22</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#allocator.requirements">active issues</a> in [allocator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.requirements">issues</a> in [allocator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 From lib-7752:
 </p>

 <p>
 I've been assuming (and probably everyone else has been assuming) that
 allocator instances have a particular property, and I don't think that
 property can be deduced from anything in Table 32.
 </p>

 <p>
 I think we have to assume that allocator type conversion is a
 homomorphism.  That is, if x1 and x2 are of type X, where
 X::value_type is T, and if type Y is X::template
 rebind&lt;U&gt;::other, then Y(x1) == Y(x2) if and only if x1 == x2.
 </p>

 <p>
 Further discussion: Howard Hinnant writes, in lib-7757:
 </p>

 <p>
 I think I can prove that this is not provable by Table 32.  And I agree
 it needs to be true except for the "and only if".  If x1 != x2, I see no
 reason why it can't be true that Y(x1) == Y(x2).  Admittedly I can't
 think of a practical instance where this would happen, or be valuable.
 But I also don't see a need to add that extra restriction.  I think we
 only need:
 </p>

 <blockquote><p>
      if (x1 == x2) then Y(x1) == Y(x2)
 </p></blockquote>

 <p>
 If we decide that == on allocators is transitive, then I think I can
 prove the above.  But I don't think == is necessarily transitive on
 allocators.  That is:
 </p>

 <p>
 Given x1 == x2  and x2 == x3, this does not mean x1 == x3.
 </p>

 <p>Example:</p>

 <blockquote>
 <p>
 x1 can deallocate pointers from:  x1, x2, x3    <br>
 x2 can deallocate pointers from:  x1, x2, x4    <br>
 x3 can deallocate pointers from:  x1, x3        <br>
 x4 can deallocate pointers from:  x2, x4
 </p>

 <p>
 x1 == x2, and x2 == x4, but x1 != x4
 </p>
 </blockquote>
 <p><i>[Toronto: LWG members offered multiple opinions.  One
 opinion is that it should not be required that <tt>x1 == x2</tt>
 implies <tt>Y(x1) == Y(x2)</tt>, and that it should not even be
 required that <tt>X(x1) == x1</tt>.  Another opinion is that
 the second line from the bottom in table 32 already implies the
 desired property.  This issue should be considered in light of
 other issues related to allocator instances.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Accept proposed wording from
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2436.pdf">N2436</a> part 3.
 </p>


 <p><i>[Lillehammer: Same conclusion as before: this should be
   considered as part of an allocator redesign, not solved on its own.]</i></p>


 <p><i>[
 Batavia:  An allocator redesign is not forthcoming and thus we fixed this one issue.
 ]</i></p>


 <p><i>[
 Toronto:  Reopened at the request of the project editor (Pete) because the proposed
 wording did not fit within the indicated table.  The intent of the resolution remains
 unchanged.  Pablo to work with Pete on improved wording.
 ]</i></p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2387 for this issue which
 was subsequently split out into a separate paper N2436 for the purposes of voting.
 The resolution in N2436 addresses this issue.  The LWG voted to accelerate this
 issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="259"></a>259. <tt>basic_string::operator[]</tt> and const correctness</h3>
 <p><b>Section:</b> 21.3.4 [string.capacity] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Chris Newton  <b>Date:</b> 2000-08-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.capacity">issues</a> in [string.capacity].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <i>Paraphrased from a message that Chris Newton posted to comp.std.c++:</i>
 </p>

 <p>
 The standard's description of <tt>basic_string&lt;&gt;::operator[]</tt>
 seems to violate const correctness.
 </p>

 <p>
 The standard (21.3.4/1) says that "If <tt>pos &lt; size()</tt>,
 returns <tt>data()[pos]</tt>." The types don't work.  The
 return value of <tt>data()</tt> is <tt>const charT*</tt>, but
 <tt>operator[]</tt> has a non-const version whose return type is <tt>reference</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In section 21.3.4, paragraph 1, change
 "<tt>data()[<i>pos</i>]</tt>" to "<tt>*(begin() +
 <i>pos</i>)</tt>".
 </p>


 <hr>
 <h3><a name="260"></a>260. Inconsistent return type of <tt>istream_iterator::operator++(int)</tt></h3>
 <p><b>Section:</b> 24.5.1.2 [istream.iterator.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-08-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.iterator.ops">issues</a> in [istream.iterator.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The synopsis of istream_iterator::operator++(int) in 24.5.1 shows
 it as returning the iterator by value. 24.5.1.2, p5 shows the same
 operator as returning the iterator by reference. That's incorrect
 given the Effects clause below (since a temporary is returned). The
 `&amp;' is probably just a typo.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the declaration in 24.5.1.2, p5 from</p>
  <pre> istream_iterator&lt;T,charT,traits,Distance&gt;&amp; operator++(int);
  </pre>
 <p>to</p>
  <pre> istream_iterator&lt;T,charT,traits,Distance&gt; operator++(int);
  </pre>
 <p>(that is, remove the `&amp;').</p>


 <hr>
 <h3><a name="261"></a>261. Missing description of <tt>istream_iterator::operator!=</tt></h3>
 <p><b>Section:</b> 24.5.1.2 [istream.iterator.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-08-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.iterator.ops">issues</a> in [istream.iterator.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 24.5.1, p3 lists the synopsis for
 </p>

 <pre>   template &lt;class T, class charT, class traits, class Distance&gt;
         bool operator!=(const istream_iterator&lt;T,charT,traits,Distance&gt;&amp; x,
                         const istream_iterator&lt;T,charT,traits,Distance&gt;&amp; y);
 </pre>

 <p>
 but there is no description of what the operator does (i.e., no Effects
 or Returns clause) in 24.5.1.2.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add paragraph 7 to the end of section 24.5.1.2 with the following text:
 </p>

 <pre>   template &lt;class T, class charT, class traits, class Distance&gt;
         bool operator!=(const istream_iterator&lt;T,charT,traits,Distance&gt;&amp; x,
                         const istream_iterator&lt;T,charT,traits,Distance&gt;&amp; y);
 </pre>

 <p>-7- Returns: !(x == y).</p>


 <hr>
 <h3><a name="262"></a>262. Bitmask operator ~ specified incorrectly</h3>
 <p><b>Section:</b> 17.3.2.1.2 [bitmask.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2000-09-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The ~ operation should be applied after the cast to int_type.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 17.3.2.1.2 [lib.bitmask.types] operator~ from:
 </p>

 <pre>   bitmask operator~ ( bitmask X )
      { return static_cast&lt; bitmask&gt;(static_cast&lt;int_type&gt;(~ X)); }
 </pre>

 <p>
 to:
 </p>

 <pre>   bitmask operator~ ( bitmask X )
      { return static_cast&lt; bitmask&gt;(~static_cast&lt;int_type&gt;(X)); }
 </pre>


 <hr>
 <h3><a name="263"></a>263. Severe restriction on <tt>basic_string</tt> reference counting</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Kevlin Henney <b>Date:</b> 2000-09-04</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The note in paragraph 6 suggests that the invalidation rules for
 references, pointers, and iterators in paragraph 5 permit a reference-
 counted implementation (actually, according to paragraph 6, they permit
 a "reference counted implementation", but this is a minor editorial fix).
 </p>

 <p>
 However, the last sub-bullet is so worded as to make a reference-counted
 implementation unviable. In the following example none of the
 conditions for iterator invalidation are satisfied:
 </p>

 <pre>    // first example: "*******************" should be printed twice
     string original = "some arbitrary text", copy = original;
     const string &amp; alias = original;

     string::const_iterator i = alias.begin(), e = alias.end();
     for(string::iterator j = original.begin(); j != original.end(); ++j)
         *j = '*';
     while(i != e)
         cout &lt;&lt; *i++;
     cout &lt;&lt; endl;
     cout &lt;&lt; original &lt;&lt; endl;
 </pre>

 <p>
 Similarly, in the following example:
 </p>

 <pre>    // second example: "some arbitrary text" should be printed out
     string original = "some arbitrary text", copy = original;
     const string &amp; alias = original;

     string::const_iterator i = alias.begin();
     original.begin();
     while(i != alias.end())
         cout &lt;&lt; *i++;
 </pre>

 <p>
 I have tested this on three string implementations, two of which were
 reference counted. The reference-counted implementations gave
 "surprising behavior" because they invalidated iterators on
 the first call to non-const begin since construction. The current
 wording does not permit such invalidation because it does not take
 into account the first call since construction, only the first call
 since various member and non-member function calls.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the following sentence in 21.3 paragraph 5 from
 </p>

 <blockquote><p>
     Subsequent to any of the above uses except the forms of insert() and
     erase() which return iterators, the first call to non-const member
     functions operator[](), at(), begin(), rbegin(), end(), or rend().
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
     Following construction or any of the above uses, except the forms of
     insert() and erase() that return iterators, the first call to non-
     const member functions operator[](), at(), begin(), rbegin(), end(),
     or rend().
 </p></blockquote>


 <hr>
 <h3><a name="264"></a>264. Associative container <tt>insert(i, j)</tt> complexity requirements are not feasible.</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> John Potter <b>Date:</b> 2000-09-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#102">102</a></p>
 <p><b>Discussion:</b></p>
 <p>
 Table 69 requires linear time if [i, j) is sorted.  Sorted is necessary but not sufficient.
 Consider inserting a sorted range of even integers into a set&lt;int&gt; containing the odd
 integers in the same range.
 </p>

 <p><i>Related issue: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#102">102</a></i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In Table 69, in section 23.1.2, change the complexity clause for
 insertion of a range from "N log(size() + N) (N is the distance
 from i to j) in general; linear if [i, j) is sorted according to
 value_comp()" to "N log(size() + N), where N is the distance
 from i to j".
 </p>

 <p><i>[Copenhagen: Minor fix in proposed resolution: fixed unbalanced
 parens in the revised wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 Testing for valid insertions could be less efficient than simply
 inserting the elements when the range is not both sorted and between
 two adjacent existing elements; this could be a QOI issue.
 </p>

 <p>
 The LWG considered two other options: (a) specifying that the
 complexity was linear if [i, j) is sorted according to value_comp()
 and between two adjacent existing elements; or (b) changing to
 Klog(size() + N) + (N - K) (N is the distance from i to j and K is the
 number of elements which do not insert immediately after the previous
 element from [i, j) including the first).  The LWG felt that, since
 we can't guarantee linear time complexity whenever the range to be
 inserted is sorted, it's more trouble than it's worth to say that it's
 linear in some special cases.
 </p>


 <hr>
 <h3><a name="265"></a>265. std::pair::pair() effects overly restrictive</h3>
 <p><b>Section:</b> 20.2.3 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-09-11</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I don't see any requirements on the types of the elements of the
 std::pair container in 20.2.2. From the descriptions of the member
 functions it appears that they must at least satisfy the requirements of
 20.1.3 [lib.copyconstructible] and 20.1.4 [lib.default.con.req], and in
 the case of the [in]equality operators also the requirements of 20.1.1
 [lib.equalitycomparable] and 20.1.2 [lib.lessthancomparable].
 </p>

 <p>
 I believe that the the CopyConstructible requirement is unnecessary in
 the case of 20.2.2, p2.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the Effects clause in 20.2.2, p2 from</p>

 <blockquote><p>
 -2- <b>Effects</b>: Initializes its members as if implemented: <tt> pair() :
 first(T1()), second(T2()) {} </tt>
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
 -2- <b>Effects</b>: Initializes its members as if implemented: <tt> pair() :
 first(), second() {} </tt>
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>The existing specification of pair's constructor appears to be a
 historical artifact: there was concern that pair's members be properly
 zero-initialized when they are built-in types.  At one time there was
 uncertainty about whether they would be zero-initialized if the
 default constructor was written the obvious way.  This has been
 clarified by core issue 178, and there is no longer any doubt that
 the straightforward implementation is correct.</p>


 <hr>
 <h3><a name="266"></a>266. bad_exception::~bad_exception() missing Effects clause</h3>
 <p><b>Section:</b> 18.7.2.1 [bad.exception] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-09-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The synopsis for std::bad_exception lists the function ~bad_exception()
 but there is no description of what the function does (the Effects
 clause is missing).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Remove the destructor from the class synopses of
 <tt>bad_alloc</tt> (18.5.2.1 [bad.alloc]),
 <tt>bad_cast</tt> (18.6.2 [bad.cast]),
 <tt>bad_typeid</tt> (18.6.3 [bad.typeid]),
 and <tt>bad_exception</tt> (18.7.2.1 [bad.exception]).
 </p>


 <p><b>Rationale:</b></p>
 <p>
 This is a general problem with the exception classes in clause 18.
 The proposed resolution is to remove the destructors from the class
 synopses, rather than to document the destructors' behavior, because
 removing them is more consistent with how exception classes are
 described in clause 19.
 </p>


 <hr>
 <h3><a name="268"></a>268. Typo in locale synopsis</h3>
 <p><b>Section:</b> 22.1.1 [locale] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-10-05</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale">issues</a> in [locale].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The synopsis of the class std::locale in 22.1.1 contains two typos:
 the semicolons after the declarations of the default ctor
 locale::locale() and the copy ctor locale::locale(const locale&amp;)
 are missing.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the missing semicolons, i.e., change</p>

 <pre>    //  construct/copy/destroy:
         locale() throw()
         locale(const locale&amp; other) throw()
 </pre>

 <p>in the synopsis in 22.1.1 to</p>

 <pre>    //  construct/copy/destroy:
         locale() throw();
         locale(const locale&amp; other) throw();
 </pre>


 <hr>
 <h3><a name="270"></a>270. Binary search requirements overly strict</h3>
 <p><b>Section:</b> 25.3.3 [alg.binary.search] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2000-10-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.binary.search">issues</a> in [alg.binary.search].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#472">472</a></p>
 <p><b>Discussion:</b></p>
 <p>
 Each of the four binary search algorithms (lower_bound, upper_bound,
 equal_range, binary_search) has a form that allows the user to pass a
 comparison function object.  According to 25.3, paragraph 2, that
 comparison function object has to be a strict weak ordering.
 </p>

 <p>
 This requirement is slightly too strict.  Suppose we are searching
 through a sequence containing objects of type X, where X is some
 large record with an integer key.  We might reasonably want to look
 up a record by key, in which case we would want to write something
 like this:
 </p>
 <pre>    struct key_comp {
       bool operator()(const X&amp; x, int n) const {
         return x.key() &lt; n;
       }
     }

     std::lower_bound(first, last, 47, key_comp());
 </pre>

 <p>
 key_comp is not a strict weak ordering, but there is no reason to
 prohibit its use in lower_bound.
 </p>

 <p>
 There's no difficulty in implementing lower_bound so that it allows
 the use of something like key_comp.  (It will probably work unless an
 implementor takes special pains to forbid it.)  What's difficult is
 formulating language in the standard to specify what kind of
 comparison function is acceptable.  We need a notion that's slightly
 more general than that of a strict weak ordering, one that can encompass
 a comparison function that involves different types.  Expressing that
 notion may be complicated.
 </p>

 <p><i>Additional questions raised at the Toronto meeting:</i></p>
 <ul>
 <li> Do we really want to specify what ordering the implementor must
      use when calling the function object?  The standard gives
      specific expressions when describing these algorithms, but it also
      says that other expressions (with different argument order) are
      equivalent.</li>
 <li> If we are specifying ordering, note that the standard uses both
      orderings when describing <tt>equal_range</tt>.</li>
 <li> Are we talking about requiring these algorithms to work properly
      when passed a binary function object whose two argument types
      are not the same, or are we talking about requirements when
      they are passed a binary function object with several overloaded
      versions of <tt>operator()</tt>?</li>
 <li> The definition of a strict weak ordering does not appear to give
      any guidance on issues of overloading; it only discusses expressions,
      and all of the values in these expressions are of the same type.
      Some clarification would seem to be in order.</li>
 </ul>

 <p><i>Additional discussion from Copenhagen:</i></p>
 <ul>
 <li>It was generally agreed that there is a real defect here: if
 the predicate is merely required to be a Strict Weak Ordering, then
 it's possible to pass in a function object with an overloaded
 operator(), where the version that's actually called does something
 completely inappropriate.  (Such as returning a random value.)</li>

 <li>An alternative formulation was presented in a paper distributed by
 David Abrahams at the meeting, "Binary Search with Heterogeneous
 Comparison", J16-01/0027 = WG21 N1313: Instead of viewing the
 predicate as a Strict Weak Ordering acting on a sorted sequence, view
 the predicate/value pair as something that partitions a sequence.
 This is almost equivalent to saying that we should view binary search
 as if we are given a unary predicate and a sequence, such that f(*p)
 is true for all p below a specific point and false for all p above it.
 The proposed resolution is based on that alternative formulation.</li>
 </ul>


 <p><b>Proposed resolution:</b></p>

 <p>Change 25.3 [lib.alg.sorting] paragraph 3 from:</p>

 <blockquote><p>
   3 For all algorithms that take Compare, there is a version that uses
   operator&lt; instead. That is, comp(*i, *j) != false defaults to *i &lt;
   *j != false. For the algorithms to work correctly, comp has to
   induce a strict weak ordering on the values.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
   3 For all algorithms that take Compare, there is a version that uses
   operator&lt; instead. That is, comp(*i, *j) != false defaults to *i
   &lt; *j != false. For algorithms other than those described in
   lib.alg.binary.search (25.3.3) to work correctly, comp has to induce
   a strict weak ordering on the values.
 </p></blockquote>

 <p>Add the following paragraph after 25.3 [lib.alg.sorting] paragraph 5:</p>

 <blockquote><p>
   -6- A sequence [start, finish) is partitioned with respect to an
   expression f(e) if there exists an integer n such that
   for all 0 &lt;= i &lt; distance(start, finish), f(*(begin+i)) is true if
   and only if i &lt; n.
 </p></blockquote>

 <p>Change 25.3.3 [lib.alg.binary.search] paragraph 1 from:</p>

 <blockquote><p>
   -1- All of the algorithms in this section are versions of binary
    search and assume that the sequence being searched is in order
    according to the implied or explicit comparison function. They work
    on non-random access iterators minimizing the number of
    comparisons, which will be logarithmic for all types of
    iterators. They are especially appropriate for random access
    iterators, because these algorithms do a logarithmic number of
    steps through the data structure. For non-random access iterators
    they execute a linear number of steps.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
    -1- All of the algorithms in this section are versions of binary
     search and assume that the sequence being searched is partitioned
     with respect to an expression formed by binding the search key to
     an argument of the implied or explicit comparison function. They
     work on non-random access iterators minimizing the number of
     comparisons, which will be logarithmic for all types of
     iterators. They are especially appropriate for random access
     iterators, because these algorithms do a logarithmic number of
     steps through the data structure. For non-random access iterators
     they execute a linear number of steps.
 </p></blockquote>

 <p>Change 25.3.3.1 [lib.lower.bound] paragraph 1 from:</p>

 <blockquote><p>
    -1- Requires: Type T is LessThanComparable
     (lib.lessthancomparable).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
    -1- Requires: The elements e of [first, last) are partitioned with
    respect to the expression e &lt; value or comp(e, value)
 </p></blockquote>


 <p>Remove 25.3.3.1 [lib.lower.bound] paragraph 2:</p>

 <blockquote><p>
    -2- Effects: Finds the first position into which value can be
     inserted without violating the ordering.
 </p></blockquote>

 <p>Change 25.3.3.2 [lib.upper.bound] paragraph 1 from:</p>

 <blockquote><p>
   -1- Requires: Type T is LessThanComparable (lib.lessthancomparable).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
    -1- Requires: The elements e of [first, last) are partitioned with
    respect to the expression !(value &lt; e) or !comp(value, e)
 </p></blockquote>

 <p>Remove 25.3.3.2 [lib.upper.bound] paragraph 2:</p>

 <blockquote><p>
    -2- Effects: Finds the furthermost position into which value can be
     inserted without violating the ordering.
 </p></blockquote>

 <p>Change 25.3.3.3 [lib.equal.range] paragraph 1 from:</p>

 <blockquote><p>
    -1- Requires: Type T is LessThanComparable
     (lib.lessthancomparable).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
    -1- Requires: The elements e of [first, last) are partitioned with
    respect to the expressions e &lt; value and !(value &lt; e) or
    comp(e, value) and !comp(value, e).  Also, for all elements e of
    [first, last), e &lt; value implies !(value &lt; e) or comp(e,
    value) implies !comp(value, e)
 </p></blockquote>

 <p>Change 25.3.3.3 [lib.equal.range] paragraph 2 from:</p>

 <blockquote><p>
    -2- Effects: Finds the largest subrange [i, j) such that the value
     can be inserted at any iterator k in it without violating the
     ordering. k satisfies the corresponding conditions: !(*k &lt; value)
     &amp;&amp; !(value &lt; *k) or comp(*k, value) == false &amp;&amp; comp(value, *k) ==
     false.
 </p></blockquote>

 <p>to:</p>

 <pre>   -2- Returns:
          make_pair(lower_bound(first, last, value),
                    upper_bound(first, last, value))
        or
          make_pair(lower_bound(first, last, value, comp),
                    upper_bound(first, last, value, comp))
 </pre>

 <p>Change 25.3.3.3 [lib.binary.search] paragraph 1 from:</p>

 <blockquote><p>
    -1- Requires: Type T is LessThanComparable
     (lib.lessthancomparable).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
    -1- Requires: The elements e of [first, last) are partitioned with
    respect to the expressions e &lt; value and !(value &lt; e) or comp(e,
    value) and !comp(value, e). Also, for all elements e of [first,
    last), e &lt; value implies !(value &lt; e) or comp(e, value) implies
    !comp(value, e)
 </p></blockquote>

 <p><i>[Copenhagen: Dave Abrahams provided this wording]</i></p>


 <p><i>[Redmond: Minor changes in wording.  (Removed "non-negative", and
 changed the "other than those described in" wording.) Also, the LWG
 decided to accept the "optional" part.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The proposed resolution reinterprets binary search. Instead of
 thinking about searching for a value in a sorted range, we view that
 as an important special case of a more general algorithm: searching
 for the partition point in a partitioned range.</p>

 <p>We also add a guarantee that the old wording did not: we ensure
 that the upper bound is no earlier than the lower bound, that
 the pair returned by equal_range is a valid range, and that the first
 part of that pair is the lower bound.</p>


 <hr>
 <h3><a name="271"></a>271. basic_iostream missing typedefs</h3>
 <p><b>Section:</b> 27.6.1.5 [iostreamclass] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-11-02</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Class template basic_iostream has no typedefs.  The typedefs it
 inherits from its base classes can't be used, since (for example)
 basic_iostream&lt;T&gt;::traits_type is ambiguous.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add the following to basic_iostream's class synopsis in
 27.6.1.5 [iostreamclass], immediately after <tt>public</tt>:</p>

 <pre>  // types:
   typedef charT                     char_type;
   typedef typename traits::int_type int_type;
   typedef typename traits::pos_type pos_type;
   typedef typename traits::off_type off_type;
   typedef traits                    traits_type;
 </pre>


 <hr>
 <h3><a name="272"></a>272. Missing parentheses around subexpression</h3>
 <p><b>Section:</b> 27.4.4.3 [iostate.flags] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-11-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostate.flags">issues</a> in [iostate.flags].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a></p>
 <p><b>Discussion:</b></p>
 <p>
 27.4.4.3, p4 says about the postcondition of the function: If
 rdbuf()!=0 then state == rdstate(); otherwise
 rdstate()==state|ios_base::badbit.
 </p>

 <p>
 The expression on the right-hand-side of the operator==() needs to be
 parenthesized in order for the whole expression to ever evaluate to
 anything but non-zero.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add parentheses like so: rdstate()==(state|ios_base::badbit).
 </p>


 <hr>
 <h3><a name="273"></a>273. Missing ios_base qualification on members of a dependent class</h3>
 <p><b>Section:</b> 27 [input.output] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-11-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.output">issues</a> in [input.output].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.5.2.4.2, p4, and 27.8.1.6, p2, 27.8.1.7, p3, 27.8.1.9, p2,
 27.8.1.10, p3 refer to in and/or out w/o ios_base:: qualification.
 That's incorrect since the names are members of a dependent base
 class (14.6.2 [temp.dep]) and thus not visible.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Qualify the names with the name of the class of which they are
 members, i.e., ios_base.</p>


 <hr>
 <h3><a name="274"></a>274. a missing/impossible allocator requirement</h3>
 <p><b>Section:</b> 20.1.2 [allocator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-11-02</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#allocator.requirements">active issues</a> in [allocator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.requirements">issues</a> in [allocator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I see that table 31 in 20.1.5, p3 allows T in std::allocator&lt;T&gt; to be of
 any type. But the synopsis in 20.4.1 calls for allocator&lt;&gt;::address() to
 be overloaded on reference and const_reference, which is ill-formed for
 all T = const U. In other words, this won't work:
 </p>

 <p>
 template class std::allocator&lt;const int&gt;;
 </p>

 <p>
 The obvious solution is to disallow specializations of allocators on
 const types. However, while containers' elements are required to be
 assignable (which rules out specializations on const T's), I think that
 allocators might perhaps be potentially useful for const values in other
 contexts. So if allocators are to allow const types a partial
 specialization of std::allocator&lt;const T&gt; would probably have to be
 provided.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the text in row 1, column 2 of table 32 in 20.1.5, p3 from</p>

     <blockquote><p>
     any type
     </p></blockquote>

 <p>to</p>
     <blockquote><p>
     any non-const, non-reference type
     </p></blockquote>

 <p><i>[Redmond: previous proposed resolution was "any non-const,
 non-volatile, non-reference type".  Got rid of the "non-volatile".]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 Two resolutions were originally proposed: one that partially
 specialized std::allocator for const types, and one that said an
 allocator's value type may not be const.  The LWG chose the second.
 The first wouldn't be appropriate, because allocators are intended for
 use by containers, and const value types don't work in containers.
 Encouraging the use of allocators with const value types would only
 lead to unsafe code.
 </p>
 <p>
 The original text for proposed resolution 2 was modified so that it
 also forbids volatile types and reference types.
 </p>

 <p><i>[Curaçao: LWG double checked and believes volatile is correctly
 excluded from the PR.]</i></p>


 <hr>
 <h3><a name="275"></a>275. Wrong type in num_get::get() overloads</h3>
 <p><b>Section:</b> 22.2.2.1.1 [facet.num.get.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2000-11-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.members">issues</a> in [facet.num.get.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 22.2.2.1.1, we have a list of overloads for num_get&lt;&gt;::get().
 There are eight overloads, all of which are identical except for the
 last parameter.  The overloads are:
 </p>
 <ul>
 <li> long&amp; </li>
 <li> unsigned short&amp; </li>
 <li> unsigned int&amp; </li>
 <li> unsigned long&amp; </li>
 <li> short&amp; </li>
 <li> double&amp; </li>
 <li> long double&amp; </li>
 <li> void*&amp; </li>
 </ul>

 <p>
 There is a similar list, in 22.2.2.1.2, of overloads for
 num_get&lt;&gt;::do_get().  In this list, the last parameter has
 the types:
 </p>
 <ul>
 <li> long&amp; </li>
 <li> unsigned short&amp; </li>
 <li> unsigned int&amp; </li>
 <li> unsigned long&amp; </li>
 <li> float&amp; </li>
 <li> double&amp; </li>
 <li> long double&amp; </li>
 <li> void*&amp; </li>
 </ul>

 <p>
 These two lists are not identical.  They should be, since
 <tt>get</tt> is supposed to call <tt>do_get</tt> with exactly
 the arguments it was given.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.1.1 [facet.num.get.members], change</p>
 <pre>  iter_type get(iter_type in, iter_type end, ios_base&amp; str,
                 ios_base::iostate&amp; err, short&amp; val) const;
 </pre>
 <p>to</p>
 <pre>  iter_type get(iter_type in, iter_type end, ios_base&amp; str,
                 ios_base::iostate&amp; err, float&amp; val) const;
 </pre>


 <hr>
 <h3><a name="276"></a>276. Assignable requirement for container value type overly strict</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2000-11-07</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 23.1/3 states that the objects stored in a container must be
 Assignable.  23.3.1 [map], paragraph 2,
 states that map satisfies all requirements for a container, while in
 the same time defining value_type as pair&lt;const Key, T&gt; - a type
 that is not Assignable.
 </p>

 <p>
 It should be noted that there exists a valid and non-contradictory
 interpretation of the current text. The wording in 23.1/3 avoids
 mentioning value_type, referring instead to "objects stored in a
 container." One might argue that map does not store objects of
 type map::value_type, but of map::mapped_type instead, and that the
 Assignable requirement applies to map::mapped_type, not
 map::value_type.
 </p>

 <p>
 However, this makes map a special case (other containers store objects of
 type value_type) and the Assignable requirement is needlessly restrictive in
 general.
 </p>

 <p>
 For example, the proposed resolution of active library issue
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> is to make set::iterator a constant iterator; this
 means that no set operations can exploit the fact that the stored
 objects are Assignable.
 </p>

 <p>
 This is related to, but slightly broader than, closed issue
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>23.1/3: Strike the trailing part of the sentence:</p>
     <blockquote><p>
     , and the additional requirements of Assignable types from 23.1/3
     </p></blockquote>
 <p>so that it reads:</p>
     <blockquote><p>
     -3- The type of objects stored in these components must meet the
     requirements of CopyConstructible types (lib.copyconstructible).
     </p></blockquote>

 <p>23.1/4: Modify to make clear that this requirement is not for all
 containers.  Change to:</p>

 <blockquote><p>
 -4- Table 64 defines the Assignable requirement.  Some containers
 require this property of the types to be stored in the container.  T is
 the type used to instantiate the container. t is a value of T, and u is
 a value of (possibly const) T.
 </p></blockquote>

 <p>23.1, Table 65: in the first row, change "T is Assignable" to "T is
 CopyConstructible".</p>

 <p>23.2.1/2: Add sentence for Assignable requirement.  Change to:</p>

 <blockquote><p>
 -2- A deque satisfies all of the requirements of a container and of a
 reversible container (given in tables in lib.container.requirements) and
 of a sequence, including the optional sequence requirements
 (lib.sequence.reqmts).  In addition to the requirements on the stored
 object described in 23.1[lib.container.requirements], the stored object
 must also meet the requirements of Assignable.  Descriptions are
 provided here only for operations on deque that are not described in one
 of these tables or for operations where there is additional semantic
 information.
 </p></blockquote>

 <p>23.2.2/2:  Add Assignable requirement to specific methods of list.
 Change to:</p>

 <blockquote>
 <p>-2- A list satisfies all of the requirements of a container and of a
 reversible container (given in two tables in lib.container.requirements)
 and of a sequence, including most of the the optional sequence
 requirements (lib.sequence.reqmts). The exceptions are the operator[]
 and at member functions, which are not provided.

 [Footnote: These member functions are only provided by containers whose
 iterators are random access iterators. --- end foonote]
 </p>

 <p>list does not require the stored type T to be Assignable unless the
 following methods are instantiated:

 [Footnote: Implementors are permitted but not required to take advantage
 of T's Assignable properties for these methods. -- end foonote]
 </p>
 <pre>     list&lt;T,Allocator&gt;&amp; operator=(const list&lt;T,Allocator&gt;&amp;  x );
      template &lt;class InputIterator&gt;
        void assign(InputIterator first, InputIterator last);
      void assign(size_type n, const T&amp; t);
 </pre>


 <p>Descriptions are provided here only for operations on list that are not
 described in one of these tables or for operations where there is
 additional semantic information.</p>
 </blockquote>

 <p>23.2.4/2:   Add sentence for Assignable requirement.  Change to:</p>

 <blockquote><p>
 -2- A vector satisfies all of the requirements of a container and of a
 reversible container (given in two tables in lib.container.requirements)
 and of a sequence, including most of the optional sequence requirements
 (lib.sequence.reqmts). The exceptions are the push_front and pop_front
 member functions, which are not provided.  In addition to the
 requirements on the stored object described in
 23.1[lib.container.requirements], the stored object must also meet the
 requirements of Assignable.  Descriptions are provided here only for
 operations on vector that are not described in one of these tables or
 for operations where there is additional semantic information.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>list, set, multiset, map, multimap are able to store non-Assignables.
 However, there is some concern about <tt>list&lt;T&gt;</tt>:
 although in general there's no reason for T to be Assignable, some
 implementations of the member functions <tt>operator=</tt> and
 <tt>assign</tt> do rely on that requirement.  The LWG does not want
 to forbid such implementations.</p>

 <p>Note that the type stored in a standard container must still satisfy
 the requirements of the container's allocator; this rules out, for
 example, such types as "const int".  See issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#274">274</a>
 for more details.
 </p>

 <p>In principle we could also relax the "Assignable" requirement for
 individual <tt>vector</tt> member functions, such as
 <tt>push_back</tt>.  However, the LWG did not see great value in such
 selective relaxation.  Doing so would remove implementors' freedom to
 implement <tt>vector::push_back</tt> in terms of
 <tt>vector::insert</tt>.</p>


 <hr>
 <h3><a name="278"></a>278. What does iterator validity mean?</h3>
 <p><b>Section:</b> 23.2.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger <b>Date:</b> 2000-11-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 23.2.4.4 [list.ops] states that
 </p>
 <pre>  void splice(iterator position, list&lt;T, Allocator&gt;&amp; x);
 </pre>
 <p>
 <i>invalidates</i> all iterators and references to list <tt>x</tt>.
 </p>

 <p>
 But what does the C++ Standard mean by "invalidate"?  You
 can still dereference the iterator to a spliced list element, but
 you'd better not use it to delimit a range within the original
 list. For the latter operation, it has definitely lost some of its
 validity.
 </p>

 <p>
 If we accept the proposed resolution to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>,
 then we'd better clarify that a "valid" iterator need no
 longer designate an element within the same container as it once did.
 We then have to clarify what we mean by invalidating a past-the-end
 iterator, as when a vector or string grows by reallocation. Clearly,
 such an iterator has a different kind of validity. Perhaps we should
 introduce separate terms for the two kinds of "validity."
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following text to the end of section 24.1 [iterator.requirements],
 after paragraph 5:</p>
 <blockquote><p>
 An <i>invalid</i> iterator is an iterator that may be
 singular. [Footnote: This definition applies to pointers, since
 pointers are iterators. The effect of dereferencing an iterator that
 has been invalidated is undefined.]
 </p></blockquote>

 <p><i>[post-Copenhagen: Matt provided wording.]</i></p>


 <p><i>[Redmond: General agreement with the intent, some objections to
 the wording.  Dave provided new wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>This resolution simply defines a term that the Standard uses but
   never defines, "invalid", in terms of a term that is defined,
   "singular".</p>

 <p>Why do we say "may be singular", instead of "is singular"?  That's
   becuase a valid iterator is one that is known to be nonsingular.
   Invalidating an iterator means changing it in such a way that it's
   no longer known to be nonsingular.  An example: inserting an
   element into the middle of a vector is correctly said to invalidate
   all iterators pointing into the vector.  That doesn't necessarily
   mean they all become singular.</p>


 <hr>
 <h3><a name="280"></a>280. Comparison of reverse_iterator to const reverse_iterator</h3>
 <p><b>Section:</b> 24.4.1 [reverse.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve Cleary <b>Date:</b> 2000-11-27</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 This came from an email from Steve Cleary to Fergus in reference to
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#179">179</a>. The library working group briefly discussed
 this in Toronto and believed it should be a separate issue.  There was
 also some reservations about whether this was a worthwhile problem to
 fix.
 </p>

 <p>
 Steve said: "Fixing reverse_iterator. std::reverse_iterator can
 (and should) be changed to preserve these additional
 requirements." He also said in email that it can be done without
 breaking user's code: "If you take a look at my suggested
 solution, reverse_iterator doesn't have to take two parameters; there
 is no danger of breaking existing code, except someone taking the
 address of one of the reverse_iterator global operator functions, and
 I have to doubt if anyone has ever done that. . .  <i>But</i>, just in
 case they have, you can leave the old global functions in as well --
 they won't interfere with the two-template-argument functions.  With
 that, I don't see how <i>any</i> user code could break."
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 <b>Section:</b> 24.4.1.1 [reverse.iterator]
 add/change the following declarations:</p>
 <pre>  A) Add a templated assignment operator, after the same manner
         as the templated copy constructor, i.e.:

   template &lt; class U &gt;
   reverse_iterator &lt; Iterator &gt;&amp; operator=(const reverse_iterator&lt; U &gt;&amp; u);

   B) Make all global functions (except the operator+) have
   two template parameters instead of one, that is, for
   operator ==, !=, &lt;, &gt;, &lt;=, &gt;=, - replace:

        template &lt; class Iterator &gt;
        typename reverse_iterator&lt; Iterator &gt;::difference_type operator-(
                  const reverse_iterator&lt; Iterator &gt;&amp; x,
                  const reverse_iterator&lt; Iterator &gt;&amp; y);

   with:

       template &lt; class Iterator1, class Iterator2 &gt;
       typename reverse_iterator &lt; Iterator1 &gt;::difference_type operator-(
                  const reverse_iterator &lt; Iterator1 &gt; &amp; x,
                  const reverse_iterator &lt; Iterator2 &gt; &amp; y);
 </pre>
 <p>
 Also make the addition/changes for these signatures in
 24.4.1.3 [reverse.iter.ops].
 </p>

 <p><i>[
 Copenhagen: The LWG is concerned that the proposed resolution
 introduces new overloads.  Experience shows that introducing
 overloads is always risky, and that it would be inappropriate to
 make this change without implementation experience.  It may be
 desirable to provide this feature in a different way.
 ]</i></p>


 <p><i>[
 Lillehammer: We now have implementation experience, and agree that
 this solution is safe and correct.
 ]</i></p>


 <hr>
 <h3><a name="281"></a>281. std::min() and max() requirements overly restrictive</h3>
 <p><b>Section:</b> 25.3.7 [alg.min.max] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-12-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.min.max">issues</a> in [alg.min.max].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#486">486</a></p>
 <p><b>Discussion:</b></p>
 <p>The requirements in 25.3.7, p1 and 4 call for T to satisfy the
 requirements of <tt>LessThanComparable</tt> ( [lessthancomparable])
 and <tt>CopyConstructible</tt> (20.1.1 [utility.arg.requirements]).
 Since the functions take and return their arguments and result by
 const reference, I believe the <tt>CopyConstructible</tt> requirement
 is unnecessary.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the <tt>CopyConstructible</tt> requirement. Specifically, replace
 25.3.7, p1 with</p>
 <p><b>-1- Requires:</b> Type T is <tt>LessThanComparable</tt>
 ( [lessthancomparable]).
 </p>
 <p>and replace 25.3.7, p4 with</p>
 <p><b>-4- Requires:</b> Type T is <tt>LessThanComparable</tt>
 ( [lessthancomparable]).
 </p>


 <hr>
 <h3><a name="282"></a>282. What types does numpunct grouping refer to?</h3>
 <p><b>Section:</b> 22.2.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2000-12-05</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.put.virtuals">issues</a> in [facet.num.put.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Paragraph 16 mistakenly singles out integral types for inserting
 thousands_sep() characters.  This conflicts with the syntax for floating
 point numbers described under 22.2.3.1/2.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change paragraph 16 from:</p>

 <blockquote><p>
 For integral types, punct.thousands_sep() characters are inserted into
 the sequence as determined by the value returned by punct.do_grouping()
 using the method described in 22.2.3.1.2 [facet.numpunct.virtuals].
 </p></blockquote>

 <p>To:</p>

 <blockquote><p>
 For arithmetic types, punct.thousands_sep() characters are inserted into
 the sequence as determined by the value returned by punct.do_grouping()
 using the method described in 22.2.3.1.2 [facet.numpunct.virtuals].
 </p></blockquote>

 <p><i>[
 Copenhagen: Opinions were divided about whether this is actually an
 inconsistency, but at best it seems to have been unintentional.  This
 is only an issue for floating-point output: The standard is
 unambiguous that implementations must parse thousands_sep characters
 when performing floating-point.  The standard is also unambiguous that
 this requirement does not apply to the "C" locale.
 ]</i></p>


 <p><i>[
 A survey of existing practice is needed; it is believed that some
 implementations do insert thousands_sep characters for floating-point
 output and others fail to insert thousands_sep characters for
 floating-point input even though this is unambiguously required by the
 standard.
 ]</i></p>


 <p><i>[Post-Curaçao: the above proposed resolution is the consensus of
 Howard, Bill, Pete, Benjamin, Nathan, Dietmar, Boris, and Martin.]</i></p>


 <hr>
 <h3><a name="283"></a>283. std::replace() requirement incorrect/insufficient</h3>
 <p><b>Section:</b> 25.2.5 [alg.replace] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-12-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.replace">issues</a> in [alg.replace].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#483">483</a></p>
 <p><b>Discussion:</b></p>
 <p>
 (revision of the further discussion)
 There are a number of problems with the requires clauses for the
 algorithms in 25.1 and 25.2. The requires clause of each algorithm
 should describe the necessary and sufficient requirements on the inputs
 to the algorithm such that the algorithm compiles and runs properly.
 Many of the requires clauses fail to do this. Here is a summary of the kinds
 of mistakes:
 </p>

 <ol>
 <li>
 Use of EqualityComparable, which only puts requirements on a single
 type, when in fact an equality operator is required between two
 different types, typically either T and the iterator's value type
 or between the value types of two different iterators.
 </li>
 <li>
 Use of Assignable for T when in fact what was needed is Assignable
 for the value_type of the iterator, and convertability from T to the
 value_type of the iterator. Or for output iterators, the requirement
 should be that T is writable to the iterator (output iterators do
 not have value types).
 </li>
 </ol>

 <p>
 Here is the list of algorithms that contain mistakes:
 </p>

 <ul>
 <li>25.1.2 std::find</li>
 <li>25.1.6 std::count</li>
 <li>25.1.8 std::equal</li>
 <li>25.1.9 std::search, std::search_n</li>
 <li>25.2.4 std::replace, std::replace_copy</li>
 <li>25.2.5 std::fill</li>
 <li>25.2.7 std::remove, std::remove_copy</li>
 </ul>

 <p>
 Also, in the requirements for EqualityComparable, the requirement that
 the operator be defined for const objects is lacking.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>20.1.1 Change p1 from</p>

 <p>In Table 28, <tt>T</tt> is a type to be supplied by a C++ program
 instantiating a template, <tt>a</tt>, <tt>b</tt>, and <tt>c</tt> are
 values of type <tt>T</tt>.
 </p>

 <p>to</p>

 <p>
 In Table 28, <tt>T</tt> is a type to be supplied by a C++ program
 instantiating a template, <tt>a</tt>, <tt>b</tt>, and <tt>c</tt> are
 values of type <tt>const T</tt>.
 </p>

 <p>25 Between p8 and p9</p>

 <p>Add the following sentence:</p>

 <p>When the description of an algorithm gives an expression such as
 <tt>*first == value</tt> for a condition, it is required that the expression
 evaluate to either true or false in boolean contexts.</p>

 <p>25.1.2 Change p1 by deleting the requires clause.</p>

 <p>25.1.6 Change p1 by deleting the requires clause.</p>

 <p>25.1.9</p>

 <p>Change p4 from</p>

 <p>-4- Requires: Type <tt>T</tt> is <tt>EqualityComparable</tt>
 (20.1.1), type Size is convertible to integral type (4.7.12.3).
 </p>

 <p>to</p>

 <p>-4- Requires: The type <tt>Size</tt> is convertible to integral
 type (4.7.12.3).</p>

 <p>25.2.4 Change p1 from</p>

 <p>-1- Requires: Type <tt>T</tt> is <tt>Assignable</tt> (23.1 ) (and, for <tt>replace()</tt>, <tt>EqualityComparable</tt> (20.1.1 )).</p>

 <p>to</p>

 <p>-1- Requires: The expression <tt>*first = new_value</tt> must be valid.</p>

 <p>and change p4 from</p>

 <p>-4- Requires: Type <tt>T</tt> is <tt>Assignable</tt> (23.1) (and,
 for <tt>replace_copy()</tt>, <tt>EqualityComparable</tt>
 (20.1.1)). The ranges <tt>[first, last)</tt> and <tt>[result, result +
 (last - first))</tt> shall not overlap.</p>

 <p>to</p>

 <p>-4- Requires: The results of the expressions <tt>*first</tt> and
 <tt>new_value</tt> must be writable to the result output iterator. The
 ranges <tt>[first, last)</tt> and <tt>[result, result + (last -
 first))</tt> shall not overlap.</p>


 <p>25.2.5 Change p1 from</p>

 <p>-1- Requires: Type <tt>T</tt> is <tt>Assignable</tt> (23.1). The
 type <tt>Size</tt> is convertible to an integral type (4.7.12.3).</p>

 <p>to</p>

 <p>-1- Requires: The expression <tt>value</tt> must be is writable to
 the output iterator. The type <tt>Size</tt> is convertible to an
 integral type (4.7.12.3).</p>

 <p>25.2.7 Change p1 from</p>

 <p>-1- Requires: Type <tt>T</tt> is <tt>EqualityComparable</tt> (20.1.1).</p>

 <p>to</p>

 <p>
 -1- Requires: The value type of the iterator must be
 <tt>Assignable</tt> (23.1).
 </p>


 <p><b>Rationale:</b></p>
 <p>
 The general idea of the proposed solution is to remove the faulty
 requires clauses and let the returns and effects clauses speak for
 themselves. That is, the returns clauses contain expressions that must
 be valid, and therefore already imply the correct requirements. In
 addition, a sentence is added at the beginning of chapter 25 saying
 that expressions given as conditions must evaluate to true or false in
 a boolean context. An alternative would be to say that the type of
 these condition expressions must be literally bool, but that would be
 imposing a greater restriction that what the standard currently says
 (which is convertible to bool).
 </p>


 <hr>
 <h3><a name="284"></a>284. unportable example in 20.3.7, p6</h3>
 <p><b>Section:</b> 20.6.7 [comparisons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-12-26</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The example in 20.6.7 [comparisons], p6 shows how to use the C
 library function <tt>strcmp()</tt> with the function pointer adapter
 <tt>ptr_fun()</tt>. But since it's unspecified whether the C library
 functions have <tt>extern "C"</tt> or <tt>extern
 "C++"</tt> linkage [17.4.2.2 [using.linkage]], and since
 function pointers with different the language linkage specifications
 (7.5 [dcl.link]) are incompatible, whether this example is
 well-formed is unspecified.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 20.6.7 [comparisons] paragraph 6 from:</p>
 <blockquote>
   <p>[<i>Example:</i></p>
   <pre>    replace_if(v.begin(), v.end(), not1(bind2nd(ptr_fun(strcmp), "C")), "C++");
   </pre>
   <p>replaces each <tt>C</tt> with <tt>C++</tt> in sequence <tt>v</tt>.</p>
 </blockquote>


 <p>to:</p>
 <blockquote>
   <p>[<i>Example:</i></p>
   <pre>    int compare(const char*, const char*);
     replace_if(v.begin(), v.end(),
                not1(bind2nd(ptr_fun(compare), "abc")), "def");
   </pre>
   <p>replaces each <tt>abc</tt> with <tt>def</tt> in sequence <tt>v</tt>.</p>
 </blockquote>

 <p>Also, remove footnote 215 in that same paragraph.</p>

 <p><i>[Copenhagen: Minor change in the proposed resolution.  Since this
 issue deals in part with C and C++ linkage, it was believed to be too
 confusing for the strings in the example to be "C" and "C++".
 ]</i></p>


 <p><i>[Redmond: More minor changes.  Got rid of the footnote (which
 seems to make a sweeping normative requirement, even though footnotes
 aren't normative), and changed the sentence after the footnote so that
 it corresponds to the new code fragment.]</i></p>


 <hr>
 <h3><a name="285"></a>285. minor editorial errors in fstream ctors</h3>
 <p><b>Section:</b> 27.8.1.7 [ifstream.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2000-12-31</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.8.1.7 [ifstream.cons], p2, 27.8.1.11 [ofstream.cons], p2, and
 27.8.1.15 [fstream.cons], p2 say about the effects of each constructor:
 </p>

 <p>... If that function returns a null pointer, calls
 <tt>setstate(failbit)</tt> (which may throw <tt>ios_base::failure</tt>).
 </p>

 <p>The parenthetical note doesn't apply since the ctors cannot throw an
 exception due to the requirement in 27.4.4.1 [basic.ios.cons], p3
 that <tt>exceptions()</tt> be initialized to <tt>ios_base::goodbit</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Strike the parenthetical note from the Effects clause in each of the
 paragraphs mentioned above.
 </p>


 <hr>
 <h3><a name="286"></a>286. &lt;cstdlib&gt; requirements missing size_t typedef</h3>
 <p><b>Section:</b> 25.4 [alg.c.library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 2000-12-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.c.library">issues</a> in [alg.c.library].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The &lt;cstdlib&gt; header file contains prototypes for bsearch and
 qsort (C++ Standard section 25.4 paragraphs 3 and 4) and other
 prototypes (C++ Standard section 21.4 paragraph 1 table 49) that
 require the typedef size_t. Yet size_t is not listed in the
 &lt;cstdlib&gt; synopsis table 78 in section 25.4.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the type size_t to Table 78 (section 25.4) and add
 the type size_t &lt;cstdlib&gt; to Table 97 (section C.2).
 </p>


 <p><b>Rationale:</b></p>
 <p>Since size_t is in &lt;stdlib.h&gt;, it must also be in &lt;cstdlib&gt;.</p>


 <hr>
 <h3><a name="288"></a>288. &lt;cerrno&gt; requirements missing macro EILSEQ</h3>
 <p><b>Section:</b> 19.3 [errno] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Judy Ward <b>Date:</b> 2000-12-30</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 ISO/IEC 9899:1990/Amendment1:1994 Section 4.3 States: "The list
 of macros defined in &lt;errno.h&gt; is adjusted to include a new
 macro, EILSEQ"
 </p>

 <p>
 ISO/IEC 14882:1998(E) section 19.3 does not refer
 to the above amendment.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Update Table 26 (section 19.3) "Header  &lt;cerrno&gt; synopsis"
 and Table 95 (section C.2) "Standard Macros" to include EILSEQ.
 </p>


 <hr>
 <h3><a name="291"></a>291. Underspecification of set algorithms</h3>
 <p><b>Section:</b> 25.3.5 [alg.set.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2001-01-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.set.operations">issues</a> in [alg.set.operations].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The standard library contains four algorithms that compute set
 operations on sorted ranges: <tt>set_union</tt>, <tt>set_intersection</tt>,
 <tt>set_difference</tt>, and <tt>set_symmetric_difference</tt>.  Each
 of these algorithms takes two sorted ranges as inputs, and writes the
 output of the appropriate set operation to an output range.  The elements
 in the output range are sorted.
 </p>

 <p>
 The ordinary mathematical definitions are generalized so that they
 apply to ranges containing multiple copies of a given element.  Two
 elements are considered to be "the same" if, according to an
 ordering relation provided by the user, neither one is less than the
 other.  So, for example, if one input range contains five copies of an
 element and another contains three, the output range of <tt>set_union</tt>
 will contain five copies, the output range of
 <tt>set_intersection</tt> will contain three, the output range of
 <tt>set_difference</tt> will contain two, and the output range of
 <tt>set_symmetric_difference</tt> will contain two.
 </p>

 <p>
 Because two elements can be "the same" for the purposes
 of these set algorithms, without being identical in other respects
 (consider, for example, strings under case-insensitive comparison),
 this raises a number of unanswered questions:
 </p>

 <ul>
 <li>If we're copying an element that's present in both of the
 input ranges, which one do we copy it from?</li>
 <li>If there are <i>n</i> copies of an element in the relevant
 input range, and the output range will contain fewer copies (say
 <i>m</i>) which ones do we choose?  The first <i>m</i>, or the last
 <i>m</i>, or something else?</li>
 <li>Are these operations stable?  That is, does a run of equivalent
 elements appear in the output range in the same order as as it
 appeared in the input range(s)?</li>
 </ul>

 <p>
 The standard should either answer these questions, or explicitly
 say that the answers are unspecified.  I prefer the former option,
 since, as far as I know, all existing implementations behave the
 same way.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add the following to the end of 25.3.5.2 [set.union] paragraph 5:</p>
 <blockquote><p>
 If [first1, last1) contains <i>m</i> elements that are equivalent to
 each other and [first2, last2) contains <i>n</i> elements that are
 equivalent to them, then max(<i>m</i>, <i>n</i>) of these elements
 will be copied to the output range: all <i>m</i> of these elements
 from [first1, last1), and the last max(<i>n-m</i>, 0) of them from
 [first2, last2), in that order.
 </p></blockquote>

 <p>Add the following to the end of 25.3.5.3 [set.intersection] paragraph 5:</p>
 <blockquote><p>
 If [first1, last1) contains <i>m</i> elements that are equivalent to each
 other and [first2, last2) contains <i>n</i> elements that are
 equivalent to them, the first min(<i>m</i>, <i>n</i>) of those
 elements from [first1, last1) are copied to the output range.
 </p></blockquote>

 <p>Add a new paragraph, <b>Notes</b>, after 25.3.5.4 [set.difference]
 paragraph 4:</p>
 <blockquote><p>
 If [first1, last1) contains <i>m</i> elements that are equivalent to each
 other and [first2, last2) contains <i>n</i> elements that are
 equivalent to them, the last max(<i>m-n</i>, 0) elements from
 [first1, last1) are copied to the output range.
 </p></blockquote>

 <p>Add a new paragraph, <b>Notes</b>, after 25.3.5.5 [set.symmetric.difference]
 paragraph 4:</p>
 <blockquote><p>
 If [first1, last1) contains <i>m</i> elements that are equivalent to
 each other and [first2, last2) contains <i>n</i> elements that are
 equivalent to them, then |<i>m - n</i>| of those elements will be
 copied to the output range: the last <i>m - n</i> of these elements
 from [first1, last1) if <i>m</i> &gt; <i>n</i>, and the last <i>n -
 m</i> of these elements from [first2, last2) if <i>m</i> &lt; <i>n</i>.
 </p></blockquote>

 <p><i>[Santa Cruz: it's believed that this language is clearer than
   what's in the Standard.  However, it's also believed that the
   Standard may already make these guarantees (although not quite in
   these words).  Bill and Howard will check and see whether they think
   that some or all of these changes may be redundant.  If so, we may
   close this issue as NAD.]</i></p>


 <p><b>Rationale:</b></p>
 <p>For simple cases, these descriptions are equivalent to what's
   already in the Standard.  For more complicated cases, they describe
   the behavior of existing implementations.</p>


 <hr>
 <h3><a name="292"></a>292. effects of a.copyfmt (a)</h3>
 <p><b>Section:</b> 27.4.4.2 [basic.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-01-05</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.ios.members">active issues</a> in [basic.ios.members].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.members">issues</a> in [basic.ios.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The Effects clause of the member function <tt>copyfmt()</tt> in
 27.4.4.2, p15 doesn't consider the case where the left-hand side
 argument is identical to the argument on the right-hand side, that is
 <tt>(this == &amp;rhs)</tt>.  If the two arguments are identical there
 is no need to copy any of the data members or call any callbacks
 registered with <tt>register_callback()</tt>.  Also, as Howard Hinnant
 points out in message c++std-lib-8149 it appears to be incorrect to
 allow the object to fire <tt>erase_event</tt> followed by
 <tt>copyfmt_event</tt> since the callback handling the latter event
 may inadvertently attempt to access memory freed by the former.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the Effects clause in 27.4.4.2, p15 from</p>

 <blockquote><p>
 <b>-15- Effects:</b>Assigns to the member objects of <tt>*this</tt>
 the corresponding member objects of <tt>rhs</tt>, except that...
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
 <b>-15- Effects:</b>If <tt>(this == &amp;rhs)</tt> does nothing. Otherwise
 assigns to the member objects of <tt>*this</tt> the corresponding member
 objects of <tt>rhs</tt>, except that...
 </p></blockquote>


 <hr>
 <h3><a name="294"></a>294. User defined macros and standard headers</h3>
 <p><b>Section:</b> 17.4.3.2.1 [macro.names] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> James Kanze <b>Date:</b> 2001-01-11</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Paragraph 2 of 17.4.3.2.1 [macro.names] reads: "A
 translation unit that includes a header shall not contain any macros
 that define names declared in that header." As I read this, it
 would mean that the following program is legal:</p>

 <pre>  #define npos 3.14
   #include &lt;sstream&gt;
 </pre>

 <p>since npos is not defined in &lt;sstream&gt;.  It is, however, defined
 in &lt;string&gt;, and it is hard to imagine an implementation in
 which &lt;sstream&gt; didn't include &lt;string&gt;.</p>

 <p>I think that this phrase was probably formulated before it was
 decided that a standard header may freely include other standard
 headers.  The phrase would be perfectly appropriate for C, for
 example.  In light of 17.4.4.1 [res.on.headers] paragraph 1, however,
 it isn't stringent enough.</p>


 <p><b>Proposed resolution:</b></p>
 <p>For 17.4.3.2.1 [macro.names], replace the current wording, which reads:</p>
 <blockquote>
      <p>Each name defined as a macro in a header is reserved to the
      implementation for any use if the translation unit includes
      the header.168)</p>

      <p>A translation unit that includes a header shall not contain any
      macros that define names declared or defined in that header. Nor shall
      such a translation unit define macros for names lexically
      identical to keywords.</p>

      <p>168) It is not permissible to remove a library macro definition by
      using the #undef directive.</p>
 </blockquote>

 <p>with the wording:</p>

 <blockquote>
      <p>A translation unit that includes a standard library header shall not
      #define or #undef names declared in any standard library header.</p>

      <p>A translation unit shall not #define or #undef names lexically
      identical to keywords.</p>
 </blockquote>

 <p><i>[Lillehammer: Beman provided new wording]</i></p>


 <hr>
 <h3><a name="295"></a>295. Is abs defined in &lt;cmath&gt;?</h3>
 <p><b>Section:</b> 26.7 [c.math] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Jens Maurer <b>Date:</b> 2001-01-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#c.math">issues</a> in [c.math].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 80 lists the contents of the &lt;cmath&gt; header.  It does not
 list <tt>abs()</tt>.  However, 26.5, paragraph 6, which lists added
 signatures present in &lt;cmath&gt;, does say that several overloads
 of <tt>abs()</tt> should be defined in &lt;cmath&gt;.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add <tt>abs</tt> to Table 80.  Also, remove the parenthetical list
 of functions "(abs(), div(), rand(), srand())" from 26.5 [numarray],
 paragraph 1.
 </p>

 <p><i>[Copenhagen: Modified proposed resolution so that it also gets
 rid of that vestigial list of functions in paragraph 1.]</i></p>


 <p><b>Rationale:</b></p>
 <p>All this DR does is fix a typo; it's uncontroversial.  A
 separate question is whether we're doing the right thing in
 putting some overloads in &lt;cmath&gt; that we aren't also
 putting in &lt;cstdlib&gt;.  That's issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>.</p>


 <hr>
 <h3><a name="297"></a>297. const_mem_fun_t&lt;&gt;::argument_type should be const T*</h3>
 <p><b>Section:</b> 20.6.8 [logical.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-01-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The class templates <tt>const_mem_fun_t</tt> in 20.5.8, p8 and
 <tt>const_mem_fun1_t</tt>
 in 20.5.8, p9 derive from <tt>unary_function&lt;T*, S&gt;</tt>, and
 <tt>binary_function&lt;T*,
 A, S&gt;</tt>, respectively. Consequently, their <tt>argument_type</tt>, and
 <tt>first_argument_type</tt>
 members, respectively, are both defined to be <tt>T*</tt> (non-const).
 However, their function call member operator takes a <tt>const T*</tt>
 argument. It is my opinion that <tt>argument_type</tt> should be <tt>const
 T*</tt> instead, so that one can easily refer to it in generic code. The
 example below derived from existing code fails to compile due to the
 discrepancy:
 </p>

 <p><tt>template &lt;class T&gt;</tt>
 <br><tt>void foo (typename T::argument_type arg)&nbsp;&nbsp; // #1</tt>
 <br><tt>{</tt>
 <br><tt>&nbsp;&nbsp;&nbsp; typename T::result_type (T::*pf) (typename
 T::argument_type)
 const =&nbsp;&nbsp; // #2</tt>
 <br><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &amp;T::operator();</tt>
 <br><tt>}</tt>
 </p>

 <p><tt>struct X { /* ... */ };</tt></p>

 <p><tt>int main ()</tt>
 <br><tt>{</tt>
 <br><tt>&nbsp;&nbsp;&nbsp; const X x;</tt>
 <br><tt>&nbsp;&nbsp;&nbsp; foo&lt;std::const_mem_fun_t&lt;void, X&gt;
 &gt;(&amp;x);&nbsp;&nbsp;
 // #3</tt>
 <br><tt>}</tt>
 </p>

 <p>#1 <tt>foo()</tt> takes a plain unqualified <tt>X*</tt> as an argument
 <br>#2 the type of the pointer is incompatible with the type of the member
 function
 <br>#3 the address of a constant being passed to a function taking a non-const
 <tt>X*</tt>
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the top portion of the definition of the class template
 const_mem_fun_t in 20.5.8, p8
 </p>
 <p><tt>template &lt;class S, class T&gt; class const_mem_fun_t</tt>
 <br><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; : public
 unary_function&lt;T*, S&gt; {</tt>
 </p>
 <p>with</p>
 <p><tt>template &lt;class S, class T&gt; class const_mem_fun_t</tt>
 <br><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; : public
 unary_function&lt;<b>const</b> T*, S&gt; {</tt>
 </p>
 <p>Also replace the top portion of the definition of the class template
 const_mem_fun1_t in 20.5.8, p9</p>
 <p><tt>template &lt;class S, class T, class A&gt; class const_mem_fun1_t</tt>
 <br><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; : public
 binary_function&lt;T*, A, S&gt; {</tt>
 </p>
 <p>with</p>
 <p><tt>template &lt;class S, class T, class A&gt; class const_mem_fun1_t</tt>
 <br><tt>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; : public
 binary_function&lt;<b>const</b> T*, A, S&gt; {</tt>
 </p>


 <p><b>Rationale:</b></p>
 <p>This is simply a contradiction: the <tt>argument_type</tt> typedef,
 and the argument type itself, are not the same.</p>


 <hr>
 <h3><a name="298"></a>298. ::operator delete[] requirement incorrect/insufficient</h3>
 <p><b>Section:</b> 18.5.1.2 [new.delete.array] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> John A. Pedretti <b>Date:</b> 2001-01-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The default behavior of <tt>operator delete[]</tt> described in 18.5.1.2, p12 -
 namely that for non-null value of <i>ptr</i>, the operator reclaims storage
 allocated by the earlier call to the default <tt>operator new[]</tt> - is not
 correct in all cases. Since the specified <tt>operator new[]</tt> default
 behavior is to call <tt>operator new</tt> (18.5.1.2, p4, p8), which can be
 replaced, along with <tt>operator delete</tt>, by the user, to implement their
 own memory management, the specified default behavior of<tt> operator
 delete[]</tt> must be to call <tt>operator delete</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 18.5.1.2, p12 from</p>
 <blockquote><p>
 <b>-12-</b> <b>Default behavior:</b></p>
 <ul>
 <li>
 For a null value of <i><tt>ptr</tt></i> , does nothing.
 </li>
 <li>
 Any other value of <i><tt>ptr</tt></i> shall be a value returned
 earlier by a call to the default <tt>operator new[](std::size_t)</tt>.
 [Footnote: The value must not have been invalidated by an intervening
 call to <tt>operator delete[](void*)</tt> (17.4.3.8 [res.on.arguments]).
 --- end footnote]
 For such a non-null value of <i><tt>ptr</tt></i> , reclaims storage
 allocated by the earlier call to the default <tt>operator new[]</tt>.
 </li>
 </ul>
 </blockquote>

 <p>to</p>

 <blockquote><p>
 <b>-12-</b> <b>Default behavior: </b>Calls <tt>operator
 delete(</tt><i>ptr</i>)
 or <tt>operator delete(<i>ptr</i>, std::nothrow)</tt> respectively.
 </p></blockquote>
 <p>and expunge paragraph 13.</p>


 <hr>
 <h3><a name="300"></a>300. list::merge() specification incomplete</h3>
 <p><b>Section:</b> 23.2.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> John Pedretti <b>Date:</b> 2001-01-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The "Effects" clause for list::merge() (23.2.4.4 [list.ops], p23)
 appears to be incomplete: it doesn't cover the case where the argument
 list is identical to *this (i.e., this == &amp;x). The requirement in the
 note in p24 (below) is that x be empty after the merge which is surely
 unintended in this case.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.2.4.4 [list.ops], replace paragraps 23-25 with:</p>
 <blockquote>
 <p>
 23 Effects: if (&amp;x == this) does nothing; otherwise, merges the two
 sorted ranges [begin(), end()) and [x.begin(), x.end()).  The result
 is a range in which the elements will be sorted in non-decreasing
 order according to the ordering defined by comp; that is, for every
 iterator i in the range other than the first, the condition comp(*i,
 *(i - 1)) will be false.
 </p>

 <p>
 24 Notes: Stable: if (&amp;x != this), then for equivalent elements in the
 two original ranges, the elements from the original range [begin(),
 end()) always precede the elements from the original range [x.begin(),
 x.end()).  If (&amp;x != this) the range [x.begin(), x.end()) is empty
 after the merge.
 </p>

 <p>
 25 Complexity: At most size() + x.size() - 1 applications of comp if
 (&amp;x !  = this); otherwise, no applications of comp are performed.  If
 an exception is thrown other than by a comparison there are no
 effects.
 </p>

 </blockquote>

 <p><i>[Copenhagen: The original proposed resolution did not fix all of
 the problems in 23.2.4.4 [list.ops], p22-25.  Three different
 paragraphs (23, 24, 25) describe the effects of <tt>merge</tt>.
 Changing p23, without changing the other two, appears to introduce
 contradictions.  Additionally, "merges the argument list into the
 list" is excessively vague.]</i></p>


 <p><i>[Post-Curaçao: Robert Klarer provided new wording.]</i></p>


 <hr>
 <h3><a name="301"></a>301. basic_string template ctor effects clause omits allocator argument</h3>
 <p><b>Section:</b> 21.3.1 [string.require] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-01-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.require">issues</a> in [string.require].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The effects clause for the basic_string template ctor in 21.3.1, p15
 leaves out the third argument of type Allocator. I believe this to be
 a mistake.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace</p>

 <blockquote>
     <p><b>-15- Effects:</b> If <i><tt>InputIterator</tt></i> is an integral
     type, equivalent to</p>

     <blockquote><p><tt>basic_string(static_cast&lt;size_type&gt;(begin),
     static_cast&lt;value_type&gt;(end))</tt></p></blockquote>
 </blockquote>

 <p>with</p>

 <blockquote>
     <p><b>-15- Effects:</b> If <i><tt>InputIterator</tt></i> is an integral
     type, equivalent to</p>

     <blockquote><p><tt>basic_string(static_cast&lt;size_type&gt;(begin),
     static_cast&lt;value_type&gt;(end), <b>a</b>)</tt></p></blockquote>
 </blockquote>


 <hr>
 <h3><a name="303"></a>303. Bitset input operator underspecified</h3>
 <p><b>Section:</b> 23.3.5.3 [bitset.operators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2001-02-05</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 23.3.5.3, we are told that <tt>bitset</tt>'s input operator
 "Extracts up to <i>N</i> (single-byte) characters from
 <i>is</i>.", where <i>is</i> is a stream of type
 <tt>basic_istream&lt;charT, traits&gt;</tt>.
 </p>

 <p>
 The standard does not say what it means to extract single byte
 characters from a stream whose character type, <tt>charT</tt>, is in
 general not a single-byte character type.  Existing implementations
 differ.
 </p>

 <p>
 A reasonable solution will probably involve <tt>widen()</tt> and/or
 <tt>narrow()</tt>, since they are the supplied mechanism for
 converting a single character between <tt>char</tt> and
 arbitrary <tt>charT</tt>.
 </p>

 <p>Narrowing the input characters is not the same as widening the
 literals <tt>'0'</tt> and <tt>'1'</tt>, because there may be some
 locales in which more than one wide character maps to the narrow
 character <tt>'0'</tt>.  Narrowing means that alternate
 representations may be used for bitset input, widening means that
 they may not be.</p>

 <p>Note that for numeric input, <tt>num_get&lt;&gt;</tt>
 (22.2.2.1.2/8) compares input characters to widened version of narrow
 character literals.</p>

 <p>From Pete Becker, in c++std-lib-8224:</p>
 <blockquote>
 <p>
 Different writing systems can have different representations for the
 digits that represent 0 and 1. For example, in the Unicode representation
 of the Devanagari script (used in many of the Indic languages) the digit 0
 is 0x0966, and the digit 1 is 0x0967. Calling narrow would translate those
 into '0' and '1'. But Unicode also provides the ASCII values 0x0030 and
 0x0031 for for the Latin representations of '0' and '1', as well as code
 points for the same numeric values in several other scripts (Tamil has no
 character for 0, but does have the digits 1-9), and any of these values
 would also be narrowed to '0' and '1'.
 </p>

 <p>...</p>

 <p>
 It's fairly common to intermix both native and Latin
 representations of numbers in a document. So I think the rule has to be
 that if a wide character represents a digit whose value is 0 then the bit
 should be cleared; if it represents a digit whose value is 1 then the bit
 should be set; otherwise throw an exception. So in a Devanagari locale,
 both 0x0966 and 0x0030 would clear the bit, and both 0x0967 and 0x0031
 would set it. Widen can't do that. It would pick one of those two values,
 and exclude the other one.
 </p>

 </blockquote>

 <p>From Jens Maurer, in c++std-lib-8233:</p>

 <blockquote>
 <p>
 Whatever we decide, I would find it most surprising if
 bitset conversion worked differently from int conversion
 with regard to alternate local representations of
 numbers.
 </p>

 <p>Thus, I think the options are:</p>
 <ul>
  <li> Have a new defect issue for 22.2.2.1.2/8 so that it will
 require the use of narrow().</li>

  <li> Have a defect issue for bitset() which describes clearly
 that widen() is to be used.</li>
 </ul>
 </blockquote>


 <p><b>Proposed resolution:</b></p>

     <p>Replace the first two sentences of paragraph 5 with:</p>

     <blockquote><p>
     Extracts up to <i>N</i> characters from <i>is</i>. Stores these
     characters in a temporary object <i>str</i> of type
     <tt>basic_string&lt;charT, traits&gt;</tt>, then evaluates the
     expression <tt><i>x</i> = bitset&lt;N&gt;(<i>str</i>)</tt>.
     </p></blockquote>

     <p>Replace the third bullet item in paragraph 5 with:</p>
     <ul><li>
     the next input character is neither <tt><i>is</i>.widen(0)</tt>
     nor <tt><i>is</i>.widen(1)</tt> (in which case the input character
     is not extracted).
     </li></ul>


 <p><b>Rationale:</b></p>
 <p>Input for <tt>bitset</tt> should work the same way as numeric
 input.  Using <tt>widen</tt> does mean that alternative digit
 representations will not be recognized, but this was a known
 consequence of the design choice.</p>


 <hr>
 <h3><a name="305"></a>305. Default behavior of codecvt&lt;wchar_t, char, mbstate_t&gt;::length()</h3>
 <p><b>Section:</b> 22.2.1.5 [locale.codecvt.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2001-01-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt.byname">issues</a> in [locale.codecvt.byname].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>22.2.1.5/3 introduces codecvt in part with:</p>

 <blockquote><p>
   codecvt&lt;wchar_t,char,mbstate_t&gt; converts between the native
   character sets for tiny and wide characters. Instantiations on
   mbstate_t perform conversion between encodings known to the library
   implementor.
 </p></blockquote>

 <p>But 22.2.1.5.2/10 describes do_length in part with:</p>

 <blockquote><p>
   ... codecvt&lt;wchar_t, char, mbstate_t&gt; ... return(s) the lesser of max and
   (from_end-from).
 </p></blockquote>

 <p>
 The semantics of do_in and do_length are linked.  What one does must
 be consistent with what the other does.  22.2.1.5/3 leads me to
 believe that the vendor is allowed to choose the algorithm that
 codecvt&lt;wchar_t,char,mbstate_t&gt;::do_in performs so that it makes
 his customers happy on a given platform.  But 22.2.1.5.2/10 explicitly
 says what codecvt&lt;wchar_t,char,mbstate_t&gt;::do_length must
 return.  And thus indirectly specifies the algorithm that
 codecvt&lt;wchar_t,char,mbstate_t&gt;::do_in must perform.  I believe
 that this is not what was intended and is a defect.
 </p>

 <p>Discussion from the -lib reflector:

 <br>This proposal would have the effect of making the semantics of
 all of the virtual functions in <tt>codecvt&lt;wchar_t, char,
 mbstate_t&gt;</tt> implementation specified.  Is that what we want, or
 do we want to mandate specific behavior for the base class virtuals
 and leave the implementation specified behavior for the codecvt_byname
 derived class?  The tradeoff is that former allows implementors to
 write a base class that actually does something useful, while the
 latter gives users a way to get known and specified---albeit
 useless---behavior, and is consistent with the way the standard
 handles other facets.  It is not clear what the original intention
 was.</p>

 <p>
 Nathan has suggest a compromise: a character that is a widened version
 of the characters in the basic execution character set must be
 converted to a one-byte sequence, but there is no such requirement
 for characters that are not part of the basic execution character set.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 22.2.1.5.2/5 from:
 </p>
 <p>
 The instantiations required in Table 51 (lib.locale.category), namely
 codecvt&lt;wchar_t,char,mbstate_t&gt; and
 codecvt&lt;char,char,mbstate_t&gt;, store no characters. Stores no more
 than (to_limit-to) destination elements. It always leaves the to_next
 pointer pointing one beyond the last element successfully stored.
 </p>
 <p>
 to:
 </p>
 <p>
 Stores no more than (to_limit-to) destination elements, and leaves the
 to_next pointer pointing one beyond the last element successfully
 stored.  codecvt&lt;char,char,mbstate_t&gt; stores no characters.
 </p>

 <p>Change 22.2.1.5.2/10 from:</p>

 <blockquote><p>
 -10- Returns: (from_next-from) where from_next is the largest value in
 the range [from,from_end] such that the sequence of values in the
 range [from,from_next) represents max or fewer valid complete
 characters of type internT. The instantiations required in Table 51
 (21.1.1.1.1), namely codecvt&lt;wchar_t, char, mbstate_t&gt; and
 codecvt&lt;char, char, mbstate_t&gt;, return the lesser of max and
 (from_end-from).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
 -10- Returns: (from_next-from) where from_next is the largest value in
 the range [from,from_end] such that the sequence of values in the range
 [from,from_next) represents max or fewer valid complete characters of
 type internT. The instantiation codecvt&lt;char, char, mbstate_t&gt; returns
 the lesser of max and (from_end-from).
 </p></blockquote>

 <p><i>[Redmond: Nathan suggested an alternative resolution: same as
 above, but require that, in the default encoding, a character from the
 basic execution character set would map to a single external
 character.  The straw poll was 8-1 in favor of the proposed
 resolution.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The default encoding should be whatever users of a given platform
 would expect to be the most natural.  This varies from platform to
 platform.  In many cases there is a preexisting C library, and users
 would expect the default encoding to be whatever C uses in the default
 "C" locale.  We could impose a guarantee like the one Nathan suggested
 (a character from the basic execution character set must map to a
 single external character), but this would rule out important
 encodings that are in common use: it would rule out JIS, for
 example, and it would rule out a fixed-width encoding of UCS-4.</p>

 <p><i>[Curaçao: fixed rationale typo at the request of Ichiro Koshida;
 "shift-JIS" changed to "JIS".]</i></p>


 <hr>
 <h3><a name="306"></a>306. offsetof macro and non-POD types</h3>
 <p><b>Section:</b> 18.1 [support.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 2001-02-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#support.types">issues</a> in [support.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Spliced together from reflector messages c++std-lib-8294 and -8295:</p>

 <p>18.1, paragraph 5, reads: "The macro <tt>offsetof</tt>
 accepts a restricted set of <i>type</i> arguments in this
 International Standard. <i>type</i> shall be a POD structure or a POD
 union (clause 9). The result of applying the offsetof macro to a field
 that is a static data member or a function member is
 undefined."</p>

 <p>For the POD requirement, it doesn't say "no diagnostic
 required" or "undefined behavior". I read 1.4 [intro.compliance], paragraph 1, to mean that a diagnostic is required.
 It's not clear whether this requirement was intended.  While it's
 possible to provide such a diagnostic, the extra complication doesn't
 seem to add any value.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 18.1, paragraph 5, to "If <i>type</i> is not a POD
 structure or a POD union the results are undefined."</p>

 <p><i>[Copenhagen: straw poll was 7-4 in favor.  It was generally
 agreed that requiring a diagnostic was inadvertent, but some LWG
 members thought that diagnostics should be required whenever
 possible.]</i></p>


 <hr>
 <h3><a name="307"></a>307. Lack of reference typedefs in container adaptors</h3>
 <p><b>Section:</b> 23.2.4 [list] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2001-03-13</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>From reflector message c++std-lib-8330.  See also lib-8317.</p>

 <p>
 The standard is currently inconsistent in 23.2.4.2 [list.capacity]
 paragraph 1 and 23.2.4.3 [list.modifiers] paragraph 1.
 23.2.3.3/1, for example, says:
 </p>

 <blockquote><p>
 -1- Any sequence supporting operations back(), push_back() and pop_back()
 can be used to instantiate stack. In particular, vector (lib.vector), list
 (lib.list) and deque (lib.deque) can be used.
 </p></blockquote>

 <p>But this is false: vector&lt;bool&gt; can not be used, because the
 container adaptors return a T&amp; rather than using the underlying
 container's reference type.</p>

 <p>This is a contradiction that can be fixed by:</p>

 <ol>
 <li>Modifying these paragraphs to say that vector&lt;bool&gt;
     is an exception.</li>
 <li>Removing the vector&lt;bool&gt; specialization.</li>
 <li>Changing the return types of stack and priority_queue to use
     reference typedef's.</li>
 </ol>

 <p>
 I propose 3.  This does not preclude option 2 if we choose to do it
 later (see issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#96">96</a>); the issues are independent.  Option
 3 offers a small step towards support for proxied containers.  This
 small step fixes a current contradiction, is easy for vendors to
 implement, is already implemented in at least one popular lib, and
 does not break any code.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Summary: Add reference and const_reference typedefs to queue,
 priority_queue and stack.  Change return types of "value_type&amp;" to
 "reference".  Change return types of "const value_type&amp;" to
 "const_reference".  Details:</p>

 <p>Change 23.2.3.1/1 from:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = deque&lt;T&gt; &gt;
     class queue {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;

     public:
       explicit queue(const Container&amp; = Container());

       bool      empty() const             { return c.empty(); }
       size_type size()  const             { return c.size(); }
       value_type&amp;       front()           { return c.front(); }
       const value_type&amp; front() const     { return c.front(); }
       value_type&amp;       back()            { return c.back(); }
       const value_type&amp; back() const      { return c.back(); }
       void push(const value_type&amp; x)      { c.push_back(x); }
       void pop()                          { c.pop_front(); }
     };
 </pre>

 <p>to:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = deque&lt;T&gt; &gt;
     class queue {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::reference             reference;
       typedef typename Container::const_reference       const_reference;
       typedef typename Container::value_type            value_type;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;

     public:
       explicit queue(const Container&amp; = Container());

       bool      empty() const             { return c.empty(); }
       size_type size()  const             { return c.size(); }
       reference         front()           { return c.front(); }
       const_reference   front() const     { return c.front(); }
       reference         back()            { return c.back(); }
       const_reference   back() const      { return c.back(); }
       void push(const value_type&amp; x)      { c.push_back(x); }
       void pop()                          { c.pop_front(); }
     };
 </pre>

 <p>Change 23.2.3.2/1 from:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = vector&lt;T&gt;,
               class Compare = less&lt;typename Container::value_type&gt; &gt;
     class priority_queue {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;
       Compare comp;

     public:
       explicit priority_queue(const Compare&amp; x = Compare(),
                               const Container&amp; = Container());
       template &lt;class InputIterator&gt;
         priority_queue(InputIterator first, InputIterator last,
                        const Compare&amp; x = Compare(),
                        const Container&amp; = Container());

       bool      empty() const       { return c.empty(); }
       size_type size()  const       { return c.size(); }
       const value_type&amp; top() const { return c.front(); }
       void push(const value_type&amp; x);
       void pop();
     };
                                   //  no equality is provided
   }
 </pre>

 <p>to:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = vector&lt;T&gt;,
               class Compare = less&lt;typename Container::value_type&gt; &gt;
     class priority_queue {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::reference             reference;
       typedef typename Container::const_reference       const_reference;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;
       Compare comp;

     public:
       explicit priority_queue(const Compare&amp; x = Compare(),
                               const Container&amp; = Container());
       template &lt;class InputIterator&gt;
         priority_queue(InputIterator first, InputIterator last,
                        const Compare&amp; x = Compare(),
                        const Container&amp; = Container());

       bool      empty() const       { return c.empty(); }
       size_type size()  const       { return c.size(); }
       const_reference   top() const { return c.front(); }
       void push(const value_type&amp; x);
       void pop();
     };
                                   //  no equality is provided
   }
 </pre>

 <p>And change 23.2.3.3/1 from:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = deque&lt;T&gt; &gt;
     class stack {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;

     public:
       explicit stack(const Container&amp; = Container());

       bool      empty() const             { return c.empty(); }
       size_type size()  const             { return c.size(); }
       value_type&amp;       top()             { return c.back(); }
       const value_type&amp; top() const       { return c.back(); }
       void push(const value_type&amp; x)      { c.push_back(x); }
       void pop()                          { c.pop_back(); }
     };

     template &lt;class T, class Container&gt;
       bool operator==(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&lt; (const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator!=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&gt; (const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&gt;=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&lt;=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
   }
 </pre>

 <p>to:</p>

 <pre>  namespace std {
     template &lt;class T, class Container = deque&lt;T&gt; &gt;
     class stack {
     public:
       typedef typename Container::value_type            value_type;
       typedef typename Container::reference             reference;
       typedef typename Container::const_reference       const_reference;
       typedef typename Container::size_type             size_type;
       typedef          Container                        container_type;
     protected:
       Container c;

     public:
       explicit stack(const Container&amp; = Container());

       bool      empty() const             { return c.empty(); }
       size_type size()  const             { return c.size(); }
       reference         top()             { return c.back(); }
       const_reference   top() const       { return c.back(); }
       void push(const value_type&amp; x)      { c.push_back(x); }
       void pop()                          { c.pop_back(); }
     };

     template &lt;class T, class Container&gt;
       bool operator==(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&lt; (const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator!=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&gt; (const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&gt;=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
     template &lt;class T, class Container&gt;
       bool operator&lt;=(const stack&lt;T, Container&gt;&amp; x,
                       const stack&lt;T, Container&gt;&amp; y);
   }
 </pre>

 <p><i>[Copenhagen: This change was discussed before the IS was released
 and it was deliberately not adopted.  Nevertheless, the LWG believes
 (straw poll: 10-2) that it is a genuine defect.]</i></p>


 <hr>
 <h3><a name="308"></a>308. Table 82 mentions unrelated headers</h3>
 <p><b>Section:</b> 27 [input.output] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-03-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.output">issues</a> in [input.output].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 82 in section 27 mentions the header &lt;cstdlib&gt; for String
 streams (27.7 [string.streams]) and the headers &lt;cstdio&gt; and
 &lt;cwchar&gt; for File streams (27.8 [file.streams]). It's not clear
 why these headers are mentioned in this context since they do not
 define any of the library entities described by the
 subclauses. According to 17.4.1.1 [contents], only such headers
 are to be listed in the summary.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove &lt;cstdlib&gt; and &lt;cwchar&gt; from
 Table 82.</p>

 <p><i>[Copenhagen: changed the proposed resolution slightly.  The
 original proposed resolution also said to remove &lt;cstdio&gt; from
 Table 82.  However, &lt;cstdio&gt; is mentioned several times within
 section 27.8 [file.streams], including 27.8.2 [c.files].]</i></p>


 <hr>
 <h3><a name="310"></a>310. Is errno a macro?</h3>
 <p><b>Section:</b> 17.4.1.2 [headers], 19.3 [errno] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 2001-03-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#headers">issues</a> in [headers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
   <p>
   Exactly how should errno be declared in a conforming C++ header?
   </p>

   <p>
   The C standard says in 7.1.4 that it is unspecified whether errno is a
   macro or an identifier with external linkage.  In some implementations
   it can be either, depending on compile-time options.  (E.g., on
   Solaris in multi-threading mode, errno is a macro that expands to a
   function call, but is an extern int otherwise.  "Unspecified" allows
   such variability.)
   </p>

   <p>The C++ standard:</p>
   <ul>
   <li>17.4.1.2 says in a note that errno must be macro in C. (false)</li>
   <li>17.4.3.1.3 footnote 166 says errno is reserved as an external
       name (true), and implies that it is an identifier.</li>
   <li>19.3 simply lists errno as a macro (by what reasoning?) and goes
       on to say that the contents of of C++ &lt;errno.h&gt; are the
       same as in C, begging the question.</li>
   <li>C.2, table 95 lists errno as a macro, without comment.</li>
   </ul>

   <p>I find no other references to errno.</p>

   <p>We should either explicitly say that errno must be a macro, even
   though it need not be a macro in C, or else explicitly leave it
   unspecified.  We also need to say something about namespace std.
   A user who includes &lt;cerrno&gt; needs to know whether to write
   <tt>errno</tt>, or <tt>::errno</tt>, or <tt>std::errno</tt>, or
   else &lt;cerrno&gt; is useless.</p>

   <p>Two acceptable fixes:</p>
   <ul>
     <li><p>errno must be a macro. This is trivially satisfied by adding<br>
         &nbsp;&nbsp;#define errno (::std::errno)<br>
         to the headers if errno is not already a macro. You then always
         write errno without any scope qualification, and it always expands
         to a correct reference. Since it is always a macro, you know to
         avoid using errno as a local identifer.</p></li>
     <li><p>errno is in the global namespace. This fix is inferior, because
         ::errno is not guaranteed to be well-formed.</p></li>
   </ul>

   <p><i>[
     This issue was first raised in 1999, but it slipped through
     the cracks.
   ]</i></p>


 <p><b>Proposed resolution:</b></p>
   <p>Change the Note in section 17.4.1.2p5 from</p>

     <blockquote><p>
     Note: the names defined as macros in C include the following:
     assert, errno, offsetof, setjmp, va_arg, va_end, and va_start.
     </p></blockquote>

   <p>to</p>

     <blockquote><p>
     Note: the names defined as macros in C include the following:
     assert, offsetof, setjmp, va_arg, va_end, and va_start.
     </p></blockquote>

   <p>In section 19.3, change paragraph 2 from</p>

     <blockquote><p>
     The contents are the same as the Standard C library header
     &lt;errno.h&gt;.
     </p></blockquote>

   <p>to</p>

     <blockquote><p>
     The contents are the same as the Standard C library header
     &lt;errno.h&gt;, except that errno shall be defined as a macro.
     </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>C++ must not leave it up to the implementation to decide whether or
 not a name is a macro; it must explicitly specify exactly which names
 are required to be macros.  The only one that really works is for it
 to be a macro.</p>

 <p><i>[Curaçao: additional rationale added.]</i></p>


 <hr>
 <h3><a name="311"></a>311. Incorrect wording in basic_ostream class synopsis</h3>
 <p><b>Section:</b> 27.6.2.1 [ostream] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andy Sawyer <b>Date:</b> 2001-03-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream">issues</a> in [ostream].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>In 27.6.2.1 [ostream], the synopsis of class basic_ostream says:</p>

 <pre>  // partial specializationss
   template&lt;class traits&gt;
     basic_ostream&lt;char,traits&gt;&amp; operator&lt;&lt;( basic_ostream&lt;char,traits&gt;&amp;,
                                             const char * );
 </pre>

 <p>Problems:</p>
 <ul>
 <li>Too many 's's at the end of "specializationss" </li>
 <li>This is an overload, not a partial specialization</li>
 </ul>


 <p><b>Proposed resolution:</b></p>
 <p>In the synopsis in 27.6.2.1 [ostream], remove the
 <i>// partial specializationss</i> comment.  Also remove the same
 comment (correctly spelled, but still incorrect) from the synopsis in
 27.6.2.6.4 [ostream.inserters.character].
 </p>

 <p><i>[
 Pre-Redmond: added 27.6.2.6.4 [ostream.inserters.character] because of Martin's
 comment in c++std-lib-8939.
 ]</i></p>


 <hr>
 <h3><a name="312"></a>312. Table 27 is missing headers</h3>
 <p><b>Section:</b> 20 [utilities] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-03-29</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Table 27 in section 20 lists the header &lt;memory&gt; (only) for
 Memory (lib.memory) but neglects to mention the headers
 &lt;cstdlib&gt; and &lt;cstring&gt; that are discussed in 20.5.5 [meta.rel].</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add &lt;cstdlib&gt; and &lt;cstring&gt; to Table 27, in the same row
 as &lt;memory&gt;.</p>


 <hr>
 <h3><a name="315"></a>315. Bad "range" in list::unique complexity</h3>
 <p><b>Section:</b> 23.2.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andy Sawyer <b>Date:</b> 2001-05-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 23.2.4.4 [list.ops], Para 21 describes the complexity of
 list::unique as: "If the range (last - first) is not empty, exactly
 (last - first) -1 applications of the corresponding predicate,
 otherwise no applications of the predicate)".
 </p>

 <p>
 "(last - first)" is not a range.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the "range" from (last - first) to [first, last).
 </p>


 <hr>
 <h3><a name="316"></a>316. Vague text in Table 69</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-05-04</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Table 69 says this about a_uniq.insert(t):</p>

 <blockquote><p>
 inserts t if and only if there is no element in the container with key
 equivalent to the key of t. The bool component of the returned pair
 indicates whether the insertion takes place and the iterator component of the
 pair points to the element with key equivalent to the key of t.
 </p></blockquote>

 <p>The description should be more specific about exactly how the bool component
 indicates whether the insertion takes place.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the text in question to</p>

 <blockquote><p>
 ...The bool component of the returned pair is true if and only if the insertion
 takes place...
 </p></blockquote>


 <hr>
 <h3><a name="317"></a>317. Instantiation vs. specialization of facets</h3>
 <p><b>Section:</b> 22 [localization] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-05-04</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#localization">issues</a> in [localization].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The localization section of the standard refers to specializations of
 the facet templates as instantiations even though the required facets
 are typically specialized rather than explicitly (or implicitly)
 instantiated. In the case of ctype&lt;char&gt; and
 ctype_byname&lt;char&gt; (and the wchar_t versions), these facets are
 actually required to be specialized. The terminology should be
 corrected to make it clear that the standard doesn't mandate explicit
 instantiation (the term specialization encompasses both explicit
 instantiations and specializations).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In the following paragraphs, replace all occurrences of the word
 instantiation or instantiations with specialization or specializations,
 respectively:
 </p>

 <blockquote><p>
 22.1.1.1.1, p4, Table 52, 22.2.1.1, p2, 22.2.1.5, p3, 22.2.1.5.1, p5,
 22.2.1.5.2, p10, 22.2.2, p2, 22.2.3.1, p1, 22.2.3.1.2, p1, p2 and p3,
 22.2.4.1, p1, 22.2.4.1.2, p1, 22,2,5, p1, 22,2,6, p2, 22.2.6.3.2, p7, and
 Footnote 242.
 </p></blockquote>

 <p>And change the text in 22.1.1.1.1, p4 from</p>

 <blockquote><p>
     An implementation is required to provide those instantiations
     for facet templates identified as members of a category, and
     for those shown in Table 52:
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
     An implementation is required to provide those specializations...
 </p></blockquote>

 <p><i>[Nathan will review these changes, and will look for places where
 explicit specialization is necessary.]</i></p>


 <p><b>Rationale:</b></p>
 <p>This is a simple matter of outdated language.  The language to
 describe templates was clarified during the standardization process,
 but the wording in clause 22 was never updated to reflect that
 change.</p>


 <hr>
 <h3><a name="318"></a>318. Misleading comment in definition of numpunct_byname</h3>
 <p><b>Section:</b> 22.2.3.2 [locale.numpunct.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-05-12</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The definition of the numpunct_byname template contains the following
 comment:</p>

 <pre>    namespace std {
         template &lt;class charT&gt;
         class numpunct_byname : public numpunct&lt;charT&gt; {
     // this class is specialized for char and wchar_t.
         ...
 </pre>

 <p>There is no documentation of the specializations and it seems
 conceivable that an implementation will not explicitly specialize the
 template at all, but simply provide the primary template.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the comment from the text in 22.2.3.2 and from the proposed
 resolution of library issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a>.</p>


 <hr>
 <h3><a name="319"></a>319. Storage allocation wording confuses "Required behavior", "Requires"</h3>
 <p><b>Section:</b> 18.5.1.1 [new.delete.single], 18.5.1.2 [new.delete.array] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2001-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#new.delete.single">issues</a> in [new.delete.single].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The standard specifies 17.3.1.3 [structure.specifications] that "Required
 behavior" elements describe "the semantics of a function definition
 provided by either the implementation or a C++ program."</p>

 <p>The standard specifies 17.3.1.3 [structure.specifications] that "Requires"
 elements describe "the preconditions for calling the function."</p>

 <p>In the sections noted below, the current wording specifies
 "Required Behavior" for what are actually preconditions, and thus
 should be specified as "Requires".</p>


 <p><b>Proposed resolution:</b></p>

 <p>In 18.5.1.1 [new.delete.single] Para 12 Change:</p>
 <blockquote>
   <p>Required behavior: accept a value of ptr that is null or that was
   returned by an earlier call ...</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>Requires: the value of ptr is null or the value returned by an
   earlier call ...</p>
 </blockquote>

 <p>In 18.5.1.2 [new.delete.array] Para 11 Change:</p>
 <blockquote>
   <p>Required behavior: accept a value of ptr that is null or that was
   returned by an earlier call ...</p>
 </blockquote>
 <p>to:</p>
 <blockquote>
   <p>Requires: the value of ptr is null or the value returned by an
   earlier call ...</p>
 </blockquote>


 <hr>
 <h3><a name="320"></a>320. list::assign overspecified</h3>
 <p><b>Section:</b> 23.2.4.1 [list.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2001-05-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.cons">issues</a> in [list.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 23.2.4.1 [list.cons], paragraphs 6-8 specify that list assign (both forms) have
 the "effects" of a call to erase followed by a call to insert.
 </p>

 <p>
 I would like to document that implementers have the freedom to implement
 assign by other methods, as long as the end result is the same and the
 exception guarantee is as good or better than the basic guarantee.
 </p>

 <p>
 The motivation for this is to use T's assignment operator to recycle
 existing nodes in the list instead of erasing them and reallocating
 them with new values.  It is also worth noting that, with careful
 coding, most common cases of assign (everything but assignment with
 true input iterators) can elevate the exception safety to strong if
 T's assignment has a nothrow guarantee (with no extra memory cost).
 Metrowerks does this.  However I do not propose that this subtlety be
 standardized.  It is a QoI issue.  </p>

 <p>Existing practise:
 Metrowerks and SGI recycle nodes, Dinkumware and Rogue Wave don't.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 23.2.4.1 [list.cons]/7 from:</p>

 <blockquote>
 <p>Effects:</p>

 <pre>   erase(begin(), end());
    insert(begin(), first, last);
 </pre>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>Effects: Replaces the contents of the list with the range [first, last).</p>
 </blockquote>

 <p>In 23.1.3 [sequence.reqmts], in Table 67 (sequence requirements),
 add two new rows:</p>
 <pre>      a.assign(i,j)     void      pre: i,j are not iterators into a.
                                   Replaces elements in a with a copy
                                   of [i, j).

       a.assign(n,t)     void      pre: t is not a reference into a.
                                   Replaces elements in a with n copies
                                   of t.
 </pre>

 <p>Change 23.2.4.1 [list.cons]/8 from:</p>

 <blockquote>
 <p>Effects:</p>
 <pre>   erase(begin(), end());
    insert(begin(), n, t);
 </pre>
 </blockquote>
 <p>to:</p>

 <blockquote>
 <p>Effects: Replaces the contents of the list with n copies of t.</p>
 </blockquote>

 <p><i>[Redmond: Proposed resolution was changed slightly.  Previous
 version made explicit statement about exception safety, which wasn't
 consistent with the way exception safety is expressed elsewhere.
 Also, the change in the sequence requirements is new.  Without that
 change, the proposed resolution would have required that assignment of
 a subrange would have to work.  That too would have been
 overspecification; it would effectively mandate that assignment use a
 temporary.  Howard provided wording.
 ]</i></p>


 <p><i>[Curaçao: Made editorial improvement in wording; changed
 "Replaces elements in a with copies of elements in [i, j)."
 with "Replaces the elements of a with a copy of [i, j)."
 Changes not deemed serious enough to requre rereview.]</i></p>


 <hr>
 <h3><a name="321"></a>321. Typo in num_get</h3>
 <p><b>Section:</b> 22.2.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Kevin Djang <b>Date:</b> 2001-05-17</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 22.2.2.1.2 at p7 states that "A length specifier is added to
 the conversion function, if needed, as indicated in Table 56."
 However, Table 56 uses the term "length modifier", not "length
 specifier".
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 22.2.2.1.2 at p7, change the text "A length specifier is added ..."
 to be "A length modifier is added ..."
 </p>


 <p><b>Rationale:</b></p>
 <p>C uses the term "length modifier".  We should be consistent.</p>


 <hr>
 <h3><a name="322"></a>322. iterator and const_iterator should have the same value type</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2001-05-17</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It's widely assumed that, if X is a container,
 iterator_traits&lt;X::iterator&gt;::value_type and
 iterator_traits&lt;X::const_iterator&gt;::value_type should both be
 X::value_type.  However, this is nowhere stated.  The language in
 Table 65 is not precise about the iterators' value types (it predates
 iterator_traits), and could even be interpreted as saying that
 iterator_traits&lt;X::const_iterator&gt;::value_type should be "const
 X::value_type".
 </p>

 <p>Related issue: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#279">279</a>.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In Table 65 ("Container Requirements"), change the return type for
 X::iterator to "iterator type whose value type is T".  Change the
 return type for X::const_iterator to "constant iterator type whose
 value type is T".</p>


 <p><b>Rationale:</b></p>
 <p>
 This belongs as a container requirement, rather than an iterator
 requirement, because the whole notion of iterator/const_iterator
 pairs is specific to containers' iterator.
 </p>
 <p>
 It is existing practice that (for example)
 iterator_traits&lt;list&lt;int&gt;::const_iterator&gt;::value_type
 is "int", rather than "const int".  This is consistent with
 the way that const pointers are handled: the standard already
 requires that iterator_traits&lt;const int*&gt;::value_type is int.
 </p>


 <hr>
 <h3><a name="324"></a>324. Do output iterators have value types?</h3>
 <p><b>Section:</b> 24.1.2 [output.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2001-06-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#output.iterators">issues</a> in [output.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>Table 73 suggests that output iterators have value types.  It
 requires the expression "*a = t".  Additionally, although Table 73
 never lists "a = t" or "X(a) = t" in the "expressions" column, it
 contains a note saying that "a = t" and "X(a) = t" have equivalent
 (but nowhere specified!) semantics.</p>

 <p>According to 24.1/9, t is supposed to be "a value of value type
 T":</p>

     <blockquote><p>
     In the following sections, a and b denote values of X, n denotes a
     value of the difference type Distance, u, tmp, and m denote
     identifiers, r denotes a value of X&amp;, t denotes a value of
     value type T.
     </p></blockquote>

 <p>Two other parts of the standard that are relevant to whether
 output iterators have value types:</p>

 <ul>
     <li>24.1/1 says "All iterators i support the expression *i,
     resulting in a value of some class, enumeration, or built-in type
     T, called the value type of the iterator".</li>

     <li>
     24.3.1/1, which says "In the case of an output iterator, the types
     iterator_traits&lt;Iterator&gt;::difference_type
     iterator_traits&lt;Iterator&gt;::value_type are both defined as void."
     </li>
 </ul>

 <p>The first of these passages suggests that "*i" is supposed to
 return a useful value, which contradicts the note in 24.1.2/2 saying
 that the only valid use of "*i" for output iterators is in an
 expression of the form "*i = t".  The second of these passages appears
 to contradict Table 73, because it suggests that "*i"'s return value
 should be void.  The second passage is also broken in the case of a an
 iterator type, like non-const pointers, that satisfies both the output
 iterator requirements and the forward iterator requirements.</p>

 <p>What should the standard say about <tt>*i</tt>'s return value when
 i is an output iterator, and what should it say about that t is in the
 expression "*i = t"?  Finally, should the standard say anything about
 output iterators' pointer and reference types?</p>


 <p><b>Proposed resolution:</b></p>
 <p>24.1 p1, change</p>

 <blockquote>
 <p>All iterators <tt>i</tt> support the expression <tt>*i</tt>, resulting
 in a value of some class, enumeration, or built-in type <tt>T</tt>,
 called the value type of the iterator.</p>
 </blockquote>

 <p>to</p>

 <blockquote>
 <p>All input iterators <tt>i</tt> support the expression <tt>*i</tt>,
 resulting in a value of some class, enumeration, or built-in type
 <tt>T</tt>, called the value type of the iterator. All output
 iterators support the expression <tt>*i = o</tt> where <tt>o</tt> is a
 value of some type that is in the set of types that are <i>writable</i> to
 the particular iterator type of <tt>i</tt>.
 </p>
 </blockquote>

 <p>24.1 p9, add</p>

 <blockquote>
 <p><tt>o</tt> denotes a value of some type that is writable to the
 output iterator.
 </p>
 </blockquote>

 <p>Table 73, change</p>

 <blockquote>
 <pre>*a = t
 </pre>
 </blockquote>

 <p>to</p>

 <blockquote>
 <pre>*r = o
 </pre>
 </blockquote>

 <p>and change</p>

 <blockquote>
 <pre>*r++ = t
 </pre>
 </blockquote>

 <p>to</p>

 <blockquote>
 <pre>*r++ = o
 </pre>
 </blockquote>

 <p><i>[post-Redmond: Jeremy provided wording]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG considered two options: change all of the language that
 seems to imply that output iterators have value types, thus making it
 clear that output iterators have no value types, or else define value
 types for output iterator consistently.  The LWG chose the former
 option, because it seems clear that output iterators were never
 intended to have value types.  This was a deliberate design decision,
 and any language suggesting otherwise is simply a mistake.</p>

 <p>A future revision of the standard may wish to revisit this design
 decision.</p>


 <hr>
 <h3><a name="325"></a>325. Misleading text in moneypunct&lt;&gt;::do_grouping</h3>
 <p><b>Section:</b> 22.2.6.3.2 [locale.moneypunct.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-07-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.moneypunct.virtuals">issues</a> in [locale.moneypunct.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The Returns clause in 22.2.6.3.2, p3 says about
 moneypunct&lt;charT&gt;::do_grouping()
 </p>

 <blockquote><p>
     Returns: A pattern defined identically as the result of
     numpunct&lt;charT&gt;::do_grouping().241)
 </p></blockquote>

 <p>Footnote 241 then reads</p>

 <blockquote><p>
     This is most commonly the value "\003" (not "3").
 </p></blockquote>

 <p>
 The returns clause seems to imply that the two member functions must
 return an identical value which in reality may or may not be true,
 since the facets are usually implemented in terms of struct std::lconv
 and return the value of the grouping and mon_grouping, respectively.
 The footnote also implies that the member function of the moneypunct
 facet (rather than the overridden virtual functions in moneypunct_byname)
 most commonly return "\003", which contradicts the C standard which
 specifies the value of "" for the (most common) C locale.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the text in Returns clause in 22.2.6.3.2, p3 with the following:</p>

 <blockquote><p>
     Returns: A pattern defined identically as, but not necessarily
     equal to, the result of numpunct&lt;charT&gt;::do_grouping().241)
 </p></blockquote>

 <p>and replace the text in Footnote 241 with the following:</p>

 <blockquote><p>
     To specify grouping by 3s the value is "\003", not "3".
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>
 The fundamental problem is that the description of the locale facet
 virtuals serves two purposes: describing the behavior of the base
 class, and describing the meaning of and constraints on the behavior
 in arbitrary derived classes.  The new wording makes that separation a
 little bit clearer.  The footnote (which is nonnormative) is not
 supposed to say what the grouping is in the "C" locale or in any other
 locale. It is just a reminder that the values are interpreted as small
 integers, not ASCII characters.
 </p>


 <hr>
 <h3><a name="327"></a>327. Typo in time_get facet in table 52</h3>
 <p><b>Section:</b> 22.1.1.1.1 [locale.category] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Tiki Wan <b>Date:</b> 2001-07-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.category">issues</a> in [locale.category].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#447">447</a></p>
 <p><b>Discussion:</b></p>
 <p>The <tt>wchar_t</tt> versions of <tt>time_get</tt> and
 <tt>time_get_byname</tt> are listed incorrectly in table 52,
 required instantiations.  In both cases the second template
 parameter is given as OutputIterator.  It should instead be
 InputIterator, since these are input facets.</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In table 52, required instantiations, in
 22.1.1.1.1 [locale.category], change</p>
 <pre>    time_get&lt;wchar_t, OutputIterator&gt;
     time_get_byname&lt;wchar_t, OutputIterator&gt;
 </pre>
 <p>to</p>
 <pre>    time_get&lt;wchar_t, InputIterator&gt;
     time_get_byname&lt;wchar_t, InputIterator&gt;
 </pre>

 <p><i>[Redmond: Very minor change in proposed resolution.  Original had
 a typo, wchart instead of wchar_t.]</i></p>


 <hr>
 <h3><a name="328"></a>328. Bad sprintf format modifier in money_put&lt;&gt;::do_put()</h3>
 <p><b>Section:</b> 22.2.6.2.2 [locale.money.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-07-07</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The sprintf format string , "%.01f" (that's the digit one), in the
 description of the do_put() member functions of the money_put facet in
 22.2.6.2.2, p1 is incorrect. First, the f format specifier is wrong
 for values of type long double, and second, the precision of 01
 doesn't seem to make sense. What was most likely intended was
 "%.0Lf"., that is a precision of zero followed by the L length
 modifier.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the format string to "%.0Lf".</p>


 <p><b>Rationale:</b></p><p>Fixes an obvious typo</p>


 <hr>
 <h3><a name="329"></a>329. vector capacity, reserve and reallocation</h3>
 <p><b>Section:</b> 23.2.6.2 [vector.capacity], 23.2.6.4 [vector.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Anthony Williams <b>Date:</b> 2001-07-13</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.capacity">issues</a> in [vector.capacity].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 There is an apparent contradiction about which circumstances can cause
 a reallocation of a vector in Section 23.2.6.2 [vector.capacity] and
 section 23.2.6.4 [vector.modifiers].
 </p>

 <p>23.2.6.2 [vector.capacity],p5 says:</p>
 <blockquote><p>
 Notes: Reallocation invalidates all the references, pointers, and iterators
 referring to the elements in the sequence. It is guaranteed that no
 reallocation takes place during insertions that happen after a call to
 reserve() until the time when an insertion would make the size of the vector
 greater than the size specified in the most recent call to reserve().
 </p></blockquote>

 <p>Which implies if I do</p>

 <pre>  std::vector&lt;int&gt; vec;
   vec.reserve(23);
   vec.reserve(0);
   vec.insert(vec.end(),1);
 </pre>

 <p>then the implementation may reallocate the vector for the insert,
 as the size specified in the previous call to reserve was zero.</p>

 <p>However, the previous paragraphs (23.2.6.2 [vector.capacity], p1-2) state:</p>
 <blockquote>
 <p>
 (capacity) Returns: The total number of elements the vector
 can hold without requiring reallocation
 </p>
 <p>
 ...After reserve(), capacity() is greater or equal to the
 argument of reserve if reallocation happens; and equal to the previous value
 of capacity() otherwise...
 </p>
 </blockquote>

 <p>
 This implies that vec.capacity() is still 23, and so the insert()
 should not require a reallocation, as vec.size() is 0. This is backed
 up by 23.2.6.4 [vector.modifiers], p1:
 </p>
 <blockquote><p>
 (insert) Notes: Causes reallocation if the new size is greater than the old
 capacity.
 </p></blockquote>

 <p>
 Though this doesn't rule out reallocation if the new size is less
 than the old capacity, I think the intent is clear.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the wording of 23.2.6.2 [vector.capacity] paragraph 5 to:</p>

 <blockquote><p>
 Notes: Reallocation invalidates all the references, pointers, and
 iterators referring to the elements in the sequence. It is guaranteed
 that no reallocation takes place during insertions that happen after a
 call to reserve() until the time when an insertion would make the size
 of the vector greater than the value of capacity().
 </p></blockquote>

 <p><i>[Redmond: original proposed resolution was modified slightly.  In
 the original, the guarantee was that there would be no reallocation
 until the size would be greater than the value of capacity() after the
 most recent call to reserve().  The LWG did not believe that the
 "after the most recent call to reserve()" added any useful
 information.]</i></p>


 <p><b>Rationale:</b></p>
 <p>There was general agreement that, when reserve() is called twice in
 succession and the argument to the second invocation is smaller than
 the argument to the first, the intent was for the second invocation to
 have no effect.  Wording implying that such cases have an effect on
 reallocation guarantees was inadvertant.</p>


 <hr>
 <h3><a name="331"></a>331. bad declaration of destructor for ios_base::failure</h3>
 <p><b>Section:</b> 27.4.2.1.1 [ios::failure] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> PremAnand M. Rao <b>Date:</b> 2001-08-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios::failure">issues</a> in [ios::failure].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 With the change in 17.4.4.9 [res.on.exception.handling] to state
    "An implementation may strengthen the exception-specification for a
     non-virtual function by removing listed exceptions."
 (issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#119">119</a>)
 and the following declaration of ~failure() in ios_base::failure
 </p>
 <pre>    namespace std {
        class ios_base::failure : public exception {
        public:
            ...
            virtual ~failure();
            ...
        };
      }
 </pre>
 <p>the class failure cannot be implemented since in 18.6.1 [type.info] the destructor of class exception has an empty
 exception specification:</p>
 <pre>    namespace std {
        class exception {
        public:
          ...
          virtual ~exception() throw();
          ...
        };
      }
 </pre>


 <p><b>Proposed resolution:</b></p>
 <p>Remove the declaration of ~failure().</p>


 <p><b>Rationale:</b></p>
 <p>The proposed resolution is consistent with the way that destructors
 of other classes derived from <tt>exception</tt> are handled.</p>


 <hr>
 <h3><a name="333"></a>333. does endl imply synchronization with the device?</h3>
 <p><b>Section:</b> 27.6.2.8 [ostream.manip] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> PremAnand M. Rao <b>Date:</b> 2001-08-27</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>A footnote in 27.6.2.8 [ostream.manip] states:</p>
 <blockquote><p>
     [Footnote: The effect of executing cout &lt;&lt; endl is to insert a
      newline character in the output sequence controlled by cout, then
      synchronize it with any external file with which it might be
      associated. --- end foonote]
 </p></blockquote>

 <p>
 Does the term "file" here refer to the external device?
 This leads to some implementation ambiguity on systems with fully
 buffered files where a newline does not cause a flush to the device.
 </p>

 <p>
 Choosing to sync with the device leads to significant performance
 penalties for each call to endl, while not sync-ing leads to
 errors under special circumstances.
 </p>

 <p>
 I could not find any other statement that explicitly defined
 the behavior one way or the other.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove footnote 300 from section 27.6.2.8 [ostream.manip].</p>


 <p><b>Rationale:</b></p>
 <p>We already have normative text saying what <tt>endl</tt> does: it
 inserts a newline character and calls <tt>flush</tt>.  This footnote
 is at best redundant, at worst (as this issue says) misleading,
 because it appears to make promises about what <tt>flush</tt>
 does.</p>


 <hr>
 <h3><a name="334"></a>334. map::operator[] specification forces inefficient implementation</h3>
 <p><b>Section:</b> 23.3.1.2 [map.access] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andrea Griffini <b>Date:</b> 2001-09-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#map.access">issues</a> in [map.access].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current standard describes map::operator[] using a
 code example. That code example is however quite
 inefficient because it requires several useless copies
 of both the passed key_type value and of default
 constructed mapped_type instances.
 My opinion is that was not meant by the comitee to
 require all those temporary copies.
 </p>

 <p>Currently map::operator[] behaviour is specified as: </p>
 <pre>  Returns:
     (*((insert(make_pair(x, T()))).first)).second.
 </pre>

 <p>
 This specification however uses make_pair that is a
 template function of which parameters in this case
 will be deduced being of type const key_type&amp; and
 const T&amp;. This will create a pair&lt;key_type,T&gt; that
 isn't the correct type expected by map::insert so
 another copy will be required using the template
 conversion constructor available in pair to build
 the required pair&lt;const key_type,T&gt; instance.
 </p>

 <p>If we consider calling of key_type copy constructor
 and mapped_type default constructor and copy
 constructor as observable behaviour (as I think we
 should) then the standard is in this place requiring
 two copies of a key_type element plus a default
 construction and two copy construction of a mapped_type
 (supposing the addressed element is already present
 in the map; otherwise at least another copy
 construction for each type).
 </p>

 <p>A simple (half) solution would be replacing the description with:</p>
 <pre>  Returns:
     (*((insert(value_type(x, T()))).first)).second.
 </pre>

 <p>This will remove the wrong typed pair construction that
 requires one extra copy of both key and value.</p>

 <p>However still the using of map::insert requires temporary
 objects while the operation, from a logical point of view,
 doesn't require any. </p>

 <p>I think that a better solution would be leaving free an
 implementer to use a different approach than map::insert
 that, because of its interface, forces default constructed
 temporaries and copies in this case.
 The best solution in my opinion would be just requiring
 map::operator[] to return a reference to the mapped_type
 part of the contained element creating a default element
 with the specified key if no such an element is already
 present in the container. Also a logarithmic complexity
 requirement should be specified for the operation.
 </p>

 <p>
 This would allow library implementers to write alternative
 implementations not using map::insert and reaching optimal
 performance in both cases of the addressed element being
 present or absent from the map (no temporaries at all and
 just the creation of a new pair inside the container if
 the element isn't present).
 Some implementer has already taken this option but I think
 that the current wording of the standard rules that as
 non-conforming.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Replace 23.3.1.2 [map.access] paragraph 1 with
 </p>
 <blockquote>
 <p>
 -1- Effects:  If there is no key equivalent to x in the map, inserts
 value_type(x, T()) into the map.
 </p>
 <p>
 -2- Returns: A reference to the mapped_type corresponding to x in *this.
 </p>
 <p>
 -3- Complexity: logarithmic.
 </p>
 </blockquote>

 <p><i>[This is the second option mentioned above.  Howard provided
 wording.  We may also wish to have a blanket statement somewhere in
 clause 17 saying that we do not intend the semantics of sample code
 fragments to be interpreted as specifing exactly how many copies are
 made.  See issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#98">98</a> for a similar problem.]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 This is the second solution described above; as noted, it is
 consistent with existing practice.
 </p>

 <p>Note that we now need to specify the complexity explicitly, because
 we are no longer defining <tt>operator[]</tt> in terms of
 <tt>insert</tt>.</p>


 <hr>
 <h3><a name="335"></a>335. minor issue with char_traits, table 37</h3>
 <p><b>Section:</b> 21.1.1 [char.traits.require] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andy Sawyer <b>Date:</b> 2001-09-06</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 37, in 21.1.1 [char.traits.require], descibes char_traits::assign
 as:
 </p>
 <pre>  X::assign(c,d)   assigns c = d.
 </pre>

 <p>And para 1 says:</p>

 <blockquote><p>
  [...] c and d denote values of type CharT [...]
 </p></blockquote>

 <p>
 Naturally, if c and d are <i>values</i>, then the assignment is
 (effectively) meaningless. It's clearly intended that (in the case of
 assign, at least), 'c' is intended to be a reference type.
 </p>

 <p>I did a quick survey of the four implementations I happened to have
 lying around, and sure enough they all have signatures:</p>
 <pre>    assign( charT&amp;, const charT&amp; );
 </pre>

 <p>(or the equivalent). It's also described this way in Nico's book.
 (Not to mention the synopses of char_traits&lt;char&gt; in 21.1.3.1
 and char_traits&lt;wchar_t&gt; in 21.1.3.2...)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following to 21.1.1 para 1:</p>
 <blockquote><p>
  r denotes an lvalue of CharT
 </p></blockquote>

 <p>and change the description of assign in the table to:</p>
 <pre>  X::assign(r,d)   assigns r = d
 </pre>


 <hr>
 <h3><a name="336"></a>336. Clause 17 lack of references to deprecated headers</h3>
 <p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Detlef Vollmann <b>Date:</b> 2001-09-05</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>From c++std-edit-873:</p>

 <p>17.4.1.2 [headers], Table 11.  In this table, the header
 &lt;strstream&gt; is missing.</p>

 <p>This shows a general problem: The whole clause 17 refers quite
 often to clauses 18 through 27, but D.7 is also a part of the standard
 library (though a deprecated one).</p>


 <p><b>Proposed resolution:</b></p>

 <p>To 17.4.1.2 [headers] Table 11, C++ Library Headers, add
 "&lt;strstream&gt;".</p>

 <p>In the following places, change "clauses 17 through 27" to "clauses
 17 through 27 and Annex D":</p>

 <ul>
 <li>1.2 [intro.refs] Normative references/1/footnote 1</li>
 <li>1.3 [intro.defs] Definitions/1</li>
 <li>7 [dcl.dcl] Library introduction/9</li>
 <li>17.3 [description] Method of description (Informative)/1</li>
 <li>17.3.2.1.3 [character.seq] Character sequences/1/bullet 2</li>
 <li>17.3.2.2 [functions.within.classes] Functions within classes/1</li>
 <li>17.3.2.3 [objects.within.classes] Private members/1/(2 places)</li>
 <li>17.4 [requirements] Library-wide requirements/1</li>
 <li>17.4.1.2 [headers] Headers/4</li>
 <li>17.4.3.5 [replacement.functions] Replacement functions/1</li>
 <li>17.4.4.3 [global.functions] Global or non-member functions/2</li>
 <li>17.4.4.7 [protection.within.classes] Protection within classes/1</li>
 </ul>


 <hr>
 <h3><a name="337"></a>337. replace_copy_if's template parameter should be InputIterator</h3>
 <p><b>Section:</b> 25.2.5 [alg.replace] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Detlef Vollmann <b>Date:</b> 2001-09-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.replace">issues</a> in [alg.replace].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>From c++std-edit-876:</p>

 <p>
 In section 25.2.5 [alg.replace] before p4: The name of the first
 parameter of template replace_copy_if should be "InputIterator"
 instead of "Iterator".  According to 17.3.2.1 [type.descriptions] p1 the
 parameter name conveys real normative meaning.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change <tt>Iterator</tt> to <tt>InputIterator</tt>.</p>


 <hr>
 <h3><a name="338"></a>338.  is whitespace allowed between `-' and a digit?</h3>
 <p><b>Section:</b> 22.2 [locale.categories] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-09-17</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#locale.categories">active issues</a> in [locale.categories].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.categories">issues</a> in [locale.categories].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 From Stage 2 processing in 22.2.2.1.2 [facet.num.get.virtuals], p8 and 9 (the
 original text or the text corrected by the proposed resolution of
 issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#221">221</a>) it seems clear that no whitespace is allowed
 within a number, but 22.2.3.1 [locale.numpunct], p2, which gives the
 format for integer and floating point values, says that whitespace is
 optional between a plusminus and a sign.
 </p>

 <p>
 The text needs to be clarified to either consistently allow or
 disallow whitespace between a plusminus and a sign. It might be
 worthwhile to consider the fact that the C library stdio facility does
 not permit whitespace embedded in numbers and neither does the C or
 C++ core language (the syntax of integer-literals is given in 2.13.1
 [lex.icon], that of floating-point-literals in 2.13.3 [lex.fcon] of the
 C++ standard).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the first part of 22.2.3.1 [locale.numpunct] paragraph 2 from:</p>
 <blockquote>
 <p>
 The syntax for number formats is as follows, where <tt>digit</tt>
 represents the radix set specified by the <tt>fmtflags</tt> argument
 value, <tt>whitespace</tt> is as determined by the facet
 <tt>ctype&lt;charT&gt;</tt> (22.2.1.1), and <tt>thousands-sep</tt> and
 <tt>decimal-point</tt> are the results of corresponding
 <tt>numpunct&lt;charT&gt;</tt> members.  Integer values have the
 format:
 </p>
 <pre>  integer   ::= [sign] units
   sign      ::= plusminus [whitespace]
   plusminus ::= '+' | '-'
   units     ::= digits [thousands-sep units]
   digits    ::= digit [digits]
 </pre>
 </blockquote>
 <p>to:</p>
 <blockquote>
 <p>
 The syntax for number formats is as follows, where <tt>digit</tt>
 represents the radix set specified by the <tt>fmtflags</tt> argument
 value, and <tt>thousands-sep</tt> and <tt>decimal-point</tt> are the
 results of corresponding <tt>numpunct&lt;charT&gt;</tt> members.
 Integer values have the format:
 </p>
 <pre>  integer   ::= [sign] units
   sign      ::= plusminus
   plusminus ::= '+' | '-'
   units     ::= digits [thousands-sep units]
   digits    ::= digit [digits]
 </pre>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>It's not clear whether the format described in 22.2.3.1 [locale.numpunct] paragraph 2 has any normative weight: nothing in the
 standard says how, or whether, it's used.  However, there's no reason
 for it to differ gratuitously from the very specific description of
 numeric processing in 22.2.2.1.2 [facet.num.get.virtuals].  The proposed
 resolution removes all mention of "whitespace" from that format.</p>


 <hr>
 <h3><a name="339"></a>339. definition of bitmask type restricted to clause 27</h3>
 <p><b>Section:</b> 22.2.1 [category.ctype], 17.3.2.1.2 [bitmask.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-09-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#category.ctype">issues</a> in [category.ctype].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>The ctype_category::mask type is declared to be an enum in 22.2.1
 [category.ctype] with p1 then stating that it is a bitmask type, most
 likely referring to the definition of bitmask type in 17.3.2.1.2
 [bitmask.types], p1. However, the said definition only applies to
 clause 27, making the reference in 22.2.1 somewhat dubious.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Clarify 17.3.2.1.2, p1 by changing the current text from</p>
     <blockquote><p>
     Several types defined in clause 27 are bitmask types. Each bitmask type
     can be implemented as an enumerated type that overloads certain operators,
     as an integer type, or as a bitset (23.3.5 [template.bitset]).
     </p></blockquote>
 <p>to read</p>
     <blockquote><p>
     Several types defined in clauses lib.language.support through
     lib.input.output and Annex D are bitmask types. Each bitmask type can
     be implemented as an enumerated type that overloads certain operators,
     as an integer  type, or as a bitset (lib.template.bitset).
     </p></blockquote>

 <p>
 Additionally, change the definition in 22.2.1 to adopt the same
 convention as in clause 27 by replacing the existing text with the
 following (note, in particluar, the cross-reference to 17.3.2.1.2 in
 22.2.1, p1):
 </p>

 <blockquote>
 <p>22.2.1 The ctype category [lib.category.ctype]</p>
 <pre>namespace std {
     class ctype_base {
     public:
         typedef <b><i>T</i></b> mask;

         // numeric values are for exposition only.
         static const mask space = 1 &lt;&lt; 0;
         static const mask print = 1 &lt;&lt; 1;
         static const mask cntrl = 1 &lt;&lt; 2;
         static const mask upper = 1 &lt;&lt; 3;
         static const mask lower = 1 &lt;&lt; 4;
         static const mask alpha = 1 &lt;&lt; 5;
         static const mask digit = 1 &lt;&lt; 6;
         static const mask punct = 1 &lt;&lt; 7;
         static const mask xdigit = 1 &lt;&lt; 8;
         static const mask alnum = alpha | digit;
         static const mask graph = alnum | punct;
     };
 }
 </pre>

 <p>The type <tt>mask</tt> is a bitmask type (17.3.2.1.2 [bitmask.types]).</p>
 </blockquote>

 <p><i>[Curaçao: The LWG notes that T above should be bold-italics to be
 consistent with the rest of the standard.]</i></p>


 <hr>
 <h3><a name="340"></a>340. interpretation of <tt>has_facet&lt;Facet&gt;(loc)</tt></h3>
 <p><b>Section:</b> 22.1.1.1.1 [locale.category] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.category">issues</a> in [locale.category].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It's unclear whether 22.1.1.1.1, p3 says that
 <tt>has_facet&lt;Facet&gt;(loc)</tt> returns true for any <tt>Facet</tt>
 from Table 51 or whether it includes Table 52 as well:
 </p>

 <blockquote><p>
 For any locale <tt>loc</tt> either constructed, or returned by
 locale::classic(), and any facet <tt>Facet</tt> that is a member of a
 standard category, <tt>has_facet&lt;Facet&gt;(loc)</tt> is true. Each
 locale member function which takes a <tt>locale::category</tt>
 argument operates on the corresponding set of facets.
 </p></blockquote>

 <p>
 It seems that it comes down to which facets are considered to be members of a
 standard category. Intuitively, I would classify all the facets in Table 52 as
 members of their respective standard categories, but there are an unbounded set
 of them...
 </p>

 <p>
 The paragraph implies that, for instance, <tt>has_facet&lt;num_put&lt;C,
 OutputIterator&gt; &gt;(loc)</tt> must always return true. I don't think that's
 possible. If it were, then <tt>use_facet&lt;num_put&lt;C, OutputIterator&gt;
 &gt;(loc)</tt> would have to return a reference to a distinct object for each
 valid specialization of <tt>num_put&lt;C, OutputIteratory&gt;</tt>, which is
 clearly impossible.
 </p>

 <p>
 On the other hand, if none of the facets in Table 52 is a member of a standard
 category then none of the locale member functions that operate on entire
 categories of facets will work properly.
 </p>

 <p>
 It seems that what p3 should mention that it's required (permitted?)
 to hold only for specializations of <tt>Facet</tt> from Table 52 on
 <tt>C</tt> from the set { <tt>char</tt>, <tt>wchar_t</tt> }, and
 <tt>InputIterator</tt> and <tt>OutputIterator</tt> from the set of
 {
 {i,o}<tt>streambuf_iterator</tt>&lt;{<tt>char</tt>,<tt>wchar_t</tt>}<tt>&gt;</tt>
 }.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.1.1.1 [locale.category], paragraph 3, change
 "that is a member of a standard category" to "shown in Table 51".</p>


 <p><b>Rationale:</b></p>
 <p>The facets in Table 52 are an unbounded set.  Locales should not be
 required to contain an infinite number of facets.</p>

 <p>It's not necessary to talk about which values of InputIterator and
 OutputIterator must be supported.  Table 51 already contains a
 complete list of the ones we need.</p>


 <hr>
 <h3><a name="341"></a>341. Vector reallocation and swap</h3>
 <p><b>Section:</b> 23.2.6.2 [vector.capacity] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Anthony Williams <b>Date:</b> 2001-09-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.capacity">issues</a> in [vector.capacity].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>It is a common idiom to reduce the capacity of a vector by swapping it with
 an empty one:</p>
 <pre>  std::vector&lt;SomeType&gt; vec;
   // fill vec with data
   std::vector&lt;SomeType&gt;().swap(vec);
   // vec is now empty, with minimal capacity
 </pre>

 <p>However, the wording of 23.2.6.2 [vector.capacity]paragraph 5 prevents
 the capacity of a vector being reduced, following a call to
 reserve(). This invalidates the idiom, as swap() is thus prevented
 from reducing the capacity. The proposed wording for issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#329">329</a> does not affect this.  Consequently, the example above
 requires the temporary to be expanded to cater for the contents of
 vec, and the contents be copied across. This is a linear-time
 operation.</p>

 <p>However, the container requirements state that swap must have constant
 complexity (23.1 [container.requirements] note to table 65).</p>

 <p>This is an important issue, as reallocation affects the validity of
 references and iterators.</p>

 <p>If the wording of 23.2.4.2p5 is taken to be the desired intent, then
 references and iterators remain valid after a call to swap, if they refer to
 an element before the new end() of the vector into which they originally
 pointed, in which case they refer to the element at the same index position.
 Iterators and references that referred to an element whose index position
 was beyond the new end of the vector are invalidated.</p>

 <p>If the note to table 65 is taken as the desired intent, then there are two
 possibilities with regard to iterators and references:</p>

 <ol>
 <li>All Iterators and references into both vectors are invalidated.</li>
 <li>Iterators and references into either vector remain valid, and remain
 pointing to the same element. Consequently iterators and references that
 referred to one vector now refer to the other, and vice-versa.</li>
 </ol>


 <p><b>Proposed resolution:</b></p>
 <p>Add a new paragraph after 23.2.6.2 [vector.capacity] paragraph 5:</p>
 <blockquote>
 <pre>  void swap(vector&lt;T,Allocator&gt;&amp; x);
 </pre>
 <p><b>Effects:</b> Exchanges the contents and capacity() of <tt>*this</tt>
 with that of <tt>x</tt>.</p>
 <p><b>Complexity:</b> Constant time.</p>
 </blockquote>

 <p><i>[This solves the problem reported for this issue.  We may also
 have a problem with a circular definition of swap() for other
 containers.]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 swap should be constant time.  The clear intent is that it should just
 do pointer twiddling, and that it should exchange all properties of
 the two vectors, including their reallocation guarantees.
 </p>


 <hr>
 <h3><a name="345"></a>345. type tm in &lt;cwchar&gt;</h3>
 <p><b>Section:</b> 21.5 [c.strings] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Clark Nelson <b>Date:</b> 2001-10-19</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#c.strings">issues</a> in [c.strings].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>C99, and presumably amendment 1 to C90, specify that &lt;wchar.h&gt;
 declares struct tm as an incomplete type. However, table 48 in 21.5
 [c.strings] does not mention the type tm as being declared in
 &lt;cwchar&gt;. Is this omission intentional or accidental?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In section 21.5 [c.strings], add "tm" to table 48.</p>


 <hr>
 <h3><a name="346"></a>346. Some iterator member functions should be const</h3>
 <p><b>Section:</b> 24.1 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Jeremy Siek <b>Date:</b> 2001-10-20</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Iterator member functions and operators that do not change the state
 of the iterator should be defined as const member functions or as
 functions that take iterators either by const reference or by
 value. The standard does not explicitly state which functions should
 be const.  Since this a fairly common mistake, the following changes
 are suggested to make this explicit.</p>

 <p>The tables almost indicate constness properly through naming: r
 for non-const and a,b for const iterators. The following changes
 make this more explicit and also fix a couple problems.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In 24.1 [iterator.requirements] Change the first section of p9 from
 "In the following sections, a and b denote values of X..." to
 "In the following sections, a and b denote values of type const X...".</p>

 <p>In Table 73, change</p>
 <pre>    a-&gt;m   U&amp;         ...
 </pre>

 <p>to</p>

 <pre>    a-&gt;m   const U&amp;   ...
     r-&gt;m   U&amp;         ...
 </pre>

 <p>In Table 73 expression column, change</p>

 <pre>    *a = t
 </pre>

 <p>to</p>

 <pre>    *r = t
 </pre>

 <p><i>[Redmond: The container requirements should be reviewed to see if
 the same problem appears there.]</i></p>


 <hr>
 <h3><a name="347"></a>347. locale::category and bitmask requirements</h3>
 <p><b>Section:</b> 22.1.1.1.1 [locale.category] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger, Nathan Myers <b>Date:</b> 2001-10-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.category">issues</a> in [locale.category].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 22.1.1.1.1 [locale.category] paragraph 1, the category members
 are described as bitmask elements.  In fact, the bitmask requirements
 in 17.3.2.1.2 [bitmask.types] don't seem quite right: <tt>none</tt>
 and <tt>all</tt> are bitmask constants, not bitmask elements.</p>

 <p>In particular, the requirements for <tt>none</tt> interact poorly
 with the requirement that the LC_* constants from the C library must
 be recognizable as C++ locale category constants.  LC_* values should
 not be mixed with these values to make category values.</p>

 <p>We have two options for the proposed resolution.  Informally:
 option 1 removes the requirement that LC_* values be recognized as
 category arguments.  Option 2 changes the category type so that this
 requirement is implementable, by allowing <tt>none</tt> to be some
 value such as 0x1000 instead of 0.</p>

 <p>Nathan writes: "I believe my proposed resolution [Option 2] merely
 re-expresses the status quo more clearly, without introducing any
 changes beyond resolving the DR.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace the first two paragraphs of 22.1.1.1 [locale.types] with:</p>
 <blockquote>
 <pre>    typedef int category;
 </pre>

 <p>Valid category values include the <tt>locale</tt> member bitmask
 elements <tt>collate</tt>, <tt>ctype</tt>, <tt>monetary</tt>,
 <tt>numeric</tt>, <tt>time</tt>, and <tt>messages</tt>, each of which
 represents a single locale category. In addition, <tt>locale</tt> member
 bitmask constant <tt>none</tt> is defined as zero and represents no
 category. And locale member bitmask constant <tt>all</tt> is defined such that
 the expression</p>
 <pre>    (collate | ctype | monetary | numeric | time | messages | all) == all
 </pre>
 <p>
 is <tt>true</tt>, and represents the union of all categories.  Further
 the expression <tt>(X | Y)</tt>, where <tt>X</tt> and <tt>Y</tt> each
 represent a single category, represents the union of the two
 categories.
 </p>

 <p>
 <tt>locale</tt> member functions expecting a <tt>category</tt>
 argument require one of the <tt>category</tt> values defined above, or
 the union of two or more such values. Such a <tt>category</tt>
 argument identifies a set of locale categories. Each locale category,
 in turn, identifies a set of locale facets, including at least those
 shown in Table 51:
 </p>
 </blockquote>
 <p><i>[Curaçao: need input from locale experts.]</i></p>


 <p><b>Rationale:</b></p>

 <p>The LWG considered, and rejected, an alternate proposal (described
   as "Option 2" in the discussion).  The main reason for rejecting it
   was that library implementors were concerened about implementation
   difficult, given that getting a C++ library to work smoothly with a
   separately written C library is already a delicate business.  Some
   library implementers were also concerned about the issue of adding
   extra locale categories.</p>

 <blockquote>
 <p><b>Option 2:</b> <br>
 Replace the first paragraph of 22.1.1.1 [locale.types] with:</p>
 <blockquote>
 <p>
 Valid category values include the enumerated values.  In addition, the
 result of applying commutative operators | and &amp; to any two valid
 values is valid, and results in the setwise union and intersection,
 respectively, of the argument categories.  The values <tt>all</tt> and
 <tt>none</tt> are defined such that for any valid value <tt>cat</tt>, the
 expressions <tt>(cat | all == all)</tt>, <tt>(cat &amp; all == cat)</tt>,
 <tt>(cat | none == cat)</tt> and <tt>(cat &amp; none == none)</tt> are
 true.  For non-equal values <tt>cat1</tt> and <tt>cat2</tt> of the
 remaining enumerated values, <tt>(cat1 &amp; cat2 == none)</tt> is true.
 For any valid categories <tt>cat1</tt> and <tt>cat2</tt>, the result
 of <tt>(cat1 &amp; ~cat2)</tt> is valid, and equals the setwise union of
 those categories found in <tt>cat1</tt> but not found in <tt>cat2</tt>.
 [Footnote: it is not required that <tt>all</tt> equal the setwise union
 of the other enumerated values; implementations may add extra categories.]
 </p>
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="349"></a>349. Minor typographical error in ostream_iterator</h3>
 <p><b>Section:</b> 24.5.2 [ostream.iterator] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andy Sawyer <b>Date:</b> 2001-10-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>24.5.2 [lib.ostream.iterator] states:</p>
 <pre>    [...]

     private:
     // basic_ostream&lt;charT,traits&gt;* out_stream; exposition only
     // const char* delim; exposition only
 </pre>

 <p>Whilst it's clearly marked "exposition only", I suspect 'delim'
 should be of type 'const charT*'.</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 24.5.2 [ostream.iterator], replace <tt>const char* delim</tt> with
 <tt>const charT* delim</tt>.
 </p>


 <hr>
 <h3><a name="352"></a>352. missing fpos requirements</h3>
 <p><b>Section:</b> 21.1.2 [char.traits.typedefs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2001-12-02</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <i>(1)</i>
 There are no requirements on the <tt>stateT</tt> template parameter of
 <tt>fpos</tt> listed in 27.4.3. The interface appears to require that
 the type be at least Assignable and CopyConstructible (27.4.3.1, p1),
 and I think also DefaultConstructible (to implement the operations in
 Table 88).
 </p>
 <p>
 21.1.2, p3, however, only requires that
 <tt>char_traits&lt;charT&gt;::state_type</tt> meet the requirements of
 CopyConstructible types.
 </p>
 <p>
 <i>(2)</i>
 Additionally, the <tt>stateT</tt> template argument has no
 corresponding typedef in fpos which might make it difficult to use in
 generic code.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Modify 21.1.2, p4 from
 </p>
 <p>
     Requires: <tt>state_type</tt> shall meet the requirements of
               CopyConstructible types (20.1.3).
 </p>
 <p>
     Requires: state_type shall meet the requirements of Assignable
               (23.1, p4), CopyConstructible (20.1.3), and
               DefaultConstructible  (20.1.4) types.
 </p>


 <p><b>Rationale:</b></p>
 <p>The LWG feels this is two issues, as indicated above. The first is
 a defect---std::basic_fstream is unimplementable without these
 additional requirements---and the proposed resolution fixes it.  The
 second is questionable; who would use that typedef?  The class
 template fpos is used only in a very few places, all of which know the
 state type already.  Unless motivation is provided, the second should
 be considered NAD.</p>


 <hr>
 <h3><a name="354"></a>354. Associative container lower/upper bound requirements</h3>
 <p><b>Section:</b> 23.1.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Hans Aberg <b>Date:</b> 2001-12-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Discussions in the thread "Associative container lower/upper bound
 requirements" on comp.std.c++ suggests that there is a defect in the
 C++ standard, Table 69 of section 23.1.2, "Associative containers",
 [lib.associative.reqmts].  It currently says:</p>

 <blockquote>
 <p>
 a.find(k): returns an iterator pointing to an element with the key equivalent to
 k, or a.end() if such an element is not found.
 </p>

 <p>
 a.lower_bound(k): returns an iterator pointing to the first element with
 key not less than k.
 </p>

 <p>
 a.upper_bound(k): returns an iterator pointing to the first element with
 key greater than k.
 </p>
 </blockquote>

 <p>
 We have "or a.end() if such an element is not found" for
 <tt>find</tt>, but not for <tt>upper_bound</tt> or
 <tt>lower_bound</tt>.  As the text stands, one would be forced to
 insert a new element into the container and return an iterator to that
 in case the sought iterator does not exist, which does not seem to be
 the intention (and not possible with the "const" versions).
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Change Table 69 of section 23.1.4 [associative.reqmts] indicated entries
 to:</p>

 <blockquote>
 <p>
 a.lower_bound(k): returns an iterator pointing to the first element with
 key not less than k, or a.end() if such an element is not found.
 </p>

 <p>
 a.upper_bound(k): returns an iterator pointing to the first element with
 key greater than k, or a.end() if such an element is not found.
 </p>
 </blockquote>

 <p><i>[Curaçao: LWG reviewed PR.]</i></p>


 <hr>
 <h3><a name="355"></a>355. Operational semantics for a.back()</h3>
 <p><b>Section:</b> 23.1.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Yaroslav Mironov <b>Date:</b> 2002-01-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>Table 68 "Optional Sequence Operations" in 23.1.1/12
 specifies operational semantics for "a.back()" as
 "*--a.end()", which may be ill-formed <i>[because calling
 operator-- on a temporary (the return) of a built-in type is
 ill-formed]</i>, provided a.end() returns a simple pointer rvalue
 (this is almost always the case for std::vector::end(), for
 example). Thus, the specification is not only incorrect, it
 demonstrates a dangerous construct: "--a.end()" may
 successfully compile and run as intended, but after changing the type
 of the container or the mode of compilation it may produce
 compile-time error. </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the specification in table 68 "Optional Sequence
 Operations" in 23.1.1/12 for "a.back()" from</p>


 <blockquote><pre>*--a.end()
 </pre></blockquote>

 <p>to</p>

 <blockquote><pre>  { iterator tmp = a.end(); --tmp; return *tmp; }
 </pre></blockquote>

 <p>and the specification for "a.pop_back()" from</p>

 <blockquote><pre>a.erase(--a.end())
 </pre></blockquote>

 <p>to</p>

 <blockquote><pre>  { iterator tmp = a.end(); --tmp; a.erase(tmp); }
 </pre></blockquote>

 <p><i>[Curaçao: LWG changed PR from "{ X::iterator tmp =
 a.end(); return *--tmp; }" to "*a.rbegin()", and from
 "{ X::iterator tmp = a.end(); a.erase(--tmp); }" to
 "a.erase(rbegin())".]</i></p>


 <p><i>[There is a second possible defect; table 68 "Optional
 Sequence Operations" in the "Operational Semantics"
 column uses operations present only in the "Reversible
 Container" requirements, yet there is no stated dependency
 between these separate requirements tables. Ask in Santa Cruz if the
 LWG would like a new issue opened.]</i></p>


 <p><i>[Santa Cruz: the proposed resolution is even worse than what's in
   the current standard: erase is undefined for reverse iterator.  If
   we're going to make the change, we need to define a temporary and
   use operator--.  Additionally, we don't know how prevalent this is:
   do we need to make this change in more than one place?  Martin has
   volunteered to review the standard and see if this problem occurs
   elsewhere.]</i></p>


 <p><i>[Oxford: Matt provided new wording to address the concerns raised
   in Santa Cruz.  It does not appear that this problem appears
   anywhere else in clauses 23 or 24.]</i></p>


 <p><i>[Kona: In definition of operational semantics of back(), change
 "*tmp" to "return *tmp;"]</i></p>


 <hr>
 <h3><a name="358"></a>358. interpreting <tt>thousands_sep</tt> after a <tt>decimal_point</tt></h3>
 <p><b>Section:</b> 22.2.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-03-12</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I don't think <tt>thousands_sep</tt> is being treated correctly after
 decimal_point has been seen. Since grouping applies only to the
 integral part of the number, the first such occurrence should, IMO,
 terminate Stage 2. (If it does not terminate it, then 22.2.2.1.2, p12
 and 22.2.3.1.2, p3 need to explain how <tt>thousands_sep</tt> is to be
 interpreted in the fractional part of a number.)
 </p>

 <p>
 The easiest change I can think of that resolves this issue would be
 something like below.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the first sentence of 22.2.2.1.2, p9 from
 </p>

 <blockquote><p>
     If discard is true then the position of the character is
     remembered, but the character is otherwise ignored. If it is not
     discarded, then a check is made to determine if c is allowed as
     the next character of an input field of the conversion specifier
     returned by stage 1. If so it is accumulated.
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
     If <tt>discard</tt> is true, then if <tt>'.'</tt> has not yet been
     accumulated, then the position of the character is remembered, but
     the character is otherwise ignored. Otherwise, if <tt>'.'</tt> has
     already been accumulated, the character is discarded and Stage 2
      terminates. ...
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>We believe this reflects the intent of the Standard.  Thousands sep
   characters after the decimal point are not useful in any locale.
   Some formatting conventions do group digits that follow the decimal
   point, but they usually introduce a different grouping character
   instead of reusing the thousand sep character.  If we want to add
   support for such conventions, we need to do so explicitly.</p>


 <hr>
 <h3><a name="359"></a>359. num_put&lt;&gt;::do_put (..., bool) undocumented</h3>
 <p><b>Section:</b> 22.2.2.2.1 [facet.num.put.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-03-12</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>22.2.2.2.1, p1:</p>

     <pre>    iter_type put (iter_type out, ios_base&amp; str, char_type fill,
                    bool val) const;
     ...

     1   Returns: do_put (out, str, fill, val).
     </pre>

 <p>AFAICS, the behavior of do_put (..., bool) is not documented anywhere,
 however, 22.2.2.2.2, p23:</p>

 <blockquote>
 <pre>iter_type put (iter_type out, ios_base&amp; str, char_type fill,
                bool val) const;
 </pre>


         <p>Effects: If (str.flags() &amp; ios_base::boolalpha) == 0 then do
              out = do_put(out, str, fill, (int)val)
            Otherwise do</p>
 <pre>             string_type s =
                  val ? use_facet&lt;ctype&lt;charT&gt; &gt;(loc).truename()
                      : use_facet&lt;ctype&lt;charT&gt; &gt;(loc).falsename();
 </pre>
            <p>and then insert the characters of s into out. <i>out</i>.</p>
 </blockquote>

 <p>
 This means that the bool overload of <tt>do_put()</tt> will never be called,
 which contradicts the first paragraph. Perhaps the declaration
 should read <tt>do_put()</tt>, and not <tt>put()</tt>?
 </p>

 <p>
 Note also that there is no <b>Returns</b> clause for this function, which
 should probably be corrected, just as should the second occurrence
 of <i>"out."</i> in the text.
 </p>

 <p>
 I think the least invasive change to fix it would be something like
 the following:
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.2.2.2.2 [facet.num.put.virtuals], just above paragraph 1, remove
   the <tt>bool</tt> overload.</p>

 <p>
 In 22.2.2.2.2 [facet.num.put.virtuals], p23, make the following changes
 </p>

 <blockquote><p>
      Replace <tt>put()</tt> with <tt>do_put()</tt> in the declaration
      of the member function.
 </p></blockquote>

 <blockquote><p>
     Change the <b>Effects</b> clause to a <b>Returns</b> clause (to
     avoid the requirement to call <tt>do_put(..., int)</tt> from <tt>
     do_put (..., bool))</tt>
     like so:
 </p></blockquote>

 <blockquote><p>
     23   <b>Returns</b>: If <tt>(str.flags() &amp;
          ios_base::boolalpha) == 0</tt> then
          <tt>do_put (out, str, fill, (long)val)</tt>
          Otherwise the function obtains a string <tt>s</tt> as if by</p>
 <pre>             string_type s =
                 val ? use_facet&lt;ctype&lt;charT&gt; &gt;(loc).truename()
                     : use_facet&lt;ctype&lt;charT&gt; &gt;(loc).falsename();
 </pre>
          <p>and then inserts each character <tt>c</tt> of s into out via
            <tt>*out++ = c</tt>
          and returns <tt>out</tt>.</p>
 </blockquote>


 <p><b>Rationale:</b></p><p>
 This fixes a couple of obvious typos, and also fixes what appears to
 be a requirement of gratuitous inefficiency.
 </p>


 <hr>
 <h3><a name="360"></a>360. locale mandates inefficient implementation</h3>
 <p><b>Section:</b> 22.1.1 [locale] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-03-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale">issues</a> in [locale].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 22.1.1, p7 (copied below) allows iostream formatters and extractors
 to make assumptions about the values returned from facet members.
 However, such assumptions are apparently not guaranteed to hold
 in other cases (e.g., when the facet members are being called directly
 rather than as a result of iostream calls, or between successive
 calls to the same iostream functions with no interevening calls to
 <tt>imbue()</tt>, or even when the facet member functions are called
 from other member functions of other facets). This restriction
 prevents locale from being implemented efficiently.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the first sentence in 22.1.1, p7 from</p>
 <blockquote><p>
     In successive calls to a locale facet member function during
     a call to an iostream inserter or extractor or a streambuf member
     function, the returned result shall be identical. [Note: This
     implies that such results may safely be reused without calling
     the locale facet member function again, and that member functions
     of iostream classes cannot safely call <tt>imbue()</tt>
     themselves, except as specified elsewhere. --end note]
 </p></blockquote>

 <p>to</p>

 <blockquote><p>
     In successive calls to a locale facet member function on a facet
     object installed in the same locale, the returned result shall be
     identical. ...
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>This change is reasonable becuase it clarifies the intent of this
   part of the standard.</p>


 <hr>
 <h3><a name="362"></a>362. bind1st/bind2nd type safety</h3>
 <p><b>Section:</b> D.8 [depr.lib.binders] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Andrew Demkin <b>Date:</b> 2002-04-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.lib.binders">issues</a> in [depr.lib.binders].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The definition of bind1st() (D.8 [depr.lib.binders]) can result in
 the construction of an unsafe binding between incompatible pointer
 types. For example, given a function whose first parameter type is
 'pointer to T', it's possible without error to bind an argument of
 type 'pointer to U' when U does not derive from T:
 </p>
 <pre>   foo(T*, int);

    struct T {};
    struct U {};

    U u;

    int* p;
    int* q;

    for_each(p, q, bind1st(ptr_fun(foo), &amp;u));    // unsafe binding
 </pre>

 <p>
 The definition of bind1st() includes a functional-style conversion to
 map its argument to the expected argument type of the bound function
 (see below):
 </p>
 <pre>  typename Operation::first_argument_type(x)
 </pre>

 <p>A functional-style conversion (D.8 [depr.lib.binders]) is defined to
 be
 semantically equivalent to an explicit cast expression (D.8
 [depr.lib.binders]), which may (according to 5.4, paragraph 5) be
 interpreted
 as a reinterpret_cast, thus masking the error.
 </p>

 <p>The problem and proposed change also apply to D.8 [depr.lib.binders].</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add this sentence to the end of D.8 [depr.lib.binders]/1:
   "Binders <tt>bind1st</tt> and <tt>bind2nd</tt> are deprecated in
   favor of <tt>std::tr1::bind</tt>."</p>

 <p>(Notes to editor: (1) when and if tr1::bind is incorporated into
   the standard, "std::tr1::bind" should be changed to "std::bind". (2)
   20.5.6 should probably be moved to Annex D.</p>


 <p><b>Rationale:</b></p>
 <p>There is no point in fixing bind1st and bind2nd.  tr1::bind is a
   superior solution.  It solves this problem and others.</p>


 <hr>
 <h3><a name="363"></a>363. Missing exception specification in 27.4.2.1.1</h3>
 <p><b>Section:</b> 27.4.2.1.1 [ios::failure] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown and Marc Paterno <b>Date:</b> 2002-05-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios::failure">issues</a> in [ios::failure].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The destructor of ios_base::failure should have an empty throw
 specification, because the destructor of its base class, exception, is
 declared in this way.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the destructor to</p>
 <pre>  virtual ~failure() throw();
 </pre>


 <p><b>Rationale:</b></p>
 <p>Fixes an obvious glitch.  This is almost editorial.</p>


 <hr>
 <h3><a name="364"></a>364. Inconsistent wording in 27.5.2.4.2</h3>
 <p><b>Section:</b> 27.5.2.4.2 [streambuf.virt.buffer] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown, Marc Paterno <b>Date:</b> 2002-05-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#streambuf.virt.buffer">issues</a> in [streambuf.virt.buffer].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 27.5.2.4.2 [streambuf.virt.buffer] paragraph 1 is inconsistent with the Effects
 clause for seekoff.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Make this paragraph, the Effects clause for setbuf, consistent in wording
 with the Effects clause for seekoff in paragraph 3 by amending paragraph 1
 to indicate the purpose of setbuf:
 </p>

 <p>Original text:</p>

 <blockquote><p>
 1 Effects: Performs an operation that is defined separately for each
 class derived from basic_streambuf in this clause (27.7.1.3, 27.8.1.4).
 </p></blockquote>

 <p>Proposed text:</p>

 <blockquote><p>
 1 Effects: Influences stream buffering in a way that is defined separately
 for each class derived from basic_streambuf in this clause
 (27.7.1.3, 27.8.1.4).
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>The LWG doesn't believe there is any normative difference between
   the existing wording and what's in the proposed resolution, but the
   change may make the intent clearer.</p>


 <hr>
 <h3><a name="365"></a>365. Lack of const-qualification in clause 27</h3>
 <p><b>Section:</b> 27 [input.output] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown, Marc Paterno <b>Date:</b> 2002-05-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#input.output">issues</a> in [input.output].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Some stream and streambuf member functions are declared non-const,
 even thought they appear only to report information rather than to
 change an object's logical state.  They should be declared const.  See
 document N1360 for details and rationale.
 </p>

 <p>The list of member functions under discussion: <tt>in_avail</tt>,
 <tt>showmanyc</tt>, <tt>tellg</tt>, <tt>tellp</tt>, <tt>is_open</tt>.</p>

 <p>Related issue: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#73">73</a></p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.8.1.5, 27.8.1.7, 27.8.1.8, 27.8.1.10, 27.8.1.11, and 27.8.1.13</p>
 <p>Replace</p>
 <pre>  bool is_open();
 </pre>
 <p>with</p>
 <pre>  bool is_open() const;
 </pre>


 <p><b>Rationale:</b></p>
 <p>Of the changes proposed in N1360, the only one that is safe is
 changing the filestreams' is_open to const.  The LWG believed that
 this was NAD the first time it considered this issue (issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#73">73</a>), but now thinks otherwise.  The corresponding streambuf
 member function, after all,is already const.</p>

 <p>The other proposed changes are less safe, because some streambuf
 functions that appear merely to report a value do actually perform
 mutating operations.  It's not even clear that they should be
 considered "logically const", because streambuf has two interfaces, a
 public one and a protected one.  These functions may, and often do,
 change the state as exposed by the protected interface, even if the
 state exposed by the public interface is unchanged.</p>

 <p>Note that implementers can make this change in a binary compatible
 way by providing both overloads; this would be a conforming extension.</p>


 <hr>
 <h3><a name="369"></a>369. io stream objects and static ctors</h3>
 <p><b>Section:</b> 27.3 [iostream.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ruslan Abdikeev <b>Date:</b> 2002-07-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostream.objects">issues</a> in [iostream.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Is it safe to use standard iostream objects from constructors of
 static objects?  Are standard iostream objects constructed and are
 their associations established at that time?
 </p>

 <p>Surpisingly enough, Standard does NOT require that.</p>

 <p>
 27.3/2 [lib.iostream.objects] guarantees that standard iostream
 objects are constructed and their associations are established before
 the body of main() begins execution.  It also refers to ios_base::Init
 class as the panacea for constructors of static objects.
 </p>

 <p>
 However, there's nothing in 27.3 [lib.iostream.objects],
 in 27.4.2 [lib.ios.base], and in 27.4.2.1.6 [lib.ios::Init],
 that would require implementations to allow access to standard
 iostream objects from constructors of static objects.
 </p>

 <p>Details:</p>

 <p>Core text refers to some magic object ios_base::Init, which will
 be discussed below:</p>

 <blockquote><p>
     "The [standard iostream] objects are constructed, and their
     associations are established at some time prior to or during
     first time an object of class basic_ios&lt;charT,traits&gt;::Init
     is constructed, and in any case before the body of main
     begins execution." (27.3/2 [lib.iostream.objects])
 </p></blockquote>

 <p>
 The first <i>non-normative</i> footnote encourages implementations
 to initialize standard iostream objects earlier than required.
 </p>

 <p>However, the second <i>non-normative</i> footnote makes an explicit
 and unsupported claim:</p>

 <blockquote><p>
   "Constructors and destructors for static objects can access these
   [standard iostream] objects to read input from stdin or write output
   to stdout or stderr." (27.3/2 footnote 265 [lib.iostream.objects])
 </p></blockquote>

 <p>
 The only bit of magic is related to that ios_base::Init class.  AFAIK,
 the rationale behind ios_base::Init was to bring an instance of this
 class to each translation unit which #included &lt;iostream&gt; or
 related header.  Such an inclusion would support the claim of footnote
 quoted above, because in order to use some standard iostream object it
 is necessary to #include &lt;iostream&gt;.
 </p>

 <p>
 However, while Standard explicitly describes ios_base::Init as
 an appropriate class for doing the trick, I failed to found a
 mention of an _instance_ of ios_base::Init in Standard.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add to 27.3 [iostream.objects], p2, immediately before the last sentence
 of the paragraph, the following two sentences:</p>

 <blockquote><p>
 If a translation unit includes &lt;iostream&gt;, or explicitly
 constructs an ios_base::Init object, these stream objects shall
 be constructed before dynamic initialization of non-local
 objects defined later in that translation unit, and these stream
 objects shall be destroyed after the destruction of dynamically
 initialized non-local objects defined later in that translation unit.
 </p></blockquote>

 <p><i>[Lillehammer: Matt provided wording.]</i></p>

 <p><i>[Mont Tremblant: Matt provided revised wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 The original proposed resolution unconditionally required
 implementations to define an ios_base::Init object of some
 implementation-defined name in the header &lt;iostream&gt;. That's an
 overspecification. First, defining the object may be unnecessary
 and even detrimental to performance if an implementation can
 guarantee that the 8 standard iostream objects will be initialized
 before any other user-defined object in a program. Second, there
 is no need to require implementations to document the name of the
 object.</p>

 <p>
 The new proposed resolution gives users guidance on what they need to
 do to ensure that stream objects are constructed during startup.</p>


 <hr>
 <h3><a name="370"></a>370. Minor error in basic_istream::get</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ray Lischner <b>Date:</b> 2002-07-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Defect report for description of basic_istream::get (section
 27.6.1.3 [istream.unformatted]), paragraph 15. The description for the
 get function
 with the following signature:</p>

 <pre>  basic_istream&lt;charT,traits&gt;&amp; get(basic_streambuf&lt;char_type,traits&gt;&amp;
   sb);
 </pre>

 <p>is incorrect. It reads</p>

 <blockquote><p>
   Effects: Calls get(s,n,widen('\n'))
 </p></blockquote>

 <p>which I believe should be:</p>

 <blockquote><p>
   Effects: Calls get(sb,widen('\n'))
 </p></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>Change the <b>Effects</b> paragraph to:</p>
 <blockquote><p>
   Effects: Calls get(sb,this-&gt;widen('\n'))
 </p></blockquote>

 <p><i>[Pre-Oxford: Minor correction from Howard: replaced 'widen'
       with 'this-&gt;widen'.]</i></p>


 <p><b>Rationale:</b></p><p>Fixes an obvious typo.</p>


 <hr>
 <h3><a name="371"></a>371. Stability of multiset and multimap member functions</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Frank Compagner <b>Date:</b> 2002-07-20</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The requirements for multiset and multimap containers (23.1
 [lib.containers.requirements], 23.1.2 [lib.associative.reqmnts],
 23.3.2 [lib.multimap] and 23.3.4 [lib.multiset]) make no mention of
 the stability of the required (mutating) member functions. It appears
 the standard allows these functions to reorder equivalent elements of
 the container at will, yet the pervasive red-black tree implementation
 appears to provide stable behaviour.
 </p>

 <p>This is of most concern when considering the behaviour of erase().
 A stability requirement would guarantee the correct working of the
 following 'idiom' that removes elements based on a certain predicate
 function.
 </p>

 <pre>  multimap&lt;int, int&gt; m;
   multimap&lt;int, int&gt;::iterator i = m.begin();
   while (i != m.end()) {
       if (pred(i))
           m.erase (i++);
       else
           ++i;
   }
 </pre>

 <p>
 Although clause 23.1.2/8 guarantees that i remains a valid iterator
 througout this loop, absence of the stability requirement could
 potentially result in elements being skipped. This would make
 this code incorrect, and, furthermore, means that there is no way
 of erasing these elements without iterating first over the entire
 container, and second over the elements to be erased. This would
 be unfortunate, and have a negative impact on both performance and
 code simplicity.
 </p>

 <p>
 If the stability requirement is intended, it should be made explicit
 (probably through an extra paragraph in clause 23.1.2).
 </p>
 <p>
 If it turns out stability cannot be guaranteed, i'd argue that a
 remark or footnote is called for (also somewhere in clause 23.1.2) to
 warn against relying on stable behaviour (as demonstrated by the code
 above).  If most implementations will display stable behaviour, any
 problems emerging on an implementation without stable behaviour will
 be hard to track down by users. This would also make the need for an
 erase_if() member function that much greater.
 </p>

 <p>This issue is somewhat related to LWG issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#130">130</a>.</p>


 <p><b>Proposed resolution:</b></p>

 <p>Add the following to the end of 23.1.4 [associative.reqmts] paragraph 4:
 "For <tt>multiset</tt> and <tt>multimap</tt>, <tt>insert</tt>and <tt>erase</tt>
   are <i>stable</i>: they preserve the relative ordering of equivalent
   elements.</p>

 <p><i>[Lillehammer: Matt provided wording]</i></p>

 <p><i>[Joe Gottman points out that the provided wording does not address
 multimap and multiset.  N1780 also addresses this issue and suggests
 wording.]</i></p>


 <p><i>[Mont Tremblant: Changed set and map to multiset and multimap.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG agrees that this guarantee is necessary for common user
   idioms to work, and that all existing implementations provide this
   property.  Note that this resolution guarantees stability for
   multimap and multiset, not for all associative containers in
   general.</p>


 <hr>
 <h3><a name="373"></a>373. Are basic_istream and basic_ostream to use (exceptions()&amp;badbit) != 0 ?</h3>
 <p><b>Section:</b> 27.6.1.2.1 [istream.formatted.reqmts], 27.6.2.6.1 [ostream.formatted.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Keith Baker <b>Date:</b> 2002-07-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.formatted.reqmts">issues</a> in [istream.formatted.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 In 27.6.1.2.1 [istream.formatted.reqmts] and 27.6.2.6.1 [ostream.formatted.reqmts]
 (exception()&amp;badbit) != 0 is used in testing for rethrow, yet
 exception() is the constructor to class std::exception in 18.6.1 [type.info] that has no return type. Should member function
 exceptions() found in 27.4.4 [ios] be used instead?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.6.1.2.1 [istream.formatted.reqmts] and 27.6.2.6.1 [ostream.formatted.reqmts], change
 "(exception()&amp;badbit) != 0" to "(exceptions()&amp;badbit) != 0".
 </p>


 <p><b>Rationale:</b></p>
 <p>Fixes an obvious typo.</p>


 <hr>
 <h3><a name="375"></a>375. basic_ios should be ios_base in 27.7.1.3</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ray Lischner <b>Date:</b> 2002-08-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In Section 27.7.1.4 [stringbuf.virtuals]: Table 90, Table 91, and paragraph
 14 all contain references to "basic_ios::" which should be
 "ios_base::".
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change all references to "basic_ios" in Table 90, Table 91, and
 paragraph 14 to "ios_base".
 </p>


 <p><b>Rationale:</b></p><p>Fixes an obvious typo.</p>


 <hr>
 <h3><a name="376"></a>376. basic_streambuf semantics</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ray Lischner <b>Date:</b> 2002-08-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In Section 27.7.1.4 [stringbuf.virtuals], Table 90, the implication is that
 the four conditions should be mutually exclusive, but they are not.
 The first two cases, as written, are subcases of the third.</p>

 <p>
 As written, it is unclear what should be the result if cases 1 and 2
 are both true, but case 3 is false.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Rewrite these conditions as:</p>
 <blockquote>
 <p>
   (which &amp; (ios_base::in|ios_base::out)) == ios_base::in
 </p>

 <p>
   (which &amp; (ios_base::in|ios_base::out)) == ios_base::out
 </p>

 <p>
   (which &amp; (ios_base::in|ios_base::out)) ==
 (ios_base::in|ios_base::out)
    and way == either ios_base::beg or ios_base::end
 </p>

 <p>Otherwise</p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>It's clear what we wanted to say, we just failed to say it.  This
   fixes it.</p>


 <hr>
 <h3><a name="379"></a>379. nonsensical ctype::do_widen() requirement</h3>
 <p><b>Section:</b> 22.2.1.1.2 [locale.ctype.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-09-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.ctype.virtuals">issues</a> in [locale.ctype.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The last sentence in 22.2.1.1.2, p11 below doesn't seem to make sense.
 </p>
 <pre>  charT do_widen (char c) const;

   -11- Effects: Applies the simplest reasonable transformation from
        a char value or sequence of char values to the corresponding
        charT value or values. The only characters for which unique
        transformations are required are those in the basic source
        character set (2.2). For any named ctype category with a
        ctype&lt;charT&gt; facet ctw and valid ctype_base::mask value
        M (is(M, c) || !ctw.is(M, do_widen(c))) is true.
 </pre>
 <p>
 Shouldn't the last sentence instead read
 </p>
 <pre>       For any named ctype category with a ctype&lt;char&gt; facet ctc
        and valid ctype_base::mask value M
        (ctc.is(M, c) || !is(M, do_widen(c))) is true.
 </pre>
 <p>
 I.e., if the narrow character c is not a member of a class of
 characters then neither is the widened form of c. (To paraphrase
 footnote 224.)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Replace the last sentence of 22.2.1.1.2 [locale.ctype.virtuals], p11 with the
 following text:
 </p>
 <pre>       For any named ctype category with a ctype&lt;char&gt; facet ctc
        and valid ctype_base::mask value M,
        (ctc.is(M, c) || !is(M, do_widen(c))) is true.
 </pre>

 <p><i>[Kona: Minor edit. Added a comma after the <i>M</i> for clarity.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG believes this is just a typo, and that this is the correct fix.</p>


 <hr>
 <h3><a name="380"></a>380. typos in codecvt tables 53 and 54</h3>
 <p><b>Section:</b> 22.2.1.5 [locale.codecvt.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-09-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt.byname">issues</a> in [locale.codecvt.byname].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Tables 53 and 54 in 22.2.1.5 [locale.codecvt.byname] are both titled "convert
 result values," when surely "do_in/do_out result values" must have
 been intended for Table 53 and "do_unshift result values" for Table
 54.
 </p>
 <p>
 Table 54, row 3 says that the meaning of partial is "more characters
 needed to be supplied to complete termination." The function is not
 supplied any characters, it is given a buffer which it fills with
 characters or, more precisely, destination elements (i.e., an escape
 sequence). So partial means that space for more than (to_limit - to)
 destination elements was needed to terminate a sequence given the
 value of state.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the title of Table 53 to "do_in/do_out result values" and
 the title of Table 54 to "do_unshift result values."
 </p>
 <p>
 Change the text in Table 54, row 3 (the <b>partial</b> row), under the
 heading Meaning, to "space for more than (to_limit - to) destination
 elements was needed to terminate a sequence given the value of state."
 </p>


 <hr>
 <h3><a name="381"></a>381. detection of invalid mbstate_t in codecvt</h3>
 <p><b>Section:</b> 22.2.1.5 [locale.codecvt.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2002-09-06</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt.byname">issues</a> in [locale.codecvt.byname].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 All but one codecvt member functions that take a state_type argument
 list as one of their preconditions that the state_type argument have
 a valid value. However, according to 22.2.1.5.2, p6,
 codecvt::do_unshift() is the only codecvt member that is supposed to
 return error if the state_type object is invalid.
 </p>

 <p>
 It seems to me that the treatment of state_type by all codecvt member
 functions should be the same and the current requirements should be
 changed. Since the detection of invalid state_type values may be
 difficult in general or computationally expensive in some specific
 cases, I propose the following:
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add a new paragraph before 22.2.1.5.2, p5, and after the function
 declaration below
 </p>
 <pre>    result do_unshift(stateT&amp; state,
     externT* to, externT* to_limit, externT*&amp; to_next) const;
 </pre>
 <p>
 as follows:
 </p>
 <pre>    Requires: (to &lt;= to_end) well defined and true; state initialized,
     if at the beginning of a sequence, or else equal to the result of
     converting the preceding characters in the sequence.
 </pre>
 <p>
 and change the text in Table 54, row 4, the <b>error</b> row, under
 the heading Meaning, from
 </p>
 <pre>    state has invalid value
 </pre>
 <p>
 to
 </p>
 <pre>    an unspecified error has occurred
 </pre>


 <p><b>Rationale:</b></p>
 <p>The intent is that implementations should not be required to detect
 invalid state values; such a requirement appears nowhere else.  An
 invalid state value is a precondition violation, <i>i.e.</i> undefined
 behavior.  Implementations that do choose to detect invalid state
 values, or that choose to detect any other kind of error, may return
 <b>error</b> as an indication.</p>


 <hr>
 <h3><a name="383"></a>383. Bidirectional iterator assertion typo</h3>
 <p><b>Section:</b> 24.1.4 [bidirectional.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> ysapir (submitted via comp.std.c++) <b>Date:</b> 2002-10-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bidirectional.iterators">issues</a> in [bidirectional.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Following a discussion on the boost list regarding end iterators and
 the possibility of performing operator--() on them, it seems to me
 that there is a typo in the standard.  This typo has nothing to do
 with that discussion.
 </p>

 <p>
 I have checked this newsgroup, as well as attempted a search of the
 Active/Defect/Closed Issues List on the site for the words "s is
 derefer" so I believe this has not been proposed before.  Furthermore,
 the "Lists by Index" mentions only DR <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a> on section
 24.1.4, and DR <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a> is not related to this issue.
 </p>

 <p>
 The standard makes the following assertion on bidirectional iterators,
 in section 24.1.4 [lib.bidirectional.iterators], Table 75:
 </p>

 <pre>                         operational  assertion/note
 expression  return type   semantics    pre/post-condition

 --r          X&amp;                        pre: there exists s such
                                        that r == ++s.
                                        post: s is dereferenceable.
                                        --(++r) == r.
                                        --r == --s implies r == s.
                                        &amp;r == &amp;--r.
 </pre>

 <p>
 (See <a href="http://aspn.activestate.com/ASPN/Mail/Message/boost/1395763">http://aspn.activestate.com/ASPN/Mail/Message/boost/1395763</a>.)
 </p>

 <p>
 In particular, "s is dereferenceable" seems to be in error.  It seems
 that the intention was to say "r is dereferenceable".
 </p>

 <p>
 If it were to say "r is dereferenceable" it would
 make perfect sense.  Since s must be dereferenceable prior to
 operator++, then the natural result of operator-- (to undo operator++)
 would be to make r dereferenceable.  Furthermore, without other
 assertions, and basing only on precondition and postconditions, we
 could not otherwise know this.  So it is also interesting information.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the guarantee to "postcondition: r is dereferenceable."
 </p>


 <p><b>Rationale:</b></p><p>Fixes an obvious typo</p>


 <hr>
 <h3><a name="384"></a>384. equal_range has unimplementable runtime complexity</h3>
 <p><b>Section:</b> 25.3.3.3 [equal.range] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Hans Bos <b>Date:</b> 2002-10-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#equal.range">issues</a> in [equal.range].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 25.3.3.3 [equal.range]
 states that at most 2 * log(last - first) + 1
 comparisons are allowed for equal_range.
 </p>

 <p>It is not possible to implement equal_range with these constraints.</p>

 <p>In a range of one element as in:</p>
 <pre>    int x = 1;
     equal_range(&amp;x, &amp;x + 1, 1)
 </pre>

 <p>it is easy to see that at least 2 comparison operations are needed.</p>

 <p>For this case at most 2 * log(1) + 1 = 1 comparison is allowed.</p>

 <p>I have checked a few libraries and they all use the same (nonconforming)
 algorithm for equal_range that has a complexity of</p>
 <pre>     2* log(distance(first, last)) + 2.
 </pre>
 <p>I guess this is the algorithm that the standard assumes for equal_range.</p>

 <p>
 It is easy to see that 2 * log(distance) + 2 comparisons are enough
 since equal range can be implemented with lower_bound and upper_bound
 (both log(distance) + 1).
 </p>

 <p>
 I think it is better to require something like 2log(distance) + O(1)  (or
 even logarithmic as multiset::equal_range).
 Then an implementation has more room to optimize for certain cases (e.g.
 have log(distance) characteristics when at most match is found in the range
 but 2log(distance) + 4 for the worst case).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 25.3.3.1 [lower.bound]/4, change <tt>log(last - first) + 1</tt>
 to <tt>log<sub>2</sub>(last - first) + <i>O</i>(1)</tt>.</p>

 <p>In 25.3.3.2 [upper.bound]/4, change <tt>log(last - first) + 1</tt>
 to <tt>log<sub>2</sub>(last - first) + <i>O</i>(1)</tt>.</p>

 <p>In 25.3.3.3 [equal.range]/4, change <tt>2*log(last - first) + 1</tt>
 to <tt>2*log<sub>2</sub>(last - first) + <i>O</i>(1)</tt>.</p>

 <p><i>[Matt provided wording]</i></p>


 <p><b>Rationale:</b></p>
 <p>The LWG considered just saying <i>O</i>(log n) for all three, but
   decided that threw away too much valuable information.  The fact
   that lower_bound is twice as fast as equal_range is important.
   However, it's better to allow an arbitrary additive constant than to
   specify an exact count.  An exact count would have to
   involve <tt>floor</tt> or <tt>ceil</tt>.  It would be too easy to
   get this wrong, and don't provide any substantial value for users.</p>


 <hr>
 <h3><a name="386"></a>386. Reverse iterator's operator[] has impossible return type</h3>
 <p><b>Section:</b> 24.4.1.3.11 [reverse.iter.op-=] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2002-10-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In 24.4.1.3.11 [reverse.iter.op-=], <tt>reverse_iterator&lt;&gt;::operator[]</tt>
 is specified as having a return type of <tt>reverse_iterator::reference</tt>,
 which is the same as <tt>iterator_traits&lt;Iterator&gt;::reference</tt>.
 (Where <tt>Iterator</tt> is the underlying iterator type.)</p>

 <p>The trouble is that <tt>Iterator</tt>'s own operator[] doesn't
   necessarily have a return type
   of <tt>iterator_traits&lt;Iterator&gt;::reference</tt>.   Its
   return type is merely required to be convertible
   to <tt>Iterator</tt>'s value type.  The return type specified for
   reverse_iterator's operator[] would thus appear to be impossible.</p>

 <p>With the resolution of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a>, the type of
   <tt>a[n]</tt> will continue to be required (for random access
   iterators) to be convertible to the value type, and also <tt>a[n] =
   t</tt> will be a valid expression.  Implementations of
   <tt>reverse_iterator</tt> will likely need to return a proxy from
   <tt>operator[]</tt> to meet these requirements. As mentioned in the
   comment from Dave Abrahams, the simplest way to specify that
   <tt>reverse_iterator</tt> meet this requirement to just mandate
   it and leave the return type of <tt>operator[]</tt> unspecified.</p>


 <p><b>Proposed resolution:</b></p>

 <p>In 24.4.1.2 [reverse.iter.requirements] change:</p>

 <blockquote>
 <pre>reference operator[](difference_type n) const;
 </pre>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <pre><b><i>unspecified</i></b> operator[](difference_type n) const; // see 24.1.5 [random.access.iterators]
 </pre>
 </blockquote>


 <p><i>[
 Comments from Dave Abrahams: IMO we should resolve 386 by just saying
     that the return type of reverse_iterator's operator[] is
     unspecified, allowing the random access iterator requirements to
     impose an appropriate return type.  If we accept 299's proposed
     resolution (and I think we should), the return type will be
     readable and writable, which is about as good as we can do.
 ]</i></p>


 <hr>
 <h3><a name="389"></a>389. Const overload of valarray::operator[] returns by value</h3>
 <p><b>Section:</b> 26.5.2.3 [valarray.access] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Gabriel Dos Reis <b>Date:</b> 2002-11-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#valarray.access">issues</a> in [valarray.access].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#77">77</a></p>
 <p><b>Discussion:</b></p>
 <p>Consider the following program:</p>
 <pre>    #include &lt;iostream&gt;
     #include &lt;ostream&gt;
     #include &lt;vector&gt;
     #include &lt;valarray&gt;
     #include &lt;algorithm&gt;
     #include &lt;iterator&gt;
     template&lt;typename Array&gt;
     void print(const Array&amp; a)
     {
     using namespace std;
     typedef typename Array::value_type T;
     copy(&amp;a[0], &amp;a[0] + a.size(),
     ostream_iterator&lt;T&gt;(std::cout, " "));
     }
     template&lt;typename T, unsigned N&gt;
     unsigned size(T(&amp;)[N]) { return N; }
     int main()
     {
     double array[] = { 0.89, 9.3, 7, 6.23 };
     std::vector&lt;double&gt; v(array, array + size(array));
     std::valarray&lt;double&gt; w(array, size(array));
     print(v); // #1
     std::cout &lt;&lt; std::endl;
     print(w); // #2
     std::cout &lt;&lt; std::endl;
     }
 </pre>

 <p>While the call numbered #1 succeeds, the call numbered #2 fails
 because the const version of the member function
 valarray&lt;T&gt;::operator[](size_t) returns a value instead of a
 const-reference. That seems to be so for no apparent reason, no
 benefit. Not only does that defeats users' expectation but it also
 does hinder existing software (written either in C or Fortran)
 integration within programs written in C++.  There is no reason why
 subscripting an expression of type valarray&lt;T&gt; that is const-qualified
 should not return a const T&amp;.</p>


 <p><b>Proposed resolution:</b></p>
 <p>In the class synopsis in 26.5.2 [template.valarray], and in
 26.5.2.3 [valarray.access] just above paragraph 1, change</p>
 <pre>  T operator[](size_t const);
 </pre>
 <p>to</p>
 <pre>  const T&amp; operator[](size_t const);
 </pre>

 <p><i>[Kona: fixed a minor typo: put semicolon at the end of the line
   wehre it belongs.]</i></p>


 <p><b>Rationale:</b></p>
 <p>Return by value seems to serve no purpose.  Valaray was explicitly
 designed to have a specified layout so that it could easily be
 integrated with libraries in other languages, and return by value
 defeats that purpose.  It is believed that this change will have no
 impact on allowable optimizations.</p>


 <hr>
 <h3><a name="391"></a>391. non-member functions specified as const</h3>
 <p><b>Section:</b> 22.1.3.2 [conversions] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> James Kanze <b>Date:</b> 2002-12-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The specifications of toupper and tolower both specify the functions as
 const, althought they are not member functions, and are not specified as
 const in the header file synopsis in section 22.1 [locales].
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 22.1.3.2 [conversions], remove <tt>const</tt> from the function
   declarations of std::toupper and std::tolower</p>


 <p><b>Rationale:</b></p><p>Fixes an obvious typo</p>


 <hr>
 <h3><a name="395"></a>395. inconsistencies in the definitions of rand() and random_shuffle()</h3>
 <p><b>Section:</b> 26.7 [c.math] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> James Kanze <b>Date:</b> 2003-01-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#c.math">issues</a> in [c.math].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 26.7 [c.math], the C++ standard refers to the C standard for the
 definition of rand(); in the C standard, it is written that "The
 implementation shall behave as if no library function calls the rand
 function."
 </p>

 <p>
 In 25.2.12 [alg.random.shuffle], there is no specification as to
 how the two parameter version of the function generates its random
 value.  I believe that all current implementations in fact call rand()
 (in contradiction with the requirement avove); if an implementation does
 not call rand(), there is the question of how whatever random generator
 it does use is seeded.  Something is missing.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In [lib.c.math], add a paragraph specifying that the C definition of
 rand shal be modified to say that "Unless otherwise specified, the
 implementation shall behave as if no library function calls the rand
 function."
 </p>

 <p>
 In [lib.alg.random.shuffle], add a sentence to the effect that "In
 the two argument form of the function, the underlying source of
 random numbers is implementation defined. [Note: in particular, an
 implementation is permitted to use <tt>rand</tt>.]
 </p>


 <p><b>Rationale:</b></p>
 <p>The original proposed resolution proposed requiring the
   two-argument from of <tt>random_shuffle</tt> to
   use <tt>rand</tt>. We don't want to do that, because some existing
   implementations already use something else: gcc
   uses <tt>lrand48</tt>, for example.  Using <tt>rand</tt> presents a
   problem if the number of elements in the sequence is greater than
   RAND_MAX.</p>


 <hr>
 <h3><a name="400"></a>400. redundant type cast in lib.allocator.members</h3>
 <p><b>Section:</b> 20.7.5.1 [allocator.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Markus Mauhart <b>Date:</b> 2003-02-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.members">issues</a> in [allocator.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 20.7.5.1 [allocator.members] allocator members, contains
 the following 3 lines:
 </p>

 <pre>  12 Returns: new((void *) p) T( val)
      void destroy(pointer p);
   13 Returns: ((T*) p)-&gt;~T()
 </pre>

 <p>
 The type cast "(T*) p" in the last line is redundant cause
 we know that std::allocator&lt;T&gt;::pointer is a typedef for T*.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Replace "((T*) p)" with "p".
 </p>


 <p><b>Rationale:</b></p><p>Just a typo, this is really editorial.</p>


 <hr>
 <h3><a name="401"></a>401.  incorrect type casts in table 32 in lib.allocator.requirements</h3>
 <p><b>Section:</b> 20.1.2 [allocator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Markus Mauhart <b>Date:</b> 2003-02-27</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#allocator.requirements">active issues</a> in [allocator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.requirements">issues</a> in [allocator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I think that in par2 of  [default.con.req] the last two
 lines of table 32 contain two incorrect type casts. The lines are ...
 </p>

 <pre>  a.construct(p,t)   Effect: new((void*)p) T(t)
   a.destroy(p)       Effect: ((T*)p)?-&gt;~T()
 </pre>

 <p>
 .... with the prerequisits coming from the preceding two paragraphs, especially
 from table 31:
 </p>

 <pre>  alloc&lt;T&gt;             a     ;// an allocator for T
   alloc&lt;T&gt;::pointer    p     ;// random access iterator
                               // (may be different from T*)
   alloc&lt;T&gt;::reference  r = *p;// T&amp;
   T const&amp;             t     ;
 </pre>

 <p>
 For that two type casts ("(void*)p" and "(T*)p") to be well-formed
 this would require then conversions to T* and void* for all
 alloc&lt;T&gt;::pointer, so it would implicitely introduce extra
 requirements for alloc&lt;T&gt;::pointer, additionally to the only
 current requirement (being a random access iterator).
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Accept proposed wording from
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2436.pdf">N2436</a> part 1.
 </p>

 <p>
 Note: Actually I would prefer to replace "((T*)p)?-&gt;dtor_name" with
 "p?-&gt;dtor_name", but AFAICS this is not possible cause of an omission
 in 13.5.6 [over.ref] (for which I have filed another DR on 29.11.2002).
 </p>

 <p><i>[Kona: The LWG thinks this is somewhere on the border between
   Open and NAD.  The intend is clear: <tt>construct</tt> constructs an
   object at the location <i>p</i>.  It's reading too much into the
   description to think that literally calling <tt>new</tt> is
   required.  Tweaking this description is low priority until we can do
   a thorough review of allocators, and, in particular, allocators with
   non-default pointer types.]</i></p>


 <p><i>[
 Batavia:  Proposed resolution changed to less code and more description.
 ]</i></p>


 <p><i>[
 post Oxford:  This would be rendered NAD Editorial by acceptance of
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2257.html">N2257</a>.
 ]</i></p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2387 for this issue which
 was subsequently split out into a separate paper N2436 for the purposes of voting.
 The resolution in N2436 addresses this issue.  The LWG voted to accelerate this
 issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="402"></a>402. wrong new expression in [some_]allocator::construct</h3>
 <p><b>Section:</b> 20.1.2 [allocator.requirements], 20.7.5.1 [allocator.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Markus Mauhart <b>Date:</b> 2003-02-27</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#allocator.requirements">active issues</a> in [allocator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.requirements">issues</a> in [allocator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 This applies to the new expression that is contained in both par12 of
 20.7.5.1 [allocator.members] and in par2 (table 32) of  [default.con.req].
 I think this new expression is wrong, involving unintended side
 effects.
 </p>


 <p>20.7.5.1 [allocator.members]  contains the following 3 lines:</p>

 <pre>  11 Returns: the largest value N for which the call allocate(N,0) might succeed.
      void construct(pointer p, const_reference val);
   12 Returns: new((void *) p) T( val)
 </pre>


 <p> [default.con.req] in table 32 has the following line:</p>
 <pre>  a.construct(p,t)   Effect: new((void*)p) T(t)
 </pre>

 <p>
 .... with the prerequisits coming from the preceding two paragraphs,
 especially from table 31:
 </p>

 <pre>  alloc&lt;T&gt;             a     ;// an allocator for T
   alloc&lt;T&gt;::pointer    p     ;// random access iterator
                               // (may be different from T*)
   alloc&lt;T&gt;::reference  r = *p;// T&amp;
   T const&amp;             t     ;
 </pre>

 <p>
 Cause of using "new" but not "::new", any existing "T::operator new"
 function will hide the global placement new function. When there is no
 "T::operator new" with adequate signature,
 every_alloc&lt;T&gt;::construct(..) is ill-formed, and most
 std::container&lt;T,every_alloc&lt;T&gt;&gt; use it; a workaround
 would be adding placement new and delete functions with adequate
 signature and semantic to class T, but class T might come from another
 party. Maybe even worse is the case when T has placement new and
 delete functions with adequate signature but with "unknown" semantic:
 I dont like to speculate about it, but whoever implements
 any_container&lt;T,any_alloc&gt; and wants to use construct(..)
 probably must think about it.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Replace "new" with "::new" in both cases.
 </p>


 <hr>
 <h3><a name="403"></a>403. basic_string::swap should not throw exceptions</h3>
 <p><b>Section:</b> 21.3.6.8 [string::swap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2003-03-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::swap">issues</a> in [string::swap].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 std::basic_string, 21.3 [basic.string] paragraph 2 says that
 basic_string "conforms to the requirements of a Sequence, as specified
 in (23.1.1)." The sequence requirements specified in (23.1.1) to not
 include any prohibition on swap members throwing exceptions.
 </p>

 <p>
 Section 23.1 [container.requirements] paragraph 10 does limit conditions under
 which exceptions may be thrown, but applies only to "all container
 types defined in this clause" and so excludes basic_string::swap
 because it is defined elsewhere.
 </p>

 <p>
 Eric Niebler points out that 21.3 [basic.string] paragraph 5 explicitly
 permits basic_string::swap to invalidates iterators, which is
 disallowed by 23.1 [container.requirements] paragraph 10. Thus the standard would
 be contradictory if it were read or extended to read as having
 basic_string meet 23.1 [container.requirements] paragraph 10 requirements.
 </p>

 <p>
 Yet several LWG members have expressed the belief that the original
 intent was that basic_string::swap should not throw exceptions as
 specified by 23.1 [container.requirements] paragraph 10, and that the standard is
 unclear on this issue. The complexity of basic_string::swap is
 specified as "constant time", indicating the intent was to avoid
 copying (which could cause a bad_alloc or other exception). An
 important use of swap is to ensure that exceptions are not thrown in
 exception-safe code.
 </p>

 <p>
 Note: There remains long standing concern over whether or not it is
 possible to reasonably meet the 23.1 [container.requirements] paragraph 10 swap
 requirements when allocators are unequal. The specification of
 basic_string::swap exception requirements is in no way intended to
 address, prejudice, or otherwise impact that concern.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 21.3.6.8 [string::swap], add a throws clause:
 </p>

 <p>
 Throws: Shall not throw exceptions.
 </p>


 <hr>
 <h3><a name="404"></a>404. May a replacement allocation function be declared inline?</h3>
 <p><b>Section:</b> 17.4.3.5 [replacement.functions], 18.5.1 [new.delete] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2003-04-24</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The eight basic dynamic memory allocation functions (single-object
 and array versions of ::operator new and ::operator delete, in the
 ordinary and nothrow forms) are replaceable.  A C++ program may
 provide an alternative definition for any of them, which will be used
 in preference to the implementation's definition.
 </p>

 <p>
 Three different parts of the standard mention requirements on
 replacement functions: 17.4.3.5 [replacement.functions], 18.5.1.1 [new.delete.single]
 and 18.5.1.2 [new.delete.array], and 3.7.2 [basic.stc.auto].
 </p>

 <p>None of these three places say whether a replacement function may
   be declared inline.  18.5.1.1 [new.delete.single] paragraph 2 specifies a
   signature for the replacement function, but that's not enough:
   the <tt>inline</tt> specifier is not part of a function's signature.
   One might also reason from 7.1.2 [dcl.fct.spec] paragraph 2, which
   requires that "an inline function shall be defined in every
   translation unit in which it is used," but this may not be quite
   specific enough either.  We should either explicitly allow or
   explicitly forbid inline replacement memory allocation
   functions.</p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add a new sentence to the end of 17.4.3.5 [replacement.functions] paragraph 3:
 "The program's definitions shall not be specified as <tt>inline</tt>.
 No diagnostic is required."
 </p>

 <p><i>[Kona: added "no diagnostic is required"]</i></p>


 <p><b>Rationale:</b></p>
 <p>
 The fact that <tt>inline</tt> isn't mentioned appears to have been
 nothing more than an oversight.  Existing implementations do not
 permit inline functions as replacement memory allocation functions.
 Providing this functionality would be difficult in some cases, and is
 believed to be of limited value.
 </p>


 <hr>
 <h3><a name="405"></a>405. qsort and POD</h3>
 <p><b>Section:</b> 25.4 [alg.c.library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ray Lischner <b>Date:</b> 2003-04-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.c.library">issues</a> in [alg.c.library].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 25.4 [alg.c.library] describes bsearch and qsort, from the C
 standard library. Paragraph 4 does not list any restrictions on qsort,
 but it should limit the base parameter to point to POD.  Presumably,
 qsort sorts the array by copying bytes, which requires POD.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 25.4 [alg.c.library] paragraph 4, just after the declarations and
 before the nonnormative note, add these words: "both of which have the
 same behavior as the original declaration.  The behavior is undefined
 unless the objects in the array pointed to by <i>base</i> are of POD
 type."
 </p>

 <p><i>[Something along these lines is clearly necessary.  Matt
   provided wording.]</i></p>


 <hr>
 <h3><a name="406"></a>406. vector::insert(s) exception safety</h3>
 <p><b>Section:</b> 23.2.6.4 [vector.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2003-04-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.modifiers">issues</a> in [vector.modifiers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 There is a possible defect in the standard: the standard text was
 never intended to prevent arbitrary ForwardIterators, whose operations
 may throw exceptions, from being passed, and it also wasn't intended
 to require a temporary buffer in the case where ForwardIterators were
 passed (and I think most implementations don't use one).  As is, the
 standard appears to impose requirements that aren't met by any
 existing implementation.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace 23.2.6.4 [vector.modifiers] paragraph 1 with:</p>
 <blockquote><p>
   1- Notes: Causes reallocation if the new size is greater than the
   old capacity. If no reallocation happens, all the iterators and
   references before the insertion point remain valid. If an exception
   is thrown other than by the copy constructor or assignment operator
   of T or by any InputIterator operation there are no effects.
 </p></blockquote>

 <p><i>[We probably need to say something similar for deque.]</i></p>


 <hr>
 <h3><a name="407"></a>407. Can singular iterators be destroyed?</h3>
 <p><b>Section:</b> 24.1 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 2003-06-03</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Clause 24.1 [iterator.requirements], paragraph 5, says that the only expression
 that is defined for a singular iterator is "an assignment of a
 non-singular value to an iterator that holds a singular value".  This
 means that destroying a singular iterator (e.g. letting an automatic
 variable go out of scope) is technically undefined behavior.  This
 seems overly strict, and probably unintentional.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the sentence in question to "... the only exceptions are
 destroying an iterator that holds a singular value, or the assignment
 of a non-singular value to an iterator that holds a singular value."
 </p>


 <hr>
 <h3><a name="409"></a>409. Closing an fstream should clear error state</h3>
 <p><b>Section:</b> 27.8.1.9 [ifstream.members], 27.8.1.13 [ofstream.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Nathan Myers <b>Date:</b> 2003-06-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ifstream.members">issues</a> in [ifstream.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 A strict reading of 27.8.1 [fstreams] shows that opening or
 closing a basic_[io]fstream does not affect the error bits.  This
 means, for example, that if you read through a file up to EOF, and
 then close the stream and reopen it at the beginning of the file,
 the EOF bit in the stream's error state is still set.  This is
 counterintuitive.
 </p>
 <p>
 The LWG considered this issue once before, as issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#22">22</a>,
 and put in a footnote to clarify that the strict reading was indeed
 correct.  We did that because we believed the standard was
 unambiguous and consistent, and that we should not make architectural
 changes in a TC.  Now that we're working on a new revision of the
 language, those considerations no longer apply.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Change 27.8.1.9 [ifstream.members], para. 3 from:</p>

 <blockquote><p>
 Calls rdbuf()-&gt;open(s,mode|in). If that function returns a null
 pointer, calls setstate(failbit) (which may throw ios_base::failure
 [Footnote: (lib.iostate.flags)].
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>Calls rdbuf()-&gt;open(s,mode|in). If that function
 returns a null pointer, calls setstate(failbit) (which may throw
 ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
 </p></blockquote>

 <p>Change 27.8.1.13 [ofstream.members], para. 3 from:</p>

 <blockquote><p>Calls rdbuf()-&gt;open(s,mode|out). If that function
 returns a null pointer, calls setstate(failbit) (which may throw
 ios_base::failure [Footnote: (lib.iostate.flags)).
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>Calls rdbuf()-&gt;open(s,mode|out). If that function
 returns a null pointer, calls setstate(failbit) (which may throw
 ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
 </p></blockquote>

 <p>Change 27.8.1.17 [fstream.members], para. 3 from:</p>

 <blockquote><p>Calls rdbuf()-&gt;open(s,mode), If that function returns
 a null pointer, calls setstate(failbit), (which may throw
 ios_base::failure). (lib.iostate.flags) )
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>Calls rdbuf()-&gt;open(s,mode), If that function returns
 a null pointer, calls setstate(failbit), (which may throw
 ios_base::failure). (lib.iostate.flags) ), else calls clear().
 </p></blockquote>


 <p><i>[Kona: the LWG agrees this is a good idea.  Post-Kona: Bill
 provided wording.  He suggests having open, not close, clear the error
 flags.]</i></p>


 <p><i>[Post-Sydney: Howard provided a new proposed resolution.  The
   old one didn't make sense because it proposed to fix this at the
   level of basic_filebuf, which doesn't have access to the stream's
   error state.  Howard's proposed resolution fixes this at the level
   of the three fstream class template instead.]</i></p>


 <hr>
 <h3><a name="410"></a>410. Missing semantics for stack and queue comparison operators</h3>
 <p><b>Section:</b> 23.2.4.1 [list.cons], 23.2.4.3 [list.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Hans Bos <b>Date:</b> 2003-06-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.cons">issues</a> in [list.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Sections 23.2.4.1 [list.cons] and 23.2.4.3 [list.modifiers] list
 comparison operators (==, !=, &lt;, &lt;=, &gt;, =&gt;) for queue and
 stack.  Only the semantics for queue::operator== (23.2.4.1 [list.cons] par2) and queue::operator&lt; (23.2.4.1 [list.cons]
 par3) are defined.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add the following new paragraphs after 23.2.4.1 [list.cons]
   paragraph 3:</p>

 <blockquote>

 <pre>  operator!=
 </pre>
 <p>Returns: <tt>x.c != y.c</tt></p>

 <pre>  operator&gt;
 </pre>
 <p>Returns: <tt>x.c &gt; y.c</tt></p>

 <pre>  operator&lt;=
 </pre>
 <p>Returns: <tt>x.c &lt;= y.c</tt></p>

 <pre>  operator&gt;=
 </pre>
 <p>Returns: <tt>x.c &gt;= y.c</tt></p>

 </blockquote>

 <p>Add the following paragraphs at the end of 23.2.4.3 [list.modifiers]:</p>

 <blockquote>

 <pre>  operator==
 </pre>
 <p>Returns: <tt>x.c == y.c</tt></p>

 <pre>  operator&lt;
 </pre>
 <p>Returns: <tt>x.c &lt; y.c</tt></p>

 <pre>  operator!=
 </pre>
 <p>Returns: <tt>x.c != y.c</tt></p>

 <pre>  operator&gt;
 </pre>
 <p>Returns: <tt>x.c &gt; y.c</tt></p>

 <pre>  operator&lt;=
 </pre>
 <p>Returns: <tt>x.c &lt;= y.c</tt></p>

 <pre>  operator&gt;=
 </pre>
 <p>Returns: <tt>x.c &gt;= y.c</tt></p>

 </blockquote>


 <p><i>[Kona: Matt provided wording.]</i></p>


 <p><b>Rationale:</b></p>
 <p>There isn't any real doubt about what these operators are
 supposed to do, but we ought to spell it out.</p>


 <hr>
 <h3><a name="411"></a>411. Wrong names of set member functions</h3>
 <p><b>Section:</b> 25.3.5 [alg.set.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Frey <b>Date:</b> 2003-07-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.set.operations">issues</a> in [alg.set.operations].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 25.3.5 [alg.set.operations] paragraph 1 reads:
 "The semantics of the set operations are generalized to multisets in a
 standard way by defining union() to contain the maximum number of
 occurrences of every element, intersection() to contain the minimum, and
 so on."
 </p>

 <p>
 This is wrong.  The name of the functions are set_union() and
 set_intersection(), not union() and intersection().
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change that sentence to use the correct names.</p>


 <hr>
 <h3><a name="412"></a>412. Typo in 27.4.4.3</h3>
 <p><b>Section:</b> 27.4.4.3 [iostate.flags] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-07-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostate.flags">issues</a> in [iostate.flags].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#429">429</a></p>
 <p><b>Discussion:</b></p>
 <p>
 The Effects clause in 27.4.4.3 [iostate.flags] paragraph 5 says that the
 function only throws if the respective bits are already set prior to
 the function call. That's obviously not the intent. The typo ought to
 be corrected and the text reworded as: "If (<i>state</i> &amp;
 exceptions()) == 0, returns. ..."
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.4.4.3 [iostate.flags] paragraph 5, replace "If (rdstate() &amp;
 exceptions()) == 0" with "If ((state | (rdbuf() ? goodbit : badbit))
 &amp; exceptions()) == 0".
 </p>

 <p><i>[Kona: the original proposed resolution wasn't quite right.  We
   really do mean rdstate(); the ambiguity is that the wording in the
   standard doesn't make it clear whether we mean rdstate() before
   setting the new state, or rdsate() after setting it.  We intend the
   latter, of course. Post-Kona: Martin provided wording.]</i></p>


 <hr>
 <h3><a name="413"></a>413. Proposed resolution to LDR#64 still wrong</h3>
 <p><b>Section:</b> 27.6.1.2.3 [istream::extractors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Bo Persson <b>Date:</b> 2003-07-13</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream::extractors">issues</a> in [istream::extractors].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The second sentence of the proposed resolution says:
 </p>

 <p>
 "If it inserted no characters because it caught an exception thrown
 while extracting characters from sb and ..."
 </p>

 <p>
 However, we are not extracting from sb, but extracting from the
 basic_istream (*this) and inserting into sb. I can't really tell if
 "extracting" or "sb" is a typo.
 </p>

 <p><i>[
 Sydney: Definitely a real issue. We are, indeed, extracting characters
 from an istream and not from sb. The problem was there in the FDIS and
 wasn't fixed by issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#64">64</a>. Probably what was intended was
 to have *this instead of sb. We're talking about the exception flag
 state of a basic_istream object, and there's only one basic_istream
 object in this discussion, so that would be a consistent
 interpretation.  (But we need to be careful: the exception policy of
 this member function must be consistent with that of other
 extractors.)  PJP will provide wording.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the sentence from:</p>

 <blockquote><p>
 If it inserted no characters because it caught an exception thrown
 while extracting characters from sb and failbit is on in exceptions(),
 then the caught exception is rethrown.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
 If it inserted no characters because it caught an exception thrown
 while extracting characters from *this and failbit is on in exceptions(),
 then the caught exception is rethrown.
 </p></blockquote>


 <hr>
 <h3><a name="414"></a>414. Which iterators are invalidated by v.erase()?</h3>
 <p><b>Section:</b> 23.2.6.4 [vector.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2003-08-19</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.modifiers">issues</a> in [vector.modifiers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Consider the following code fragment:
 </p>
 <blockquote>
 <pre>int A[8] = { 1,3,5,7,9,8,4,2 };
 std::vector&lt;int&gt; v(A, A+8);

 std::vector&lt;int&gt;::iterator i1 = v.begin() + 3;
 std::vector&lt;int&gt;::iterator i2 = v.begin() + 4;
 v.erase(i1);
 </pre>
 </blockquote>

 <p>
 Which iterators are invalidated by <tt>v.erase(i1)</tt>: i1, i2,
 both, or neither?
 </p>

 <p>
 On all existing implementations that I know of, the status of i1 and
 i2 is the same: both of them will be iterators that point to some
 elements of the vector (albeit not the same elements they did
 before).  You won't get a crash if you use them.  Depending on
 exactly what you mean by "invalidate", you might say that neither one
 has been invalidated because they still point to <i>something</i>,
 or you might say that both have been invalidated because in both
 cases the elements they point to have been changed out from under the
 iterator.
 </p>

 <p>
 The standard doesn't say either of those things.  It says that erase
 invalidates all iterators and references "after the point of the
 erase".  This doesn't include i1, since it's at the point of the
 erase instead of after it.  I can't think of any sensible definition
 of invalidation by which one can say that i2 is invalidated but i1
 isn't.
 </p>

 <p>
 (This issue is important if you try to reason about iterator validity
 based only on the guarantees in the standard, rather than reasoning
 from typical implementation techniques.  Strict debugging modes,
 which some programmers find useful, do not use typical implementation
 techniques.)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 23.2.6.4 [vector.modifiers] paragraph 3, change "Invalidates all the
 iterators and references after the point of the erase" to
 "Invalidates iterators and references at or after the point of the
 erase".
 </p>


 <p><b>Rationale:</b></p>
 <p>I believe this was essentially a typographical error, and that it
   was taken for granted that erasing an element invalidates iterators
   that point to it.  The effects clause in question treats iterators
   and references in parallel, and it would seem counterintuitive to
   say that a reference to an erased value remains valid.</p>


 <hr>
 <h3><a name="415"></a>415. behavior of std::ws</h3>
 <p><b>Section:</b> 27.6.1.4 [istream.manip] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 According to 27.6.1.4, the ws() manipulator is not required to construct
 the sentry object. The manipulator is also not a member function so the
 text in 27.6.1, p1 through 4 that describes the exception policy for
 istream member functions does not apply. That seems inconsistent with
 the rest of extractors and all the other input functions (i.e., ws will
 not cause a tied stream to be flushed before extraction, it doesn't check
 the stream's exceptions or catch exceptions thrown during input, and it
 doesn't affect the stream's gcount).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add to 27.6.1.4 [istream.manip], immediately before the first sentence
 of paragraph 1, the following text:
 </p>

     <blockquote><p>
     Behaves as an unformatted input function (as described in
     27.6.1.3, paragraph 1), except that it does not count the number
     of characters extracted and does not affect the value returned by
     subsequent calls to is.gcount(). After constructing a sentry
     object...
     </p></blockquote>

 <p><i>[Post-Kona: Martin provided wording]</i></p>


 <hr>
 <h3><a name="416"></a>416. definitions of XXX_MIN and XXX_MAX macros in climits</h3>
 <p><b>Section:</b> 18.2.2 [c.limits] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 Given two overloads of the function foo(), one taking an argument of type
 int and the other taking a long, which one will the call foo(LONG_MAX)
 resolve to? The expected answer should be foo(long), but whether that
 is true depends on the #defintion of the LONG_MAX macro, specifically
 its type. This issue is about the fact that the type of these macros
 is not actually required to be the same as the the type each respective
 limit.
 <br>

 Section 18.2.2 of the C++ Standard does not specify the exact types of
 the XXX_MIN and XXX_MAX macros #defined in the &lt;climits&gt; and &lt;limits.h&gt;
 headers such as INT_MAX and LONG_MAX and instead defers to the C standard.
 <br>

 Section 5.2.4.2.1, p1 of the C standard specifies that "The values [of
 these constants] shall be replaced by constant expressions suitable for use
 in #if preprocessing directives. Moreover, except for CHAR_BIT and MB_LEN_MAX,
 the following shall be replaced by expressions that have the same type as
 would an expression that is an object of the corresponding type converted
 according to the integer promotions."
 <br>

 The "corresponding type converted according to the integer promotions" for
 LONG_MAX is, according to 6.4.4.1, p5 of the C standard, the type of long
 converted to the first of the following set of types that can represent it:
 int, long int, long long int. So on an implementation where (sizeof(long)
 == sizeof(int)) this type is actually int, while on an implementation where
 (sizeof(long) &gt; sizeof(int)) holds this type will be long.
 <br>

 This is not an issue in C since the type of the macro cannot be detected
 by any conforming C program, but it presents a portability problem in C++
 where the actual type is easily detectable by overload resolution.

         </p>
 <p><i>[Kona: the LWG does not believe this is a defect.  The C macro
   definitions are what they are; we've got a better
   mechanism, <tt>std::numeric_limits</tt>, that is specified more
   precisely than the C limit macros.  At most we should add a
   nonnormative note recommending that users who care about the exact
   types of limit quantities should use &lt;limits&gt; instead of
   &lt;climits&gt;.]</i></p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change 18.2.2 [c.limits], paragraph 2:
 </p>

 <blockquote><p>
 -2- The contents are the same as the Standard C library header <tt>&lt;limits.h&gt;</tt>.
 <ins>[<i>Note:</i> The types of the macros in <tt>&lt;climits&gt;</tt> are not guaranteed
 to match the type to which they refer.<i>--end note</i>]</ins>
 </p></blockquote>


 <hr>
 <h3><a name="420"></a>420. is std::FILE a complete type?</h3>
 <p><b>Section:</b> 27.8.1 [fstreams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#fstreams">issues</a> in [fstreams].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 7.19.1, p2, of C99 requires that the FILE type only be declared in
 &lt;stdio.h&gt;.  None of the (implementation-defined) members of the
 struct is mentioned anywhere for obvious reasons.
 </p>

 <p>
 C++ says in 27.8.1, p2 that FILE is a type that's defined in &lt;cstdio&gt;. Is
 it really the intent that FILE be a complete type or is an implementation
 allowed to just declare it without providing a full definition?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In the first sentence of 27.8.1 [fstreams] paragraph 2, change
   "defined" to "declared".</p>


 <p><b>Rationale:</b></p>
 <p>We don't want to impose any restrictions beyond what the C standard
   already says. We don't want to make anything implementation defined,
   because that imposes new requirements in implementations.</p>


 <hr>
 <h3><a name="422"></a>422. explicit specializations of member functions of class templates</h3>
 <p><b>Section:</b> 17.4.3.2 [reserved.names] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#reserved.names">issues</a> in [reserved.names].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It has been suggested that 17.4.3.1, p1 may or may not allow programs to
 explicitly specialize members of standard templates on user-defined types.
 The answer to the question might have an impact where library requirements
 are given using the "as if" rule. I.e., if programs are allowed to specialize
 member functions they will be able to detect an implementation's strict
 conformance to Effects clauses that describe the behavior of the function
 in terms of the other member function (the one explicitly specialized by
 the program) by relying on the "as if" rule.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>
   Add the following sentence to 17.4.3.2 [reserved.names], p1:
 </p>

 <blockquote><p>
 It is undefined for a C++ program to add declarations or definitions to
 namespace std or namespaces within namespace <tt>std</tt> unless otherwise specified. A
 program may add template specializations for any standard library template to
 namespace <tt>std</tt>. Such a specialization (complete or partial) of a standard library
 template results in undefined behavior unless the declaration depends on a
 user-defined type of external linkage and unless the specialization meets the
 standard library requirements for the original template.<sup>168)</sup>
 <ins>A program has undefined behavior if it declares</ins>
 </p>
 <ul>
 <li><ins>an explicit specialization of any member function of a standard
             library class template, or</ins></li>
 <li><ins>an explicit specialization of any member function template of a
             standard library class or class template, or</ins></li>
 <li><ins>an explicit or partial specialization of any member class
             template of a standard library class or class template.</ins></li>
 </ul>
 <p>
 A program may explicitly instantiate any templates in the standard library only
 if the declaration depends on the name of a user-defined type of external
 linkage and the instantiation meets the standard library requirements for the
 original template.
 </p></blockquote>

 <p><i>[Kona: straw poll was 6-1 that user programs should not be
   allowed to specialize individual member functions of standard
   library class templates, and that doing so invokes undefined
   behavior. Post-Kona: Martin provided wording.]</i></p>


 <p><i>[Sydney: The LWG agrees that the standard shouldn't permit users
 to specialize individual member functions unless they specialize the
 whole class, but we're not sure these words say what we want them to;
 they could be read as prohibiting the specialization of any standard
 library class templates. We need to consult with CWG to make sure we
 use the right wording.]</i></p>


 <hr>
 <h3><a name="425"></a>425. return value of std::get_temporary_buffer</h3>
 <p><b>Section:</b> 20.7.8 [temporary.buffer] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The standard is not clear about the requirements on the value returned from
 a call to get_temporary_buffer(0). In particular, it fails to specify whether
 the call should return a distinct pointer each time it is called (like
 operator new), or whether the value is unspecified (as if returned by
 malloc). The standard also fails to mention what the required behavior
 is when the argument is less than 0.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 20.5.3 [meta.help] paragraph 2 from "...or a pair of 0
 values if no storage can be obtained" to "...or a pair of 0 values if
 no storage can be obtained or if <i>n</i> &lt;= 0."</p>
 <p><i>[Kona: Matt provided wording]</i></p>


 <hr>
 <h3><a name="426"></a>426. search_n(), fill_n(), and generate_n() with negative n</h3>
 <p><b>Section:</b> 25.1.12 [alg.search], 25.2.6 [alg.fill], 25.2.7 [alg.generate] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.search">issues</a> in [alg.search].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The complexity requirements for these function templates are incorrect
 (or don't even make sense) for negative n:</p>

 <p>25.1.9, p7 (search_n):
 <br>
 Complexity: At most (last1 - first1) * count applications
 of the corresponding predicate.</p>

 <p>25.2.5, p3 (fill_n):
 <br>
 Complexity: Exactly last - first (or n) assignments.</p>

 <p>25.2.6, p3 (generate_n):
 <br>
 Complexity: Exactly last - first (or n) assignments.</p>

 <p>
 In addition, the Requirements or the Effects clauses for the latter two
 templates don't say anything about the behavior when n is negative.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 25.1.9, p7 to</p>

 <blockquote><p>
 Complexity: At most (last1 - first1) * count applications
 of the corresponding predicate if count is positive,
 or 0 otherwise.
 </p></blockquote>

 <p>Change 25.2.5, p2 to</p>
 <blockquote><p>
 Effects: Assigns value through all the iterators in the range [first,
 last), or [first, first + n) if n is positive, none otherwise.
 </p></blockquote>

 <p>Change 25.2.5, p3 to:</p>
 <blockquote><p>
 Complexity: Exactly last - first (or n if n is positive,
 or 0 otherwise) assignments.
 </p></blockquote>

 <p>
 Change 25.2.6, p1
 to (notice the correction for the misspelled "through"):
 </p>
 <blockquote><p>
 Effects: Invokes the function object genand assigns the return
 value of gen through all the iterators in the range [first, last),
 or [first, first + n) if n is positive, or [first, first)
 otherwise.
 </p></blockquote>

 <p>Change 25.2.6, p3 to:</p>
 <blockquote><p>
 Complexity: Exactly last - first (or n if n is positive,
 or 0 otherwise) assignments.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>Informally, we want to say that whenever we see a negative number
   we treat it the same as if it were zero.  We believe the above
   changes do that (although they may not be the minimal way of saying
   so).  The LWG considered and rejected the alternative of saying that
   negative numbers are undefined behavior.</p>


 <hr>
 <h3><a name="428"></a>428. string::erase(iterator) validity</h3>
 <p><b>Section:</b> 21.3.6.5 [string::erase] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-09-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::erase">issues</a> in [string::erase].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 23.1.1, p3 along with Table 67 specify as a prerequisite for a.erase(q)
 that q must be a valid dereferenceable iterator into the sequence a.
 </p>

 <p>
 However, 21.3.5.5, p5 describing string::erase(p) only requires that
 p be a valid iterator.
 </p>

 <p>
 This may be interepreted as a relaxation of the general requirement,
 which is most likely not the intent.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Remove 21.3.6.5 [string::erase] paragraph 5.</p>


 <p><b>Rationale:</b></p>
 <p>The LWG considered two options: changing the string requirements to
   match the general container requirements, or just removing the
   erroneous string requirements altogether.  The LWG chose the latter
   option, on the grounds that duplicating text always risks the
   possibility that it might be duplicated incorrectly.</p>


 <hr>
 <h3><a name="432"></a>432. stringbuf::overflow() makes only one write position available</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Christian W Brock <b>Date:</b> 2003-09-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.7.1.3 par 8 says:</p>
 <blockquote><p>
 Notes: The function can make a write position available only if
     ( mode &amp; ios_base::out) != 0. To make a write position
     available, the function reallocates (or initially allocates) an
     array object with a sufficient number of elements to hold the
     current array object (if any), plus one additional write position.
     If ( mode &amp; ios_base::in) != 0, the function alters the read end
     pointer egptr() to point just past the new write position (as
     does the write end pointer epptr()).
 </p></blockquote>

 <p>
 The sentences "plus one additional write position." and especially
     "(as does the write end pointer epptr())" COULD by interpreted
     (and is interpreted by at least my library vendor) as:
 </p>

 <blockquote><p>
     post-condition: epptr() == pptr()+1
 </p></blockquote>

 <p>
 This WOULD force sputc() to call the virtual overflow() each time.
 </p>

 <p>The proposed change also affects Defect Report 169.</p>


 <p><b>Proposed resolution:</b></p>
 <p>27.7.1.1/2 Change:</p>

 <blockquote><p>
 2- Notes: The function allocates no array object.
 </p></blockquote>

 <p>
 to:
 </p>

 <blockquote><p>
 2- Postcondition: str() == "".
 </p></blockquote>

 <p>
 27.7.1.1/3 Change:
 </p>

 <blockquote>
 <p>
 -3- Effects: Constructs an object of class basic_stringbuf,
 initializing the base class with basic_streambuf()
 (lib.streambuf.cons), and initializing mode with which . Then copies
 the content of str into the basic_stringbuf underlying character
 sequence and initializes the input and output sequences according to
 which. If which &amp; ios_base::out is true, initializes the output
 sequence with the underlying sequence. If which &amp; ios_base::in is
 true, initializes the input sequence with the underlying sequence.
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 -3- Effects: Constructs an object of class basic_stringbuf,
 initializing the base class with basic_streambuf()
 (lib.streambuf.cons), and initializing mode with which. Then copies
 the content of str into the basic_stringbuf underlying character
 sequence. If which &amp; ios_base::out is true, initializes the output
 sequence such that pbase() points to the first underlying character,
 epptr() points one past the last underlying character, and if (which &amp;
 ios_base::ate) is true, pptr() is set equal to
 epptr() else pptr() is set equal to pbase(). If which &amp; ios_base::in
 is true, initializes the input sequence such that eback() and gptr()
 point to the first underlying character and egptr() points one past
 the last underlying character.
 </p>
 </blockquote>

 <p>27.7.1.2/1 Change:</p>

 <blockquote>
 <p>
 -1- Returns: A basic_string object whose content is equal to the
 basic_stringbuf underlying character sequence. If the buffer is only
 created in input mode, the underlying character sequence is equal to
 the input sequence; otherwise, it is equal to the output sequence. In
 case of an empty underlying character sequence, the function returns
 basic_string&lt;charT,traits,Allocator&gt;().
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 -1- Returns: A basic_string object whose content is equal to the
 basic_stringbuf underlying character sequence. If the basic_stringbuf
 was created only in input mode, the resultant basic_string contains
 the character sequence in the range [eback(), egptr()).  If the
 basic_stringbuf was created with (which &amp; ios_base::out) being true
 then the resultant basic_string contains the character sequence in the
 range [pbase(), high_mark) where high_mark represents the position one
 past the highest initialized character in the buffer.  Characters can
 be initialized either through writing to the stream, or by
 constructing the basic_stringbuf with a basic_string, or by calling
 the str(basic_string) member function.  In the case of calling the
 str(basic_string) member function, all characters initialized prior to
 the call are now considered uninitialized (except for those
 characters re-initialized by the new basic_string).  Otherwise the
 basic_stringbuf has been created in neither input nor output mode and
 a zero length basic_string is returned.
 </p>
 </blockquote>

 <p>
 27.7.1.2/2 Change:
 </p>

 <blockquote>
 <p>
 -2- Effects: If the basic_stringbuf's underlying character sequence is
 not empty, deallocates it. Then copies the content of s into the
 basic_stringbuf underlying character sequence and initializes the
 input and output sequences according to the mode stored when creating
 the basic_stringbuf object. If (mode&amp;ios_base::out) is true, then
 initializes the output sequence with the underlying sequence. If
 (mode&amp;ios_base::in) is true, then initializes the input sequence with
 the underlying sequence.
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 -2- Effects: Copies the content of s into the basic_stringbuf
 underlying character sequence. If mode &amp; ios_base::out is true,
 initializes the output sequence such that pbase() points to the first
 underlying character, epptr() points one past the last underlying
 character, and if (mode &amp; ios_base::ate) is true,
 pptr() is set equal to epptr() else pptr() is set equal to pbase(). If
 mode &amp; ios_base::in is true, initializes the input sequence such that
 eback() and gptr() point to the first underlying character and egptr()
 points one past the last underlying character.
 </p>
 </blockquote>

 <p>Remove 27.2.1.2/3.  (Same rationale as issue 238: incorrect and unnecessary.)</p>

 <p>27.7.1.3/1 Change:</p>

 <blockquote>
 <p>
 1- Returns: If the input sequence has a read position available,
 returns traits::to_int_type(*gptr()).  Otherwise, returns
 traits::eof().
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 1- Returns: If the input sequence has a read position available,
 returns traits::to_int_type(*gptr()).  Otherwise, returns
 traits::eof().  Any character in the underlying buffer which has been
 initialized is considered to be part of the input sequence.
 </p>
 </blockquote>

 <p>27.7.1.3/9 Change:</p>

 <blockquote>
 <p>
 -9- Notes: The function can make a write position available only if (
 mode &amp; ios_base::out) != 0. To make a write position available, the
 function reallocates (or initially allocates) an array object with a
 sufficient number of elements to hold the current array object (if
 any), plus one additional write position. If ( mode &amp; ios_base::in) !=
 0, the function alters the read end pointer egptr() to point just past
 the new write position (as does the write end pointer epptr()).
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 -9- The function can make a write position available only if ( mode &amp;
 ios_base::out) != 0. To make a write position available, the function
 reallocates (or initially allocates) an array object with a sufficient
 number of elements to hold the current array object (if any), plus one
 additional write position. If ( mode &amp; ios_base::in) != 0, the
 function alters the read end pointer egptr() to point just past the
 new write position.
 </p>
 </blockquote>

 <p>27.7.1.3/12 Change:</p>

 <blockquote>
 <p>
 -12- _ If (newoff + off) &lt; 0, or (xend - xbeg) &lt; (newoff + off), the
 positioning operation fails. Otherwise, the function assigns xbeg +
 newoff + off to the next pointer xnext .
 </p>
 </blockquote>

 <p>to:</p>

 <blockquote>
 <p>
 -12- _ If (newoff + off) &lt; 0, or if (newoff + off) refers to an
 uninitialized character (as defined in 27.7.1.3 [stringbuf.members]
 paragraph 1), the positioning operation fails. Otherwise, the function
 assigns xbeg + newoff + off to the next pointer xnext .
 </p>
 </blockquote>

 <p><i>[post-Kona: Howard provided wording.  At Kona the LWG agreed that
   something along these lines was a good idea, but the original
   proposed resolution didn't say enough about the effect of various
   member functions on the underlying character sequences.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The current basic_stringbuf description is over-constrained in such
 a way as to prohibit vendors from making this the high-performance
 in-memory stream it was meant to be.  The fundamental problem is that
 the pointers: eback(), gptr(), egptr(), pbase(), pptr(), epptr() are
 observable from a derived client, and the current description
 restricts the range [pbase(), epptr()) from being grown geometrically.
 This change allows, but does not require, geometric growth of this
 range.</p>

 <p>Backwards compatibility issues: These changes will break code that
 derives from basic_stringbuf, observes epptr(), and depends upon
 [pbase(), epptr()) growing by one character on each call to overflow()
 (i.e. test suites).  Otherwise there are no backwards compatibility
 issues.</p>

 <p>27.7.1.1/2: The non-normative note is non-binding, and if it were
 binding, would be over specification.  The recommended change focuses
 on the important observable fact.</p>

 <p>27.7.1.1/3: This change does two things: 1.  It describes exactly
 what must happen in terms of the sequences.  The terms "input
 sequence" and "output sequence" are not well defined.  2.  It
 introduces a common extension: open with app or ate mode.  I concur
 with issue 238 that paragraph 4 is both wrong and unnecessary.</p>

 <p>27.7.1.2/1: This change is the crux of the efficiency issue.  The
 resultant basic_string is not dependent upon epptr(), and thus
 implementors are free to grow the underlying buffer geometrically
 during overflow() *and* place epptr() at the end of that buffer.</p>

 <p>27.7.1.2/2:  Made consistent with the proposed 27.7.1.1/3.</p>

 <p>27.7.1.3/1: Clarifies that characters written to the stream beyond
 the initially specified string are available for reading in an i/o
 basic_streambuf.</p>

 <p>27.7.1.3/9: Made normative by removing "Notes:", and removed the
 trailing parenthetical comment concerning epptr().</p>

 <p>27.7.1.3/12: Restricting the positioning to [xbeg, xend) is no
 longer allowable since [pbase(), epptr()) may now contain
 uninitialized characters.  Positioning is only allowable over the
 initialized range.</p>


 <hr>
 <h3><a name="434"></a>434. bitset::to_string() hard to use</h3>
 <p><b>Section:</b> 23.3.5.2 [bitset.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-10-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bitset.members">issues</a> in [bitset.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It has been pointed out a number of times that the bitset to_string() member
 function template is tedious to use since callers must explicitly specify the
 entire template argument list (3 arguments). At least two implementations
 provide a number of overloads of this template to make it easier to use.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In order to allow callers to specify no template arguments at all, just the
 first one (charT), or the first 2 (charT and traits), in addition to all
 three template arguments, add the following three overloads to both the
 interface (declarations only) of the class template bitset as well as to
 section 23.3.5.2, immediately after p34, the Returns clause of the existing
 to_string() member function template:</p>

 <pre>    template &lt;class charT, class traits&gt;
     basic_string&lt;charT, traits, allocator&lt;charT&gt; &gt;
     to_string () const;

     -34.1- Returns: to_string&lt;charT, traits, allocator&lt;charT&gt; &gt;().

     template &lt;class charT&gt;
     basic_string&lt;charT, char_traits&lt;charT&gt;, allocator&lt;charT&gt; &gt;
     to_string () const;

     -34.2- Returns: to_string&lt;charT, char_traits&lt;charT&gt;, allocator&lt;charT&gt; &gt;().

     basic_string&lt;char, char_traits&lt;char&gt;, allocator&lt;char&gt; &gt;
     to_string () const;

     -34.3- Returns: to_string&lt;char, char_traits&lt;char&gt;, allocator&lt;char&gt; &gt;().
 </pre>

 <p><i>[Kona: the LWG agrees that this is an improvement over the
   status quo.  Dietmar thought about an alternative using a proxy
   object but now believes that the proposed resolution above is the
   right choice.
 ]</i></p>


 <hr>
 <h3><a name="435"></a>435. bug in DR 25</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-10-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 It has been pointed out that the proposed resolution in DR 25 may not be
 quite up to snuff: <br>
 http://gcc.gnu.org/ml/libstdc++/2003-09/msg00147.html
 http://anubis.dkuug.dk/jtc1/sc22/wg21/docs/lwg-defects.html#25<br>
 </p>

 <p>
 It looks like Petur is right. The complete corrected text is copied below.
 I think we may have have been confused by the reference to 22.2.2.2.2 and
 the subsequent description of `n' which actually talks about the second
 argument to sputn(), not about the number of fill characters to pad with.
 </p>

 <p>
 So the question is: was the original text correct? If the intent was to
 follow classic iostreams then it most likely wasn't, since setting width()
 to less than the length of the string doesn't truncate it on output. This
 is also the behavior of most implementations (except for SGI's standard
 iostreams where the operator does truncate).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the text in 21.3.7.9, p4 from</p>
     <blockquote><p>
     If bool(k) is true, inserts characters as if by calling
     os.rdbuf()-&gt;sputn(str.data(), n), padding as described in stage 3
     of lib.facet.num.put.virtuals, where n is the larger of os.width()
     and str.size();
     </p></blockquote>
 <p>to</p>
     <blockquote><p>
     If bool(k) is true, determines padding as described in
     lib.facet.num.put.virtuals, and then inserts the resulting
     sequence of characters <tt>seq</tt> as if by calling
     <tt>os.rdbuf()-&gt;sputn(seq, n)</tt>, where <tt>n</tt> is the larger of
     <tt>os.width()</tt> and <tt>str.size()</tt>;
      </p></blockquote>

 <p><i>[Kona: it appears that neither the original wording, DR25, nor the
   proposed resolution, is quite what we want.  We want to say that
   the string will be output, padded to os.width() if necessary.  We
   don't want to duplicate the padding rules in clause 22, because
   they're complicated, but we need to be careful because they weren't
   quite written with quite this case in mind.  We need to say what
   the character sequence is, and then defer to clause 22.  Post-Kona:
   Benjamin provided wording.]</i></p>


 <hr>
 <h3><a name="436"></a>436. are cv-qualified facet types valid facets?</h3>
 <p><b>Section:</b> 22.1.1.1.2 [locale.facet] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2003-10-15</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Is "const std::ctype&lt;char&gt;" a valid template argument to has_facet, use_facet,
 and the locale template ctor? And if so, does it designate the same Facet as
 the non-const "std::ctype&lt;char&gt;?" What about "volatile std::ctype&lt;char&gt;?"
 Different implementations behave differently: some fail to compile, others
 accept such types but behave inconsistently.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 22.1.1.1.2, p1 to read:</p>

 <p>Template parameters in this clause which are required to be facets
 are those named Facet in declarations. A program that passes a type
 that is not a facet, or a type that refers to volatile-qualified
 facet, as an (explicit or deduced) template parameter to a locale
 function expecting a facet, is ill-formed.  A const-qualified facet is
 a valid template argument to any locale function that expects a Facet
 template parameter.</p>

 <p><i>[Kona: changed the last sentence from a footnote to normative
 text.]</i></p>


 <hr>
 <h3><a name="438"></a>438. Ambiguity in the "do the right thing" clause</h3>
 <p><b>Section:</b> 23.1.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2003-10-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>Section 23.1.3 [sequence.reqmts], paragraphs 9-11, fixed up the problem
 noticed with statements like:</p>
 <pre>vector&lt;int&gt; v(10, 1);
 </pre>

 <p>The intent of the above statement was to construct with:</p>
 <pre>vector(size_type, const value_type&amp;);
 </pre>

 <p>but early implementations failed to compile as they bound to:</p>
 <pre>template &lt;class InputIterator&gt;
 vector(InputIterator f, InputIterator l);
 </pre>
 <p>instead.</p>

 <p>Paragraphs 9-11 say that if InputIterator is an integral type, then the
 member template constructor will have the same effect as:</p>
 <pre>vector&lt;static_cast&lt;size_type&gt;(f), static_cast&lt;value_type&gt;(l));
 </pre>
 <p>(and similarly for the other member template functions of sequences).</p>

 <p>There is also a note that describes one implementation technique:</p>
 <blockquote><p>
    One way that sequence implementors can satisfy this requirement is to
    specialize the member template for every integral type.
 </p></blockquote>

 <p>This might look something like:</p>
 <blockquote>
 <pre>template &lt;class T&gt;
 struct vector
 {
      typedef unsigned size_type;

      explicit vector(size_type) {}
      vector(size_type, const T&amp;) {}

      template &lt;class I&gt;
      vector(I, I);

      // ...
 };

 template &lt;class T&gt;
 template &lt;class I&gt;
 vector&lt;T&gt;::vector(I, I) { ... }

 template &lt;&gt;
 template &lt;&gt;
 vector&lt;int&gt;::vector(int, int) { ... }

 template &lt;&gt;
 template &lt;&gt;
 vector&lt;int&gt;::vector(unsigned, unsigned) { ... }

 //  ...
 </pre>
 </blockquote>

 <p>Label this solution 'A'.</p>

 <p>The standard also says:</p>
 <blockquote><p>
  Less cumbersome implementation techniques also exist.
 </p></blockquote>
 <p>
 A popular technique is to not specialize as above, but instead catch
 every call with the member template, detect the type of InputIterator,
 and then redirect to the correct logic.  Something like:
 </p>
 <blockquote>
 <pre>template &lt;class T&gt;
 template &lt;class I&gt;
 vector&lt;T&gt;::vector(I f, I l)
 {
      choose_init(f, l, int2type&lt;is_integral&lt;I&gt;::value&gt;());
 }

 template &lt;class T&gt;
 template &lt;class I&gt;
 vector&lt;T&gt;::choose_init(I f, I l, int2type&lt;false&gt;)
 {
     // construct with iterators
 }

 template &lt;class T&gt;
 template &lt;class I&gt;
 vector&lt;T&gt;::choose_init(I f, I l, int2type&lt;true&gt;)
 {
     size_type sz = static_cast&lt;size_type&gt;(f);
     value_type v = static_cast&lt;value_type&gt;(l);
     // construct with sz,v
 }
 </pre>
 </blockquote>

 <p>Label this solution 'B'.</p>

 <p>Both of these solutions solve the case the standard specifically
 mentions:</p>
 <pre>vector&lt;int&gt; v(10, 1);  // ok, vector size 10, initialized to 1
 </pre>

 <p>
 However, (and here is the problem), the two solutions have different
 behavior in some cases where the value_type of the sequence is not an
 integral type.  For example consider:
 </p>
 <blockquote><pre>     pair&lt;char, char&gt;                     p('a', 'b');
      vector&lt;vector&lt;pair&lt;char, char&gt; &gt; &gt;   d('a', 'b');
 </pre></blockquote>
 <p>
 The second line of this snippet is likely an error.  Solution A catches
 the error and refuses to compile.  The reason is that there is no
 specialization of the member template constructor that looks like:
 </p>
 <pre>template &lt;&gt;
 template &lt;&gt;
 vector&lt;vector&lt;pair&lt;char, char&gt; &gt; &gt;::vector(char, char) { ... }
 </pre>

 <p>
 So the expression binds to the unspecialized member template
 constructor, and then fails (compile time) because char is not an
 InputIterator.
 </p>

 <p>
 Solution B compiles the above example though.  'a' is casted to an
 unsigned integral type and used to size the outer vector.  'b' is
 static casted to the inner vector using it's explicit constructor:
 </p>

 <pre>explicit vector(size_type n);
 </pre>

 <p>
 and so you end up with a static_cast&lt;size_type&gt;('a') by
 static_cast&lt;size_type&gt;('b') matrix.
 </p>

 <p>
 It is certainly possible that this is what the coder intended.  But the
 explicit qualifier on the inner vector has been thwarted at any rate.
 </p>

 <p>
 The standard is not clear whether the expression:
 </p>

 <pre>     vector&lt;vector&lt;pair&lt;char, char&gt; &gt; &gt;   d('a', 'b');
 </pre>

 <p>
 (and similar expressions) are:
 </p>

 <ol>
 <li>  undefined behavior.</li>
 <li>  illegal and must be rejected.</li>
 <li>  legal and must be accepted.</li>
 </ol>

 <p>My preference is listed in the order presented.</p>

 <p>There are still other techniques for implementing the requirements of
 paragraphs 9-11, namely the "restricted template technique" (e.g.
 enable_if).  This technique is the most compact and easy way of coding
 the requirements, and has the behavior of #2 (rejects the above
 expression).
 </p>

 <p>
 Choosing 1 would allow all implementation techniques I'm aware of.
 Choosing 2 would allow only solution 'A' and the enable_if technique.
 Choosing 3 would allow only solution 'B'.
 </p>

 <p>
 Possible wording for a future standard if we wanted to actively reject
 the expression above would be to change "static_cast" in paragraphs
 9-11 to "implicit_cast" where that is defined by:
 </p>

 <blockquote>
 <pre>template &lt;class T, class U&gt;
 inline
 T implicit_cast(const U&amp; u)
 {
      return u;
 }
 </pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>

 <p>Replace 23.1.3 [sequence.reqmts] paragraphs 9 - 11 with:</p>

 <p>For every sequence defined in this clause and in clause lib.strings:</p>

 <ul>
   <li>
     <p>If the constructor</p>
        <pre>       template &lt;class InputIterator&gt;
        X(InputIterator f, InputIterator l,
          const allocator_type&amp; a = allocator_type())
        </pre>
     <p>is called with a type InputIterator that does not qualify as
     an input iterator, then the constructor will behave as if the
     overloaded constructor:</p>
        <pre>       X(size_type, const value_type&amp; = value_type(),
          const allocator_type&amp; = allocator_type())
        </pre>
     <p>were called instead, with the arguments static_cast&lt;size_type&gt;(f), l and a, respectively.</p>
   </li>

   <li>
     <p>If the member functions of the forms:</p>
        <pre>       template &lt;class InputIterator&gt;          //  such as  insert()
        rt fx1(iterator p, InputIterator f, InputIterator l);

        template &lt;class InputIterator&gt;          //  such as  append(), assign()
        rt fx2(InputIterator f, InputIterator l);

        template &lt;class InputIterator&gt;          //  such as  replace()
        rt fx3(iterator i1, iterator i2, InputIterator f, InputIterator l);
        </pre>
     <p>are called with a type InputIterator that does not qualify as
     an input iterator, then these functions will behave as if the
     overloaded member functions:</p>
        <pre>       rt fx1(iterator, size_type, const value_type&amp;);

        rt fx2(size_type, const value_type&amp;);

        rt fx3(iterator, iterator, size_type, const value_type&amp;);
        </pre>
     <p>were called instead, with the same arguments.</p>
   </li>
 </ul>

 <p>In the previous paragraph the alternative binding will fail if f
 is not implicitly convertible to X::size_type or if l is not implicitly
 convertible to X::value_type.</p>

 <p>
 The extent to which an implementation determines that a type cannot be
 an input iterator is unspecified, except that as a minimum integral
 types shall not qualify as input iterators.
 </p>


 <p><i>[
 Kona: agreed that the current standard requires <tt>v('a', 'b')</tt>
 to be accepted, and also agreed that this is surprising behavior.  The
 LWG considered several options, including something like
 implicit_cast, which doesn't appear to be quite what we want.  We
 considered Howards three options: allow acceptance or rejection,
 require rejection as a compile time error, and require acceptance.  By
 straw poll (1-6-1), we chose to require a compile time error.
 Post-Kona: Howard provided wording.
 ]</i></p>


 <p><i>[
 Sydney: The LWG agreed with this general direction, but there was some
 discomfort with the wording in the original proposed resolution.
 Howard submitted new wording, and we will review this again in
 Redmond.
 ]</i></p>


 <p><i>[Redmond: one very small change in wording: the first argument
   is cast to size_t.  This fixes the problem of something like
   <tt>vector&lt;vector&lt;int&gt; &gt;(5, 5)</tt>, where int is not
   implicitly convertible to the value type.]</i></p>


 <p><b>Rationale:</b></p>
 <p>The proposed resolution fixes:</p>

 <pre>  vector&lt;int&gt; v(10, 1);
 </pre>

 <p>
 since as integral types 10 and 1 must be disqualified as input
 iterators and therefore the (size,value) constructor is called (as
 if).</p>

 <p>The proposed resolution breaks:</p>

 <pre>  vector&lt;vector&lt;T&gt; &gt; v(10, 1);
 </pre>

 <p>
 because the integral type 1 is not *implicitly* convertible to
 vector&lt;T&gt;.  The wording above requires a diagnostic.</p>

 <p>
 The proposed resolution leaves the behavior of the following code
 unspecified.
 </p>

 <pre>  struct A
   {
     operator int () const {return 10;}
   };

   struct B
   {
     B(A) {}
   };

   vector&lt;B&gt; v(A(), A());
 </pre>

 <p>
 The implementation may or may not detect that A is not an input
 iterator and employee the (size,value) constructor.  Note though that
 in the above example if the B(A) constructor is qualified explicit,
 then the implementation must reject the constructor as A is no longer
 implicitly convertible to B.
 </p>


 <hr>
 <h3><a name="441"></a>441. Is fpos::state const?</h3>
 <p><b>Section:</b> 27.4.3 [fpos] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Vincent Leloup <b>Date:</b> 2003-11-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#fpos">issues</a> in [fpos].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In section 27.4.3.1 [fpos.members] fpos&lt;stateT&gt;::state() is declared
 non const, but in section 27.4.3 [fpos] it is declared const.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In section 27.4.3.1 [fpos.members], change the declaration of
 <tt>fpos&lt;stateT&gt;::state()</tt> to const.
 </p>


 <hr>
 <h3><a name="442"></a>442. sentry::operator bool() inconsistent signature</h3>
 <p><b>Section:</b> 27.6.2.4 [ostream::sentry] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Vincent Leloup <b>Date:</b> 2003-11-18</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#ostream::sentry">active issues</a> in [ostream::sentry].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream::sentry">issues</a> in [ostream::sentry].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In section 27.6.2.4 [ostream::sentry] paragraph 4, in description part
 basic_ostream&lt;charT, traits&gt;::sentry::operator bool() is declared
 as non const, but in section 27.6.2.3, in synopsis it is declared
 const.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In section 27.6.2.4 [ostream::sentry] paragraph 4, change the declaration
 of <tt>sentry::operator bool()</tt> to const.
 </p>


 <hr>
 <h3><a name="443"></a>443. filebuf::close() inconsistent use of EOF</h3>
 <p><b>Section:</b> 27.8.1.4 [filebuf.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Vincent Leloup <b>Date:</b> 2003-11-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#filebuf.members">issues</a> in [filebuf.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In section 27.8.1.4 [filebuf.members] par6, in effects description of
 basic_filebuf&lt;charT, traits&gt;::close(), overflow(EOF) is used twice;
 should be overflow(traits::eof()).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change overflow(EOF) to overflow(traits::eof()).
 </p>


 <hr>
 <h3><a name="444"></a>444. Bad use of casts in fstream</h3>
 <p><b>Section:</b> 27.8.1 [fstreams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Vincent Leloup <b>Date:</b> 2003-11-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#fstreams">issues</a> in [fstreams].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>27.8.1.9 [ifstream.members] p1, 27.8.1.13 [ofstream.members] p1,
 27.8.1.17 [fstream.members] p1 seems have same problem as exposed in
 LWG issue
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#252">252</a>.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p><i>[Sydney: Genuine defect. 27.8.1.13 needs a cast to cast away
  constness. The other two places are stylistic: we could change the
  C-style casts to const_cast. Post-Sydney: Howard provided wording.
 ]</i></p>


 <p>Change 27.8.1.7/1 from:</p>
 <blockquote><p>
   Returns: (basic_filebuf&lt;charT,traits&gt;*)&amp;sb.
 </p></blockquote>

 <p>to:</p>
 <blockquote><p>
   Returns: const_cast&lt;basic_filebuf&lt;charT,traits&gt;*&gt;(&amp;sb).
 </p></blockquote>

 <p>Change 27.8.1.10/1 from:</p>
 <blockquote><p>
   Returns: (basic_filebuf&lt;charT,traits&gt;*)&amp;sb.
 </p></blockquote>

 <p>to:</p>
 <blockquote><p>
   Returns: const_cast&lt;basic_filebuf&lt;charT,traits&gt;*&gt;(&amp;sb).
 </p></blockquote>

 <p>Change 27.8.1.13/1 from:</p>
 <blockquote><p>
   Returns: &amp;sb.
 </p></blockquote>

 <p>to:</p>
 <blockquote><p>
   Returns: const_cast&lt;basic_filebuf&lt;charT,traits&gt;*&gt;(&amp;sb).
 </p></blockquote>


 <hr>
 <h3><a name="445"></a>445. iterator_traits::reference unspecified for some iterator categories</h3>
 <p><b>Section:</b> 24.3.1 [iterator.traits] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2003-12-09</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The standard places no restrictions at all on the reference type
 of input, output, or forward iterators (for forward iterators it
 only specifies that *x must be value_type&amp; and doesn't mention
 the reference type).  Bidirectional iterators' reference type is
 restricted only by implication, since the base iterator's
 reference type is used as the return type of reverse_iterator's
 operator*, which must be T&amp; in order to be a conforming forward
 iterator.
 </p>

 <p>
 Here's what I think we ought to be able to expect from an input
 or forward iterator's reference type R, where a is an iterator
 and V is its value_type
 </p>

 <ul>
   <li>
       *a is convertible to R
   </li>

   <li>
       R is convertible to V
   </li>

   <li>
       static_cast&lt;V&gt;(static_cast&lt;R&gt;(*a)) is equivalent to
       static_cast&lt;V&gt;(*a)
   </li>
 </ul>

 <p>A mutable forward iterator ought to satisfy, for x of type V:</p>
   <pre>      { R r = *a; r = x; } is equivalent to *a = x;
   </pre>

 <p>
 I think these requirements capture existing container iterators
 (including vector&lt;bool&gt;'s), but render istream_iterator invalid;
 its reference type would have to be changed to a constant
 reference.
 </p>


 <p>
 (Jeremy Siek) During the discussion in Sydney, it was felt that a
 simpler long term solution for this was needed. The solution proposed
 was to require <tt>reference</tt> to be the same type as <tt>*a</tt>
 and <tt>pointer</tt> to be the same type as <tt>a-&gt;</tt>.  Most
 iterators in the Standard Library already meet this requirement. Some
 iterators are output iterators, and do not need to meet the
 requirement, and others are only specified through the general
 iterator requirements (which will change with this resolution). The
 sole case where there is an explicit definition of the reference type
 that will need to change is <tt>istreambuf_iterator</tt> which returns
 <tt>charT</tt> from <tt>operator*</tt> but has a reference type of
 <tt>charT&amp;</tt>. We propose changing the reference type of
 <tt>istreambuf_iterator</tt> to <tt>charT</tt>.
 </p>

 <p>The other option for resolving the issue with <tt>pointer</tt>,
   mentioned in the note below, is to remove <tt>pointer</tt>
   altogether. I prefer placing requirements on <tt>pointer</tt> to
   removing it for two reasons. First, <tt>pointer</tt> will become
   useful for implementing iterator adaptors and in particular,
   <tt>reverse_iterator</tt> will become more well defined. Second,
   removing <tt>pointer</tt> is a rather drastic and publicly-visible
   action to take.</p>

 <p>The proposed resolution technically enlarges the requirements for
 iterators, which means there are existing iterators (such as
 <tt>istreambuf_iterator</tt>, and potentially some programmer-defined
 iterators) that will no longer meet the requirements. Will this break
 existing code? The scenario in which it would is if an algorithm
 implementation (say in the Standard Library) is changed to rely on
 <tt>iterator_traits::reference</tt>, and then is used with one of the
 iterators that do not have an appropriately defined
 <tt>iterator_traits::reference</tt>.
 </p>


 <p>The proposed resolution makes one other subtle change. Previously,
 it was required that output iterators have a <tt>difference_type</tt>
 and <tt>value_type</tt> of <tt>void</tt>, which means that a forward
 iterator could not be an output iterator. This is clearly a mistake,
 so I've changed the wording to say that those types may be
 <tt>void</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>In 24.3.1 [iterator.traits], after:</p>

 <blockquote><p>
 be defined as the iterator's difference type, value type and iterator
 category, respectively.
 </p></blockquote>

 <p>add</p>

 <blockquote><p>
 In addition, the types</p>
 <pre>iterator_traits&lt;Iterator&gt;::reference
 iterator_traits&lt;Iterator&gt;::pointer
 </pre>
 <p>must be defined as the iterator's reference and pointer types, that
 is, the same type as the type of <tt>*a</tt> and <tt>a-&gt;</tt>,
 respectively.</p>
 </blockquote>

 <p>In 24.3.1 [iterator.traits], change:</p>

 <blockquote><p>
 In the case of an output iterator, the types</p>
 <pre>iterator_traits&lt;Iterator&gt;::difference_type
 iterator_traits&lt;Iterator&gt;::value_type
 </pre>
 <p>are both defined as <tt>void</tt>.</p>
 </blockquote>

 <p>to:</p>
 <blockquote><p>
 In the case of an output iterator, the types</p>
 <pre>iterator_traits&lt;Iterator&gt;::difference_type
 iterator_traits&lt;Iterator&gt;::value_type
 iterator_traits&lt;Iterator&gt;::reference
 iterator_traits&lt;Iterator&gt;::pointer
 </pre>
 <p>may be defined as <tt>void</tt>.</p>
 </blockquote>

 <p>In 24.5.3 [istreambuf.iterator], change:</p>
 <blockquote>
 <pre>typename traits::off_type, charT*, charT&amp;&gt;
 </pre>
 </blockquote>
 <p>to:</p>
 <blockquote>
 <pre>typename traits::off_type, charT*, charT&gt;
 </pre>
 </blockquote>

 <p><i>[
 Redmond: there was concern in Sydney that this might not be the only place
 where things were underspecified and needed to be changed.  Jeremy
 reviewed iterators in the standard and confirmed that nothing else
 needed to be changed.
 ]</i></p>


 <hr>
 <h3><a name="448"></a>448. Random Access Iterators over abstract classes</h3>
 <p><b>Section:</b> 24.1.5 [random.access.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2004-01-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#random.access.iterators">issues</a> in [random.access.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 76, the random access iterator requirement table, says that the
 return type of a[n] must be "convertible to T".  When an iterator's
 value_type T is an abstract class, nothing is convertible to T.
 Surely this isn't an intended restriction?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the return type to "convertible to T const&amp;".
 </p>


 <hr>
 <h3><a name="449"></a>449. Library Issue 306 Goes Too Far</h3>
 <p><b>Section:</b> 18.1 [support.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Pete Becker <b>Date:</b> 2004-01-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#support.types">issues</a> in [support.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Original text:</p>
 <blockquote><p>
 The macro offsetof accepts a restricted set of type arguments in this
 International Standard. type shall be a POD structure or a POD union
 (clause 9). The result of applying the offsetof macro to a field that
 is a static data member or a function member is undefined."
 </p></blockquote>

 <p>Revised text:</p>
 <blockquote><p>
 "If type is not a POD structure or a POD union the results are undefined."
 </p></blockquote>

 <p>
 Looks to me like the revised text should have replaced only the second
 sentence. It doesn't make sense standing alone.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change 18.1, paragraph 5, to:</p>

 <blockquote><p>
 The macro offsetof accepts a restricted set of type arguments in this
 International Standard.  If type is not a POD structure or a POD union
 the results are undefined.  The result of applying the offsetof macro
 to a field that is a static data member or a function member is
 undefined."
 </p></blockquote>


 <hr>
 <h3><a name="453"></a>453. basic_stringbuf::seekoff need not always fail for an empty stream</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bill Plauger <b>Date:</b> 2004-01-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <pre>  pos_type basic_stringbuf::seekoff(off_type, ios_base::seekdir,
                                     ios_base::openmode);
 </pre>
 <p>
 is obliged to fail if nothing has been inserted into the stream. This
 is unnecessary and undesirable. It should be permissible to seek to
 an effective offset of zero.</p>

 <p><i>[
  Sydney: Agreed that this is an annoying problem: seeking to zero should be
  legal. Bill will provide wording.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>Change the sentence from:</p>
 <blockquote><p>
 For a sequence to be positioned, if its next pointer (either
 gptr() or pptr()) is a null pointer, the positioning operation
 fails.
 </p></blockquote>

 <p>to:</p>

 <blockquote><p>
 For a sequence to be positioned, if its next pointer (either
 gptr() or pptr()) is a null pointer and the new offset newoff
 is nonzero, the positioning operation fails.
 </p></blockquote>


 <hr>
 <h3><a name="455"></a>455. cerr::tie() and wcerr::tie() are overspecified</h3>
 <p><b>Section:</b> 27.3 [iostream.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Bill Plauger <b>Date:</b> 2004-01-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostream.objects">issues</a> in [iostream.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Both cerr::tie() and wcerr::tie() are obliged to be null at program
 startup. This is overspecification and overkill. It is both traditional
 and useful to tie cerr to cout, to ensure that standard output is drained
 whenever an error message is written. This behavior should at least be
 permitted if not required. Same for wcerr::tie().
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>Add to the description of cerr:</p>
 <blockquote><p>
 After the object cerr is initialized, cerr.tie() returns &amp;cout.
 Its state is otherwise the same as required for basic_ios&lt;char&gt;::init
 (lib.basic.ios.cons).
 </p></blockquote>

 <p>Add to the description of wcerr:</p>

 <blockquote><p>
 After the object wcerr is initialized, wcerr.tie() returns &amp;wcout.
 Its state is otherwise the same as required for basic_ios&lt;wchar_t&gt;::init
 (lib.basic.ios.cons).
 </p></blockquote>

 <p><i>[Sydney: straw poll (3-1): we should <i>require</i>, not just
   permit, cout and cerr to be tied on startup.  Pre-Redmond: Bill will
   provide wording.]</i></p>


 <hr>
 <h3><a name="456"></a>456. Traditional C header files are overspecified</h3>
 <p><b>Section:</b> 17.4.1.2 [headers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bill Plauger <b>Date:</b> 2004-01-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#headers">issues</a> in [headers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>The C++ Standard effectively requires that the traditional C headers
 (of the form &lt;xxx.h&gt;) be defined in terms of the newer C++
 headers (of the form &lt;cxxx&gt;). Clauses 17.4.1.2/4 and D.5 combine
 to require that:</p>

 <ul>
  <li>Including the header &lt;cxxx&gt; declares a C name in namespace std.</li>

  <li> Including the header &lt;xxx.h&gt; declares a C name in namespace std
     (effectively by including &lt;cxxx&gt;), then imports it into the global
     namespace with an individual using declaration.</li>
 </ul>

 <p>
 The rules were left in this form despited repeated and heated objections
 from several compiler vendors. The C headers are often beyond the direct
 control of C++ implementors. In some organizations, it's all they can do
 to get a few #ifdef __cplusplus tests added. Third-party library vendors
 can perhaps wrap the C headers. But neither of these approaches supports
 the drastic restructuring required by the C++ Standard. As a result, it is
 still widespread practice to ignore this conformance requirement, nearly
 seven years after the committee last debated this topic. Instead, what is
 often implemented is:
 </p>

 <ul>
  <li> Including the header &lt;xxx.h&gt; declares a C name in the
  global namespace.</li>

  <li> Including the header &lt;cxxx&gt; declares a C name in the
  global namespace (effectively by including &lt;xxx.h&gt;), then
  imports it into namespace std with an individual using declaration.</li>
 </ul>

 <p>
 The practical benefit for implementors with the second approach is that
 they can use existing C library headers, as they are pretty much obliged
 to do. The practical cost for programmers facing a mix of implementations
 is that they have to assume weaker rules:</p>

 <ul>
   <li> If you want to assuredly declare a C name in the global
   namespace, include &lt;xxx.h&gt;. You may or may not also get the
   declaration in namespace std.</li>

   <li> If you want to assuredly declare a C name in namespace std,
   include &lt;cxxx&gt;. You may or may not also get the declaration in
   the global namespace.</li>
 </ul>

 <p>
 There also exists the <i>possibility</i> of subtle differences due to
 Koenig lookup, but there are so few non-builtin types defined in the C
 headers that I've yet to see an example of any real problems in this
 area.
 </p>

 <p>
 It is worth observing that the rate at which programmers fall afoul of
 these differences has remained small, at least as measured by newsgroup
 postings and our own bug reports. (By an overwhelming margin, the
 commonest problem is still that programmers include &lt;string&gt; and can't
 understand why the typename string isn't defined -- this a decade after
 the committee invented namespace std, nominally for the benefit of all
 programmers.)
 </p>

 <p>
 We should accept the fact that we made a serious mistake and rectify it,
 however belatedly, by explicitly allowing either of the two schemes for
 declaring C names in headers.
 </p>

 <p><i>[Sydney: This issue has been debated many times, and will
   certainly have to be discussed in full committee before any action
   can be taken.  However, the preliminary sentiment of the LWG was in
   favor of the change.  (6 yes, 0 no, 2 abstain) Robert Klarer
   suggests that we might also want to undeprecate the
   C-style <tt>.h</tt> headers.]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add to 17.4.1.2 [headers], para. 4:
 </p>

 <blockquote><p>
 Except as noted in clauses 18 through 27 and Annex D, the contents of each
 header <i>cname</i> shall be the same as that of the corresponding header
 <i>name.h</i>, as specified in ISO/IEC 9899:1990 Programming Languages C (Clause
 7), or ISO/IEC:1990 Programming Languages-C AMENDMENT 1: C Integrity, (Clause
 7), as appropriate, as if by inclusion. In the C++ Standard Library, however,
 the declarations <del>and definitions</del> (except for names which are defined
 as macros in C) are within namespace scope (3.3.5) of the namespace std.
 <ins>It is unspecified whether these names are first declared within the global
 namespace scope and are then injected into namespace std by explicit
 using-declarations (7.3.3 [namespace.udecl]).</ins>
 </p></blockquote>

 <p>
 Change D.5 [depr.c.headers], para. 2-3:
 </p>

 <blockquote>
 <p>
 -2- Every C header, each of which has a name of the form <i>name.h</i>, behaves
 as if each name placed in the Standard library namespace by the corresponding
 <i>cname</i> header is <del>also</del> placed within the <ins>global</ins>
 namespace scope<ins>.</ins> <del>of the namespace <tt>std</tt> and is followed
 by an explicit <i>using-declaration</i> (7.3.3 [namespace.udecl]).</del>
 <ins>It is unspecified whether these names are first declared or defined within
 namespace scope (3.3.5 [basic.scope.namespace]) of the namespace
 <tt>std</tt> and are then injected into the global namespace scope by explicit
 using-declarations (7.3.3 [namespace.udecl]).</ins>
 </p>
 <p>
 -3- [<i>Example:</i> The header <tt>&lt;cstdlib&gt;</tt> <ins>assuredly</ins>
 provides its declarations and definitions within the namespace <tt>std</tt>.
 <ins>It may also provide these names within the global namespace.</ins> The
 header <tt>&lt;stdlib.h&gt;</tt> <del>makes these available also in</del>
 <ins>assuredly provides the same declarations and definitions within</ins> the
 global namespace, much as in the C Standard. <ins>It may also provide these
 names within the namespace <tt>std</tt>.</ins> <i>-- end example</i>]
 </p>
 </blockquote>


 <hr>
 <h3><a name="457"></a>457. bitset constructor: incorrect number of initialized bits</h3>
 <p><b>Section:</b> 23.3.5.1 [bitset.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Dag Henriksson <b>Date:</b> 2004-01-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bitset.cons">issues</a> in [bitset.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The constructor from unsigned long says it initializes "the first M
 bit positions to the corresponding bit values in val. M is the smaller
 of N and the value CHAR_BIT * sizeof(unsigned long)."
 </p>

 <p>
 Object-representation vs. value-representation strikes again. CHAR_BIT *
 sizeof (unsigned long) does not give us the number of bits an unsigned long
 uses to hold the value. Thus, the first M bit position above is not
 guaranteed to have any corresponding bit values in val.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.3.5.1 [bitset.cons] paragraph 2, change "M is the smaller of
   N and the value CHAR_BIT * sizeof (unsigned long). (249)" to
   "<tt>M</tt> is the smaller of <tt>N</tt> and the number of bits in
   the value representation (section 3.9 [basic.types]) of <tt>unsigned
   long</tt>."
 </p>


 <hr>
 <h3><a name="460"></a>460. Default modes missing from basic_fstream member specifications</h3>
 <p><b>Section:</b> 27.8.1 [fstreams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Ben Hutchings <b>Date:</b> 2004-04-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#fstreams">issues</a> in [fstreams].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The second parameters of the non-default constructor and of the open
 member function for basic_fstream, named "mode", are optional
 according to the class declaration in 27.8.1.11 [lib.fstream].  The
 specifications of these members in 27.8.1.12 [lib.fstream.cons] and
 27.8.1.13 lib.fstream.members] disagree with this, though the
 constructor declaration has the "explicit" function-specifier implying
 that it is intended to be callable with one argument.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 27.8.1.15 [fstream.cons], change</p>
 <pre>  explicit basic_fstream(const char* s, ios_base::openmode mode);
 </pre>
 <p>to</p>
 <pre>  explicit basic_fstream(const char* s,
                          ios_base::openmode mode = ios_base::in|ios_base::out);
 </pre>
 <p>In 27.8.1.17 [fstream.members], change</p>
 <pre>  void open(const char*s, ios_base::openmode mode);
 </pre>
 <p>to</p>
 <pre>  void open(const char*s,
             ios_base::openmode mode = ios_base::in|ios_base::out);
 </pre>


 <hr>
 <h3><a name="461"></a>461. time_get hard or impossible to implement</h3>
 <p><b>Section:</b> 22.2.5.1.2 [locale.time.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bill Plauger <b>Date:</b> 2004-03-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Template time_get currently contains difficult, if not impossible,
 requirements for do_date_order, do_get_time, and do_get_date. All require
 the implementation to scan a field generated by the %x or %X conversion
 specifier in strftime. Yes, do_date_order can always return no_order, but
 that doesn't help the other functions. The problem is that %x can be
 nearly anything, and it can vary widely with locales. It's horribly
 onerous to have to parse "third sunday after Michaelmas in the year of
 our Lord two thousand and three," but that's what we currently ask of
 do_get_date. More practically, it leads some people to think that if
 %x produces 10.2.04, we should know to look for dots as separators. Still
 not easy.
 </p>

 <p>
 Note that this is the <i>opposite</i> effect from the intent stated in the
 footnote earlier in this subclause:
 </p>

 <blockquote><p>
 "In other words, user confirmation is required for reliable parsing of
 user-entered dates and times, but machine-generated formats can be
 parsed reliably. This allows parsers to be aggressive about interpreting
 user variations on standard formats."
 </p></blockquote>

 <p>
 We should give both implementers and users an easier and more reliable
 alternative: provide a (short) list of alternative delimiters and say
 what the default date order is for no_order. For backward compatibility,
 and maximum latitude, we can permit an implementation to parse whatever
 %x or %X generates, but we shouldn't require it.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p><b>In the description:</b></p>
 <pre>iter_type do_get_time(iter_type s, iter_type end, ios_base&amp; str,
         ios_base::iostate&amp; err, tm* t) const;
 </pre>

 <p>
 2 Effects: Reads characters starting at suntil it has extracted those
 struct tm members, and remaining format characters, used by
 time_put&lt;&gt;::put to produce the format specified by 'X', or until it
 encounters an error or end of sequence.
 </p>

 <p><b>change:</b> 'X'</p>

 <p><b>to:</b> "%H:%M:%S"</p>


 <p>Change</p>
 <pre>iter_type do_get_date(iter_type s, iter_type end, ios_base&amp; str,
         ios_base::iostate&amp; err, tm* t) const;

 4 Effects: Reads characters starting at s until it has extracted those
 struct tm members, and remaining format characters, used by
 time_put&lt;&gt;::put to produce the format specified by 'x', or until it
 encounters an error.
 </pre>

 <p>to</p>
 <pre>iter_type do_get_date(iter_type s, iter_type end, ios_base&amp; str,
         ios_base::iostate&amp; err, tm* t) const;
 </pre>

 <p>
 4 Effects: Reads characters starting at s until it has extracted those
 struct tm members, and remaining format characters, used by
 time_put&lt;&gt;::put to produce one of the following formats, or until it
 encounters an error. The format depends on the value returned by
 date_order() as follows:
 </p>

 <pre>        date_order()  format

         no_order      "%m/%d/%y"
         dmy           "%d/%m/%y"
         mdy           "%m/%d/%y"
         ymd           "%y/%m/%d"
         ydm           "%y/%d/%m"
 </pre>
 <p>
 An implementation may also accept additional implementation-defined formats.
 </p>

 <p><i>[Redmond: agreed that this is a real problem.  The solution is
   probably to match C99's parsing rules.  Bill provided wording.
 ]</i></p>


 <hr>
 <h3><a name="464"></a>464. Suggestion for new member functions in standard containers</h3>
 <p><b>Section:</b> 23.2.6 [vector], 23.3.1 [map] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thorsten Ottosen <b>Date:</b> 2004-05-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector">issues</a> in [vector].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>To add slightly more convenience to vector&lt;T&gt; and map&lt;Key,T&gt; we should consider to add</p>
 <ol>
 <li> add vector&lt;T&gt;::data() member (const and non-const version)
 semantics: if( empty() ) return 0; else return buffer_;</li>
 <li> add map&lt;Key,T&gt;::at( const Key&amp; k ) member (const and non-const version)
 <i>semantics</i>: iterator i = find( k ); if( i != end() ) return *i; else throw range_error();</li>
 </ol>

 <p>Rationale:</p>

 <ul>
 <li>To obtain a pointer to the vector's buffer, one must use either
 operator[]() (which can give undefined behavior for empty vectors) or
 at() (which will then throw if the vector is empty). </li>
 <li>tr1::array&lt;T,sz&gt; already has a data() member</li>
 <li>e cannot use operator[]() when T is not DefaultDonstructible</li>
 <li>Neither when the map is const.</li>
 <li>when we want to make sure we don't add an element accidently</li>
 <li>when it should be considered an error if a key is not in the map</li>
 </ul>


 <p><b>Proposed resolution:</b></p>
 <p>In 23.2.6 [vector], add the following to the <tt>vector</tt>
   synopsis after "element access" and before "modifiers":</p>
 <pre>  // <i>[lib.vector.data] data access</i>
   pointer       data();
   const_pointer data() const;
 </pre>

 <p>Add a new subsection of 23.2.6 [vector]:</p>
 <blockquote>
 <p>23.2.4.x <tt>vector</tt> data access</p>
 <pre>   pointer       data();
    const_pointer data() const;
 </pre>
 <p><b>Returns:</b> A pointer such that [data(), data() + size()) is a valid
    range.  For a non-empty vector, data() == &amp;front().</p>
 <p><b>Complexity:</b> Constant time.</p>
 <p><b>Throws:</b> Nothing.</p>
 </blockquote>

 <p>In 23.3.1 [map], add the following to the <tt>map</tt>
 synopsis immediately after the line for operator[]:</p>
 <pre>  T&amp;       at(const key_type&amp; x);
   const T&amp; at(const key_type&amp; x) const;
 </pre>

 <p>Add the following to 23.3.1.2 [map.access]:</p>
 <blockquote>
 <pre>  T&amp;       at(const key_type&amp; x);
   const T&amp; at(const key_type&amp; x) const;
 </pre>

 <p><b>Returns:</b> A reference to the element whose key is equivalent
   to x, if such an element is present in the map.</p>
 <p><b>Throws:</b> <tt>out_of_range</tt> if no such element is present.</p>

 </blockquote>


 <p><b>Rationale:</b></p>
 <p>Neither of these additions provides any new functionality but the
   LWG agreed that they are convenient, especially for novices.  The
   exception type chosen for <tt>at</tt>, <tt>std::out_of_range</tt>,
   was chosen to match <tt>vector::at</tt>.</p>


 <hr>
 <h3><a name="465"></a>465. Contents of &lt;ciso646&gt;</h3>
 <p><b>Section:</b> 17.4.1.2 [headers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve Clamage <b>Date:</b> 2004-06-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#headers">issues</a> in [headers].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>C header &lt;iso646.h&gt; defines macros for some operators, such as
 not_eq for !=.</p>

 <p>Section 17.4.1.2 [headers] "Headers" says that except as noted in
 clauses 18 through 27, the &lt;cname&gt; C++ header contents are the same
 as the C header &lt;name.h&gt;. In particular, table 12 lists
 &lt;ciso646&gt; as a C++ header.</p>

 <p>I don't find any other mention of &lt;ciso646&gt;, or any mention of
 &lt;iso646.h&gt;, in clauses 17 thorough 27. That implies that the
 contents of &lt;ciso646&gt; are the same as C header &lt;iso646.h&gt;.</p>

 <p>Annex C (informative, not normative) in [diff.header.iso646.h] C.2.2.2
 "Header &lt;iso646.h&gt;" says that the alternative tokens are not
 defined as macros in &lt;ciso646&gt;, but does not mention the contents
 of &lt;iso646.h&gt;.</p>

 <p>I don't find any normative text to support C.2.2.2.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add to section 17.4.1.2 Headers [lib.headers] a new paragraph after
   paragraph 6 (the one about functions must be functions):</p>

 <blockquote>
 <p>Identifiers that are keywords or operators in C++ shall not be defined
 as macros in C++ standard library headers.
 [Footnote:In particular, including the standard header &lt;iso646.h&gt;
 or &lt;ciso646&gt; has no effect. </p>
 </blockquote>

 <p><i>[post-Redmond: Steve provided wording.]</i></p>


 <hr>
 <h3><a name="467"></a>467. char_traits::lt(), compare(), and memcmp()</h3>
 <p><b>Section:</b> 21.1.3.1 [char.traits.specializations.char] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2004-06-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 Table 37 describes the requirements on Traits::compare() in terms of
 those on Traits::lt(). 21.1.3.1, p6 requires char_traits&lt;char&gt;::lt()
 to yield the same result as operator&lt;(char, char).
 </p>

 <p>
 Most, if not all, implementations of char_traits&lt;char&gt;::compare()
 call memcmp() for efficiency. However, the C standard requires both
 memcmp() and strcmp() to interpret characters under comparison as
 unsigned, regardless of the signedness of char. As a result, all
 these char_traits implementations fail to meet the requirement
 imposed by Table 37 on compare() when char is signed.
 </p>


 <p>Read email thread starting with c++std-lib-13499 for more. </p>


 <p><b>Proposed resolution:</b></p>


 <p>Change 21.1.3.1, p6 from</p>
 <blockquote><p>
     The two-argument members assign, eq, and lt are defined identically
     to the built-in operators =, ==, and &lt; respectively.
 </p></blockquote>
 <p>to</p>
 <blockquote><p>
   The two-argument member assign is defined identically to
   the built-in operator =. The two
   argument members eq and lt are defined identically to
   the built-in operators == and &lt; for type unsigned char.
 </p></blockquote>

 <p><i>[Redmond: The LWG agreed with this general direction, but we
   also need to change <tt>eq</tt> to be consistent with this change.
   Post-Redmond: Martin provided wording.]</i></p>


 <hr>
 <h3><a name="468"></a>468. unexpected consequences of ios_base::operator void*()</h3>
 <p><b>Section:</b> 27.4.4.3 [iostate.flags] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2004-06-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostate.flags">issues</a> in [iostate.flags].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>The program below is required to compile but when run it typically
 produces unexpected results due to the user-defined conversion from
 std::cout or any object derived from basic_ios to void*.
 </p>

 <pre>    #include &lt;cassert&gt;
     #include &lt;iostream&gt;

     int main ()
     {
         assert (std::cin.tie () == std::cout);
         // calls std::cout.ios::operator void*()
     }
 </pre>


 <p><b>Proposed resolution:</b></p>

 <p>
 Replace std::basic_ios&lt;charT, traits&gt;::operator void*() with another
 conversion operator to some unspecified type that is guaranteed not
 to be convertible to any other type except for bool (a pointer-to-member
 might be one such suitable type). In addition, make it clear that the
 pointer type need not be a pointer to a complete type and when non-null,
 the value need not be valid.
 </p>

 <p>Specifically, change in [lib.ios] the signature of</p>
 <pre>    operator void*() const;
 </pre>
 <p>to</p>
 <pre>    operator unspecified-bool-type() const;
 </pre>
 <p>and change [lib.iostate.flags], p1 from</p>
 <pre>    operator void*() const;
 </pre>
 <p>to</p>
 <pre>operator unspecified-bool-type() const;

      -1- Returns: if fail() then a value that will evaluate false in a
       boolean context; otherwise a value that will evaluate true in a
       boolean context. The value type returned shall not be
       convertible to int.

      -2- [Note: This conversion can be used in contexts where a bool
       is expected (e.g., an if condition); however, implicit
       conversions (e.g., to int) that can occur with bool are not
       allowed, eliminating some sources of user error. One possible
       implementation choice for this type is pointer-to-member.  - end
       note]
 </pre>

 <p><i>[Redmond: 5-4 straw poll in favor of doing this.]</i></p>

 <p><i>[Lillehammer: Doug provided revised wording for
   "unspecified-bool-type".]</i></p>


 <hr>
 <h3><a name="469"></a>469. vector&lt;bool&gt; ill-formed relational operators</h3>
 <p><b>Section:</b> 23.2.6 [vector] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2004-06-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector">issues</a> in [vector].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 The overloads of relational operators for vector&lt;bool&gt; specified
 in [lib.vector.bool] are redundant (they are semantically identical
 to those provided for the vector primary template) and may even be
 diagnosed as ill-formed (refer to Daveed Vandevoorde's explanation
 in c++std-lib-13647).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Remove all overloads of overloads of relational operators for
 vector&lt;bool&gt; from [lib.vector.bool].
 </p>


 <hr>
 <h3><a name="474"></a>474. confusing Footnote 297</h3>
 <p><b>Section:</b> 27.6.2.6.4 [ostream.inserters.character] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2004-07-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.inserters.character">issues</a> in [ostream.inserters.character].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 I think Footnote 297 is confused. The paragraph it applies to seems
 quite clear in that widen() is only called if the object is not a char
 stream (i.e., not basic_ostream&lt;char&gt;), so it's irrelevant what the
 value of widen(c) is otherwise.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 I propose to strike the Footnote.
 </p>


 <hr>
 <h3><a name="475"></a>475. May the function object passed to for_each modify the elements of the iterated sequence?</h3>
 <p><b>Section:</b> 25.1.4 [alg.foreach] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Stephan T. Lavavej, Jaakko Jarvi <b>Date:</b> 2004-07-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.foreach">issues</a> in [alg.foreach].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It is not clear whether the function object passed to for_each is allowed to
 modify the elements of the sequence being iterated over.
 </p>

 <p>
 for_each is classified without explanation in [lib.alg.nonmodifying], "25.1
 Non-modifying sequence operations". 'Non-modifying sequence operation' is
 never defined.
 </p>

 <p>
 25(5) says: "If an algorithm's Effects section says that a value pointed to
 by any iterator passed as an argument is modified, then that algorithm has
 an additional type requirement: The type of that argument shall satisfy the
 requirements of a mutable iterator (24.1)."
 </p>

 <p>for_each's Effects section does not mention whether arguments can be
 modified:</p>

 <blockquote><p>
   "Effects: Applies f to the result of dereferencing every iterator in the
    range [first, last), starting from first and proceeding to last - 1."
 </p></blockquote>

 <p>
 Every other algorithm in [lib.alg.nonmodifying] is "really" non-modifying in
 the sense that neither the algorithms themselves nor the function objects
 passed to the algorithms may modify the sequences or elements in any way.
 This DR affects only for_each.
 </p>

 <p>
 We suspect that for_each's classification in "non-modifying sequence
 operations" means that the algorithm itself does not inherently modify the
 sequence or the elements in the sequence, but that the function object
 passed to it may modify the elements it operates on.
 </p>

 <p>
 The original STL document by Stepanov and Lee explicitly prohibited the
 function object from modifying its argument.
 The "obvious" implementation of for_each found in several standard library
 implementations, however, does not impose this restriction.
 As a result, we suspect that the use of for_each with function objects that modify
 their arguments is wide-spread.
 If the restriction was reinstated, all such code would become non-conforming.
 Further, none of the other algorithms in the Standard
 could serve the purpose of for_each (transform does not guarantee the order in
 which its function object is called).
 </p>

 <p>
 We suggest that the standard be clarified to explicitly allow the function object
 passed to for_each modify its argument.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Add a nonnormative note to the Effects in 25.1.4 [alg.foreach]: If
 the type of 'first' satisfies the requirements of a mutable iterator,
 'f' may apply nonconstant functions through the dereferenced iterators
 passed to it.
 </p>


 <p><b>Rationale:</b></p>
 <p>The LWG believes that nothing in the standard prohibits function
   objects that modify the sequence elements. The problem is that
   for_each is in a secion entitled "nonmutating algorithms", and the
   title may be confusing.  A nonnormative note should clarify that.</p>


 <hr>
 <h3><a name="478"></a>478. Should forward iterator requirements table have a line for r-&gt;m?</h3>
 <p><b>Section:</b> 24.1.3 [forward.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Dave Abrahams <b>Date:</b> 2004-07-11</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#forward.iterators">issues</a> in [forward.iterators].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#477">477</a></p>
 <p><b>Discussion:</b></p>
 <p>
 The Forward Iterator requirements table contains the following:
 </p>
 <pre> expression  return type         operational  precondition
                                   semantics
   ==========  ==================  ===========  ==========================
   a-&gt;m        U&amp; if X is mutable, (*a).m       pre: (*a).m is well-defined.
               otherwise const U&amp;

   r-&gt;m        U&amp;                  (*r).m       pre: (*r).m is well-defined.
 </pre>

 <p>The second line may be unnecessary.  Paragraph 11 of
   [lib.iterator.requirements] says:
 </p>

 <blockquote><p>
    In the following sections, a and b denote values of type const X, n
    denotes a value of the difference type Distance, u, tmp, and m
    denote identifiers, r denotes a value of X&amp;, t denotes a value of
    value type T, o denotes a value of some type that is writable to
    the output iterator.
 </p></blockquote>

 <p>
 Because operators can be overloaded on an iterator's const-ness, the
 current requirements allow iterators to make many of the operations
 specified using the identifiers a and b invalid for non-const
 iterators.</p>

 <p>Related issue: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#477">477</a></p>


 <p><b>Proposed resolution:</b></p>

 <p>Remove the "r-&gt;m" line from the Forward Iterator requirements
 table. Change</p>
 <blockquote><p>
     "const X"
 </p></blockquote>

 <p> to </p>

 <blockquote><p>
     "X or const X"
 </p></blockquote>

 <p>in paragraph 11 of [lib.iterator.requirements].</p>


 <p><b>Rationale:</b></p>
 <p>
 This is a defect because it constrains an lvalue to returning a modifiable lvalue.
 </p>


 <hr>
 <h3><a name="488"></a>488. rotate throws away useful information</h3>
 <p><b>Section:</b> 25.2.11 [alg.rotate] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2004-11-22</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 rotate takes 3 iterators:  first, middle and last which point into a
 sequence, and rearranges the sequence such that the subrange [middle,
 last) is now at the beginning of the sequence and the subrange [first,
 middle) follows.  The return type is void.
 </p>

 <p>
 In many use cases of rotate, the client needs to know where the
 subrange [first, middle) starts after the rotate is performed.  This
 might look like:
 </p>
 <pre>  rotate(first, middle, last);
   Iterator i = advance(first, distance(middle, last));
 </pre>

 <p>
 Unless the iterators are random access, the computation to find the
 start of the subrange [first, middle) has linear complexity.  However,
 it is not difficult for rotate to return this information with
 negligible additional computation expense.  So the client could code:
 </p>
 <pre>  Iterator i = rotate(first, middle, last);
 </pre>

 <p>
 and the resulting program becomes significantly more efficient.
 </p>

 <p>
 While the backwards compatibility hit with this change is not zero, it
 is very small (similar to that of lwg <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#130">130</a>), and there is
 a significant benefit to the change.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>In 25 [algorithms] p2, change:</p>

 <blockquote><pre>  template&lt;class ForwardIterator&gt;
     <del>void</del> <ins>ForwardIterator</ins> rotate(ForwardIterator first, ForwardIterator middle,
                 ForwardIterator last);
 </pre></blockquote>

 <p>In 25.2.11 [alg.rotate], change:</p>

 <blockquote><pre>  template&lt;class ForwardIterator&gt;
     <del>void</del> <ins>ForwardIterator</ins> rotate(ForwardIterator first, ForwardIterator middle,
                 ForwardIterator last);
 </pre></blockquote>

 <p>In 25.2.11 [alg.rotate] insert a new paragraph after p1:</p>

 <blockquote>
 <p><b>Returns</b>: <tt>first + (last - middle)</tt>.</p>
 </blockquote>

 <p><i>[
 The LWG agrees with this idea, but has one quibble: we want to make
 sure not to give the impression that the function "advance" is
 actually called, just that the nth iterator is returned.  (Calling
 advance is observable behavior, since users can specialize it for
 their own iterators.)  Howard will provide wording.
 ]</i></p>


 <p><i>[Howard provided wording for mid-meeting-mailing Jun. 2005.]</i></p>


 <p><i>[
 Toronto: moved to Ready.
 ]</i></p>


 <hr>
 <h3><a name="495"></a>495. Clause 22 template parameter requirements</h3>
 <p><b>Section:</b> 22 [localization] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2005-01-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#localization">issues</a> in [localization].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>It appears that there are no requirements specified for many of the
 template parameters in clause 22. It looks like this issue has never
 come up, except perhaps for Facet.</p>

 <p>Clause 22 isn't even listed in 17.3.2.1 [lib.type.descriptions],
 either, which is the wording that allows requirements on template
 parameters to be identified by name.</p>

 <p>So one issue is that 17.3.2.1 [lib.type.descriptions] Should be
 changed to cover clause 22. A better change, which will cover us in
 the future, would be to say that it applies to all the library
 clauses. Then if a template gets added to any library clause we are
 covered.</p>

 <p>charT, InputIterator, and other names with requirements defined
 elsewhere are fine, assuming the 17.3.2.1 [lib.type.descriptions] fix.
 But there are a few template arguments names which I don't think have
 requirements given elsewhere:</p>

 <ul>
 <li>internT and externT.  The fix is to add wording saying that internT
 and externT must meet the same requirements as template arguments
 named charT.</li>

 <li>stateT.  I'm not sure about this one. There already is some wording,
 but it seems a bit vague.</li>

 <li>Intl.  [lib.locale.moneypunct.byname] The fix for this one is to
 rename "Intl" to "International". The name is important because other
 text identifies the requirements for the name International but not
 for Intl.</li>
 </ul>

 <p><b>Proposed resolution:</b></p>
 <p>Change 17.3.2.1 [type.descriptions], paragraph 1, from:</p>
 <blockquote><p>
 The Requirements subclauses may describe names that are used to
 specify constraints on template arguments.153) These names are used in
 clauses 20, 23, 25, and 26 to describe the types that may be supplied
 as arguments by a C++ program when instantiating template components
 from the library.
 </p></blockquote>
 <p>to:</p>
 <blockquote><p>
 The Requirements subclauses may describe names that are used to
 specify constraints on template arguments.153) These names are used in
 library clauses to describe the types that may be supplied as
 arguments by a C++ program when instantiating template components from
 the library.
 </p></blockquote>

 <p>In the front matter of class 22, locales, add:</p>
 <blockquote><p>
 Template parameter types internT and externT shall meet the
 requirements of charT (described in 21 [strings]).
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>
  Again, a blanket clause isn't blanket enough. Also, we've got a
  couple of names that we don't have blanket requirement statements
  for. The only issue is what to do about stateT. This wording is
  thin, but probably adequate.</p>


 <hr>
 <h3><a name="496"></a>496. Illegal use of "T" in vector&lt;bool&gt;</h3>
 <p><b>Section:</b> 23.2.6 [vector] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> richard@ex-parrot.com <b>Date:</b> 2005-02-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector">issues</a> in [vector].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In the synopsis of the std::vector&lt;bool&gt; specialisation in 23.2.6 [vector],
 the non-template assign() function has the signature</p>

 <pre>  void assign( size_type n, const T&amp; t );
 </pre>

 <p>The type, T, is not defined in this context.</p>


 <p><b>Proposed resolution:</b></p>
 <p>Replace "T" with "value_type".</p>


 <hr>
 <h3><a name="497"></a>497. meaning of numeric_limits::traps for floating point types</h3>
 <p><b>Section:</b> 18.2.1.2 [numeric.limits.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2005-03-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numeric.limits.members">issues</a> in [numeric.limits.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>18.2.1.2, p59 says this much about the traps member of numeric_limits:</p>

 <blockquote>
 <p>static const bool traps;<br>
 -59- true if trapping is implemented for the type.204)
 <br>
 Footnote 204: Required by LIA-1.
 </p>
 </blockquote>

 <p>It's not clear what is meant by "is implemented" here.</p>

 <p>
 In the context of floating point numbers it seems reasonable to expect
 to be able to use traps to determine whether a program can "safely" use
 infinity(), quiet_NaN(), etc., in arithmetic expressions, that is
 without causing a trap (i.e., on UNIX without having to worry about
 getting a signal). When traps is true, I would expect any of the
 operations in section 7 of IEEE 754 to cause a trap (and my program
 to get a SIGFPE). So, for example, on Alpha, I would expect traps
 to be true by default (unless I compiled my program with the -ieee
 option), false by default on most other popular architectures,
 including IA64, MIPS, PA-RISC, PPC, SPARC, and x86 which require
 traps to be explicitly enabled by the program.
 </p>

 <p>
 Another possible interpretation of p59 is that traps should be true
 on any implementation that supports traps regardless of whether they
 are enabled by default or not. I don't think such an interpretation
 makes the traps member very useful, even though that is how traps is
 implemented on several platforms. It is also the only way to implement
 traps on platforms that allow programs to enable and disable trapping
 at runtime.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Change p59 to read:</p>
 <blockquote><p>True if, at program startup, there exists a value of the type that
   would cause an arithmetic operation using that value to trap.</p></blockquote>


 <p><b>Rationale:</b></p>
 <p>
  Real issue, since trapping can be turned on and off. Unclear what a
  static query can say about a dynamic issue. The real advice we should
  give users is to use cfenv for these sorts of queries. But this new
  proposed resolution is at least consistent and slightly better than
  nothing.</p>


 <hr>
 <h3><a name="505"></a>505. Result_type in random distribution requirements</h3>
 <p><b>Section:</b> 26.4.1 [rand.req], TR1 5.1.1 [tr.rand.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown <b>Date:</b> 2005-07-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.req">issues</a> in [rand.req].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 17: Random distribution requirements
 </p>
 <p>
 Row 1 requires that each random distribution provide a nested type "input_type";
 this type denotes the type of the values that the distribution consumes.
 </p>
 <p>
 Inspection of all distributions in [tr.rand.dist] reveals that each distribution
 provides a second typedef ("result_type") that denotes the type of the values the
 distribution produces when called.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 It seems to me that this is also a requirement
 for all distributions and should therefore be  indicated as such via a new second
 row to this table 17:
 </p>
 <table border="1" cellpadding="5">
 <tbody><tr><td>X::result_type</td><td>T</td><td>---</td><td>compile-time</td></tr>
 </tbody></table>

 <p><i>[
 Berlin:  Voted to WP.  N1932 adopts the proposed resolution:  see Table 5 row 1.
 ]</i></p>


 <hr>
 <h3><a name="507"></a>507. Missing requirement for variate_generator::operator()</h3>
 <p><b>Section:</b> 26.4 [rand], TR1 5.1.3 [tr.rand.var] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown <b>Date:</b> 2005-07-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand">issues</a> in [rand].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Paragraph 11 of [tr.rand.var] equires that the member template
 </p>
 <blockquote><pre>template&lt;class T&gt; result_type operator() (T value);
 </pre></blockquote>
 <p>
 return
 </p>
 <blockquote><pre>distribution()(e, value)
 </pre></blockquote>
 <p>
 However, not all distributions have an operator() with a corresponding signature.
 </p>

 <p><i>[
 Berlin:  As a working group we voted in favor of N1932 which makes this moot:
 variate_generator has been eliminated.  Then in full committee we voted to give
 this issue WP status (mistakenly).
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 We therefore  recommend that we insert the following precondition before paragraph 11:
 </p>
 <blockquote><p>
 Precondition:  <tt>distribution().operator()(e,value)</tt> is well-formed.
 </p></blockquote>


 <hr>
 <h3><a name="508"></a>508. Bad parameters for ranlux64_base_01</h3>
 <p><b>Section:</b> 26.4.5 [rand.predef], TR1 5.1.5 [tr.rand.predef] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown <b>Date:</b> 2005-07-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.predef">issues</a> in [rand.predef].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The fifth of these engines with predefined parameters, ranlux64_base_01,
 appears to have an unintentional error for which there is a simple correction.
 The two pre-defined  subtract_with_carry_01 engines are given as:
 </p>
 <blockquote><pre>typedef subtract_with_carry_01&lt;float,  24, 10, 24&gt; ranlux_base_01;
 typedef subtract_with_carry_01&lt;double, 48, 10, 24&gt; ranlux64_base_01;
 </pre></blockquote>
 <p>
 We demonstrate below that ranlux64_base_01 fails to meet the intent of the
 random number generation proposal, but that the simple correction to
 </p>
 <blockquote><pre>typedef subtract_with_carry_01&lt;double, 48,  5, 12&gt; ranlux64_base_01;
 </pre></blockquote>
 <p>
 does meet the intent of defining well-known good parameterizations.
 </p>
 <p>
 The ranlux64_base_01 engine as presented fails to meet the intent for
 predefined engines, stated in proposal N1398 (section E):
 </p>
 <blockquote><p>
 In order to make good random numbers available to a large number of library
 users, this proposal not only defines generic random-number engines, but also
 provides a number of predefined well-known good parameterizations for those.
 </p></blockquote>
 <p>
 The predefined ranlux_base_01 engine has been proven [1,2,3] to have a very
 long period and so meets this criterion.  This property makes it suitable for
 use in the excellent discard_block  engines defined subsequently.  The proof
 of long period relies on the fact (proven in [1]) that 2**(w*r) - 2**(w*s)
 + 1 is prime (w, r, and s are template parameters to subtract_with_carry_01,
 as defined in [tr.rand.eng.sub1]).
 </p>
 <p>
 The ranlux64_base_01 engine as presented in [tr.rand.predef] uses w=48, r=24, s=10.
 For these numbers, the combination 2**(w*r)-2**(w*s)+1 is non-prime (though
 explicit factorization  would be a challenge).  In consequence, while it is
 certainly possible for some seeding states that this engine would have a very
 long period, it is not at all "well-known" that this is the case. The intent
 in the N1398 proposal involved the base of the ranlux64 engine, which finds heavy
 use in the physics community.  This is isomorphic to the predefined ranlux_base_01,
 but exploits the ability of double variables to hold (at least) 48 bits of mantissa,
 to deliver 48 random bits at a time rather than 24.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 To achieve this intended behavior, the correct template parameteriztion  would be:
 </p>
 <blockquote><pre>typedef subtract_with_carry_01&lt;double, 48, 5, 12&gt; ranlux64_base_01;
 </pre></blockquote>
 <p>
 The sequence of mantissa bits delivered by this is isomorphic (treating each
 double as having the  bits of two floats) to that delivered by ranlux_base_01.
 </p>
 <p>
 <b>References:</b>
 </p>
 <ol>
 <li>F. James, Comput. Phys. Commun. 60(1990) 329</li>
 <li>G. Marsaglia and A. Zaman, Ann. Appl. Prob 1(1991) 462</li>
 <li>M. Luscher, Comput. Phys. Commun. 79(1994) 100-110</li>
 </ol>

 <p><i>[
 Berlin: Voted to WP.  N1932 adopts the proposed resolution in 26.3.5,
 just above paragraph 5.
 ]</i></p>


 <hr>
 <h3><a name="518"></a>518. Are insert and erase stable for unordered_multiset and unordered_multimap?</h3>
 <p><b>Section:</b> 23.1.5 [unord.req], TR1 6.3.1 [tr.unord.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2005-07-03</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Issue 371 deals with stability of multiset/multimap under insert and erase
 (i.e. do they preserve the relative order in ranges of equal elements).
 The same issue applies to unordered_multiset and unordered_multimap.
 </p>
 <p><i>[
 Moved to open (from review):  There is no resolution.
 ]</i></p>


 <p><i>[
 Toronto:  We have a resolution now.  Moved to Review.  Some concern was noted
 as to whether this conflicted with existing practice or not.  An additional
 concern was in specifying (partial) ordering for an unordered container.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Wording for the proposed resolution is taken from the equivalent text for associative containers.
 </p>

 <p>
 Change 23.1.5 [unord.req], Unordered associative containers, paragraph 6 to:
 </p>

 <blockquote><p>
 An unordered associative container supports <i>unique</i> keys if it may
 contain at most one element for each key. Otherwise, it supports <i>equivalent
 keys</i>. <tt>unordered_set</tt> and <tt>unordered_map</tt> support
 unique keys. <tt>unordered_multiset</tt> and <tt>unordered_multimap</tt>
 support equivalent keys. In containers that support equivalent keys, elements
 with equivalent keys are adjacent to each other. <ins>For
 <tt>unordered_multiset</tt>
 and <tt>unordered_multimap</tt>,<tt> insert</tt> and <tt>erase</tt>
 preserve the relative ordering of equivalent elements.</ins>
 </p></blockquote>

 <p>
 Change 23.1.5 [unord.req], Unordered associative containers, paragraph 8 to:
 </p>

 <blockquote>
 <p>The elements of an unordered associative container are organized into <i>
 buckets</i>. Keys with the same hash code appear in the same bucket. The number
 of buckets is automatically increased as elements are added to an unordered
 associative container, so that the average number of elements per bucket is kept
 below a bound. Rehashing invalidates iterators, changes ordering between
 elements, and changes which buckets elements appear in, but does not invalidate
 pointers or references to elements. <ins>For <tt>unordered_multiset</tt>
 and <tt>unordered_multimap</tt>, rehashing
 preserves the relative ordering of equivalent elements.</ins></p>
 </blockquote>


 <hr>
 <h3><a name="519"></a>519. Data() undocumented</h3>
 <p><b>Section:</b> 23.2.1 [array], TR1 6.2.2 [tr.array.array] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Pete Becker <b>Date:</b> 2005-07-03</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#array">active issues</a> in [array].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#array">issues</a> in [array].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>array&lt;&gt;::data()</tt> is present in the class synopsis, but not documented.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add a new section, after 6.2.2.3:
 </p>
 <blockquote><pre>T*       data()
 const T* data() const;
 </pre></blockquote>
 <p>
 <b>Returns:</b> <tt>elems</tt>.
 </p>
 <p>
 Change 6.2.2.4/2 to:
 </p>
 <blockquote><p>
 In the case where <tt>N == 0</tt>, <tt>begin() == end()</tt>. The return value
 of <tt>data()</tt> is unspecified.
 </p></blockquote>


 <hr>
 <h3><a name="520"></a>520. Result_of and pointers to data members</h3>
 <p><b>Section:</b> 20.6.11.1 [func.bind], TR1 3.6 [tr.func.bind] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Pete Becker <b>Date:</b> 2005-07-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In the original proposal for binders, the return type of bind() when
 called with a pointer to member data as it's callable object was
 defined to be mem_fn(ptr); when Peter Dimov and I  unified the
 descriptions of the TR1 function objects we hoisted the descriptions
 of return types into the INVOKE pseudo-function and into result_of.
 Unfortunately, we left pointer to member data out of result_of, so
 bind doesn't have any specified behavior when called with a pointer
 to  member data.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p><i>[
 Pete and Peter will provide wording.
 ]</i></p>


 <p>
 In 20.5.4 [lib.func.ret] ([tr.func.ret]) p3 add the following bullet after bullet 2:
 </p>
 <ol start="3">
 <li>If <tt>F</tt> is a member data pointer type <tt>R T::*</tt>, <tt>type</tt>
 shall be <tt><i>cv</i> R&amp;</tt> when <tt>T1</tt> is <tt><i>cv</i> U1&amp;</tt>,
 <tt>R</tt> otherwise.</li>
 </ol>

 <p><i>[
 Peter provided wording.
 ]</i></p>


 <hr>
 <h3><a name="521"></a>521. Garbled requirements for argument_type in reference_wrapper</h3>
 <p><b>Section:</b> 20.6.5 [refwrap], TR1 2.1.2 [tr.util.refwrp.refwrp] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Pete Becker <b>Date:</b> 2005-07-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 2.1.2/3, second bullet item currently says that reference_wrapper&lt;T&gt; is
 derived from unary_function&lt;T, R&gt; if T is:
 </p>
 <blockquote><p>
 a pointer to member function type with cv-qualifier cv and no arguments;
 the type T1 is cv T* and R is the return type of the pointer to member function;
 </p></blockquote>
 <p>
 The type of T1 can't be cv T*, 'cause that's a pointer to a pointer to member
 function. It should be a pointer to the class that T is a pointer to member of.
 Like this:
 </p>
 <blockquote><p>
 a pointer to a member function R T0::f() cv (where cv represents the member
 function's cv-qualifiers); the type T1 is cv T0*
 </p></blockquote>
 <p>
 Similarly, bullet item 2 in 2.1.2/4 should be:
 </p>
 <blockquote><p>
 a pointer to a member function R T0::f(T2) cv (where cv represents the member
 function's cv-qualifiers); the type T1 is cv T0*
 </p></blockquote>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change bullet item 2 in 2.1.2/3:
 </p>

 <blockquote>
 <ul>
 <li>
 a pointer to member function <del>type with cv-qualifier <tt><i>cv</i></tt> and no arguments;
 the type <tt>T1</tt> is <tt><i>cv</i> T*</tt> and <tt>R</tt> is the return
 type of the pointer to member function</del> <ins><tt>R T0::f() <i>cv</i></tt>
 (where <tt><i>cv</i></tt> represents the member function's cv-qualifiers);
 the type <tt>T1</tt> is <tt><i>cv</i> T0*</tt></ins>
 </li>
 </ul>
 </blockquote>

 <p>
 Change bullet item 2 in 2.1.2/4:
 </p>

 <blockquote>
 <ul>
 <li>
 a pointer to member function <del>with cv-qualifier <tt><i>cv</i></tt> and taking one argument
 of type <tt>T2</tt>; the type <tt>T1</tt> is <tt><i>cv</i> T*</tt> and
 <tt>R</tt> is the return type of the pointer to member function</del>
 <ins><tt>R T0::f(T2) <i>cv</i></tt> (where <tt><i>cv</i></tt> represents the member
 function's cv-qualifiers); the type <tt>T1</tt> is <tt><i>cv</i> T0*</tt></ins>
 </li>
 </ul>
 </blockquote>


 <hr>
 <h3><a name="524"></a>524. regex named character classes and case-insensitivity don't mix</h3>
 <p><b>Section:</b> 28 [re] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Eric Niebler <b>Date:</b> 2005-07-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re">issues</a> in [re].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 This defect is also being discussed on the Boost developers list. The
 full discussion can be found here:
 http://lists.boost.org/boost/2005/07/29546.php
 </p>
 <p>
 -- Begin original message --
 </p>
 <p>
 Also, I may have found another issue, closely related to the one under
 discussion. It regards case-insensitive matching of named character
 classes. The regex_traits&lt;&gt; provides two functions for working with
 named char classes: lookup_classname and isctype. To match a char class
 such as [[:alpha:]], you pass "alpha" to lookup_classname and get a
 bitmask. Later, you pass a char and the bitmask to isctype and get a
 bool yes/no answer.
 </p>
 <p>
 But how does case-insensitivity work in this scenario? Suppose we're
 doing a case-insensitive match on [[:lower:]]. It should behave as if it
 were [[:lower:][:upper:]], right? But there doesn't seem to be enough
 smarts in the regex_traits interface to do this.
 </p>
 <p>
 Imagine I write a traits class which recognizes [[:fubar:]], and the
 "fubar" char class happens to be case-sensitive. How is the regex engine
 to know that? And how should it do a case-insensitive match of a
 character against the [[:fubar:]] char class? John, can you confirm this
 is a legitimate problem?
 </p>
 <p>
 I see two options:
 </p>
 <p>
 1) Add a bool icase parameter to lookup_classname. Then,
 lookup_classname( "upper", true ) will know to return lower|upper
 instead of just upper.
 </p>
 <p>
 2) Add a isctype_nocase function
 </p>
 <p>
 I prefer (1) because the extra computation happens at the time the
 pattern is compiled rather than when it is executed.
 </p>
 <p>
 -- End original message --
 </p>

 <p>
 For what it's worth, John has also expressed his preference for option
 (1) above.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2409.pdf">N2409</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="527"></a>527. tr1::bind has lost its Throws clause</h3>
 <p><b>Section:</b> 20.6.11.1.3 [func.bind.bind], TR1 3.6.3 [tr.func.bind.bind] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2005-10-01</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#func.bind.bind">active issues</a> in [func.bind.bind].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.bind.bind">issues</a> in [func.bind.bind].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The original bind proposal gives the guarantee that tr1::bind(f, t1,
 ..., tN) does not throw when the copy constructors of f, t1, ..., tN
 don't.
 </p>

 <p>
 This guarantee is not present in the final version of TR1.
 </p>

 <p>
 I'm pretty certain that we never removed it on purpose. Editorial omission? :-)
 </p>

 <p><i>[
 Berlin: not quite editorial, needs proposed wording.
 ]</i></p>

 <p><i>[
 Batavia:  Doug to translate wording to variadic templates.
 ]</i></p>


 <p><i>[
 Toronto:  We agree but aren't quite happy with the wording.  The "t"'s no
 longer refer to anything.  Alan to provide improved wording.
 ]</i></p>


 <p><i>[
 Pre-Bellevue:  Alisdair provided wording.
 ]</i></p>


 <p>
 TR1 proposed resolution:
 </p>

 <blockquote>
 <p>
 In TR1 3.6.3 [tr.func.bind.bind], add a new paragraph after p2:
 </p>
 <blockquote><p>
 <i>Throws:</i> Nothing unless one of the copy constructors of <tt>f, t1, t2, ..., tN</tt>
 throws an exception.
 </p></blockquote>

 <p>
 Add a new paragraph after p4:
 </p>
 <blockquote><p>
 <i>Throws:</i> nothing unless one of the copy constructors of <tt>f, t1, t2, ..., tN</tt>
 throws an exception.
 </p></blockquote>

 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 20.6.11.1.3 [func.bind.bind], add a new paragraph after p2:
 </p>

 <blockquote>
 <i>Throws:</i> Nothing unless the copy constructor of <tt>F</tt> or of one of the types
 in the <tt>BoundArgs...</tt> pack expansion throws an exception.
 </blockquote>

 <p>
 In 20.6.11.1.3 [func.bind.bind], add a new paragraph after p4:
 </p>

 <blockquote>
 <i>Throws:</i> Nothing unless the copy constructor of <tt>F</tt> or of one of the types
 in the <tt>BoundArgs...</tt> pack expansion throws an exception.
 </blockquote>


 <hr>
 <h3><a name="530"></a>530. Must elements of a string be contiguous?</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2005-11-15</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#69">69</a>, which was incorporated into C++03, mandated
    that the elements of a vector must be stored in contiguous memory.
    Should the same also apply to <tt>basic_string</tt>?</p>

 <p>We almost require contiguity already. Clause 23.3.4 [multiset]
   defines <tt>operator[]</tt> as <tt>data()[pos]</tt>. What's missing
   is a similar guarantee if we access the string's elements via the
   iterator interface.</p>

 <p>Given the existence of <tt>data()</tt>, and the definition of
   <tt>operator[]</tt> and <tt>at</tt> in terms of <tt>data</tt>,
   I don't believe it's possible to write a useful and standard-
   conforming <tt>basic_string</tt> that isn't contiguous. I'm not
   aware of any non-contiguous implementation. We should just require
   it.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>Add the following text to the end of 21.3 [basic.string],
 paragraph 2. </p>

 <blockquote>
   <p>The characters in a string are stored contiguously, meaning that if
   <tt>s</tt> is a <tt>basic_string&lt;charT, Allocator&gt;</tt>, then
   it obeys the identity
   <tt>&amp;*(s.begin() + n) == &amp;*s.begin() + n</tt>
   for all <tt>0 &lt;= n &lt; s.size()</tt>.
   </p>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>
 Not standardizing this existing practice does not give implementors more
 freedom.  We thought it might a decade ago.  But the vendors have spoken
 both with their implementations, and with their voice at the LWG
 meetings.  The implementations are going to be contiguous no matter what
 the standard says.  So the standard might as well give string clients
 more design choices.
 </p>


 <hr>
 <h3><a name="531"></a>531. array forms of unformatted input functions</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2005-11-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The array forms of unformatted input functions don't seem to have well-defined
 semantics for zero-element arrays in a couple of cases. The affected ones
 (<tt>istream::get()</tt> and <tt>istream::getline()</tt>) are supposed to
 terminate when <tt>(n - 1)</tt> characters are stored, which obviously can
 never be true when <tt>(n == 0)</tt> holds to start with. See
 c++std-lib-16071.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 I suggest changing 27.6.1.3, p7 (<tt>istream::get()</tt>), bullet 1 to read:
 </p>
             <ul>
                 <li>
                     <tt>(n &lt; 1)</tt> is true or <tt>(n - 1)</tt> characters
                     are stored;
                 </li>
             </ul>
 <p>
 Change 27.6.1.3, p9:
 </p>

 <blockquote><p>
 If the function stores no characters, it calls <tt>setstate(failbit)</tt> (which
 may throw <tt>ios_base::failure</tt> (27.4.4.3)).  In any case, <ins>if <tt>(n
 &gt; 0)</tt> is true</ins> it then stores a null character into the next
 successive location of the array.
 </p></blockquote>

         <p>

 and similarly p17 (<tt>istream::getline()</tt>), bullet 3 to:

         </p>
             <ul>
                 <li>
                     <tt>(n &lt; 1)</tt> is true or <tt>(n - 1)</tt> characters
                     are stored (in which case the function calls
                     <tt>setstate(failbit)</tt>).
                 </li>
             </ul>

         <p>

 In addition, to clarify that <tt>istream::getline()</tt> must not store the
 terminating NUL character unless the the array has non-zero size, Robert
 Klarer suggests in c++std-lib-16082 to change 27.6.1.3, p20 to read:

         </p>
             <blockquote><p>

 In any case, provided <tt>(n &gt; 0)</tt> is true, it then stores a null character
 (using charT()) into the next successive location of the array.

             </p></blockquote>

 <p><i>[
 post-Redmond:  Pete noticed that the current resolution for <tt>get</tt> requires
 writing to out of bounds memory when <tt>n == 0</tt>.  Martin provided fix.
 ]</i></p>


 <hr>
 <h3><a name="533"></a>533. typo in 2.2.3.10/1</h3>
 <p><b>Section:</b> 20.7.12.2.11 [util.smartptr.getdeleter], TR1 2.2.3.10 [tr.util.smartptr.getdeleter] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>
  <b>Submitter:</b> Paolo Carlini <b>Date:</b> 2005-11-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.getdeleter">issues</a> in [util.smartptr.getdeleter].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#DR">DR</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I'm seeing something that looks like a typo. The Return of <tt>get_deleter</tt>
 says:
 </p>
 <blockquote><p>
 If <tt>*this</tt> <i>owns</i> a deleter <tt>d</tt>...
 </p></blockquote>
 <p>
 but <tt>get_deleter</tt> is a free function!
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Therefore, I think should be:
 </p>
 <blockquote><p>
 If <tt><del>*this</del> <ins>p</ins></tt> <i>owns</i> a deleter <tt>d</tt>...
 </p></blockquote>


 <hr>
 <h3><a name="534"></a>534. Missing basic_string members</h3>
 <p><b>Section:</b> 21.3 [basic.string] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alisdair Meredith <b>Date:</b> 2005-11-16</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.string">active issues</a> in [basic.string].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.string">issues</a> in [basic.string].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 OK, we all know std::basic_string is bloated and already has way too
 many members.  However, I propose it is missing 3 useful members that
 are often expected by users believing it is a close approximation of the
 container concept.  All 3 are listed in table 71 as 'optional'
 </p>

 <p>
 i/  pop_back.
 </p>

 <p>
 This is the one I feel most strongly about, as I only just discovered it
 was missing as we are switching to a more conforming standard library
 &lt;g&gt;
 </p>

 <p>
 I find it particularly inconsistent to support push_back, but not
 pop_back.
 </p>

 <p>
 ii/ back.
 </p>

 <p>
 There are certainly cases where I want to examine the last character of
 a string before deciding to append, or to trim trailing path separators
 from directory names etc.  *rbegin() somehow feels inelegant.
 </p>

 <p>
 iii/ front
 </p>

 <p>
 This one I don't feel strongly about, but if I can get the first two,
 this one feels that it should be added as a 'me too' for consistency.
 </p>

 <p>
 I believe this would be similarly useful to the data() member recently
 added to vector, or at() member added to the maps.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the following members to definition of class template basic_string, 21.3p7
 </p>
 <blockquote><pre>void pop_back ()

 const charT &amp; front() const
 charT &amp; front()

 const charT &amp; back() const
 charT &amp; back()
 </pre></blockquote>
 <p>
 Add the following paragraphs to basic_string description
 </p>

 <p>
 21.3.4p5
 </p>
 <blockquote>
 <pre>const charT &amp; front() const
 charT &amp; front()
 </pre>
 <p>
 <i>Precondition:</i> <tt>!empty()</tt>
 </p>
 <p>
 <i>Effects:</i> Equivalent to <tt>operator[](0)</tt>.
 </p>
 </blockquote>

 <p>
 21.3.4p6
 </p>
 <blockquote>
 <pre>const charT &amp; back() const
 charT &amp; back()
 </pre>
 <p>
 <i>Precondition:</i> <tt>!empty()</tt>
 </p>
 <p>
 <i>Effects:</i> Equivalent to <tt>operator[]( size() - 1)</tt>.
 </p>
 </blockquote>

 <p>
 21.3.5.5p10
 </p>
 <blockquote>
 <pre>void pop_back ()
 </pre>
 <p>
 <i>Precondition:</i> <tt>!empty()</tt>
 </p>
 <p>
 <i>Effects:</i> Equivalent to <tt>erase( size() - 1, 1 )</tt>.
 </p>
 </blockquote>

 <p>
 Update Table 71: (optional sequence operations)
 Add basic_string to the list of containers for the following operations.
 </p>
 <blockquote><pre>a.front()
 a.back()
 a.push_back()
 a.pop_back()
 a[n]
 </pre></blockquote>

 <p><i>[
 Berlin: Has support.  Alisdair provided wording.
 ]</i></p>


 <hr>
 <h3><a name="535"></a>535. std::string::swap specification poorly worded</h3>
 <p><b>Section:</b> 21.3.6.8 [string::swap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2005-12-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string::swap">issues</a> in [string::swap].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 std::string::swap currently says for effects and postcondition:
 </p>

 <blockquote>
 <p>
 <i>Effects:</i> Swaps the contents of the two strings.
 </p>

 <p>
 <i>Postcondition:</i> <tt>*this</tt> contains the characters that were in <tt><i>s</i></tt>,
 <tt><i>s</i></tt> contains the characters that were in <tt>*this</tt>.
 </p>
 </blockquote>

 <p>
 Specifying both Effects and Postcondition seems redundant, and the postcondition
 needs to be made stronger. Users would be unhappy if the characters were not in
 the same order after the swap.
 </p>


 <p><b>Proposed resolution:</b></p>
 <blockquote>
 <p>
 <del><i>Effects:</i> Swaps the contents of the two strings.</del>
 </p>

 <p>
 <i>Postcondition:</i> <tt>*this</tt> contains the <ins>same sequence of</ins>
 characters that <del>were</del> <ins>was</ins> in <tt><i>s</i></tt>,
 <tt><i>s</i></tt> contains the <ins>same sequence of</ins> characters that
 <del>were</del> <ins>was</ins> in <tt>*this</tt>.
 </p>
 </blockquote>


 <hr>
 <h3><a name="537"></a>537. Typos in the signatures in 27.6.1.3/42-43 and 27.6.2.4</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Paolo Carlini <b>Date:</b> 2006-02-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In the most recent working draft, I'm still seeing:
 </p>

 <blockquote><pre>seekg(off_type&amp; off, ios_base::seekdir dir)
 </pre></blockquote>

 <p>
 and
 </p>

 <blockquote><pre>seekp(pos_type&amp; pos)

 seekp(off_type&amp; off, ios_base::seekdir dir)
 </pre></blockquote>

 <p>
 that is, by reference off and pos arguments.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 After 27.6.1.3p42 change:
 </p>

 <blockquote><pre>basic_istream&lt;charT,traits&gt;&amp; seekg(off_type<del>&amp;</del> <i>off</i>, ios_base::seekdir <i>dir</i>);
 </pre></blockquote>

 <p>
 After 27.6.2.4p1 change:
 </p>

 <blockquote><pre>basic_ostream&lt;charT,traits&gt;&amp; seekp(pos_type<del>&amp;</del> <i>pos</i>);
 </pre></blockquote>

 <p>
 After 27.6.2.4p3 change:
 </p>

 <blockquote><pre>basic_ostream&lt;charT,traits&gt;&amp; seekp(off_type<del>&amp;</del> <i>off</i>, ios_base::seekdir <i>dir</i>);
 </pre></blockquote>


 <hr>
 <h3><a name="538"></a>538. 241 again: Does unique_copy() require CopyConstructible and Assignable?</h3>
 <p><b>Section:</b> 25.2.9 [alg.unique] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2006-02-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.unique">issues</a> in [alg.unique].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I believe I botched the resolution of
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">
 241 "Does unique_copy() require CopyConstructible and Assignable?"</a> which now
 has WP status.
 </p>

 <p>
 This talks about <tt>unique_copy</tt> requirements and currently reads:
 </p>

 <blockquote><p>
 -5- <i>Requires:</i> The ranges <tt>[<i>first</i>, <i>last</i>)</tt> and
 <tt>[<i>result</i>, <i>result</i>+(<i>last</i>-<i>first</i>))</tt>
 shall not overlap. The expression <tt>*<i>result</i> = *<i>first</i></tt> shall
 be valid. If neither <tt>InputIterator</tt> nor <tt>OutputIterator</tt> meets the
 requirements of forward iterator then the value type of <tt>InputIterator</tt>
 must be CopyConstructible (20.1.3). Otherwise CopyConstructible is not required.
 </p></blockquote>

 <p>
 The problem (which Paolo discovered) is that when the iterators are at their
 most restrictive (<tt>InputIterator</tt>, <tt>OutputIterator</tt>), then we want
 <tt>InputIterator::value_type</tt> to be both <tt>CopyConstructible</tt> and
 <tt>CopyAssignable</tt> (for the most efficient implementation).  However this
 proposed resolution only makes it clear that it is <tt>CopyConstructible</tt>,
 and that one can assign from <tt>*<i>first</i></tt> to <tt>*<i>result</i></tt>.
 This latter requirement does not necessarily imply that you can:
 </p>

 <blockquote><pre>*<i>first</i> = *<i>first</i>;
 </pre></blockquote>


 <p><b>Proposed resolution:</b></p>
 <blockquote><p>
 -5- <i>Requires:</i> The ranges <tt>[<i>first</i>, <i>last</i>)</tt> and
 <tt>[<i>result</i>, <i>result</i>+(<i>last</i>-<i>first</i>))</tt>
 shall not overlap. The expression <tt>*<i>result</i> = *<i>first</i></tt>
 shall
 be valid. If neither <tt>InputIterator</tt> nor <tt>OutputIterator</tt> meets the
 requirements of forward iterator then the <del>value type</del>
 <ins><tt>value_type</tt></ins> of <tt>InputIterator</tt>
 must be CopyConstructible (20.1.3) <ins>and Assignable</ins>.
 Otherwise CopyConstructible is not required.
 </p></blockquote>


 <hr>
 <h3><a name="540"></a>540. shared_ptr&lt;void&gt;::operator*()</h3>
 <p><b>Section:</b> 20.7.12.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2005-10-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared.obs">issues</a> in [util.smartptr.shared.obs].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I'm trying to reconcile the note in tr.util.smartptr.shared.obs, p6
 that talks about the operator*() member function of shared_ptr:
 </p>

 <blockquote><p>
   Notes: When T is void, attempting to instantiate this member function
   renders the program ill-formed. [Note: Instantiating shared_ptr&lt;void&gt;
   does not necessarily result in instantiating this member function.
   --end note]
 </p></blockquote>

 <p>
 with the requirement in temp.inst, p1:
 </p>

 <blockquote><p>
   The implicit instantiation of a class template specialization causes
   the implicit instantiation of the declarations, but not of the
   definitions...
 </p></blockquote>

 <p>
 I assume that what the note is really trying to say is that
 "instantiating shared_ptr&lt;void&gt; *must not* result in instantiating
 this member function." That is, that this function must not be
 declared a member of shared_ptr&lt;void&gt;. Is my interpretation
 correct?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 2.2.3.5p6
 </p>

 <blockquote><p>
 -6- <del><i>Notes:</i></del> When <tt>T</tt> is <tt>void</tt>, <del>attempting to instantiate
 this member function renders the program ill-formed. [<i>Note:</i>
 Instantiating <tt>shared_ptr&lt;void&gt;</tt> does not necessarily result in
 instantiating this member function. <i>--end note</i>]</del> <ins>it is
 unspecified whether this member function is declared or not, and if so, what its
 return type is, except that the declaration (although not necessarily the
 definition) of the function shall be well-formed.</ins>
 </p></blockquote>


 <hr>
 <h3><a name="541"></a>541. shared_ptr template assignment and void</h3>
 <p><b>Section:</b> 20.7.12.2 [util.smartptr.shared], TR1 2.2.3 [tr.util.smartptr.shared] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2005-10-16</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#util.smartptr.shared">active issues</a> in [util.smartptr.shared].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared">issues</a> in [util.smartptr.shared].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Is the void specialization of the template assignment operator taking
 a shared_ptr&lt;void&gt; as an argument supposed be well-formed?
 </p>
 <p>
 I.e., is this snippet well-formed:
 </p>
 <blockquote><pre>shared_ptr&lt;void&gt; p;
 p.operator=&lt;void&gt;(p);
 </pre></blockquote>

 <p>
 Gcc complains about auto_ptr&lt;void&gt;::operator*() returning a reference
 to void. I suspect it's because shared_ptr has two template assignment
 operators, one of which takes auto_ptr, and the auto_ptr template gets
 implicitly instantiated in the process of overload resolution.
 </p>

 <p>
 The only way I see around it is to do the same trick with auto_ptr&lt;void&gt;
 operator*() as with the same operator in shared_ptr&lt;void&gt;.
 </p>

 <p>
 PS Strangely enough, the EDG front end doesn't mind the code, even
 though in a small test case (below) I can reproduce the error with
 it as well.
 </p>

 <blockquote><pre>template &lt;class T&gt;
 struct A { T&amp; operator*() { return *(T*)0; } };

 template &lt;class T&gt;
 struct B {
     void operator= (const B&amp;) { }
     template &lt;class U&gt;
     void operator= (const B&lt;U&gt;&amp;) { }
     template &lt;class U&gt;
     void operator= (const A&lt;U&gt;&amp;) { }
 };

 int main ()
 {
     B&lt;void&gt; b;
     b.operator=&lt;void&gt;(b);
 }
 </pre></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 In [lib.memory] change:
 </p>
 <blockquote><pre>template&lt;class X&gt; class auto_ptr;
 <ins>template&lt;&gt; class auto_ptr&lt;void&gt;;</ins>
 </pre></blockquote>

 <p>
 In [lib.auto.ptr]/2 add the following before the last closing brace:
 </p>

 <blockquote><pre>template&lt;&gt; class auto_ptr&lt;void&gt;
 {
 public:
     typedef void element_type;
 };
 </pre></blockquote>


 <hr>
 <h3><a name="542"></a>542. shared_ptr observers</h3>
 <p><b>Section:</b> 20.7.12.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2005-10-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared.obs">issues</a> in [util.smartptr.shared.obs].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Peter Dimov wrote:
 To: C++ libraries mailing list
 Message c++std-lib-15614
 [...]
 The intent is for both use_count() and unique() to work in a threaded environment.
 They are intrinsically prone to race conditions, but they never return garbage.
 </p>

 <p>
 This is a crucial piece of information that I really wish were
 captured in the text. Having this in a non-normative note would
 have made everything crystal clear to me and probably stopped
 me from ever starting this discussion :) Instead, the sentence
 in p12 "use only for debugging and testing purposes, not for
 production code" very strongly suggests that implementations
 can and even are encouraged to return garbage (when threads
 are involved) for performance reasons.
 </p>
 <p>
 How about adding an informative note along these lines:
 </p>
 <blockquote><p>
   Note: Implementations are encouraged to provide well-defined
   behavior for use_count() and unique() even in the presence of
   multiple threads.
 </p></blockquote>
 <p>
 I don't necessarily insist on the exact wording, just that we
 capture the intent.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 20.7.12.2.5 [util.smartptr.shared.obs] p12:
 </p>
 <blockquote><p>
 [<i>Note:</i> <tt>use_count()</tt> is not necessarily efficient. <del>Use only for
 debugging and testing purposes, not for production code.</del> --<i>end note</i>]
 </p></blockquote>

 <p>
 Change 20.7.12.3.5 [util.smartptr.weak.obs] p3:
 </p>
 <blockquote><p>
 [<i>Note:</i> <tt>use_count()</tt> is not necessarily efficient. <del>Use only for
 debugging and testing purposes, not for production code.</del> --<i>end note</i>]
 </p></blockquote>


 <hr>
 <h3><a name="543"></a>543. valarray slice default constructor</h3>
 <p><b>Section:</b> 26.5.4 [class.slice] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2005-11-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 If one explicitly constructs a slice or glice with the default
 constructor, does the standard require this slice to have any usable
 state?  It says "creates a slice which specifies no elements", which
 could be interpreted two ways:
 </p>
 <ol>
 <li>There are no elements to which the slice refers (i.e. undefined).</li>
 <li>The slice specifies an array with no elements in it (i.e. defined).</li>
 </ol>
 <p>
 Here is a bit of code to illustrate:
 </p>
 <blockquote><pre>#include &lt;iostream&gt;
 #include &lt;valarray&gt;

 int main()
 {
     std::valarray&lt;int&gt; v(10);
     std::valarray&lt;int&gt; v2 = v[std::slice()];
     std::cout &lt;&lt; "v[slice()].size() = " &lt;&lt; v2.size() &lt;&lt; '\n';
 }
 </pre></blockquote>

 <p>
 Is the behavior undefined?  Or should the output be:
 </p>

 <blockquote><pre>v[slice()].size() = 0
 </pre></blockquote>

 <p>
 There is a similar question and wording for gslice at 26.3.6.1p1.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p><i>[Martin suggests removing the second sentence in 26.5.4.1 [cons.slice] as well.]</i></p>


 <p>
 Change 26.5.4.1 [cons.slice]:
 </p>

 <blockquote><p>
 1 - <del>The default constructor for <tt>slice</tt> creates a <tt>slice</tt>
 which specifies no elements.</del> <ins>The default constructor is equivalent to
 <tt>slice(0, 0, 0)</tt>.</ins> A default constructor is provided only to permit
 the declaration of arrays of slices. The constructor with arguments for a slice
 takes a start, length, and stride parameter.
 </p></blockquote>

 <p>
 Change 26.5.6.1 [gslice.cons]:
 </p>

 <blockquote><p>
 1 - <del>The default constructor creates a <tt>gslice</tt> which specifies no
 elements.</del> <ins>The default constructor is equivalent to <tt>gslice(0,
 valarray&lt;size_t&gt;(), valarray&lt;size_t&gt;())</tt>.</ins> The constructor
 with arguments builds a <tt>gslice</tt> based on a specification of start,
 lengths, and strides, as explained in the previous section.
 </p></blockquote>


 <hr>
 <h3><a name="545"></a>545. When is a deleter deleted?</h3>
 <p><b>Section:</b> 20.7.12.2.11 [util.smartptr.getdeleter], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2006-01-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.getdeleter">issues</a> in [util.smartptr.getdeleter].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The description of ~shared_ptr doesn't say when the shared_ptr's deleter, if
 any, is destroyed. In principle there are two possibilities: it is destroyed
 unconditionally whenever ~shared_ptr is executed (which, from an implementation
 standpoint, means that the deleter is copied whenever the shared_ptr is copied),
 or it is destroyed immediately after the owned pointer is destroyed (which, from
 an implementation standpoint, means that the deleter object is shared between
 instances). We should say which it is.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add after the first sentence of 20.7.12.2.11 [util.smartptr.getdeleter]/1:
 </p>
 <blockquote>
 <p>
 The returned pointer remains valid as long as there exists a <tt>shared_ptr</tt> instance
 that owns <tt><i>d</i></tt>.
 </p>
 <p>
 [<i>Note:</i> it is unspecified whether the pointer remains valid longer than that.
 This can happen if the implementation doesn't destroy the deleter until all
 <tt>weak_ptr</tt> instances in the ownership group are destroyed. <i>-- end note</i>]
 </p>
 </blockquote>


 <hr>
 <h3><a name="550"></a>550. What should the return type of pow(float,int) be?</h3>
 <p><b>Section:</b> 26.7 [c.math] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2006-01-12</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#c.math">issues</a> in [c.math].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Assuming we adopt the
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf">C
 compatibility package from C99</a>  what should be the return type of the
 following signature be:
 </p>
 <blockquote><pre>?  pow(float, int);
 </pre></blockquote>
 <p>
 C++03 says that the return type should be <tt>float</tt>.
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1836.pdf">
 TR1</a> and C90/99 say the return type should be <tt>double</tt>.  This can put
 clients into a situation where C++03 provides answers that are not as high
 quality as C90/C99/TR1.  For example:
 </p>
 <blockquote><pre>#include &lt;math.h&gt;

 int main()
 {
     float x = 2080703.375F;
     double y = pow(x, 2);
 }
 </pre></blockquote>
 <p>
 Assuming an IEEE 32 bit float and IEEE 64 bit double, C90/C99/TR1 all suggest:
 </p>

 <blockquote><pre>y = 4329326534736.390625
 </pre></blockquote>

 <p>
 which is exactly right.  While C++98/C++03 demands:
 </p>

 <blockquote><pre>y = 4329326510080.
 </pre></blockquote>

 <p>
 which is only approximately right.
 </p>

 <p>
 I recommend that C++0X adopt the mixed mode arithmetic already adopted by
 Fortran, C and TR1 and make the return type of <tt>pow(float,int)</tt> be
 <tt>double</tt>.
 </p>

 <p><i>[
 Kona (2007): Other functions that are affected by this issue include
 <tt>ldexp</tt>, <tt>scalbln</tt>, and <tt>scalbn</tt>. We also believe that there is a typo in
 26.7/10: <tt>float nexttoward(float, long double);</tt> [sic] should be <tt>float
 nexttoward(float, float);</tt> Proposed Disposition: Review (the proposed
 resolution appears above, rather than below, the heading "Proposed
 resolution")
 ]</i></p>


 <p><i>[
 <p>
 Howard, post Kona:
 </p>
 <blockquote>
 <p>
 Unfortunately I strongly disagree with a part of the resolution
 from Kona.  I am moving from New to Open instead of to Review because I do not believe
 we have consensus on the intent of the resolution.
 </p>
 <p>
 This issue does not include <tt>ldexp</tt>, <tt>scalbln</tt>, and <tt>scalbn</tt> because
 the second integral parameter in each of these signatures (from C99) is <b>not</b> a
 <i>generic parameter</i> according to C99 7.22p2.  The corresponding C++ overloads are
 intended (as far as I know) to correspond directly to C99's definition of <i>generic parameter</i>.
 </p>
 <p>
 For similar reasons, I do not believe that the second <tt>long double</tt> parameter of
 <tt>nexttoward</tt>, nor the return type of this function, is in error.  I believe the
 correct signature is:
 </p>
 <blockquote>
 <pre>float nexttoward(float, long double);
 </pre>
 </blockquote>
 <p>
 which is what both the C++0X working paper and C99 state (as far as I currently understand).
 </p>
 <p>
 This is really <b>only</b> about <tt>pow(float, int)</tt>.  And this is because C++98 took one
 route (with <tt>pow</tt> only) and C99 took another (with many math functions in <tt>&lt;tgmath.h&gt;</tt>.
 The proposed resolution basically says: C++98 got it wrong and C99 got it right; let's go with C99.
 </p>
 </blockquote>
 ]</i></p>


 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 This signature was not picked up from C99. Instead, if one types
 pow(2.0f,2), the promotion rules will invoke "double pow(double,
 double)", which generally gives special treatment for integral
 exponents, preserving full accuracy of the result.  New proposed
 wording provided.
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 26.7 [c.math] p10:
 </p>

 <blockquote>
 <p>
 The added signatures are:
 </p>
 <blockquote><pre>...
 <del>float pow(float, int);</del>
 ...
 <del>double pow(double, int);</del>
 ...
 <del>long double pow(long double, int);</del>
 </pre></blockquote>
 </blockquote>


 <hr>
 <h3><a name="551"></a>551. &lt;ccomplex&gt;</h3>
 <p><b>Section:</b> 26.3.11 [cmplxh], TR1 8.3 [tr.c99.cmplxh] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2006-01-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Previously xxx.h was parsable by C++.  But in the case of C99's &lt;complex.h&gt;
 it isn't.  Otherwise we could model it just like &lt;string.h&gt;, &lt;cstring&gt;, &lt;string&gt;:
 </p>

 <ul>
 <li>&lt;string&gt;   : C++ API in namespace std</li>
 <li>&lt;cstring&gt;  : C API in namespace std</li>
 <li>&lt;string.h&gt; : C API in global namespace</li>
 </ul>

 <p>
 In the case of C's complex, the C API won't compile in C++.  So we have:
 </p>

 <ul>
 <li>&lt;complex&gt;   : C++ API in namespace std</li>
 <li>&lt;ccomplex&gt;  : ?</li>
 <li>&lt;complex.h&gt; : ?</li>
 </ul>

 <p>
 The ? can't refer to the C API.  TR1 currently says:
 </p>

 <ul>
 <li>&lt;complex&gt;   : C++ API in namespace std</li>
 <li>&lt;ccomplex&gt;  : C++ API in namespace std</li>
 <li>&lt;complex.h&gt; : C++ API in global namespace</li>
 </ul>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 26.3.11 [cmplxh]:
 </p>

 <blockquote>
 <p>
 The header behaves as if it includes the header
 <tt>&lt;ccomplex&gt;</tt><ins>.</ins><del>, and provides sufficient using
 declarations to declare in the global namespace all function and type names
 declared or defined in the neader <tt>&lt;complex&gt;</tt>.</del>
 <ins>[<i>Note:</i> <tt>&lt;complex.h&gt;</tt> does not promote any interface
 into the global namespace as there is no C interface to promote. <i>--end
 note</i>]</ins>
 </p>
 </blockquote>


 <hr>
 <h3><a name="552"></a>552. random_shuffle and its generator</h3>
 <p><b>Section:</b> 25.2.12 [alg.random.shuffle] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-01-25</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 ...is specified to shuffle its range by calling swap but not how
 (or even that) it's supposed to use the RandomNumberGenerator
 argument passed to it.
 </p>
 <p>
 Shouldn't we require that the generator object actually be used
 by the algorithm to obtain a series of random numbers and specify
 how many times its operator() should be invoked by the algorithm?
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="559"></a>559. numeric_limits&lt;const T&gt;</h3>
 <p><b>Section:</b> 18.2.1 [limits] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-02-19</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#limits">issues</a> in [limits].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 18.2.1 [limits], p2 requires implementations  to provide specializations of the
 <code>numeric_limits</code> template for  each scalar type. While this
 could be interepreted to include cv-qualified forms of such types such
 an  interepretation   is  not  reflected   in  the  synopsis   of  the
 <code>&lt;limits&gt;</code> header.

         </p>
         <p>

 The absence  of specializations of the template  on cv-qualified forms
 of  fundamental types  makes <code>numeric_limits</code>  difficult to
 use in generic  code where the constness (or volatility)  of a type is
 not  always  immediately  apparent.  In  such  contexts,  the  primary
 template  ends   up  being   instantiated  instead  of   the  provided
 specialization, typically yielding unexpected behavior.

         </p>
         <p>

 Require   that  specializations   of   <code>numeric_limits</code>  on
 cv-qualified fundamental types have the same semantics as those on the
 unqualifed forms of the same types.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 Add  to  the   synopsis  of  the  <code>&lt;limits&gt;</code>  header,
 immediately  below  the  declaration  of  the  primary  template,  the
 following:
 </p>

 <pre>
 template &lt;class T&gt; class numeric_limits&lt;const T&gt;;
 template &lt;class T&gt; class numeric_limits&lt;volatile T&gt;;
 template &lt;class T&gt; class numeric_limits&lt;const volatile T&gt;;

 </pre>

         <p>

 Add  a new paragraph  to the  end of  18.2.1.1 [numeric.limits], with  the following
 text:

         </p>
         <p>

 -new-para- The  value of each member  of a <code>numeric_limits</code>
 specialization on a  cv-qualified T is equal to the  value of the same
 member of <code>numeric_limits&lt;T&gt;</code>.

         </p>

 <p><i>[
 Portland: Martin will clarify that user-defined types get cv-specializations
 automatically.
 ]</i></p>


 <hr>
 <h3><a name="561"></a>561. inserter overly generic</h3>
 <p><b>Section:</b> 24.4.2.6.5 [inserter] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2006-02-21</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The declaration of <tt>std::inserter</tt> is:
 </p>

 <blockquote><pre>template &lt;class Container, class Iterator&gt;
 insert_iterator&lt;Container&gt;
 inserter(Container&amp; x, Iterator i);
 </pre></blockquote>

 <p>
 The template parameter <tt>Iterator</tt> in this function is completely unrelated
 to the template parameter <tt>Container</tt> when it doesn't need to be.  This
 causes the code to be overly generic.  That is, any type at all can be deduced
 as <tt>Iterator</tt>, whether or not it makes sense.  Now the same is true of
 <tt>Container</tt>.  However, for every free (unconstrained) template parameter
 one has in a signature, the opportunity for a mistaken binding grows geometrically.
 </p>

 <p>
 It would be much better if <tt>inserter</tt> had the following signature instead:
 </p>

 <blockquote><pre>template &lt;class Container&gt;
 insert_iterator&lt;Container&gt;
 inserter(Container&amp; x, typename Container::iterator i);
 </pre></blockquote>

 <p>
 Now there is only one free template parameter.  And the second argument to
 <tt>inserter</tt> must be implicitly convertible to the container's iterator,
 else the call will not be a viable overload (allowing other functions in the
 overload set to take precedence).  Furthermore, the first parameter must have a
 nested type named <tt>iterator</tt>, or again the binding to <tt>std::inserter</tt>
 is not viable.  Contrast this with the current situation
 where any type can bind to <tt>Container</tt> or <tt>Iterator</tt> and those
 types need not be anything closely related to containers or iterators.
 </p>

 <p>
 This can adversely impact well written code.  Consider:
 </p>

 <blockquote><pre>#include &lt;iterator&gt;
 #include &lt;string&gt;

 namespace my
 {

 template &lt;class String&gt;
 struct my_type {};

 struct my_container
 {
 template &lt;class String&gt;
 void push_back(const my_type&lt;String&gt;&amp;);
 };

 template &lt;class String&gt;
 void inserter(const my_type&lt;String&gt;&amp; m, my_container&amp; c) {c.push_back(m);}

 }  // my

 int main()
 {
     my::my_container c;
     my::my_type&lt;std::string&gt; m;
     inserter(m, c);
 }
 </pre></blockquote>

 <p>
 Today this code fails because the call to <tt>inserter</tt> binds to
 <tt>std::inserter</tt> instead of to <tt>my::inserter</tt>.  However with the
 proposed change <tt>std::inserter</tt> will no longer be a viable function which
 leaves only <tt>my::inserter</tt> in the overload resolution set.  Everything
 works as the client intends.
 </p>

 <p>
 To make matters a little more insidious, the above example works today if you
 simply change the first argument to an rvalue:
 </p>

 <blockquote><pre>    inserter(my::my_type(), c);
 </pre></blockquote>

 <p>
 It will also work if instantiated with some string type other than
 <tt>std::string</tt> (or any other <tt>std</tt> type).  It will also work if
 <tt>&lt;iterator&gt;</tt> happens to not get included.
 </p>

 <p>
 And it will fail again for such inocuous reaons as <tt>my_type</tt> or
 <tt>my_container</tt> privately deriving from any <tt>std</tt> type.
 </p>

 <p>
 It seems unfortunate that such simple changes in the client's code can result
 in such radically differing behavior.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 24.2:
 </p>

 <blockquote><p>
 <b>24.2 Header</b> <tt>&lt;iterator&gt;</tt> <b>synopsis</b>
 </p>
 <blockquote><pre>...
 template &lt;class Container<del>, class Iterator</del>&gt;
    insert_iterator&lt;Container&gt; inserter(Container&amp; x, <del>Iterator</del> <ins>typename Container::iterator</ins> i);
 ...
 </pre></blockquote>
 </blockquote>

 <p>
 Change 24.4.2.5:
 </p>

 <blockquote><p>
 <b>24.4.2.5 Class template</b> <tt>insert_iterator</tt></p>
 <blockquote><pre>...
 template &lt;class Container<del>, class Iterator</del>&gt;
    insert_iterator&lt;Container&gt; inserter(Container&amp; x, <del>Iterator</del> <ins>typename Container::iterator</ins> i);
 ...
 </pre></blockquote>
 </blockquote>

 <p>
 Change 24.4.2.6.5:
 </p>

 <blockquote>
 <p>
 <b>24.4.2.6.5</b> <tt>inserter</tt>
 </p>
 <pre>template &lt;class Container<del>, class Inserter</del>&gt;
    insert_iterator&lt;Container&gt; inserter(Container&amp; x, <del>Inserter</del> <ins>typename Container::iterator</ins> i);
 </pre>
 <blockquote><p>
 -1- <i>Returns:</i> <tt>insert_iterator&lt;Container&gt;(x,<del>typename Container::iterator(</del>i<del>)</del>)</tt>.
 </p></blockquote>
 </blockquote>


 <p><i>[
 Kona (2007): This issue will probably be addressed as a part of the
 concepts overhaul of the library anyway, but the proposed resolution is
 correct in the absence of concepts. Proposed Disposition: Ready
 ]</i></p>


 <hr>
 <h3><a name="562"></a>562. stringbuf ctor inefficient</h3>
 <p><b>Section:</b> 27.7 [string.streams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-02-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.streams">issues</a> in [string.streams].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 For  better efficiency,  the requirement  on the  stringbuf  ctor that
 takes  a  string  argument  should  be  loosened  up  to  let  it  set
 <code>epptr()</code>  beyond  just   one  past  the  last  initialized
 character  just like  <code>overflow()</code> has  been changed  to be
 allowed  to  do   (see  issue  432).  That  way   the  first  call  to
 <code>sputc()</code> on  an object won't  necessarily cause a  call to
 <code>overflow</code>. The corresponding change  should be made to the
 string overload of the <code>str()</code> member function.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 Change 27.7.1.1, p3 of the Working Draft, N1804, as follows:

         </p>

 <blockquote><pre>explicit basic_stringbuf(const basic_string&lt;charT,traits,Allocator&gt;&amp; <i>s<del>tr</del></i>,
                ios_base::openmode <i>which</i> = ios_base::in | ios_base::out);
 </pre>

 <p>
 -3- <i>Effects:</i>  Constructs an object of class <tt>basic_stringbuf</tt>,
 initializing the base class with <tt>basic_streambuf()</tt>
 (27.5.2.1), and initializing <tt><i>mode</i></tt> with <tt><i>which</i></tt>.
 Then <ins>calls <tt>str(<i>s</i>)</tt>.</ins> <del>copies the content of
 <i>str</i> into the <tt>basic_stringbuf</tt> underlying character
 sequence. If <tt><i>which</i> &amp; ios_base::out</tt> is true, initializes the
 output sequence such that <tt>pbase()</tt> points to the first underlying
 character, <tt>epptr()</tt> points one past the last underlying character, and
 <tt>pptr()</tt> is equal to <tt>epptr()</tt> if <tt><i>which</i> &amp; ios_base::ate</tt>
 is true, otherwise <tt>pptr()</tt> is equal to <tt>pbase()</tt>. If
 <tt>which &amp; ios_base::in</tt> is true, initializes the input sequence such
 that <tt>eback()</tt> and <tt>gptr()</tt> point to the first underlying
 character and <tt>egptr()</tt> points one past the last underlying character.</del>
 </p>
 </blockquote>

         <p>

 Change the Effects clause of the <code>str()</code> in 27.7.1.2, p2 to
 read:

         </p>
 <blockquote>
 <p>
 -2- <i>Effects:</i> Copies the content<ins>s</ins> of <tt><i>s</i></tt> into the
 <tt>basic_stringbuf</tt> underlying character sequence <ins>and
 initializes the input and output sequences according to <tt><i>mode</i></tt></ins>.
 <del>If
 <tt><i>mode</i> &amp; ios_base::out</tt> is true, initializes the output
 sequence such that <tt>pbase()</tt> points to the first underlying character,
 <tt>epptr()</tt> points one past the last underlying character, and <tt>pptr()</tt>
 is equal to <tt>epptr()</tt> if <tt><i>mode</i> &amp; ios_base::in</tt>
 is true, otherwise <tt>pptr()</tt> is equal to <tt>pbase()</tt>. If
 <tt>mode &amp; ios_base::in</tt> is true, initializes the input sequence
 such that <tt>eback()</tt> and <tt>gptr()</tt> point to the first underlying
 character and <tt>egptr()</tt> points one past the last underlying character.</del>
 </p>

         <p>

 <ins>-3- <i>Postconditions:</i>  If  <code>mode  &amp; ios_base::out</code>  is  true,
 <code>pbase()</code>  points  to the  first  underlying character  and
 <code>(epptr() &gt;= pbase() + s.size())</code> holds; in addition, if
 <code>mode &amp; ios_base::in</code> is true, <code>(pptr() == pbase()
 + s.data())</code>  holds, otherwise <code>(pptr()  == pbase())</code>
 is   true.    If  <code>mode   &amp;   ios_base::in</code>  is   true,
 <code>eback()</code>  points to  the first  underlying  character, and
 <code>(gptr()  ==  eback())</code>  and  <code>(egptr() ==  eback()  +
 s.size())</code> hold.</ins>

         </p>
 </blockquote>


 <p><i>[
 Kona (2007) Moved to Ready.
 ]</i></p>


 <hr>
 <h3><a name="563"></a>563. stringbuf seeking from end</h3>
 <p><b>Section:</b> 27.7.1.4 [stringbuf.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-02-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.virtuals">issues</a> in [stringbuf.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 According to  Table 92  (unchanged by issue  432), when  <code>(way ==
 end)</code> the  <code>newoff</code> value in out mode  is computed as
 the difference between <code>epptr()</code> and <code>pbase()</code>.
 </p>
         <p>

 This value  isn't meaningful unless the  value of <code>epptr()</code>
 can be  precisely controlled by a  program.  That used  to be possible
 until  we accepted the  resolution of  issue 432,  but since  then the
 requirements on <code>overflow()</code> have  been relaxed to allow it
 to  make  more than  1  write  position  available (i.e.,  by  setting
 <code>epptr()</code>     to     some     unspecified    value     past
 <code>pptr()</code>).      So    after     the    first     call    to
 <code>overflow()</code>  positioning the  output sequence  relative to
 end will have unspecified results.

         </p>
         <p>

 In  addition,  in <code>in|out</code>  mode,  since <code>(egptr()  ==
 epptr())</code> need not hold, there are two different possible values
 for   <code>newoff</code>:    <code>epptr()   -   pbase()</code>   and
 <code>egptr() - eback()</code>.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 Change the <code>newoff</code>  column in the last row  of Table 94 to
 read:

         </p>
 <blockquote><p>

 the <del>end</del> <ins>high mark</ins> pointer minus the beginning
 pointer (<code><del>xend</del> <ins>high_mark</ins> - xbeg</code>).

 </p></blockquote>


 <p><i>[
 Kona (2007) Moved to Ready.
 ]</i></p>


 <hr>
 <h3><a name="566"></a>566. array forms of unformatted input function undefined for zero-element arrays</h3>
 <p><b>Section:</b> 27.6.1.3 [istream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-02-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.unformatted">issues</a> in [istream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The array forms of unformatted input functions don't have well-defined
 semantics for zero-element  arrays in a couple of  cases. The affected
 ones (<tt>istream::get()</tt> and  <tt>getline()</tt>) are supposed to
 terminate when <tt>(n - 1)</tt> characters are stored, which obviously
 can never be true when <tt>(n == 0)</tt> to start with.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 I  propose  the following  changes  (references  are  relative to  the
 Working Draft (document N1804).

         </p>
         <p>

 Change 27.6.1.3, p8 (<tt>istream::get()</tt>), bullet 1 as follows:

         </p>
         <blockquote>
             <p>

 <ins>if  <tt>(n  &lt; 1)</tt>  is  true  or  </ins> <tt>(n  -  1)</tt>
 characters are stored;

             </p>
         </blockquote>
         <p>

 Similarly, change  27.6.1.3, p18 (<tt>istream::getline()</tt>), bullet
 3 as follows:

         </p>
         <blockquote>
             <p>

 <ins><tt>(n &lt; 1)</tt> is  true or </ins><tt>(n - 1)</tt> characters
 are     stored     (in    which     case     the    function     calls
 <tt>setstate(failbit)</tt>).

             </p>
         </blockquote>
         <p>

 Finally, change p21 as follows:

         </p>
         <blockquote>
             <p>

 In any  case, <ins>provided  <tt>(n &gt; 0)</tt>  is true,  </ins>it then
 stores  a null  character  (using charT())  into  the next  successive
 location of the array.

             </p>
         </blockquote>


 <hr>
 <h3><a name="567"></a>567. streambuf inserter and extractor should be unformatted</h3>
 <p><b>Section:</b> 27.6 [iostream.format] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-02-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostream.format">issues</a> in [iostream.format].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 Issue  60 explicitly made  the extractor  and inserter  operators that
 take a  <tt>basic_streambuf*</tt> argument formatted  input and output
 functions,  respectively.  I  believe that's  wrong, certainly  in the
 case of  the extractor, since formatted functions  begin by extracting
 and  discarding  whitespace.  The  extractor  should  not discard  any
 characters.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 I propose to  change each operator to behave  as unformatted input and
 output function,  respectively. The changes below are  relative to the
 working draft document number N1804.

         </p>
         <p>

 Specifically, change 27.6.1.2.3, p14 as follows:

         </p>

             <blockquote>
         <p>

 <i>Effects</i>:  Behaves as  a<ins>n un</ins>formatted  input function
 (as   described   in   <del>27.6.1.2.1</del><ins>27.6.1.3,   paragraph
 1</ins>).

         </p>
             </blockquote>
         <p>

 And change 27.6.2.5.3, p7 as follows:

         </p>

             <blockquote>
         <p>

 <i>Effects</i>: Behaves  as a<ins>n un</ins>formatted  output function
 (as   described   in   <del>27.6.2.5.1</del><ins>27.6.2.6,   paragraph
 1</ins>).

         </p>
             </blockquote>


 <p><i>[
 Kona (2007): Proposed Disposition: Ready
 ]</i></p>


 <hr>
 <h3><a name="574"></a>574. DR 369 Contradicts Text</h3>
 <p><b>Section:</b> 27.3 [iostream.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Pete Becker <b>Date:</b> 2006-04-18</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostream.objects">issues</a> in [iostream.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 lib.iostream.objects requires that the standard stream objects are never
 destroyed, and it requires that they be destroyed.
 </p>
 <p>
 DR 369 adds words to say that we really mean for ios_base::Init objects to force
 construction of standard stream objects. It ends, though, with the phrase "these
 stream objects shall be destroyed after the destruction of dynamically ...".
 However, the rule for destruction is stated in the standard: "The objects are
 not destroyed during program execution."
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 27.3 [iostream.objects]/1:
 </p>

 <blockquote>
 <p>
 -2- The objects are constructed and the associations are established at
 some time prior to or during the first time an object of class
 <tt>ios_base::Init</tt> is constructed, and in any case before the body of main
 begins execution.<sup>290)</sup> The objects are not destroyed during program
 execution.<sup>291)</sup> If a translation unit includes <tt>&lt;iostream&amp;t;</tt> or explicitly
 constructs an <tt>ios_base::Init</tt> object, these stream objects shall be
 constructed before dynamic initialization of non-local objects defined
 later in that translation unit<del>, and these stream objects shall be
 destroyed after the destruction of dynamically initialized non-local
 objects defined later in that translation unit</del>.
 </p>
 </blockquote>


 <p><i>[
 Kona (2007): From 27.3 [iostream.objects]/2, strike the words "...and these stream objects
 shall be destroyed after the destruction of dynamically initialized
 non-local objects defined later in that translation unit." Proposed
 Disposition: Review
 ]</i></p>


 <hr>
 <h3><a name="575"></a>575. the specification of ~shared_ptr is MT-unfriendly, makes implementation assumptions</h3>
 <p><b>Section:</b> 20.7.12.2.2 [util.smartptr.shared.dest], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2006-04-23</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 [tr.util.smartptr.shared.dest] says in its second bullet:
 </p>

 <p>
 "If *this shares ownership with another shared_ptr instance (use_count() &gt; 1),
 decrements that instance's use count."
 </p>

 <p>
 The problem with this formulation is that it presupposes the existence of an
 "use count" variable that can be decremented and that is part of the state of a
 shared_ptr instance (because of the "that instance's use count".)
 </p>

 <p>
 This is contrary to the spirit of the rest of the specification that carefully
 avoids to require an use count variable. Instead, use_count() is specified to
 return a value, a number of instances.
 </p>

 <p>
 In multithreaded code, the usual implicit assumption is that a shared variable
 should not be accessed by more than one thread without explicit synchronization,
 and by introducing the concept of an "use count" variable, the current wording
 implies that two shared_ptr instances that share ownership cannot be destroyed
 simultaneously.
 </p>

 <p>
 In addition, if we allow the interpretation that an use count variable is part
 of shared_ptr's state, this would lead to other undesirable consequences WRT
 multiple threads. For example,
 </p>

 <blockquote><pre>p1 = p2;
 </pre></blockquote>

 <p>
 would now visibly modify the state of p2, a "write" operation, requiring a lock.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the first two bullets of [lib.util.smartptr.shared.dest]/1 to:
 </p>

 <blockquote>
 <ul>
 <li>If <tt>*this</tt> is <i>empty</i> <ins>or shares ownership with another
 <tt>shared_ptr</tt> instance (<tt>use_count() &gt; 1</tt>)</ins>, there are no side effects.</li>
 <li><del>If <tt>*this</tt> <i>shares ownership</i> with another <tt>shared_ptr</tt> instance
 (<tt>use_count() &gt; 1</tt>), decrements that instance's use count.</del></li>
 </ul>
 </blockquote>

 <p>
 Add the following paragraph after [lib.util.smartptr.shared.dest]/1:
 </p>

 <blockquote><p>
 [<i>Note:</i> since the destruction of <tt>*this</tt> decreases the number of instances in
 <tt>*this</tt>'s ownership group by one, all <tt>shared_ptr</tt> instances that share ownership
 with <tt>*this</tt> will report an <tt>use_count()</tt> that is one lower than its previous value
 after <tt>*this</tt> is destroyed. <i>--end note</i>]
 </p></blockquote>


 <hr>
 <h3><a name="576"></a>576. find_first_of is overconstrained</h3>
 <p><b>Section:</b> 25.1.7 [alg.find.first.of] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Doug Gregor <b>Date:</b> 2006-04-25</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.find.first.of">issues</a> in [alg.find.first.of].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 25.1.4 Find First [lib.alg.find.first], the two iterator type parameters to
 find_first_of are specified to require Forward Iterators, as follows:
 </p>

 <blockquote><pre>template&lt;class ForwardIterator1, class ForwardIterator2&gt;
   ForwardIterator1
   find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
                         ForwardIterator2 first2, ForwardIterator2 last2);
 template&lt;class ForwardIterator1, class ForwardIterator2,
                   class BinaryPredicate&gt;
 ForwardIterator1
   find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
                          ForwardIterator2 first2, ForwardIterator2 last2,
                         BinaryPredicate pred);
 </pre></blockquote>

 <p>
 However, ForwardIterator1 need not actually be a Forward Iterator; an Input
 Iterator suffices, because we do not need the multi-pass property of the Forward
 Iterator or a true reference.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the declarations of <tt>find_first_of</tt> to:
 </p>

 <blockquote><pre>template&lt;class <del>ForwardIterator1</del><ins>InputIterator1</ins>, class ForwardIterator2&gt;
   <del>ForwardIterator1</del><ins>InputIterator1</ins>
   find_first_of(<del>ForwardIterator1</del><ins>InputIterator1</ins> first1, <del>ForwardIterator1</del><ins>InputIterator1</ins> last1,
                         ForwardIterator2 first2, ForwardIterator2 last2);
 template&lt;class <del>ForwardIterator1</del><ins>InputIterator1</ins>, class ForwardIterator2,
                   class BinaryPredicate&gt;
 <del>ForwardIterator1</del><ins>InputIterator1</ins>
   find_first_of(<del>ForwardIterator1</del><ins>InputIterator1</ins> first1, <del>ForwardIterator1</del><ins>InputIterator1</ins> last1,
                          ForwardIterator2 first2, ForwardIterator2 last2,
                         BinaryPredicate pred);
 </pre></blockquote>


 <hr>
 <h3><a name="577"></a>577. upper_bound(first, last, ...) cannot return last</h3>
 <p><b>Section:</b> 25.3.3.2 [upper.bound] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Seungbeom Kim <b>Date:</b> 2006-05-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 ISO/IEC 14882:2003 says:
 </p>

 <blockquote>
 <p>
 25.3.3.2 upper_bound
 </p>
 <p>
 <i>Returns:</i> The furthermost iterator <tt>i</tt> in the range
 <tt>[<i>first</i>, <i>last</i>)</tt> such that
 for any iterator <tt>j</tt> in the range <tt>[<i>first</i>, i)</tt> the following corresponding
 conditions hold: <tt>!(value &lt; *j)</tt> or <tt><i>comp</i>(<i>value</i>, *j) == false</tt>.
 </p>
 </blockquote>

 <p>
 From the description above, upper_bound cannot return last, since it's
 not in the interval [first, last). This seems to be a typo, because if
 value is greater than or equal to any other values in the range, or if
 the range is empty, returning last seems to be the intended behaviour.
 The corresponding interval for lower_bound is also [first, last].
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change [lib.upper.bound]:
 </p>

 <blockquote>
 <p>
 <i>Returns:</i> The furthermost iterator <tt>i</tt> in the range
 <tt>[<i>first</i>, <i>last</i><del>)</del><ins>]</ins></tt> such that
 for any iterator <tt>j</tt> in the range <tt>[<i>first</i>, i)</tt> the following corresponding
 conditions hold: <tt>!(value &lt; *j)</tt> or <tt><i>comp</i>(<i>value</i>, *j) == false</tt>.
 </p>
 </blockquote>


 <hr>
 <h3><a name="578"></a>578. purpose of hint to allocator::allocate()</h3>
 <p><b>Section:</b> 20.7.5.1 [allocator.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-05-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.members">issues</a> in [allocator.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The     description    of     the     allocator    member     function
 <code>allocate()</code>  requires  that  the <i>hint</i>  argument  be
 either 0 or a  value previously returned from <code>allocate()</code>.
 Footnote 227 further suggests that  containers may pass the address of
 an adjacent element as this argument.

         </p>
         <p>

 I  believe  that  either  the  footnote  is  wrong  or  the  normative
 requirement that  the argument be  a value previously returned  from a
 call to  <code>allocate()</code> is wrong. The latter  is supported by
 the resolution  to issue 20-004 proposed in  c++std-lib-3736 by Nathan
 Myers. In addition,  the <i>hint</i> is an ordinary  void* and not the
 <code>pointer</code>  type returned  by  <code>allocate()</code>, with
 the  two  types potentially  being  incompatible  and the  requirement
 impossible to satisfy.

         </p>
         <p>

 See also c++std-lib-14323 for some  more context on where this came up
 (again).

         </p>


     <p><b>Proposed resolution:</b></p>
         <p>

 Remove  the requirement  in  20.6.1.1, p4  that  the hint  be a  value
 previously returned from <code>allocate()</code>. Specifically, change
 the paragraph as follows:

         </p>
 <p>
 <del><i>Requires</i>: <i>hint</i> either 0 or previously obtained  from  member
 <code>allocate</code>  and  not  yet passed  to member  <code>deallocate</code>.
 The value hint may be used by an implementation to help improve performance
 <sup>223)</sup>.</del> <ins>[<i>Note:</i> The value <i>hint</i> may be used by an
 implementation to help improve performance. -- <i>end note</i>]</ins>
 </p>
 <blockquote><p>
 <del>[Footnote: <sup>223)</sup>In a container member function, the address of an
 adjacent element is often a good choice to pass for this argument.</del>
 </p></blockquote>


 <hr>
 <h3><a name="581"></a>581. <code>flush()</code> not unformatted function</h3>
 <p><b>Section:</b> 27.6.2.7 [ostream.unformatted] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-06-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.unformatted">issues</a> in [ostream.unformatted].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The resolution of issue 60 changed <code>basic_ostream::flush()</code>
 so as not  to require it to behave as  an unformatted output function.
 That has at least two in my opinion problematic consequences:

         </p>
         <p>

 First, <code>flush()</code>  now calls <code>rdbuf()-&gt;pubsync()</code>
 unconditionally, without  regard to the  state of the stream.  I can't
 think of any reason why <code>flush()</code> should behave differently
 from the vast majority of stream functions in this respect.

         </p>
         <p>

 Second, <code>flush()</code> is not  required to catch exceptions from
 <code>pubsync()</code> or set  <code>badbit</code> in response to such
 events. That doesn't seem right either, as most other stream functions
 do so.

         </p>


     <p><b>Proposed resolution:</b></p>
         <p>

 I  propose  to revert  the  resolution of  issue  60  with respect  to
 <code>flush()</code>. Specifically,  I propose to  change 27.6.2.6, p7
 as follows:

         </p>

 <p>
 Effects: <ins>Behaves as an  unformatted output function (as described
 in 27.6.2.6, paragraph 1). </ins>If <code>rdbuf()</code> is not a null
 pointer,  <ins>constructs a  sentry  object.  If  this object  returns
 <code>true</code> when converted to a  value of type bool the function
 </ins>calls <code>rdbuf()-&gt;pubsync()</code>.  If that function returns
 -1    calls    <code>setstate(badbit)</code>    (which    may    throw
 <code>ios_base::failure</code>  (27.4.4.3)).   <ins>Otherwise, if  the
 sentry object returns <code>false</code>, does nothing.</ins><del>Does
 not  behave  as  an  unformatted  output  function  (as  described  in
 27.6.2.6, paragraph 1).</del>
 </p>


 <p><i>[
 Kona (2007): Proposed Disposition: Ready
 ]</i></p>


 <hr>
 <h3><a name="586"></a>586. string inserter not a formatted function</h3>
 <p><b>Section:</b> 21.3.8.9 [string.io] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-06-22</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#string.io">issues</a> in [string.io].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 Section  and paragraph  numbers  in  this paper  are  relative to  the
 working draft document number N2009 from 4/21/2006.

         </p>

         <p>

 The  <code>basic_string</code> extractor  in 21.3.7.9,  p1  is clearly
 required  to  behave  as  a   formatted  input  function,  as  is  the
 <code>std::getline()</code> overload for string described in p7.

         </p>
         <p>

 However, the <code>basic_string</code> inserter described in p5 of the
 same section has no such requirement. This has implications on how the
 operator  responds  to  exceptions thrown  from  <code>xsputn()</code>
 (formatted  output functions are  required to  set <code>badbit</code>
 and swallow  the exception unless  <code>badbit</code> is also  set in
 <code>exceptions()</code>; the  string inserter doesn't  have any such
 requirement).

         </p>
         <p>

 I don't  see anything in the  spec for the string  inserter that would
 justify requiring  it to treat  exceptions differently from  all other
 similar operators. (If it did, I think it should be made this explicit
 by saying  that the  operator "does not  behave as a  formatted output
 function" as has been made customary by the adoption of the resolution
 of issue 60).

         </p>


     <p><b>Proposed resolution:</b></p>
         <p>

 I propose to change the Effects clause in 21.3.7.9, p5, as follows:

         </p>
             <blockquote>
         <p>

 <i>Effects</i>: <del>Begins by constructing a  sentry object k as if k
 were    constructed    by    typename    <code>basic_ostream&lt;charT,
 traits&gt;::sentry   k   (os)</code>.    If  <code>bool(k)</code>   is
 <code>true</code>, </del><ins>Behaves  as a formatted  output function
 (27.6.2.5.1).   After constructing  a  <code>sentry</code> object,  if
 this  object returns <code>true</code>  when converted  to a  value of
 type   <code>bool</code>,   determines   padding   as   described   in
 22.2.2.2.2</ins>,  then inserts the  resulting sequence  of characters
 <code><i>seq</i></code> as if by calling <code>os.rdbuf()-&gt;sputn(seq ,
 n)</code>,    where   <code><i>n</i></code>    is   the    larger   of
 <code>os.width()</code>   and   <code>str.size()</code>;  then   calls
 <code>os.width(0)</code>.  <del>If  the  call  to sputn  fails,  calls
 <code>os.setstate(ios_base::failbit)</code>.</del>

         </p>
             </blockquote>
         <p>

 This proposed  resilution assumes the  resolution of issue  394 (i.e.,
 that   all   formatted   output   functions  are   required   to   set
 <code>ios_base::badbit</code>  in response  to any  kind  of streambuf
 failure),   and   implicitly   assumes   that  a   return   value   of
 <code>sputn(seq,  <i>n</i>)</code>  other  than  <code><i>n</i></code>
 indicates a failure.

         </p>


 <hr>
 <h3><a name="589"></a>589. Requirements on iterators of member template functions of containers</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2006-08-02</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a></p>
 <p><b>Discussion:</b></p>
 <p>
 There appears to be no requirements on the InputIterators used in sequences in 23.1.1 in
 terms of their value_type, and the requirements in 23.1.2 appear to be overly strict
 (requires InputIterator::value_type be the same type as the container's value_type).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 23.1.1 p3:
 </p>

 <blockquote><p>
 In Tables 82 and 83, <tt>X</tt> denotes a sequence class, <tt>a</tt> denotes a
 value of <tt>X</tt>, <tt>i</tt> and <tt>j</tt> denote iterators satisfying input
 iterator requirements <ins>and refer to elements <ins>implicitly
 convertible to</ins> <tt>value_type</tt></ins>, <tt>[i, j)</tt> denotes a valid
 range, <tt>n</tt> denotes a value of <tt>X::size_type</tt>, <tt>p</tt> denotes a
 valid iterator to <tt>a</tt>, <tt>q</tt> denotes a valid dereferenceable
 iterator to <tt>a</tt>, <tt>[q1, q2)</tt> denotes a valid range in <tt>a</tt>,
 and <tt>t</tt> denotes a value of <tt>X::value_type</tt>.
 </p></blockquote>

 <p>
 Change 23.1.2 p7:
 </p>

 <blockquote><p>
 In Table 84, <tt>X</tt> is an associative container class, <tt>a</tt> is a value
 of <tt>X</tt>, <tt>a_uniq</tt> is a value of <tt>X</tt> when <tt>X</tt> supports
 unique keys, and <tt>a_eq</tt> is a value of <tt>X</tt> when <tt>X</tt> supports
 multiple keys, <tt>i</tt> and <tt>j</tt> satisfy input iterator requirements and
 refer to elements <del>of</del> <ins>implicitly convertible to</ins>
 <tt>value_type</tt>, <tt>[i, j)</tt> is a valid range, <tt>p</tt> is a valid
 iterator to <tt>a</tt>, <tt>q</tt> is a valid dereferenceable iterator to
 <tt>a</tt>, <tt>[q1, q2)</tt> is a valid range in <tt>a</tt>, <tt>t</tt> is a
 value of <tt>X::value_type</tt>, <tt>k</tt> is a value of <tt>X::key_type</tt>
 and <tt>c</tt> is a value of type <tt>X::key_compare</tt>.
 </p></blockquote>


 <p><b>Rationale:</b></p>
 <p>
 Concepts will probably come in and rewrite this section anyway.  But just in case it is
 easy to fix this up as a safety net and as a clear statement of intent.
 </p>


 <hr>
 <h3><a name="593"></a>593. __STDC_CONSTANT_MACROS</h3>
 <p><b>Section:</b> 18.3 [cstdint], TR1 8.22 [tr.c99.cstdint] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter Brown <b>Date:</b> 2006-08-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#cstdint">issues</a> in [cstdint].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Clause 18.3 of the current Working Paper (N2009) deals with the new C++ headers
 &lt;cstdint&gt; and &lt;stdint.h&gt;.  These are of course based on the C99 header
 &lt;stdint.h&gt;, and were part of TR1.
 </p>

 <p>
 Per 18.3.1/1, these headers define a number of macros and function macros.
 While the WP does not mention __STDC_CONSTANT_MACROS in this context, C99
 footnotes do mention __STDC_CONSTANT_MACROS.  Further, 18.3.1/2 states that "The
 header defines all ... macros the same as C99 subclause 7.18."
 </p>

 <p>
 Therefore, if I wish to have the above-referenced macros and function macros
 defined, must I #define __STDC_CONSTANT_MACROS before I #include &lt;cstdint&gt;, or
 does the C++ header define these macros/function macros unconditionally?
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 To put this issue to rest for C++0X, I propose the following addition to
 18.3.1/2 of the Working Paper N2009:
 </p>

 <blockquote><p>
 [Note: The macros defined by &lt;cstdint&gt; are provided unconditionally: in
 particular, the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
 (mentioned in C99 footnotes 219, 220, and 222) play no role in C++. --end note]
 </p></blockquote>


 <hr>
 <h3><a name="595"></a>595. TR1/C++0x: fabs(complex&lt;T&gt;) redundant / wrongly specified</h3>
 <p><b>Section:</b> 26.3.7 [complex.value.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Stefan Große Pawig <b>Date:</b> 2006-09-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.value.ops">issues</a> in [complex.value.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 TR1 introduced, in the C compatibility chapter, the function
 fabs(complex&lt;T&gt;):
 </p>
 <blockquote><pre>----- SNIP -----
 8.1.1 Synopsis                                [tr.c99.cmplx.syn]

   namespace std {
   namespace tr1 {
 [...]
   template&lt;class T&gt; complex&lt;T&gt; fabs(const complex&lt;T&gt;&amp; x);
   } // namespace tr1
   } // namespace std

 [...]

 8.1.8 Function fabs                          [tr.c99.cmplx.fabs]

 1 Effects: Behaves the same as C99 function cabs, defined in
   subclause 7.3.8.1.
 ----- SNIP -----
 </pre></blockquote>

 <p>
 The current C++0X draft document (n2009.pdf) adopted this
 definition in chapter 26.3.1 (under the comment // 26.3.7 values)
 and 26.3.7/7.
 </p>
 <p>
 But in C99 (ISO/IEC 9899:1999 as well as the 9899:TC2 draft document
 n1124), the referenced subclause reads
 </p>

 <blockquote><pre>----- SNIP -----
 7.3.8.1 The cabs functions

   Synopsis

 1 #include &lt;complex.h&gt;
   double cabs(double complex z);
   float cabsf(float complex z);
   long double cabsl(long double z);

   Description

 2 The cabs functions compute the complex absolute value (also called
   norm, modulus, or magnitude) of z.

   Returns

 3 The cabs functions return the complex absolute value.
 ----- SNIP -----
 </pre></blockquote>

 <p>
 Note that the return type of the cabs*() functions is not a complex
 type.  Thus, they are equivalent to the already well established
   template&lt;class T&gt; T abs(const complex&lt;T&gt;&amp; x);
 (26.2.7/2 in ISO/IEC 14882:1998, 26.3.7/2 in the current draft
 document n2009.pdf).
 </p>
 <p>
 So either the return value of fabs() is specified wrongly, or fabs()
 does not behave the same as C99's cabs*().
 </p>

 <b>Possible Resolutions</b>

 <p>
 This depends on the intention behind the introduction of fabs().
 </p>
 <p>
 If the intention was to provide a /complex/ valued function that
 calculates the magnitude of its argument, this should be
 explicitly specified.  In TR1, the categorization under "C
 compatibility" is definitely wrong, since C99 does not provide
 such a complex valued function.
 </p>
 <p>
 Also, it remains questionable if such a complex valued function
 is really needed, since complex&lt;T&gt; supports construction and
 assignment from real valued arguments.  There is no difference
 in observable behaviour between
 </p>
 <blockquote><pre>  complex&lt;double&gt; x, y;
   y = fabs(x);
   complex&lt;double&gt; z(fabs(x));
 </pre></blockquote>
 <p>
 and
 </p>
 <blockquote><pre>  complex&lt;double&gt; x, y;
   y = abs(x);
   complex&lt;double&gt; z(abs(x));
 </pre></blockquote>
 <p>
 If on the other hand the intention was to provide the intended
 functionality of C99, fabs() should be either declared deprecated
 or (for C++0X) removed from the standard, since the functionality
 is already provided by the corresponding overloads of abs().
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 Bill believes that abs() is a suitable overload. We should remove fabs().
 </blockquote>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change the synopsis in 26.3.1 [complex.synopsis]:
 </p>

 <blockquote><pre><del>template&lt;class T&gt; complex&lt;T&gt; fabs(const complex&lt;T&gt;&amp;);</del>
 </pre></blockquote>

 <p>
 Remove 26.3.7 [complex.value.ops], p7:
 </p>

 <blockquote>
 <pre><del>template&lt;class T&gt; complex&lt;T&gt; fabs(const complex&lt;T&gt;&amp; <i>x</i>);</del>
 </pre>
 <blockquote>
 <p>
 <del>-7- <i>Effects:</i> Behaves the same as C99 function <tt>cabs</tt>, defined in subclause 7.3.8.1.</del>
 </p>
 </blockquote>
 </blockquote>


 <p><i>[
 Kona (2007): Change the return type of <tt>fabs(complex)</tt> to <tt>T</tt>.
 Proposed Disposition: Ready
 ]</i></p>


 <hr>
 <h3><a name="596"></a>596. 27.8.1.3 Table 112 omits "a+" and "a+b" modes</h3>
 <p><b>Section:</b> 27.8.1.4 [filebuf.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thomas Plum <b>Date:</b> 2006-09-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#filebuf.members">issues</a> in [filebuf.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In testing 27.8.1.4 [filebuf.members], Table 112 (in the latest N2009 draft), we invoke
 </p>
 <blockquote><pre>   ostr.open("somename", ios_base::out | ios_base::in | ios_base::app)
 </pre></blockquote>
 <p>
 and we expect the open to fail, because out|in|app is not listed in
 Table 92, and just before the table we see very specific words:
 </p>
 <blockquote><p>
   If mode is not some combination of flags shown in the table
   then the open fails.
 </p></blockquote>
 <p>
 But the corresponding table in the C standard, 7.19.5.3, provides two
 modes "a+" and "a+b", to which the C++ modes out|in|app and
 out|in|app|binary would presumably apply.
 </p>
 <p>
 We would like to argue that the intent of Table 112 was to match the
 semantics of 7.19.5.3 and that the omission of "a+" and "a+b" was
 unintentional.  (Otherwise there would be valid and useful behaviors
 available in C file I/O which are unavailable using C++, for no
 valid functional reason.)
 </p>
 <p>
 We further request that the missing modes be explicitly restored to
 the WP, for inclusion in C++0x.
 </p>

 <p><i>[
 Martin adds:
 ]</i></p>


 <p>
 ...besides "a+" and "a+b" the C++ table is also missing a row
 for a lone app bit which in at least two current implementation
 as well as in Classic Iostreams corresponds to the C stdio "a"
 mode and has been traditionally documented as implying ios::out.
 Which means the table should also have a row for in|app meaning
 the same thing as "a+" already proposed in the issue.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add to the table "File open modes" in 27.8.1.4 [filebuf.members]:
 </p>

 <blockquote>
 <table border="1">
 <caption> File open modes</caption>
 <tbody><tr>
 <th colspan="5"><tt>ios_base</tt> Flag combination</th>
 <th><tt>stdio</tt> equivalent</th>
 </tr>
 <tr>
 <th><tt>binary</tt></th><th><tt>in</tt></th><th><tt>out</tt></th><th><tt>trunc</tt></th><th><tt>app</tt></th><th><tt>&nbsp;</tt></th>
 </tr>

 <tr>
 <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"w"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>"a"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"a"</tt></ins></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>"w"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"r"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"r+"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>"w+"</tt></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>+</tt></ins></td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"a+"</tt></ins></td>
 </tr>
 <tr>
 <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"a+"</tt></ins></td>
 </tr>

 <tr>
 <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"wb"</tt></td>
 </tr>
 <tr>
 <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>"ab"</tt></td>
 </tr>
 <tr>
 <td><ins><tt>+</tt></ins></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"ab"</tt></ins></td>
 </tr>
 <tr>
 <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>"wb"</tt></td>
 </tr>
 <tr>
 <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"rb"</tt></td>
 </tr>
 <tr>
 <td><tt>+</tt></td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><tt>"r+b"</tt></td>
 </tr>
 <tr>
 <td><tt>+</tt></td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td><tt>+</tt></td> <td>&nbsp;</td> <td><tt>"w+b"</tt></td>
 </tr><tr>
 <td><ins><tt>+</tt></ins></td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>+</tt></ins></td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"a+b"</tt></ins></td>
 </tr>
 <tr>
 <td><ins><tt>+</tt></ins></td> <td><ins><tt>+</tt></ins></td> <td>&nbsp;</td> <td>&nbsp;</td> <td><ins><tt>+</tt></ins></td> <td><ins><tt>"a+b"</tt></ins></td>
 </tr>


 </tbody></table>
 </blockquote>


 <p><i>[
 Kona (2007) Added proposed wording and moved to Review.
 ]</i></p>


 <hr>
 <h3><a name="598"></a>598. Decimal: Conversion to integral should truncate, not round.</h3>
 <p><b>Section:</b> TRDecimal 3.2 [trdec.types.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Daniel Krugler <b>Date:</b> 2006-05-28</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#trdec.types.types">active issues</a> in [trdec.types.types].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#trdec.types.types">issues</a> in [trdec.types.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>

 <p>
 In a private email, Daniel writes:
 </p>
 <blockquote>
 <p>
 I would like to
 ask, what where the reason for the decision to
 define the semantics of the integral conversion of the decimal types, namely
 </p>
 <pre>"operator long long() const;

      Returns: Returns the result of the
 conversion of *this to the type long long, as if
 performed by the expression llrounddXX(*this)."
 </pre>
 <p>
 where XX stands for either 32, 64, or 128,
 corresponding to the proper decimal type. The
 exact meaning of llrounddXX is not given in that
 paper, so I compared it to the corresponding
 definition given in C99, 2nd edition (ISO 9899), which says in 7.12.9.7 p. 2:
 </p>
 <p>
 "The lround and llround functions round their
 argument to the nearest integer value,
 rounding halfway cases away from zero, regardless
 of the current rounding direction. [..]"
 </p>
 <p>
 Now considering the fact that integral conversion
 of the usual floating-point types ("4.9
 Floating-integral conversions") has truncation
 semantic I wonder why this conversion behaviour
 has not been transferred for the decimal types.
 </p>
 </blockquote>
 <p>
 Robert comments:
 </p>
 <p>
 Also, there is a further error in the <b>Returns:</b> clause for converting <code>decimal::decimal128</code> to <code>long long</code>.  It currently calls <code>llroundd64</code>, not <code>llroundd128</code>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the <b>Returns:</b> clause in 3.2.2.4 to:
 </p>
 <blockquote><p>
 <b>Returns:</b> Returns the result of the conversion of <code>*this</code> to the type <code>long long</code>, as if performed by the expression <code>llroundd32(*this)</code> <ins>while the decimal rounding direction mode [3.5.2] <code>FE_DEC_TOWARD_ZERO</code> is in effect</ins>.
 </p></blockquote>
 <p>
 Change the <b>Returns:</b> clause in 3.2.3.4 to:
 </p>
 <blockquote><p>
 <b>Returns:</b> Returns the result of the conversion of <code>*this</code> to the type <code>long long</code>, as if performed by the expression <code>llroundd64(*this)</code> <ins>while the decimal rounding direction mode [3.5.2] <code>FE_DEC_TOWARD_ZERO</code> is in effect</ins>.
 </p></blockquote>
 <p>
 Change the <b>Returns:</b> clause in 3.2.4.4 to:
 </p>
 <blockquote><p>
 <b>Returns:</b> Returns the result of the conversion of <code>*this</code> to the type <code>long long</code>, as if performed by the expression <del><code>llroundd64(*this)</code></del> <ins><code>llroundd128(*this)</code> while the decimal rounding direction mode [3.5.2] <code>FE_DEC_TOWARD_ZERO</code> is in effect</ins>.
 </p></blockquote>


 <hr>
 <h3><a name="599"></a>599. Decimal: Say "octets" instead of "bytes."</h3>
 <p><b>Section:</b> TRDecimal 3.1 [trdec.types.encodings] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Daniel Krugler <b>Date:</b> 2006-05-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Daniel writes in a private email:
 </p>

 <blockquote>
 <p>
 - 3.1 'Decimal type encodings' says in its note:
 </p>
 <pre>"this implies that
 sizeof(std::decimal::decimal32) == 4,
 sizeof(std::decimal::decimal64) == 8, and
 sizeof(std::decimal::decimal128) == 16."
 </pre>
 <p>
 This is a wrong assertion, because the definition
 of 'byte' in 1.7 'The C+ + memory model' of ISO
 14882 (2nd edition) does not specify that a byte
 must be necessarily 8 bits large, which would be
 necessary to compare with the specified bit sizes
 of the types decimal32, decimal64, and decimal128.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 3.1 as follows:
 </p>
 <blockquote>
 <p>
 The three decimal encoding formats defined in IEEE-754R correspond to the three decimal floating types as follows:
 </p>
 <ul>
 <li>
 decimal32 is a <em>decimal32</em> number, which is encoded in four consecutive <del>bytes</del> <ins>octets</ins> (32 bits)
 </li>
 <li>
 decimal64 is a <em>decimal64</em> number, which is encoded in eight consecutive <del>bytes</del> <ins>octets</ins> (64 bits)

 </li>
 <li>
 decimal128 is a <em>decimal128</em> number, which is encoded in 16 consecutive <del>bytes</del> <ins>octets</ins> (128 bits)
 </li>
 </ul>
 <p>
 <del>[<i>Note:</i> this implies that <code>sizeof(std::decimal::decimal32) == 4</code>, <code>sizeof(std::decimal::decimal64) == 8</code>, and <code>sizeof(std::decimal::decimal128) == 16</code>.  <i>--end note</i>]</del>
 </p>
 </blockquote>


 <hr>
 <h3><a name="600"></a>600. Decimal: Wrong parameters for wcstod* functions</h3>
 <p><b>Section:</b> TRDecimal 3.9 [trdec.types.cwchar] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Daniel Krugler <b>Date:</b> 2006-05-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Daniel writes:
 </p>
 <blockquote><p>
 - 3.9.1 'Additions to &lt;cwchar&gt;' provides wrong
 signatures to the wcstod32, wcstod64, and
 wcstod128 functions ([the parameters have type pointer-to-] char instead of wchar_t).
 </p></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change "3.9.1 Additions to <code>&lt;cwchar&gt;</code> synopsis" to:
 </p>
 <pre>       namespace std {
        namespace decimal {
          // 3.9.2 wcstod functions:
          decimal32  wcstod32  (const <del>char</del> <ins>wchar_t</ins> * nptr, <del>char</del> <ins>wchar_t</ins> ** endptr);
          decimal64  wcstod64  (const <del>char</del> <ins>wchar_t</ins> * nptr, <del>char</del> <ins>wchar_t</ins> ** endptr);
          decimal128 wcstod128 (const <del>char</del> <ins>wchar_t</ins> * nptr, <del>char</del> <ins>wchar_t</ins> ** endptr);
        }
        }
 </pre>


 <hr>
 <h3><a name="601"></a>601. Decimal: numeric_limits typos</h3>
 <p><b>Section:</b> TRDecimal 3.3 [trdec.types.limits] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Daniel Krugler <b>Date:</b> 2006-05-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Daniel writes in a private email:
 </p>

 <blockquote>
 <p>
 - 3.3 'Additions to header &lt;limits&gt;' contains two
 errors in the specialisation of numeric_limits&lt;decimal::decimal128&gt;:
 </p>
 <ol>
 <li>The static member max() returns DEC128_MIN, this should be DEC128_MAX.</li>
 <li>The static member digits is assigned to 384,
 this should be 34 (Probably mixed up with the
 max. exponent for decimal::decimal64).</li>
 </ol>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 In "3.3 Additions to header <code>&lt;limits&gt;</code>" change numeric_limits&lt;decimal::decimal128&gt; as follows:
 </p>
 <pre>        template&lt;&gt; class numeric_limits&lt;decimal::decimal128&gt; {
           public:
             static const bool is_specialized = true;

             static decimal::decimal128 min() throw() { return DEC128_MIN; }
             static decimal::decimal128 max() throw() { return <del>DEC128_MIN;</del> <ins>DEC128_MAX;</ins> }

             static const int digits       = <del>384</del> <ins>34</ins>;
             /* ... */
 </pre>


 <hr>
 <h3><a name="602"></a>602. Decimal: "generic floating type" not defined.</h3>
 <p><b>Section:</b> TRDecimal 3 [trdec.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Daniel Krugler <b>Date:</b> 2006-05-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#trdec.types">issues</a> in [trdec.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The document uses the term "generic floating types," but defines it nowhere.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the first paragraph of "3 Decimal floating-point types" as follows:
 </p>
 <blockquote><p>
 This Technical Report introduces three decimal floating-point types, named
 decimal32, decimal64, and decimal128. The set of values of type decimal32 is a
 subset of the set of values of type decimal64; the set of values of the type
 decimal64 is a subset of the set of values of the type decimal128. Support for
 decimal128 is optional.  <ins>These types supplement the Standard C++ types
 <code>float</code>, <code>double</code>, and <code>long double</code>, which are
 collectively described as the <i>basic floating types</i></ins>.
 </p></blockquote>


 <hr>
 <h3><a name="603"></a>603. Decimal: Trivially simplifying decimal classes.</h3>
 <p><b>Section:</b> TRDecimal 3 [trdec.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-05-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#trdec.types">issues</a> in [trdec.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>In c++std-lib-17198, Martin writes:</p>

 <blockquote><p>
 Each of the three classes proposed in the paper (decimal32, decimal64,
 and decimal128) explicitly declares and specifies the semantics of its
 copy constructor, copy assignment operator, and destructor. Since the
 semantics of all three functions are identical to the trivial versions
 implicitly generated by the compiler in the absence of any declarations
 it is safe to drop them from the spec. This change would make the
 proposed classes consistent with other similar classes already in the
 standard (e.g., std::complex).
 </p></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change "3.2.2 Class <code>decimal32</code>" as follows:
 </p>
 <pre>      namespace std {
       namespace decimal {
         class decimal32 {
           public:
             // 3.2.2.1 construct/copy/destroy:
             decimal32();
             <del>decimal32(const decimal32 &amp; d32);</del>
             <del>decimal32 &amp; operator=(const decimal32 &amp; d32);</del>
             <del>~decimal32();</del>
             /* ... */
 </pre>
 <p>
 Change "3.2.2.1 construct/copy/destroy" as follows:
 </p>
 <pre>        decimal32();

     Effects: Constructs an object of type decimal32 with the value 0;

         <del>decimal32(const decimal32 &amp; d32);</del>
         <del>decimal32 &amp; operator=(const decimal32 &amp; d32);</del>

     <del>Effects: Copies an object of type decimal32.</del>

         <del>~decimal32();</del>

     <del>Effects: Destroys an object of type decimal32.</del>

 </pre>
 <p>
 Change "3.2.3 Class <code>decimal64</code>" as follows:
 </p>
 <pre>      namespace std {
       namespace decimal {
         class decimal64 {
           public:
             // 3.2.3.1 construct/copy/destroy:
             decimal64();
             <del>decimal64(const decimal64 &amp; d64);</del>
             <del>decimal64 &amp; operator=(const decimal64 &amp; d64);</del>
             <del>~decimal64();</del>
             /* ... */
 </pre>
 <p>
 Change "3.2.3.1 construct/copy/destroy" as follows:
 </p>
 <pre>        decimal64();

     Effects: Constructs an object of type decimal64 with the value 0;

         <del>decimal64(const decimal64 &amp; d64);</del>
         <del>decimal64 &amp; operator=(const decimal64 &amp; d64);</del>

     <del>Effects: Copies an object of type decimal64.</del>

         <del>~decimal64();</del>

     <del>Effects: Destroys an object of type decimal64.</del>

 </pre>
 <p>
 Change "3.2.4 Class <code>decimal128</code>" as follows:
 </p>
 <pre>      namespace std {
       namespace decimal {
         class decimal128 {
           public:
             // 3.2.4.1 construct/copy/destroy:
             decimal128();
             <del>decimal128(const decimal128 &amp; d128);</del>
             <del>decimal128 &amp; operator=(const decimal128 &amp; d128);</del>
             <del>~decimal128();</del>
             /* ... */
 </pre>
 <p>
 Change "3.2.4.1 construct/copy/destroy" as follows:
 </p>
 <pre>        decimal128();

     Effects: Constructs an object of type decimal128 with the value 0;

         <del>decimal128(const decimal128 &amp; d128);</del>
         <del>decimal128 &amp; operator=(const decimal128 &amp; d128);</del>

     <del>Effects: Copies an object of type decimal128.</del>

         <del>~decimal128();</del>

     <del>Effects: Destroys an object of type decimal128.</del>

 </pre>


 <hr>
 <h3><a name="604"></a>604. Decimal: Storing a reference to a facet unsafe.</h3>
 <p><b>Section:</b> TRDecimal 3 [trdec.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2006-05-28</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#trdec.types">issues</a> in [trdec.types].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In c++std-lib-17197, Martin writes:
 </p>
 <blockquote><p>
 The extended_num_get and extended_num_put facets are designed
 to store a reference to a num_get or num_put facet which the
 extended facets delegate the parsing and formatting of types
 other than decimal. One form of the extended facet's ctor (the
 default ctor and the size_t overload) obtains the reference
 from the global C++ locale while the other form takes this
 reference as an argument.
 </p></blockquote>
 <blockquote><p>
 The problem with storing a reference to a facet in another
 object (as opposed to storing the locale object in which the
 facet is installed) is that doing so bypasses the reference
 counting mechanism designed to prevent a facet that is still
 being referenced (i.e., one that is still installed in some
 locale) from being destroyed when another locale that contains
 it is destroyed. Separating a facet reference from the locale
 it comes from van make it cumbersome (and in some cases might
 even make it impossible) for programs to prevent invalidating
 the reference. (The danger of this design is highlighted in
 the paper.)
 </p></blockquote>
 <blockquote><p>
 This problem could be easily avoided by having the extended
 facets store a copy of the locale from which they would extract
 the base facet either at construction time or when needed. To
 make it possible, the forms of ctors of the extended facets that
 take a reference to the base facet would need to be changed to
 take a locale argument instead.
 </p></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 1. Change the <code>extended_num_get</code> synopsis in 3.10.2 as follows:
 </p>
 <pre>            extended_num_get(const <del>std::num_get&lt;charT, InputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0);

             /* ... */

             <del>// <i>const std::num_get&lt;charT, InputIterator&gt; &amp; <b>base</b></i>;        <i><b>exposition only</b></i></del>
             <ins>// <i>std::locale <b>baseloc</b></i>;                                    <i><b>exposition only</b></i></ins>
 </pre>
 <p>
 2. Change the description of the above constructor in 3.10.2.1:
 </p>
 <pre>            extended_num_get(const <del>std::num_get&lt;charT, InputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0);

 </pre>
 <blockquote>
 <p>
 <b>Effects:</b> Constructs an <code>extended_num_get</code> facet as if by:
 </p>
 <pre>       extended_num_get(const <del>std::num_get&lt;charT, InputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0)
                 : facet(<i>refs</i>), <i>base<ins>loc</ins></i>(<i>b</i>)
                 { /* ... */ }

 </pre>
 <p>
 <del><b>Notes:</b> Care must be taken by the implementation to ensure that the lifetime of the facet referenced by <i>base</i> exceeds that of the resulting <code>extended_num_get</code> facet.</del>
 </p>
 </blockquote>
 <p>
 3. Change the <b>Returns:</b> clause for <code>do_get(iter_type, iter_type, ios_base &amp;, ios_base::iostate &amp;, bool &amp;) const</code>, <i>et al</i> to
 </p>
 <blockquote><p>
 <b>Returns:</b> <code><del><i>base</i></del> <ins>std::use_facet&lt;std::num_get&lt;charT, InputIterator&gt; &gt;(<i>baseloc</i>)</ins>.get(<i>in</i>, <i>end</i>, <i>str</i>, <i>err</i>, <i>val</i>)</code>.
 </p></blockquote>
 <p>
 4. Change the <code>extended_num_put</code> synopsis in 3.10.3 as follows:
 </p>
 <pre>            extended_num_put(const <del>std::num_put&lt;charT, OutputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0);

             /* ... */

             <del>// <i>const std::num_put&lt;charT, OutputIterator&gt; &amp; <b>base</b></i>;       <i><b>exposition only</b></i></del>
             <ins>// <i>std::locale <b>baseloc</b></i>;                                    <i><b>exposition only</b></i></ins>
 </pre>
 <p>
 5. Change the description of the above constructor in 3.10.3.1:
 </p>
 <pre>            extended_num_put(const <del>std::num_put&lt;charT, OutputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0);
 </pre>
 <blockquote>
 <p>
 <b>Effects:</b> Constructs an <code>extended_num_put</code> facet as if by:
 </p>
 <pre>       extended_num_put(const <del>std::num_put&lt;charT, OutputIterator&gt;</del> <ins>std::locale</ins> &amp; <i>b</i>, size_t <i>refs</i> = 0)
                 : facet(<i>refs</i>), <i>base<ins>loc</ins></i>(<i>b</i>)
                 { /* ... */ }

 </pre>
 <p>
 <del><b>Notes:</b> Care must be taken by the implementation to ensure that the lifetime of the facet referenced by <i>base</i> exceeds that of the resulting <code>extended_num_put</code> facet.</del>
 </p>
 </blockquote>
 <p>
 6. Change the <b>Returns:</b> clause for <code>do_put(iter_type, ios_base &amp;, char_type, bool &amp;) const</code>, <i>et al</i> to
 </p>
 <blockquote><p>
 <b>Returns:</b> <code><del><i>base</i></del> <ins>std::use_facet&lt;std::num_put&lt;charT, OutputIterator&gt; &gt;(<i>baseloc</i>)</ins>.put(<i>s</i>, <i>f</i>, <i>fill</i>, <i>val</i>)</code>.
 </p></blockquote>

 <p><i>[
 Redmond:  We would prefer to rename "extended" to "decimal".
 ]</i></p>


 <hr>
 <h3><a name="605"></a>605. Decimal: &lt;decfloat.h&gt; doesn't live here anymore.</h3>
 <p><b>Section:</b> TRDecimal 3.4 [trdec.types.cdecfloat] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TRDec">TRDec</a>
  <b>Submitter:</b> Robert Klarer <b>Date:</b> 2006-10-17</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#TRDec">TRDec</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In Berlin, WG14 decided to drop the &lt;decfloat.h&gt; header. The
 contents of that header have been moved into &lt;float.h&gt;. For the
 sake of C compatibility, we should make corresponding changes.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 1. Change the heading of subclause 3.4, "Headers <code>&lt;cdecfloat&gt;</code> and <code>&lt;decfloat.h&gt;</code>" to "Additions to headers <code>&lt;cfloat&gt;</code> and <code>&lt;float.h&gt;</code>."
 </p>
 <p>
 2. Change the text of subclause 3.4 as follows:
 </p>
 <blockquote>
 <p>
 <del>The standard C++ headers <code>&lt;cfloat&gt;</code> and <code>&lt;float.h&gt;</code> define characteristics of the floating-point types <code>float</code>, <code>double</code>, and <code>long double</code>.  Their contents remain unchanged by this Technical Report.</del>
 </p>
 <p>
 <del>Headers <code>&lt;cdecfloat&gt;</code> and <code>&lt;decfloat.h&gt;</code> define characteristics of the decimal floating-point types <code>decimal32</code>, <code>decimal64</code>, and <code>decimal128</code>.  As well, <code>&lt;decfloat.h&gt;</code> defines the convenience typedefs <code>_Decimal32</code>, <code>_Decimal64</code>, and <code>_Decimal128</code>, for compatibilty with the C programming language.</del>
 </p>
 <p>
 <ins>The header <code>&lt;cfloat&gt;</code> is described in [tr.c99.cfloat].  The header <code>&lt;float.h&gt;</code>
 is described in [tr.c99.floath]. These headers are extended by this
 Technical Report to define characteristics of the decimal
 floating-point types <code>decimal32</code>, <code>decimal64</code>, and <code>decimal128</code>.  As well, <code>&lt;float.h&gt;</code> is extended to define the convenience typedefs <code>_Decimal32</code>, <code>_Decimal64</code>, and <code>_Decimal128</code> for compatibility with the C programming language.</ins>
 </p>
 </blockquote>
 <p>
 3. Change the heading of subclause 3.4.1, "Header <code>&lt;cdecfloat&gt;</code> synopsis"  to "Additions to header <code>&lt;cfloat&gt;</code> synopsis."
 </p>
 <p>
 4. Change the heading of subclause 3.4.2, "Header <code>&lt;decfloat.h&gt;</code> synopsis" to "Additions to header <code>&lt;float.h&gt;</code> synopsis."
 </p>
 <p>
 5. Change the contents of 3.4.2 as follows:
 </p>
 <pre>      <del>#include &lt;cdecfloat&gt;</del>

       // <i>C-compatibility convenience typedefs:</i>

       typedef std::decimal::decimal32  _Decimal32;
       typedef std::decimal::decimal64  _Decimal64;
       typedef std::decimal::decimal128 _Decimal128;
 </pre>


 <hr>
 <h3><a name="607"></a>607. Concern about short seed vectors</h3>
 <p><b>Section:</b> 26.4.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Charles Karney <b>Date:</b> 2006-10-26</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.util.seedseq">active issues</a> in [rand.util.seedseq].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Short seed vectors of 32-bit quantities all result in different states. However
 this is not true of seed vectors of 16-bit (or smaller) quantities.  For example
 these two seeds
 </p>

 <blockquote><pre>unsigned short seed = {1, 2, 3};
 unsigned short seed = {1, 2, 3, 0};
 </pre></blockquote>

 <p>
 both pack to
 </p>

 <blockquote><pre>unsigned seed = {0x20001, 0x3};
 </pre></blockquote>

 <p>
 yielding the same state.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="608"></a>608. Unclear seed_seq construction details</h3>
 <p><b>Section:</b> 26.4.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Charles Karney <b>Date:</b> 2006-10-26</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.util.seedseq">active issues</a> in [rand.util.seedseq].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 26.4.7.1 [rand.util.seedseq] /6, the order of packing the inputs into b and the
 treatment of signed quantities is unclear. Better to spell it out.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="609"></a>609. missing static const</h3>
 <p><b>Section:</b> 26.4.4.2 [rand.adapt.ibits], TR1 5.1 [tr.rand] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Walter E. Brown <b>Date:</b> 2006-11-02</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In preparing N2111, an error on my part resulted in the omission of the
 following line from the template synopsis in the cited section:
 </p>

 <blockquote><pre>static const size_t word_size = w;
 </pre></blockquote>

 <p>
 (This same constant is found, for example, in 26.4.3.3 [rand.eng.sub].)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the above declaration as the first line after the comment in [rand.adapt.ibits] p4:
 </p>

 <blockquote><pre>// engine characteristics
 <ins>static const size_t word_size = w;</ins>
 </pre></blockquote>

 <p>
 and accept my apologies for the oversight.
 </p>


 <hr>
 <h3><a name="610"></a>610. Suggested non-normative note for C++0x</h3>
 <p><b>Section:</b> 20.6.15.2.1 [func.wrap.func.con], TR1 3.7.2.1 [tr.func.wrap.func.con] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Scott Meyers <b>Date:</b> 2006-11-02</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 My suggestion is that implementers of both tr1::function and its
 official C++0x successor be explicitly encouraged (but not required) to
 optimize for the cases mentioned above, i.e., function pointers and
 small function objects.  They could do this by using a small internal
 buffer akin to the buffer used by implementations of the small string
 optimization.  (That would make this the small functor optimization --
 SFO :-})  The form of this encouragement could be a note in the standard
 akin to footnote 214 of the current standard.
 </p>

 <p>
 Dave Abrahams notes:
 </p>

 <p>
 "shall not throw exceptions" should really be "nothing," both to be more
 grammatical and to be consistent with existing wording in the standard.
 </p>

 <p>
 Doug Gregor comments: I think this is a good idea. Currently, implementations of
 tr1::function are required to have non-throwing constructors and assignment
 operators when the target function object is a function pointer or a
 reference_wrapper. The common case, however, is for a tr1::function to store
 either an empty function object or a member pointer + an object pointer.
 </p>
 <p>
 The function implementation in the upcoming Boost 1.34.0 uses the
 "SFO", so that the function objects for typical bind expressions like
 </p>
 <blockquote><pre>bind(&amp;X::f, this, _1, _2, _3)
 </pre></blockquote>

 <p>
 do not require heap allocation when stored in a boost::function. I
 believe Dinkumware's implementation also performs this optimization.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Revise 20.5.14.2.1 p6 [func.wrap.func.con] to add a note as follows:
 </p>

 <blockquote>
 <p>
 <i>Throws:</i> shall not throw exceptions if <tt>f</tt>'s target is a function
 pointer or a function object passed via <tt>reference_wrapper</tt>. Otherwise,
 may throw <tt>bad_alloc</tt> or any exception thrown by the copy constructor of
 the stored function object.
 </p>
 <p>
 <ins><i>Note:</i> Implementations are encouraged to avoid the use of dynamically
 allocated memory for "small" function objects, e.g., where <tt>f</tt>'s target
 is an object holding only a pointer or reference to an object and a member
 function pointer (a "bound member function").</ins>
 </p>
 </blockquote>


 <hr>
 <h3><a name="611"></a>611. Standard library templates and incomplete types</h3>
 <p><b>Section:</b> 17.4.3.7 [res.on.functions] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nicola Musatti <b>Date:</b> 2006-11-13</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In the latest available draft standard
 (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2134.pdf">N2134</a>)
 § 17.4.3.6 [res.on.functions] states:
 </p>

 <blockquote>
 <p>
 -1- In certain cases (replacement functions, handler functions, operations on
 types used to instantiate standard library template components), the C++
 Standard Library depends on components supplied by a C++ program. If these
 components do not meet their requirements, the Standard places no requirements
 on the implementation.
 </p>

 <p>
 -2- In particular, the effects are undefined in the following cases:
 </p>
 <p>
 [...]
 </p>
 <ul>
 <li>if an incomplete type (3.9) is used as a template argument when
 instantiating a template component. </li>
 </ul>
 </blockquote>

 <p>
 This is contradicted by § 20.6.6.2/2 [util.smartptr.shared] which
 states:
 </p>

 <blockquote>
 <p>
 [...]
 </p>

 <p>
 The template parameter <tt>T</tt> of <tt>shared_ptr</tt> may be an incomplete type.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Modify the last bullet of § 17.4.3.6/2 [res.on.functions] to allow for
 exceptions:
 </p>

 <blockquote>
 <ul>
 <li>if an incomplete type (3.9) is used as a template argument when
 instantiating a template component<ins>, unless specifically allowed for the
 component</ins>. </li>
 </ul>
 </blockquote>


 <hr>
 <h3><a name="612"></a>612. numeric_limits::is_modulo insufficiently defined</h3>
 <p><b>Section:</b> 18.2.1.2 [numeric.limits.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Chris Jefferson <b>Date:</b> 2006-11-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numeric.limits.members">issues</a> in [numeric.limits.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 18.2.1.2 55 states that "A type is modulo if it is possible to add two
 positive numbers together and have a result that wraps around to a
 third number that is less".
 This seems insufficient for the following reasons:
 </p>

 <ol>
 <li>Doesn't define what that value received is.</li>
 <li>Doesn't state the result is repeatable</li>
 <li> Doesn't require that doing addition, subtraction and other
 operations on all values is defined behaviour.</li>
 </ol>

 <p><i>[
 Batavia: Related to
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2144.pdf">N2144</a>.
 Pete: is there an ISO definition of modulo?  Underflow on signed behavior is undefined.
 ]</i></p>


 <p><i>[
 Bellevue:  accept resolution, move to ready status.
 Does this mandate that is_modulo be true on platforms for which int
 happens to b modulo? A: the standard already seems to require that.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Suggest 18.2.1.2 [numeric.limits.members], paragraph 57 is amended to:
 </p>

 <blockquote><p>
 A type is modulo if<ins>,</ins> <del>it is possible to add two positive numbers
 and have a result that wraps around to a third number that is less.</del>
 <ins>given any operation involving +,- or * on values of that type whose value
 would fall outside the range <tt>[min(), max()]</tt>, then the value returned
 differs from the true value by an integer multiple of <tt>(max() - min() +
 1)</tt>.</ins>
 </p></blockquote>


 <hr>
 <h3><a name="613"></a>613. max_digits10 missing from numeric_limits</h3>
 <p><b>Section:</b> 18.2.1.5 [numeric.special] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bo Persson <b>Date:</b> 2006-11-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numeric.special">issues</a> in [numeric.special].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 18.2.1.5 [numeric.special] starts out by saying that "All members shall be provided
 for all specializations."
 </p>
 <p>
 Then it goes on to show specializations for float and bool, where one member
 is missing (max_digits10).
 </p>

 <p>
 Maarten Kronenburg adds:
 </p>

 <p>
 I agree, just adding the comment that the exact number of decimal digits
 is digits * ln(radix) / ln(10), where probably this real number is
 rounded downward for digits10, and rounded upward for max_digits10
 (when radix=10, then digits10=max_digits10).
 Why not add this exact definition also to the standard, so the user
 knows what these numbers exactly mean.
 </p>

 <p>
 Howard adds:
 </p>

 <p>
 For reference, here are the correct formulas from
 <a href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1822.pdf">N1822</a>:
 </p>

 <blockquote><pre>digits10 = floor((digits-1) * log10(2))
 max_digits10 = ceil((1 + digits) * log10(2))
 </pre></blockquote>

 <p>
 We are also missing a statement regarding for what specializations this member has meaning.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change and add after 18.2.1.2 [numeric.limits.members], p11:
 </p>

 <blockquote>
 <pre>static const int max_digits10;</pre>
 <blockquote>
 <p>
 -11- Number of base 10 digits required to ensure that values which
 differ <del>by only one epsilon</del> are always differentiated.
 </p>
 <p><ins>
 -12- Meaningful for all floating point types.
 </ins></p>
 </blockquote>
 </blockquote>

 <p>
 Change 18.2.1.5 [numeric.special], p2:
 </p>

 <blockquote><pre>template&lt;&gt; class numeric_limits&lt;float&gt; {
 public:
   static const bool is_specialized = true;
   ...
   static const int digits10 = 6;
   <ins>static const int max_digits10 = 9</ins>;
   ...
 </pre></blockquote>

 <p>
 Change 18.2.1.5 [numeric.special], p3:
 </p>

 <blockquote><pre>template&lt;&gt; class numeric_limits&lt;bool&gt; {
 public:
   static const bool is_specialized = true;
   ...
   static const int digits10 = 0;
   <ins>static const int max_digits10 = 0</ins>;
   ...
 </pre></blockquote>


 <hr>
 <h3><a name="616"></a>616. missing 'typename' in ctype_byname</h3>
 <p><b>Section:</b> 22.2.1.2 [locale.ctype.byname] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bo Persson <b>Date:</b> 2006-12-16</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.ctype.byname">issues</a> in [locale.ctype.byname].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 22.2.1.2 defines the ctype_byname class template. It contains the
 line
 </p>

 <blockquote><pre>typedef ctype&lt;charT&gt;::mask   mask;
 </pre></blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 as this is a dependent type, it should obviously be
 </p>

 <blockquote><pre>typedef <ins>typename</ins> ctype&lt;charT&gt;::mask   mask;
 </pre></blockquote>


 <hr>
 <h3><a name="618"></a>618. valarray::cshift() effects on empty array</h3>
 <p><b>Section:</b> 26.5.2.7 [valarray.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Gabriel Dos Reis <b>Date:</b> 2007-01-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I would respectfully request an issue be opened with the intention to
 clarify the wording for <tt>size() == 0</tt> for <tt>cshift</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 26.5.2.7 [valarray.members], paragraph 10:
 </p>

 <blockquote>

 <pre>valarray&lt;T&gt; cshift(int <i>n</i>) const;
 </pre>

 <blockquote>
 <p>
 This function returns an object of class <tt>valarray&lt;T&gt;</tt>, of
 length <tt>size()</tt>, <del>each of whose elements <tt>I</tt> is
 <tt>(*this)[(I + n ) % size()]</tt>. Thus, if element zero is taken as
 the leftmost element, a positive value of <i>n</i> shifts the elements
 circularly left <i>n</i> places.</del> <ins>that is a circular shift of <tt>*this</tt>. If
 element zero is taken as the leftmost element, a non-negative value of
 <i>n</i> shifts the elements circularly left <i>n</i> places and a
 negative value of <i>n</i> shifts the elements circularly right
 -<i>n</i> places.</ins>
 </p>
 </blockquote>
 </blockquote>


 <p><b>Rationale:</b></p>
 <p>
 We do not believe that there is any real ambiguity about what happens
 when <tt>size() == 0</tt>, but we do believe that spelling this out as a C++
 expression causes more trouble that it solves. The expression is
 certainly wrong when <tt>n &lt; 0</tt>, since the sign of % with negative arguments
 is implementation defined.
 </p>


 <p><i>[
 Kona (2007) Changed proposed wording, added rationale and set to Review.
 ]</i></p>


 <hr>
 <h3><a name="619"></a>619. Longjmp wording problem</h3>
 <p><b>Section:</b> 18.9 [support.runtime] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Lawrence Crowl <b>Date:</b> 2007-01-12</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The wording for <tt>longjmp</tt> is confusing.
 </p>
 <p>
 18.9 [support.runtime] -4- Other runtime support
 </p>
 <blockquote><p>
 The function signature <tt>longjmp(jmp_buf jbuf, int val)</tt> has more restricted
 behavior in this International Standard.  If any automatic objects would
 be destroyed by a thrown exception transferring control to another
 (destination) point in the program, then a call to <tt>longjmp(jbuf, val)</tt> that
 the throw point that transfers control to the same (destination) point has
 undefined behavior.
 </p></blockquote>
 <p>
 Someone at Google thinks that should say "then a call to <tt>longjmp(jbuf, val)</tt>
 *at* the throw point that transfers control".
 </p>
 <p>
 Bill Gibbons thinks it should say something like "If any automatic objects
 would be destroyed by an exception thrown at the point of the longjmp and
 caught only at the point of the setjmp, the behavior is undefined."
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In general, accept Bill Gibbons' recommendation,
 but add "call" to indicate that the undefined behavior
 comes from the dynamic call, not from its presence in the code.
 In 18.9 [support.runtime] paragraph 4, change
 </p>

 <blockquote><p>
 The function signature <tt>longjmp(jmp_buf jbuf, int val)</tt> has more
 restricted behavior in this International Standard.  <del>If any automatic
 objects would be destroyed by a thrown exception transferring control to another
 (destination) point in the program, then a call to <tt>longjmp(jbuf, val)</tt>
 that the throw point that transfers control to the same (destination) point has
 undefined behavior.</del> <ins>A <tt>setjmp</tt>/<tt>longjmp</tt> call pair has
 undefined behavior if replacing the <tt>setjmp</tt> and <tt>longjmp</tt> by
 <tt>catch</tt> and <tt>throw</tt> would destroy any automatic objects.</ins>
 </p></blockquote>


 <hr>
 <h3><a name="620"></a>620. valid uses of empty valarrays</h3>
 <p><b>Section:</b> 26.5.2.1 [valarray.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-01-20</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#valarray.cons">active issues</a> in [valarray.cons].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#valarray.cons">issues</a> in [valarray.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The <i>Effects</i>  clause for the  default <code>valarray</code> ctor
 suggests  that  it  is possible  to  increase  the  size of  an  empty
 <code>valarray</code>  object   by  calling  other   non-const  member
 functions of the class besides <code>resize()</code>. However, such an
 interpretation would  be contradicted by  the requirement on  the copy
 assignment  operator  (and  apparently   also  that  on  the  computed
 assignments)  that the  assigned arrays  be  the same  size.  See  the
 reflector discussion starting with c++std-lib-17871.

         </p>
         <p>

 In  addition,  <i>Footnote</i> 280  uses  some questionable  normative
 language.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 Reword the <i>Effects</i> clause and <i>Footnote 280</i> as follows (26.5.2.1 [valarray.cons]):

         </p>
         <blockquote>
             <p>

 <code>valarray();</code>

             </p>
             <p>

 <i>Effects</i>:      Constructs      an      object      of      class
 <code>valarray&lt;T&gt;</code>,<sup>279)</sup>    which    has    zero
 length<del> until it is passed into a library function as a modifiable
 lvalue or through a non-constant this pointer</del>.<sup>280)</sup>

             </p>
             <p>

 <ins><i>Postcondition</i>: <code>size() == 0</code>.</ins>

             </p>
             <p>

 <i>Footnote  280</i>:  This default  constructor  is essential,  since
 arrays  of  <code>valarray</code>  <del>are  likely to  prove  useful.
 There  shall also  be  a way  to change  the  size of  an array  after
 initialization;  this  is  supplied  by the  semantics</del>  <ins>may be
 useful.   The  length  of  an  empty  array  can  be  increased  after
 initialization  by  means</ins>  of the  <code>resize()</code>  member
 function.

             </p>
         </blockquote>


 <hr>
 <h3><a name="621"></a>621. non-const copy assignment operators of helper arrays</h3>
 <p><b>Section:</b> 26.5 [numarray] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-01-20</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numarray">issues</a> in [numarray].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The computed and  "fill" assignment operators of <code>valarray</code>
 helper     array     class    templates     (<code>slice_array</code>,
 <code>gslice_array</code>,         <code>mask_array</code>,        and
 <code>indirect_array</code>) are const  member functions of each class
 template     (the     latter    by     the     resolution    of  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#123">123</a>
 since  they have reference  semantics and thus do  not affect
 the state of  the object on which they are  called.  However, the copy
 assignment  operators  of  these  class  templates,  which  also  have
 reference semantics,  are non-const.   The absence of  constness opens
 the door to speculation about whether they really are intended to have
 reference semantics (existing implementations vary widely).

         </p>

 <p>
 Pre-Kona, Martin adds:
 </p>

 <p>
 I realized that adding the const qualifier to the
 functions as I suggested would break the const correctness of the
 classes. A few possible solutions come to mind:
 </p>

 <ol>
 <li>Add the const qualifier to the return types of these functions.</li>
 <li>Change the return type of all the functions to void to match
 the signatures of all the other assignment operators these classes
 define.</li>
 <li>Prohibit the copy assignment of these classes by declaring the
 copy assignment operators private (as is done and documented by
 some implementations).</li>
 </ol>


 <p><b>Proposed resolution:</b></p>
         <p>

 Declare  the  copy  assignment  operators  of all  four  helper  array
 class templates const.

         </p>
         <p>

 Specifically,  make the following edits:

         </p>
         <p>

 Change     the    signature     in     26.5.5 [template.slice.array]    and
 26.5.5.1 [slice.arr.assign] as follows:

         </p>
         <blockquote><pre>
 <code><ins>const</ins> slice_array&amp; operator= (const slice_array&amp;)<ins> const</ins>;</code>

         </pre></blockquote>
         <p>

 Change     the     signature     in    26.5.7 [template.gslice.array]     and
 26.5.7.1 [gslice.array.assign] as follows:

         </p>
         <blockquote><pre>
 <code><ins>const</ins> gslice_array&amp; operator= (const gslice_array&amp;)<ins> const</ins>;</code>

         </pre></blockquote>
         <p>

 Change the  signature in 26.5.8 [template.mask.array]  and 26.5.8.1 [mask.array.assign] as
 follows:

         </p>
         <blockquote><pre>
 <code><ins>const</ins> mask_array&amp; operator= (const mask_array&amp;)<ins> const</ins>;</code>

         </pre></blockquote>
         <p>

 Change     the     signature     in    26.5.9 [template.indirect.array] and
 26.5.9.1 [indirect.array.assign] as follows:

         </p>
         <blockquote><pre>
 <code><ins>const</ins> indirect_array&amp; operator= (const indirect_array&amp;)<ins> const</ins>;</code>

         </pre></blockquote>


 <p><i>[
 Kona (2007) Added const qualification to the return types and set to Ready.
 ]</i></p>


 <hr>
 <h3><a name="622"></a>622. behavior of <code>filebuf</code> dtor and <code>close</code> on error</h3>
 <p><b>Section:</b> 27.8.1.17 [fstream.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-01-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 <code>basic_filebuf</code>  dtor is  specified to  have  the following
 straightforward effects:

         </p>
         <blockquote><p>

 <i>Effects</i>:       Destroys      an      object       of      class
 <code>basic_filebuf</code>. Calls <code>close()</code>.

         </p></blockquote>
         <p>

 <code>close()</code> does a lot of potentially complicated processing,
 including calling <code>overflow()</code> to write out the termination
 sequence  (to   bring  the  output  sequence  to   its  initial  shift
 state). Since  any of the  functions called during the  processing can
 throw an exception, what should the  effects of an exception be on the
 dtor? Should the  dtor catch and swallow it or  should it propagate it
 to the caller?  The text doesn't  seem to provide any guidance in this
 regard  other  than  the  general  restriction on  throwing  (but  not
 propagating)  exceptions  from   destructors  of  library  classes  in
 17.4.4.9 [res.on.exception.handling].

         </p>
         <p>

 Further,  the last thing  <code>close()</code> is  specified to  do is
 call <code>fclose()</code> to close the <code>FILE</code> pointer. The
 last sentence of the <i>Effects</i> clause reads:

         </p>
         <blockquote><p>

 ...   If    any   of    the   calls   to    <code>overflow</code>   or
 <code>std::fclose</code> fails then <code>close</code> fails.

         </p></blockquote>
         <p>

 This  suggests that  <code>close()</code>  might be  required to  call
 <code>fclose()</code>   if  and  only   if  none   of  the   calls  to
 <code>overflow()</code> fails, and avoid closing the <code>FILE</code>
 otherwise. This  way, if  <code>overflow()</code> failed to  flush out
 the data, the caller  would have  the opportunity to  try to  flush it
 again (perhaps  after trying  to deal with  whatever problem  may have
 caused the failure), rather than losing it outright.

         </p>
         <p>

 On the other hand,  the function's <i>Postcondition</i> specifies that
 <code>is_open() ==  false</code>, which  suggests that it  should call
 <code>fclose()</code>       unconditionally.       However,      since
 <i>Postcondition</i> clauses  are specified for many  functions in the
 standard,  including constructors  where they  obviously  cannot apply
 after an  exception, it's not clear  whether this <i>Postcondition</i>
 clause is intended to apply even after an exception.

         </p>
         <p>

 It  might  be worth  noting  that  the  traditional behavior  (Classic
 Iostreams  <code>fstream::close()</code> and  C <code>fclose()</code>)
 is  to  close  the  <code>FILE</code> unconditionally,  regardless  of
 errors.

         </p>

 <p><i>[
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#397">397</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#418">418</a> for related issues.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
         <p>

 After discussing this  on the reflector (see the  thread starting with
 c++std-lib-17650) we propose that <code>close()</code> be clarified to
 match the traditional behavior, that is to close the <code>FILE</code>
 unconditionally,  even after  errors or  exceptions.  In  addition, we
 propose the dtor description be amended so as to explicitly require it
 to catch and swallow any exceptions thrown by <code>close()</code>.

         </p>
         <p>

 Specifically,   we   propose   to   make  the   following   edits   in
 27.8.1.4 [filebuf.members]:

         </p>
         <blockquote>
             <pre>
 <code>basic_filebuf&lt;charT,traits&gt;* close();</code>

             </pre>
             <p>

 <i>Effects</i>:  If <code>is_open()  == false</code>,  returns  a null
 pointer.        If      a       put      area       exists,      calls
 <code>overflow(traits::eof())</code> to flush  characters. If the last
 virtual   member  function   called  on   <code>*this</code>  (between
 <code>underflow</code>,  <code>overflow</code>,  <code>seekoff</code>,
 and   <code>seekpos</code>)  was   <code>overflow</code>   then  calls
 <code>a_codecvt.unshift</code> (possibly several times) to determine a
 termination   sequence,    inserts   those   characters    and   calls
 <code>overflow(traits::eof())</code>  again.  Finally<ins>, regardless
 of whether  any of the preceding  calls fails or  throws an exception,
 the  function</ins> <del>it</del>  closes   the  file   ("as   if"  by   calling
 <code>std::fclose(file)</code>).<sup>334)</sup>  If any  of  the calls
 <ins>made    by   the    function</ins><del>to   <code>overflow</code>
 or</del><ins>,  including  </ins><code>std::fclose</code><ins>, </ins>
 fails then <code>close</code> fails<ins>  by returning a null pointer.
 If one of these calls throws an exception, the exception is caught and
 rethrown after closing the file.</ins>

             </p>
         </blockquote>
         <p>

 And to make the following edits in 27.8.1.2 [filebuf.cons].

         </p>
         <blockquote>
             <pre>
 <code>virtual ~basic_filebuf();</code>

             </pre>
             <p>

 <i>Effects</i>:       Destroys      an      object       of      class
 <code>basic_filebuf&lt;charT,traits&gt;</code>.                   Calls
 <code>close()</code>.    <ins>If  an   exception  occurs   during  the
 destruction of the object, including the call to <code>close()</code>,
 the     exception    is     caught    but     not     rethrown    (see
 17.4.4.9 [res.on.exception.handling]).</ins>

             </p>
         </blockquote>


 <hr>
 <h3><a name="623"></a>623. <code>pubimbue</code> forbidden to call <code>imbue</code></h3>
 <p><b>Section:</b> 27.1.1 [iostream.limits.imbue] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-01-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 27.1.1 [iostream.limits.imbue]  specifies  that  "no  function  described  in
 clause 27 except  for <code>ios_base::imbue</code> causes any instance
 of                   <code>basic_ios::imbue</code>                  or
 <code>basic_streambuf::imbue</code> to be called."

         </p>
         <p>

 That      contradicts      the      <i>Effects</i>     clause      for
 <code>basic_streambuf::pubimbue()</code>  which requires  the function
 to do just that: call <code>basic_streambuf::imbue()</code>.

         </p>


 <p><b>Proposed resolution:</b></p>
         <p>

 To    fix   this,    rephrase    the   sentence    above   to    allow
 <code>pubimbue</code> to do what  it was designed to do. Specifically.
 change 27.1.1 [iostream.limits.imbue], p1 to read:

         </p>
         <blockquote><p>

 No     function    described     in    clause     27     except    for
 <code>ios_base::imbue</code>  <ins>and <code>basic_filebuf::pubimbue</code></ins>
 causes    any    instance    of    <code>basic_ios::imbue</code>    or
 <code>basic_streambuf::imbue</code> to be called. ...

         </p></blockquote>


 <hr>
 <h3><a name="624"></a>624. <code>valarray</code> assignment and arrays of unequal length</h3>
 <p><b>Section:</b> 26.5.2.2 [valarray.assign] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-01-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
         <p>

 The behavior of the  <code>valarray</code> copy assignment operator is
 defined only when both sides have  the same number of elements and the
 spec is explicit about assignments of arrays of unequal lengths having
 undefined behavior.

         </p>
         <p>

 However, the generalized  subscripting assignment operators overloaded
 on <code>slice_array</code>  et al (26.5.2.2 [valarray.assign])  don't have any
 such restriction, leading  the reader to believe that  the behavior of
 these  overloads is  well defined  regardless  of the  lengths of  the
 arguments.

         </p>
         <p>

 For example,  based on  the reading  of the spec  the behavior  of the
 snippet below can be expected to be well-defined:

         </p>
         <pre>    const std::slice from_0_to_3 (0, 3, 1);   // refers to elements 0, 1, 2
     const std::valarray&lt;int&gt; a (1, 3);        // a = { 1, 1, 1 }
     std::valarray&lt;int&gt;       b (2, 4);        // b = { 2, 2, 2, 2 }

     b = a [from_0_to_3];
         </pre>
         <p>

 In practice, <code>b</code> may end up being <code>{ 1, 1, 1 }</code>,
 <code>{  1,  1, 1,  2  }</code>,  or  anything else,  indicating  that
 existing implementations vary.

         </p>

 <p>
 Quoting from Section 3.4, Assignment operators, of Al Vermeulen's
 Proposal for Standard C++ Array Classes (see c++std-lib-704;
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/1993/N0308.asc">N0308</a>):
 </p>
 <blockquote><p>
   ...if the size of the array on the right hand side of the equal
   sign differs from the size of the array on the left, a run time
   error occurs. How this error is handled is implementation
   dependent; for compilers which support it, throwing an exception
   would be reasonable.
 </p></blockquote>

 <p>
 And see more history in
 <a href="http://www.open-std.org/JTC1/SC22/WG21/docs/papers/1993/N0280.pdf">N0280</a>.
 </p>

         <p>

 It has  been argued in  discussions on the committee's  reflector that
 the semantics of all <code>valarray</code> assignment operators should
 be permitted to be undefined unless  the  length  of the arrays  being
 assigned is the same as the length of the one being assigned from. See
 the thread starting at c++std-lib-17786.

         </p>
         <p>

 In order  to reflect  such views, the  standard must specify  that the
 size of the  array referred to by the argument  of the assignment must
 match the size of the array  under assignment, for example by adding a
 <i>Requires</i> clause to 26.5.2.2 [valarray.assign] as follows:

         </p>
         <blockquote><p>

 <i>Requires</i>: The length of the  array to which the argument refers
 equals <code>size()</code>.

         </p></blockquote>

         <p>

 Note that it's  far from clear that such leeway  is necessary in order
 to implement <code>valarray</code> efficiently.

         </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Insert new paragraph into 26.5.2.2 [valarray.assign]:
 </p>

 <blockquote>
 <pre>valarray&lt;T&gt;&amp; operator=(const slice_array&lt;T&gt;&amp;);
 valarray&lt;T&gt;&amp; operator=(const gslice_array&lt;T&gt;&amp;);
 valarray&lt;T&gt;&amp; operator=(const mask_array&lt;T&gt;&amp;);
 valarray&lt;T&gt;&amp; operator=(const indirect_array&lt;T&gt;&amp;);
 </pre>
 <blockquote>
 <p><ins>
 <i>Requires</i>: The length of the  array to which the argument refers
 equals <code>size()</code>.
 </ins></p>
 <p>
 These operators allow the results of a generalized subscripting operation to be assigned directly to a <tt>valarray</tt>.
 </p>
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="628"></a>628. Inconsistent definition of basic_regex constructor</h3>
 <p><b>Section:</b> 28.8 [re.regex] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bo Persson <b>Date:</b> 2007-01-23</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.regex">issues</a> in [re.regex].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 28.8 [re.regex] lists a constructor
 </p>

 <blockquote><pre>template&lt;class InputIterator&gt;
 basic_regex(InputIterator first, InputIterator last,
                        flag_type f = regex_constants::ECMAScript);
 </pre></blockquote>

 <p>
 However, in section 28.8.2 [re.regex.construct], this constructor takes a
 pair of <tt>ForwardIterator</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 28.8.2 [re.regex.construct]:
 </p>

 <blockquote><pre>template &lt;class <del>ForwardIterator</del> <ins>InputIterator</ins>&gt;
   basic_regex(<del>ForwardIterator</del> <ins>InputIterator</ins> first, <del>ForwardIterator</del> <ins>InputIterator</ins> last,
               flag_type f = regex_constants::ECMAScript);
 </pre></blockquote>


 <hr>
 <h3><a name="634"></a>634. <tt>allocator.address()</tt> doesn't work for types overloading <tt>operator&amp;</tt></h3>
 <p><b>Section:</b> 20.7.5.1 [allocator.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-02-07</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#allocator.members">issues</a> in [allocator.members].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a></p>
 <p><b>Discussion:</b></p>

 <p>
 20.7.5.1 [allocator.members] says:
 </p>
 <blockquote>
 <pre>pointer address(reference <i>x</i>) const;</pre>
 <blockquote>
 <p>
 -1- <i>Returns:</i> <tt>&amp;<i>x</i></tt>.
 </p>
 </blockquote>
 </blockquote>

 <p>
 20.7.5.1 [allocator.members] defines <tt>CopyConstructible</tt> which currently not
 only defines the semantics of copy construction, but also restricts what an overloaded
 <tt>operator&amp;</tt> may do.  I believe proposals are in the works (such as concepts
 and rvalue reference) to decouple these two requirements.  Indeed it is not evident
 that we should disallow overloading <tt>operator&amp;</tt> to return something other
 than the address of <tt>*this</tt>.
 </p>

 <p>
 An example of when you want to overload <tt>operator&amp;</tt> to return something
 other than the object's address is proxy references such as <tt>vector&lt;bool&gt;</tt>
 (or its replacement, currently code-named <tt>bit_vector</tt>).  Taking the address of
 such a proxy reference should logically yield a proxy pointer, which when dereferenced,
 yields a copy of the original proxy reference again.
 </p>

 <p>
 On the other hand, some code truly needs the address of an object, and not a proxy
 (typically for determining the identity of an object compared to a reference object).
 <a href="http://www.boost.org/">boost</a> has long recognized this dilemma and solved it with
 <a href="http://www.boost.org/libs/utility/utility.htm#addressof"><tt>boost::addressof</tt></a>.
 It appears to me that this would be useful functionality for the default allocator.  Adopting
 this definition for <tt>allocator::address</tt> would free the standard of requiring
 anything special from types which overload <tt>operator&amp;</tt>.  Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#580">580</a>
 is expected to make use of <tt>allocator::address</tt> mandatory for containers.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 20.7.5.1 [allocator.members]:
 </p>

 <blockquote>
 <pre>pointer address(reference <i>x</i>) const;</pre>
 <blockquote>
 <p>
 -1- <i>Returns:</i> <del><tt>&amp;<i>x</i></tt>.</del> <ins>The actual address of object referenced by <i>x</i>,
 even in the presence of an overloaded <tt>operator&amp;</tt>.</ins>
 </p>
 </blockquote>

 <pre>const_pointer address(address(const_reference <i>x</i>) const;</pre>
 <blockquote>
 <p>
 -2- <i>Returns:</i> <del><tt>&amp;<i>x</i></tt>.</del> <ins>The actual address of object referenced by <i>x</i>,
 even in the presence of an overloaded <tt>operator&amp;</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 <p><i>[
 post Oxford:  This would be rendered NAD Editorial by acceptance of
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2257.html">N2257</a>.
 ]</i></p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2387 for this issue which
 was subsequently split out into a separate paper N2436 for the purposes of voting.
 The resolution in N2436 addresses this issue.  The LWG voted to accelerate this
 issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="638"></a>638. deque end invalidation during erase</h3>
 <p><b>Section:</b> 23.2.2.3 [deque.modifiers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Steve LoBasso <b>Date:</b> 2007-02-17</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The standard states at 23.2.2.3 [deque.modifiers]/4:
 </p>
 <blockquote><pre>deque erase(...)
 </pre>
  <p>
 <i>Effects:</i> ... An erase at either end of the deque invalidates only
 the iterators and the references to the erased elements.
 </p>
 </blockquote>
 <p>
 This does not state that iterators to end will be invalidated.
 It needs to be amended in such a way as to account for end invalidation.
 </p>
 <p>
 Something like:
 </p>
 <blockquote><p>
 Any time the last element is erased, iterators to end are invalidated.
 </p></blockquote>

 <p>
 This would handle situations like:
 </p>
 <blockquote><pre>erase(begin(), end())
 erase(end() - 1)
 pop_back()
 resize(n, ...) where n &lt; size()
 pop_front() with size() == 1

 </pre></blockquote>

 <p><i>[
 Post Kona, Steve LoBasso notes:
 ]</i></p>


 <blockquote>
 My only issue with the proposed resolution is that it might not be clear
 that <tt>pop_front()</tt> [where <tt>size() == 1</tt>] can invalidate past-the-end
 iterators.
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 23.2.2.3 [deque.modifiers], p4:
 </p>

 <blockquote>
 <pre>iterator erase(const_iterator position);
 iterator erase(const_iterator first, const_iterator last);
 </pre>

 <blockquote>
 <p>
 -4- <i>Effects:</i> An erase in the middle of the <tt>deque</tt>
 invalidates all the iterators and references to elements of the
 <tt>deque</tt> <ins>and the past-the-end iterator</ins>. An erase at
 either end of the <tt>deque</tt> invalidates only the iterators and the
 references to the erased elements<ins>, except that erasing at the end
 also invalidates the past-the-end iterator</ins>.
 </p>
 </blockquote>
 </blockquote>


 <p><i>[
 Kona (2007): Proposed wording added and moved to Review.
 ]</i></p>


 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 Note that there is existing code that relies on iterators not being
 invalidated, but there are also existing implementations that do
 invalidate iterators. Thus, such code is not portable in any case. There
 is a pop_front() note, which should possibly be a separate issue. Mike
 Spertus to evaluate and, if need be, file an issue.
 </blockquote>


 <hr>
 <h3><a name="640"></a>640. 27.6.2.5.2 does not handle (unsigned) long long</h3>
 <p><b>Section:</b> 27.6.2.6.2 [ostream.inserters.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-02-17</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream.inserters.arithmetic">issues</a> in [ostream.inserters.arithmetic].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The arithmetic inserters are described in 27.6.2.6.2 [ostream.inserters.arithmetic].
 Although the section starts with a listing of the inserters including
 the new ones:
 </p>

 <blockquote><pre>operator&lt;&lt;(long long val );
 operator&lt;&lt;(unsigned long long val );
 </pre></blockquote>

 <p>
 the text in paragraph 1, which describes the corresponding effects
 of the inserters, depending on the actual type of val, does not
 handle the types <tt>long long</tt> and <tt>unsigned long long</tt>.
 </p>

 <p><i>[
 Alisdair: In addition to the (unsigned) long long problem, that whole paragraph
 misses any reference to extended integral types supplied by the
 implementation - one of the additions by core a couple of working papers
 back.
 ]</i></p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.6.2.6.2 [ostream.inserters.arithmetic]/1 change the third sentence
 </p>

 <blockquote>
 When val is of type <tt>bool</tt>, <tt>long</tt>, <tt>unsigned
 long</tt>, <ins>long long, unsigned long long,</ins> <tt>double</tt>,
 <tt>long double</tt>, or <tt>const void*</tt>, the formatting conversion
 occurs as if it performed the following code fragment:
 </blockquote>


 <hr>
 <h3><a name="643"></a>643. Impossible "as if" clauses</h3>
 <p><b>Section:</b> 27.8.1.1 [filebuf], 22.2.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-02-20</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current standard 14882:2003(E) as well as N2134 have the
 following
 defects:
 </p>

 <p>
 27.8.1.1 [filebuf]/5 says:
 </p>

 <blockquote>
 <p>
 In order to support file I/O and multibyte/wide character conversion, conversions are performed using members of a
 facet, referred to as <tt><i>a_codecvt</i></tt> in following sections, obtained "as if" by
 </p>
 <blockquote><pre>codecvt&lt;charT,char,typename traits::state_type&gt; <i>a_codecvt</i> =
   use_facet&lt;codecvt&lt;charT,char,typename traits::state_type&gt; &gt;(getloc());
 </pre></blockquote>
 </blockquote>

 <p>
 <tt>use_facet</tt> returns a <tt>const facet</tt> reference and no facet is
 copyconstructible, so the codecvt construction should fail to compile.
 </p>

 <p>
 A similar issue arises in 22.2.2.2.2 [facet.num.put.virtuals]/15 for <tt>num_punct</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 27.8.1.1 [filebuf]/5 change the "as if" code
 </p>

 <blockquote><pre><ins>const </ins>codecvt&lt;charT,char,typename traits::state_type&gt;<ins>&amp;</ins> <i>a_codecvt</i> =
   use_facet&lt;codecvt&lt;charT,char,typename traits::state_type&gt; &gt;(getloc());
 </pre></blockquote>

 <p>
 In 22.2.2.2.2 [facet.num.put.virtuals]/15 (This is para 5 in N2134) change
 </p>

 <blockquote>
 <p>
 A local variable <tt><i>punct</i></tt> is initialized via
 </p>
 <blockquote><pre><ins>const </ins>numpunct&lt;charT&gt;<ins>&amp;</ins> <i>punct</i> = use_facet&lt; numpunct&lt;charT&gt; &gt;(<i>str</i>.getloc() )<ins>;</ins>
 </pre></blockquote>
 </blockquote>

 <p>
 (Please note also the additional provided trailing semicolon)
 </p>


 <hr>
 <h3><a name="646"></a>646. const incorrect match_result members</h3>
 <p><b>Section:</b> 28.10.4 [re.results.form] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-02-26</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 28.10.4 [re.results.form] (root and para 3) in N2134 defines the two function template
 members format as non-const functions, although they are declared
 as const in 28.10 [re.results]/3.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the missing <tt>const</tt> specifier to both <tt>format</tt> overloads described
 in section 28.10.4 [re.results.form].
 </p>


 <hr>
 <h3><a name="650"></a>650. regex_token_iterator and const correctness</h3>
 <p><b>Section:</b> 28.12.2 [re.tokiter] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-03-05</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.tokiter">issues</a> in [re.tokiter].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Both the class definition of regex_token_iterator (28.12.2
 [re.tokiter]/6) and the latter member specifications (28.12.2.2
 [re.tokiter.comp]/1+2) declare both comparison operators as
 non-const functions. Furtheron, both dereference operators are
 unexpectedly also declared as non-const in 28.12.2 [re.tokiter]/6
 as well as in (28.12.2.3 [re.tokiter.deref]/1+2).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 1) In (28.12.2 [re.tokiter]/6) change the current declarations
 </p>

 <blockquote><pre>bool operator==(const regex_token_iterator&amp;) <ins>const</ins>;
 bool operator!=(const regex_token_iterator&amp;) <ins>const</ins>;
 const value_type&amp; operator*() <ins>const</ins>;
 const value_type* operator-&gt;() <ins>const</ins>;
 </pre></blockquote>

 <p>
 2) In 28.12.2.2 [re.tokiter.comp] change the following declarations
 </p>

 <blockquote><pre>bool operator==(const regex_token_iterator&amp; right) <ins>const</ins>;
 bool operator!=(const regex_token_iterator&amp; right) <ins>const</ins>;
 </pre></blockquote>

 <p>
 3) In 28.12.2.3 [re.tokiter.deref] change the following declarations
 </p>

 <blockquote><pre>const value_type&amp; operator*() <ins>const</ins>;
 const value_type* operator-&gt;() <ins>const</ins>;
 </pre></blockquote>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
 is to adopt the proposed wording in this issue).
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="651"></a>651. Missing preconditions for regex_token_iterator c'tors</h3>
 <p><b>Section:</b> 28.12.2.1 [re.tokiter.cnstr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-03-05</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.tokiter.cnstr">issues</a> in [re.tokiter.cnstr].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The text provided in 28.12.2.1 [re.tokiter.cnstr]/2+3 describes
 the effects of the three non-default constructors of class
 template regex_token_iterator but is does not clarify which values
 are legal values for submatch/submatches. This becomes
 an issue, if one takes 28.12.2 [re.tokiter]/9 into account, which explains
 the notion of a "current match" by saying:
 </p>

 <blockquote><p>
 The <i>current match</i> is <tt>(*position).prefix()</tt> if <tt>subs[N]
 == -1</tt>, or <tt>(*position)[subs[N]]</tt> for any other value of
 <tt>subs[N]</tt>.
 </p></blockquote>

 <p>
 It's not clear to me, whether other negative values except -1
 are legal arguments or not - it seems they are not.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the following precondition paragraph just before the current
 28.12.2.1 [re.tokiter.cnstr]/2:
 </p>

 <blockquote><p>
 <i>Requires:</i> Each of the initialization values of <tt>subs</tt> must be <tt>&gt;= -1</tt>.
 </p></blockquote>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
 is to adopt the proposed wording in this issue).
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="652"></a>652. regex_iterator and const correctness</h3>
 <p><b>Section:</b> 28.12.1 [re.regiter] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-03-05</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Both the class definition of regex_iterator (28.12.1 [re.regiter]/1)
 and the latter member specification (28.12.1.2 [re.regiter.comp]/1+2)
 declare both comparison operators as
 non-const functions. Furtheron, both dereference operators are
 unexpectedly also declared as non-const in 28.12.1 [re.regiter]/1
 as well as in (28.12.1.3 [re.regiter.deref]/1+2).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 1) In (28.12.1 [re.regiter]/1) change the current declarations
 </p>

 <blockquote><pre>bool operator==(const regex_iterator&amp;) <ins>const</ins>;
 bool operator!=(const regex_iterator&amp;) <ins>const</ins>;
 const value_type&amp; operator*() <ins>const</ins>;
 const value_type* operator-&gt;() <ins>const</ins>;
 </pre></blockquote>

 <p>
 2) In 28.12.1.3 [re.regiter.deref] change the following declarations
 </p>

 <blockquote><pre>const value_type&amp; operator*() <ins>const</ins>;
 const value_type* operator-&gt;() <ins>const</ins>;
 </pre></blockquote>

 <p>
 3) In 28.12.1.2 [re.regiter.comp] change the following declarations
 </p>

 <blockquote><pre>bool operator==(const regex_iterator&amp; right) <ins>const</ins>;
 bool operator!=(const regex_iterator&amp; right) <ins>const</ins>;
 </pre></blockquote>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue (which
 is to adopt the proposed wording in this issue).
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="654"></a>654. Missing IO roundtrip for random number engines</h3>
 <p><b>Section:</b> 26.4.1.3 [rand.req.eng] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-03-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.req.eng">issues</a> in [rand.req.eng].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Table 98 and para 5 in 26.4.1.3 [rand.req.eng] specify
 the IO insertion and extraction semantic of random
 number engines. It can be shown, v.i., that the specification
 of the extractor cannot guarantee to fulfill the requirement
 from para 5:
 </p>

 <blockquote><p>
 If a textual representation written via os &lt;&lt; x was
 subsequently read via is &gt;&gt; v, then x == v provided that
 there have been no intervening invocations of x or of v.
 </p></blockquote>

 <p>
 The problem is, that the extraction process described in
 table 98 misses to specify that it will initially set the
 if.fmtflags to ios_base::dec, see table 104:
 </p>

 <blockquote><p>
 dec: converts integer input or generates integer output
 in decimal base
 </p></blockquote>

 <p>
 Proof: The following small program demonstrates the violation
 of requirements (exception safety not fulfilled):
 </p>

 <blockquote><pre>#include &lt;cassert&gt;
 #include &lt;ostream&gt;
 #include &lt;iostream&gt;
 #include &lt;iomanip&gt;
 #include &lt;sstream&gt;

 class RanNumEngine {
   int state;
 public:
   RanNumEngine() : state(42) {}

   bool operator==(RanNumEngine other) const {
 	  return state == other.state;
   }

   template &lt;typename Ch, typename Tr&gt;
   friend std::basic_ostream&lt;Ch, Tr&gt;&amp; operator&lt;&lt;(std::basic_ostream&lt;Ch, Tr&gt;&amp; os, RanNumEngine engine) {
 	Ch old = os.fill(os.widen(' ')); // Sets space character
 	std::ios_base::fmtflags f = os.flags();
 	os &lt;&lt; std::dec &lt;&lt; std::left &lt;&lt; engine.state; // Adds ios_base::dec|ios_base::left
 	os.fill(old); // Undo
 	os.flags(f);
 	return os;
   }

   template &lt;typename Ch, typename Tr&gt;
   friend std::basic_istream&lt;Ch, Tr&gt;&amp; operator&gt;&gt;(std::basic_istream&lt;Ch, Tr&gt;&amp; is, RanNumEngine&amp; engine) {
        // Uncomment only for the fix.

 	//std::ios_base::fmtflags f = is.flags();
 	//is &gt;&gt; std::dec;
 	is &gt;&gt; engine.state;
 	//is.flags(f);
 	return is;
   }
 };

 int main() {
 	std::stringstream s;
 	s &lt;&lt; std::setfill('#'); // No problem
         s &lt;&lt; std::oct; // Yikes!
         // Here starts para 5 requirements:
 	RanNumEngine x;
 	s &lt;&lt; x;
 	RanNumEngine v;
 	s &gt;&gt; v;
 	assert(x == v); // Fails: 42 == 34
 }
 </pre></blockquote>

 <p>
 A second, minor issue seems to be, that the insertion
 description from table 98 unnecessarily requires the
 addition of ios_base::fixed (which only influences floating-point
 numbers). Its not entirely clear to me whether the proposed
 standard does require that the state of random number engines
 is stored in integral types or not, but I have the impression
 that this is the indent, see e.g. p. 3
 </p>

 <blockquote><p>
 The specification of each random number engine defines the
 size of its state in multiples of the size of its result_type.
 </p></blockquote>

 <p>
 If other types than integrals are supported, then I wonder why
 no requirements are specified for the precision of the stream.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="655"></a>655. Signature of generate_canonical not useful</h3>
 <p><b>Section:</b> 26.4.7.2 [rand.util.canonical] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-03-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.canonical">issues</a> in [rand.util.canonical].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 26.4.2 [rand.synopsis] we have the declaration
 </p>

 <blockquote><pre>template&lt;class RealType, class UniformRandomNumberGenerator,
   size_t bits&gt;
 result_type generate_canonical(UniformRandomNumberGenerator&amp; g);
 </pre></blockquote>

 <p>
 Besides the "result_type" issue (already recognized by Bo Persson
 at Sun, 11 Feb 2007 05:26:47 GMT in this group) it's clear, that
 the template parameter order is not reasonably choosen: Obviously
 one always needs to specify all three parameters, although usually
 only two are required, namely the result type RealType and the
 wanted bits, because UniformRandomNumberGenerator can usually
 be deduced.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="660"></a>660. Missing Bitwise Operations</h3>
 <p><b>Section:</b> 20.6 [function.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2007-04-02</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#function.objects">issues</a> in [function.objects].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>Section 20.6 [function.objects] provides <span id="st" name="st" class="st">function</span>
 <span id="st" name="st" class="st">objects</span> for some unary and binary
 operations, but others are missing. In a LWG reflector discussion, beginning
 with c++std-lib-18078, pros and cons of adding some of the missing operations
 were discussed. Bjarne Stroustrup commented "Why standardize what isn't used?
 Yes, I see the chicken and egg problems here, but it would be nice to see a
 couple of genuine uses before making additions."</p>
 <p>A number of libraries, including Rogue Wave, GNU, Adobe ASL, and Boost, have
 already added these functions, either publicly or for internal use. For example,
 Doug Gregor commented: "Boost will also add ... (|, &amp;, ^) in 1.35.0, because we
 need those <span id="st" name="st" class="st">function</span>
 <span id="st" name="st" class="st">objects</span> to represent various parallel
 collective operations (reductions, prefix reductions, etc.) in the new Message
 Passing Interface (MPI) library."</p>
 <p>Because the bitwise operators have the strongest use cases, the proposed
 resolution is limited to them.</p>


 <p><b>Proposed resolution:</b></p>
 <p>To 20.6 [function.objects], Function objects, paragraph 2, add to the header
 &lt;functional&gt; synopsis:</p>
 <blockquote>
   <pre>template &lt;class T&gt; struct bit_and;
 template &lt;class T&gt; struct bit_or;
 template &lt;class T&gt; struct bit_xor;</pre>
 </blockquote>
 <p>At a location in clause 20 to be determined by the Project Editor, add:</p>
 <blockquote>
   <p>The library provides basic function object classes for all of the bitwise
   operators in the language ([expr.bit.and], [expr.or], [exp.xor]).</p>
   <pre>template &lt;class T&gt; struct bit_and : binary_function&lt;T,T,T&gt; {
   T operator()(const T&amp; x , const T&amp; y ) const;
 };</pre>
   <blockquote>
     <p><code>operator()</code> returns<code> x &amp; y</code> .</p>
   </blockquote>
   <pre>template &lt;class T&gt; struct bit_or : binary_function&lt;T,T,T&gt; {
   T operator()(const T&amp; x , const T&amp; y ) const;
 };</pre>
   <blockquote>
     <p><code>operator()</code> returns <code>x | y</code> .</p>
   </blockquote>
   <pre>template &lt;class T&gt; struct bit_xor : binary_function&lt;T,T,T&gt; {
   T operator()(const T&amp; x , const T&amp; y ) const;
 };</pre>
   <blockquote>
     <p><code>operator()</code> returns <code>x ^ y</code> .</p>
   </blockquote>
 </blockquote>


 <hr>
 <h3><a name="661"></a>661. New 27.6.1.2.2 changes make special extractions useless</h3>
 <p><b>Section:</b> 27.6.1.2.2 [istream.formatted.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-04-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istream.formatted.arithmetic">issues</a> in [istream.formatted.arithmetic].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 To the more drastic changes of 27.6.1.2.2 [istream.formatted.arithmetic] in the current draft N2134 belong
 the explicit description of the extraction of the types short and int in
 terms of as-if code fragments.
 </p>

 <ol>
 <li>
 The corresponding as-if extractions in paragraph 2 and 3 will never
 result in a change of the operator&gt;&gt; argument val, because the
 contents of the local variable lval is in no case written into val.
 Furtheron both fragments need a currently missing parentheses in the
 beginning of the if-statement to be valid C++.
 </li>
 <li>I would like to ask whether the omission of a similar explicit
 extraction of unsigned short and unsigned int in terms of long -
 compared to their corresponding new insertions, as described in
 27.6.2.6.2 [ostream.inserters.arithmetic], is a deliberate decision or
 an
 oversight.
 </li>
 </ol>


 <p><b>Proposed resolution:</b></p>
 <ol>
 <li>
 <p>
 In 27.6.1.2.2 [istream.formatted.arithmetic]/2 change the current as-if code fragment
 </p>
 <blockquote><pre>typedef num_get&lt;charT,istreambuf_iterator&lt;charT,traits&gt; &gt; numget;
 iostate err = 0;
 long lval;
 use_facet&lt;numget&gt;(loc).get(*this, 0, *this, err, lval );
 if (err == 0) <ins>{</ins>
   <del>&amp;&amp;</del> <ins>if</ins> (lval &lt; numeric_limits&lt;short&gt;::min() || numeric_limits&lt;short&gt;::max() &lt; lval)<del>)</del>
       err = ios_base::failbit;
   <ins>else
     val = static_cast&lt;short&gt;(lval);
 }</ins>
 setstate(err);
 </pre></blockquote>

 <p>
 Similarily in 27.6.1.2.2 [istream.formatted.arithmetic]/3 change the current as-if fragment
 </p>

 <blockquote><pre>typedef num_get&lt;charT,istreambuf_iterator&lt;charT,traits&gt; &gt; numget;
 iostate err = 0;
 long lval;
 use_facet&lt;numget&gt;(loc).get(*this, 0, *this, err, lval );
 if (err == 0) <ins>{</ins>
   <del>&amp;&amp;</del> <ins>if</ins> (lval &lt; numeric_limits&lt;int&gt;::min() || numeric_limits&lt;int&gt;::max() &lt; lval)<del>)</del>
       err = ios_base::failbit;
   <ins>else
     val = static_cast&lt;int&gt;(lval);
 }</ins>
 setstate(err);
 </pre></blockquote>
 </li>
 <li>
 ---
 </li>
 </ol>


 <p><i>[
 Kona (2007): Note to the editor: the name lval in the call to <tt>use_facet</tt>
 is incorrectly italicized in the code fragments corresponding to
 <tt>operator&gt;&gt;(short &amp;)</tt> and <tt>operator &gt;&gt;(int &amp;)</tt>. Also, val -- which appears
 twice on the line with the <tt>static_cast</tt> in the proposed resolution --
 should be italicized. Also, in response to part two of the issue: this
 is deliberate.
 ]</i></p>


 <hr>
 <h3><a name="664"></a>664. <tt>do_unshift</tt> for <tt>codecvt&lt;char, char, mbstate_t&gt;</tt></h3>
 <p><b>Section:</b> 22.2.1.4.2 [locale.codecvt.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thomas Plum <b>Date:</b> 2007-04-16</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt.virtuals">issues</a> in [locale.codecvt.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 22.2.1.4.2 [locale.codecvt.virtuals], para 7 says (regarding <tt>do_unshift</tt>):
 </p>

 <blockquote><p>
 <i>Effects:</i> Places characters starting at to that should be appended to
 terminate a sequence when the current <tt>stateT</tt> is given by
 <tt><i>state</i></tt>.<sup>237)</sup> Stores no more than <tt>(<i>to_limit</i> -
 <i>to</i>)</tt> destination elements, and leaves the <tt><i>to_next</i></tt>
 pointer pointing one beyond the last element successfully stored.
 <em><tt>codecvt&lt;char, char, mbstate_t&gt;</tt> stores no characters.</em>
 </p></blockquote>

 <p>
 The following objection has been raised:
 </p>

 <blockquote><p>
 Since the C++ Standard permits a nontrivial conversion for the required
 instantiations of <tt>codecvt</tt>, it is overly restrictive to say that
 <tt>do_unshift</tt> must store no characters and return <tt>noconv</tt>.
 </p></blockquote>

 <p>
 [Plum ref _222152Y50]
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 22.2.1.4.2 [locale.codecvt.virtuals], p7:
 </p>

 <blockquote>
 <p>
 <i>Effects:</i> Places characters starting at <i>to</i> that should be
 appended to terminate a sequence when the current <tt>stateT</tt> is
 given by state.<sup>237)</sup> Stores no more than (<i>to_limit -to</i>)
 destination elements, and leaves the <i>to_next</i> pointer pointing one
 beyond the last element successfully stored. <del><tt>codecvt&lt;char, char,
 mbstate_t&gt;</tt> stores no characters.</del>
 </p>
 </blockquote>


 <hr>
 <h3><a name="665"></a>665. <tt>do_unshift</tt> return value</h3>
 <p><b>Section:</b> 22.2.1.4.2 [locale.codecvt.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thomas Plum <b>Date:</b> 2007-04-16</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.codecvt.virtuals">issues</a> in [locale.codecvt.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 22.2.1.4.2 [locale.codecvt.virtuals], para 8 says:
 </p>

 <blockquote><p>
 <tt>codecvt&lt;char,char,mbstate_t&gt;</tt>, returns <tt>noconv</tt>.
 </p></blockquote>

 <p>
 The following objection has been raised:
 </p>

 <blockquote><p>
 Despite what the C++ Standard
 says, <tt>unshift</tt> can't always return <tt>noconv</tt> for the default facets, since
 they can be nontrivial. At least one implementation does whatever the
 C functions do.
 </p></blockquote>

 <p>
 [Plum ref _222152Y62]
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 22.2.1.4.2 [locale.codecvt.virtuals], p8:
 </p>

 <blockquote>
 <p><i>Returns:</i> An enumeration value, as summarized in Table 76:</p>
 <p>...</p>
 <p>
 <del><tt>codecvt&lt;char,char,mbstate_t&gt;</tt>, returns <tt>noconv</tt>.</del>
 </p>
 </blockquote>


 <hr>
 <h3><a name="666"></a>666. <tt>moneypunct::do_curr_symbol()</tt></h3>
 <p><b>Section:</b> 22.2.6.3.2 [locale.moneypunct.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thomas Plum <b>Date:</b> 2007-04-16</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.moneypunct.virtuals">issues</a> in [locale.moneypunct.virtuals].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 22.2.6.3.2 [locale.moneypunct.virtuals], para 4 footnote 257 says
 </p>

 <blockquote><p>
 <sup>257)</sup> For international
 specializations (second template parameter <tt>true</tt>) this is always four
 characters long, usually three letters and a space.
 </p></blockquote>

 <p>
 The following objection has been raised:
 </p>

 <blockquote><p>
 The international currency
 symbol is whatever the underlying locale says it is, not necessarily
 four characters long.
 </p></blockquote>

 <p>
 [Plum ref _222632Y41]
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change footnote 253 in 22.2.6.3.2 [locale.moneypunct.virtuals]:
 </p>

 <blockquote>
 <p>
 <sup>253)</sup> For international specializations (second template
 parameter <tt>true</tt>) this is <del>always</del> <ins>typically</ins>
 four characters long, usually three letters and a space.
 </p>
 </blockquote>


 <hr>
 <h3><a name="672"></a>672. Swappable requirements need updating</h3>
 <p><b>Section:</b> 20.1.1 [utility.arg.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-05-04</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#utility.arg.requirements">active issues</a> in [utility.arg.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#utility.arg.requirements">issues</a> in [utility.arg.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current <tt>Swappable</tt> is:
 </p>

 <blockquote>
 <table border="1">
 <caption>Table 37: <tt>Swappable</tt> requirements <b>[swappable]</b></caption>
 <tbody><tr><th>expression</th><th>return type</th><th>post-condition</th></tr>
 <tr><td><tt>swap(s,t)</tt></td><td><tt>void</tt></td><td><tt>t</tt> has the value originally held by <tt>u</tt>, and <tt>u</tt> has the value originally
 held by <tt>t</tt></td></tr>
 <tr><td colspan="3">
 <p>
 The Swappable requirement is met by satisfying one or more of the following conditions:
 </p>
 <ul>
 <li>
 <tt>T</tt> is Swappable if <tt>T</tt> satisfies the <tt>CopyConstructible</tt> requirements (Table 34)
 and the <tt>CopyAssignable</tt> requirements (Table 36);
 </li>
 <li>
 <tt>T</tt> is Swappable if a namespace scope function named <tt>swap</tt> exists in the same
 namespace as the definition of <tt>T</tt>, such that the expression <tt>swap(t,u)</tt> is valid
 and has the semantics described in this table.
 </li>
 </ul>
 </td></tr>
 </tbody></table>
 </blockquote>

 <p>
 With the passage of rvalue reference into the language, <tt>Swappable</tt> needs to be updated to
 require only <tt>MoveConstructible</tt> and <tt>MoveAssignable</tt>.  This is a minimum.
 </p>

 <p>
 Additionally we may want to support proxy references such that the following code is acceptable:
 </p>

 <blockquote><pre>namespace Mine {

 template &lt;class T&gt;
 struct proxy {...};

 template &lt;class T&gt;
 struct proxied_iterator
 {
    typedef T value_type;
    typedef proxy&lt;T&gt; reference;
    reference operator*() const;
    ...
 };

 struct A
 {
    // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
    void swap(A&amp;);
    ...
 };

 void swap(A&amp;, A&amp;);
 void swap(proxy&lt;A&gt;, A&amp;);
 void swap(A&amp;, proxy&lt;A&gt;);
 void swap(proxy&lt;A&gt;, proxy&lt;A&gt;);

 }  // Mine

 ...

 Mine::proxied_iterator&lt;Mine::A&gt; i(...)
 Mine::A a;
 swap(*i1, a);
 </pre></blockquote>

 <p>
 I.e. here is a call to <tt>swap</tt> which the user enables swapping between a proxy to a class and the class
 itself.  We do not need to anything in terms of implementation except not block their way with overly
 constrained concepts.  That is, the <tt>Swappable</tt> concept should be expanded to allow swapping
 between two different types for the case that one is binding to a user-defined <tt>swap</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change 20.1.1 [utility.arg.requirements]:
 </p>

 <blockquote>

 <p>
 -1- The template definitions in the C++ Standard Library refer to various
 named requirements whose details are set out in tables 31-38. In these
 tables, <tt>T</tt> is a type to be supplied by a C++ program
 instantiating a template; <tt>a</tt>, <tt>b</tt>, and <tt>c</tt> are
 values of type <tt>const T</tt>; <tt>s</tt> and <tt>t</tt> are modifiable
 lvalues of type <tt>T</tt>; <tt>u</tt> is a value of type (possibly
 <tt>const</tt>) <tt>T</tt>; and <tt>rv</tt> is a non-<tt>const</tt>
 rvalue of type <tt>T</tt>.
 </p>

 <table border="1">
 <caption>Table 37: <tt>Swappable</tt> requirements <b>[swappable]</b></caption>
 <tbody><tr><th>expression</th><th>return type</th><th>post-condition</th></tr>
 <tr><td><tt>swap(s,t)</tt></td><td><tt>void</tt></td>
 <td><tt>t</tt> has the value originally
 held by <tt>u</tt>, and
 <tt>u</tt> has the value originally held
 by <tt>t</tt></td></tr>
 <tr><td colspan="3">
 <p>
 The <tt>Swappable</tt> requirement is met by satisfying one or more of the following conditions:
 </p>
 <ul>
 <li>
 <tt>T</tt> is <tt>Swappable</tt> if <tt>T</tt> satisfies the
 <del><tt>CopyConstructible</tt></del> <ins>MoveConstructible</ins>
 requirements (Table <del>34</del> <ins>33</ins>) and the <del><tt>CopyAssignable</tt></del> <ins>MoveAssignable</ins>
 requirements (Table <del>36</del> <ins>35</ins>);
 </li>
 <li>
 <tt>T</tt> is <tt>Swappable</tt> if a namespace scope function named
 <tt>swap</tt> exists in the same namespace as the definition of
 <tt>T</tt>, such that the expression
 <tt>swap(t,u)</tt> is valid and has the
 semantics described in this table.
 </li>
 </ul>
 </td></tr>
 </tbody></table>
 </blockquote>


 <p><i>[
 Kona (2007): We like the change to the <tt>Swappable</tt> requirements to use
 move semantics. The issue relating to the support of proxies is
 separable from the one relating to move semantics, and it's bigger than
 just swap. We'd like to address only the move semantics changes under
 this issue, and open a separated issue (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>) to handle proxies. Also, there
 may be a third issue, in that the current definition of <tt>Swappable</tt> does
 not permit rvalues to be operands to a swap operation, and Howard's
 proposed resolution would allow the right-most operand to be an rvalue,
 but it would not allow the left-most operand to be an rvalue (some swap
 functions in the library have been overloaded to permit left operands to
 swap to be rvalues).
 ]</i></p>


 <hr>
 <h3><a name="673"></a>673. <tt>unique_ptr</tt> update</h3>
 <p><b>Section:</b> 20.7.11 [unique.ptr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-05-04</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr">issues</a> in [unique.ptr].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Since the publication of
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1856.html">N1856</a>
 there have been a few small but significant advances which should be included into
 <tt>unique_ptr</tt>.  There exists a
 <a href="http://home.twcny.rr.com/hinnant/cpp_extensions/unique_ptr.html">example implmenation</a>
 for all of these changes.
 </p>

 <ul>

 <li>
 <p>
 Even though <tt>unique_ptr&lt;void&gt;</tt> is not a valid use case (unlike for <tt>shared_ptr&lt;void&gt;</tt>),
 unexpected cases to crop up which require the instantiation of the interface of <tt>unique_ptr&lt;void&gt;</tt>
 even if it is never used.  For example see
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">LWG 541</a> for how this accidently
 happened to <tt>auto_ptr</tt>.  I believe the most robust way to protect <tt>unique_ptr</tt> against this
 type of failure is to augment the return type of <tt>unique_ptr&lt;T&gt;:operator*()</tt> with
 <tt>add_lvalue_reference&lt;T&gt;::type</tt>.  This means that given an instantiated <tt>unique_ptr&lt;void&gt;</tt>
 the act of dereferencing it will simply return <tt>void</tt> instead of causing a compile time failure.
 This is simpler than creating a <tt>unique_ptr&lt;void&gt;</tt> specialization which isn't robust in the
 face of <tt><i>cv-</i></tt>qualified <tt>void</tt> types.
 </p>

 <p>
 This resolution also supports instantiations such as <tt>unique_ptr&lt;void, free_deleter&gt;</tt>
 which could be very useful to the client.
 </p>

 </li>

 <li>
 <p>
 Efforts have been made to better support containers and smart pointers in shared
 memory contexts.  One of the key hurdles in such support is not assuming that a
 pointer type is actually a <tt>T*</tt>.  This can easily be accomplished
 for <tt>unique_ptr</tt> by having the deleter define the pointer type:
 <tt>D::pointer</tt>.  Furthermore this type can easily be defaulted to
 <tt>T*</tt> should the deleter <tt>D</tt> choose not to define a pointer
 type (example implementation
 <a href="http://home.twcny.rr.com/hinnant/cpp_extensions/unique_ptr.html">here</a>).
 This change has no run time overhead.  It has no interface overhead on
 authors of custom delter types.  It simply allows (but not requires)
 authors of custom deleter types to define a smart pointer for the
 storage type of <tt>unique_ptr</tt> if they find such functionality
 useful.  <tt>std::default_delete</tt> is an example of a deleter which
 defaults <tt>pointer</tt> to <tt>T*</tt> by simply ignoring this issue
 and not including a <tt>pointer typedef</tt>.
 </p>
 </li>

 <li>
 <p>
 When the deleter type is a function pointer then it is unsafe to construct
 a <tt>unique_ptr</tt> without specifying the function pointer in the constructor.
 This case is easy to check for with a <tt>static_assert</tt> assuring that the
 deleter is not a pointer type in those constructors which do not accept deleters.
 </p>

 <blockquote><pre>unique_ptr&lt;A, void(*)(void*)&gt; p(new A);  // error, no function given to delete the pointer!
 </pre></blockquote>

 </li>

 </ul>

 <p><i>[
 Kona (2007): We don't like the solution given to the first bullet in
 light of concepts. The second bullet solves the problem of supporting
 fancy pointers for one library component only. The full LWG needs to
 decide whether to solve the problem of supporting fancy pointers
 piecemeal, or whether a paper addressing the whole library is needed. We
 think that the third bullet is correct.
 ]</i></p>


 <p><i>[
 Post Kona: Howard adds example user code related to the first bullet:
 ]</i></p>


 <blockquote>
 <pre>void legacy_code(void*, std::size_t);

 void foo(std::size_t N)
 {
     std::unique_ptr&lt;void, void(*)(void*)&gt; ptr(std::malloc(N), std::free);
     legacy_code(ptr.get(), N);
 }   // unique_ptr used for exception safety purposes
 </pre>
 </blockquote>

 <p>
 I.e. <tt>unique_ptr&lt;void&gt;</tt> <i>is</i> a useful tool that we don't want
 to disable with concepts.  The only part of <tt>unique_ptr&lt;void&gt;</tt> we
 want to disable (with concepts or by other means) are the two member functions:
 </p>

 <blockquote><pre>T&amp; operator*() const;
 T* operator-&gt;() const;
 </pre></blockquote>


 <p><b>Proposed resolution:</b></p>

 <p><i>[
 I am grateful for the generous aid of Peter Dimov and Ion Gaztañaga in helping formulate and review
 the proposed resolutions below.
 ]</i></p>


 <ul>
 <li>

 <p>
 Change 20.7.11.2 [unique.ptr.single]:
 </p>

 <blockquote><pre>template &lt;class T, class D = default_delete&lt;T&gt;&gt; class unique_ptr {
    ...
    <del>T&amp;</del> <ins>typename add_lvalue_reference&lt;T&gt;::type</ins> operator*() const;
    ...
 };
 </pre></blockquote>

 <p>
 Change 20.7.11.2.4 [unique.ptr.single.observers]:
 </p>

 <blockquote><pre><del>T&amp;</del> <ins>typename add_lvalue_reference&lt;T&gt;::type</ins> operator*() const;
 </pre></blockquote>

 </li>

 <li>
 <p>
 Change 20.7.11.2 [unique.ptr.single]:
 </p>

 <blockquote><pre>template &lt;class T, class D = default_delete&lt;T&gt;&gt; class unique_ptr {
 public:
   <ins>typedef <i>implementation (see description below)</i> pointer;</ins>
    ...
    explicit unique_ptr(<del>T*</del> <ins>pointer</ins> p);
    ...
    unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined (see description below)</i> d);
    unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined (see description below)</i> d);
    ...
    <del>T*</del> <ins>pointer</ins> operator-&gt;() const;
    <del>T*</del> <ins>pointer</ins> get() const;
    ...
    <del>T*</del> <ins>pointer</ins> release();
    void reset(<del>T*</del> <ins>pointer</ins> p = <del>0</del> <ins>pointer()</ins>);
 };
 </pre></blockquote>

 <p>
 <ins>
 -3- If the type <tt>remove_reference&lt;D&gt;::type::pointer</tt>
 exists, then <tt>unique_ptr&lt;T, D&gt;::pointer</tt> is a typedef to
 <tt>remove_reference&lt;D&gt;::type::pointer</tt>.  Otherwise
 <tt>unique_ptr&lt;T, D&gt;::pointer</tt> is a typedef to <tt>T*</tt>.
 The type <tt>unique_ptr&lt;T, D&gt;::pointer</tt> shall be <tt>CopyConstructible</tt>
 and <tt>CopyAssignable</tt>.
 </ins>
 </p>

 <p>
 Change 20.7.11.2.1 [unique.ptr.single.ctor]:
 </p>

 <blockquote><pre>unique_ptr(<del>T*</del> <ins>pointer</ins> p);
 ...
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
 ...
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, const A&amp; d);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, A&amp;&amp; d);
 ...
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, A&amp; d);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, A&amp;&amp; d);
 ...
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, const A&amp; d);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, const A&amp;&amp; d);
 ...
 </pre></blockquote>

 <p>
 -23- <i>Requires:</i> If <tt>D</tt> is not a reference type,
 construction of the deleter <tt>D</tt> from an rvalue of type <tt>E</tt>
 <del>must</del> <ins>shall</ins> be well formed and not throw an exception. If <tt>D</tt> is a
 reference type, then <tt>E</tt> <del>must</del> <ins>shall</ins> be the same type as <tt>D</tt>
 (diagnostic required). <del><tt>U*</tt></del> <ins><tt>unique_ptr&lt;U,E&gt;::pointer</tt></ins>
 <del>must</del> <ins>shall</ins> be implicitly convertible to <del><tt>T*</tt></del>
 <ins>pointer</ins>.
 </p>

 <p>
 -25- <i>Postconditions:</i> <tt>get() == value u.get()</tt> had before
 the construction, modulo any required offset adjustments resulting from
 the cast from <del><tt>U*</tt></del>
 <ins><tt>unique_ptr&lt;U,E&gt;::pointer</tt></ins> to <del><tt>T*</tt></del>
 <ins>pointer</ins>. <tt>get_deleter()</tt> returns a reference to the
 internally stored deleter which was constructed from
 <tt>u.get_deleter()</tt>.
 </p>

 <p>
 Change 20.7.11.2.3 [unique.ptr.single.asgn]:
 </p>

 <blockquote>
 <p>
 -8- <i>Requires:</i> Assignment of the deleter <tt>D</tt> from an rvalue
 <tt>D</tt> <del>must</del> <ins>shall</ins> not throw an exception. <del><tt>U*</tt></del>
 <ins><tt>unique_ptr&lt;U,E&gt;::pointer</tt></ins> <del>must</del> <ins>shall</ins> be implicitly
 convertible to <del><tt>T*</tt></del> <ins>pointer</ins>.
 </p>
 </blockquote>

 <p>
 Change 20.7.11.2.4 [unique.ptr.single.observers]:
 </p>

 <blockquote>
 <pre><del>T*</del> <ins>pointer</ins> operator-&gt;() const;</pre>
 ...
 <pre><del>T*</del> <ins>pointer</ins> get() const;</pre>
 </blockquote>

 <p>
 Change 20.7.11.2.5 [unique.ptr.single.modifiers]:
 </p>

 <blockquote>
 <pre><del>T*</del> <ins>pointer</ins> release();</pre>
 ...
 <pre>void reset(<del>T*</del> <ins>pointer</ins> p = <del>0</del> <ins>pointer()</ins>);</pre>
 </blockquote>

 <p>
 Change 20.7.11.3 [unique.ptr.runtime]:
 </p>

 <blockquote><pre>template &lt;class T, class D&gt; class unique_ptr&lt;T[], D&gt; {
 public:
   <ins>typedef <i>implementation</i> pointer;</ins>
    ...
    explicit unique_ptr(<del>T*</del> <ins>pointer</ins> p);
    ...
    unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
    unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
    ...
    <del>T*</del> <ins>pointer</ins> get() const;
    ...
    <del>T*</del> <ins>pointer</ins> release();
    void reset(<del>T*</del> <ins>pointer</ins> p = <del>0</del> <ins>pointer()</ins>);
 };
 </pre></blockquote>

 <p>
 Change 20.7.11.3.1 [unique.ptr.runtime.ctor]:
 </p>

 <blockquote>
 <pre>unique_ptr(<del>T*</del> <ins>pointer</ins> p);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
 unique_ptr(<del>T*</del> <ins>pointer</ins> p, <i>implementation defined</i> d);
 </pre>

 <p>
 These constructors behave the same as in the primary template except
 that they do not accept pointer types which are convertible to
 <del><tt>T*</tt></del> <ins><tt>pointer</tt></ins>. [<i>Note:</i> One
 implementation technique is to create private templated overloads of
 these members. <i>-- end note</i>]
 </p>
 </blockquote>

 <p>
 Change 20.7.11.3.3 [unique.ptr.runtime.modifiers]:
 </p>

 <blockquote>
 <pre>void reset(<del>T*</del> <ins>pointer</ins> p = <del>0</del> <ins>pointer()</ins>);
 </pre>

 <p>
 -1- <i>Requires:</i> Does not accept pointer types which are convertible
 to <del><tt>T*</tt></del> <ins><tt>pointer</tt></ins> (diagnostic
 required). [<i>Note:</i> One implementation technique is to create a private
 templated overload. <i>-- end note</i>]
 </p>
 </blockquote>

 </li>

 <li>

 <p>
 Change 20.7.11.2.1 [unique.ptr.single.ctor]:
 </p>

 <blockquote>
 <pre>unique_ptr();</pre>
 <blockquote>
 <p>
 <i>Requires:</i> <tt>D</tt> <del>must</del> <ins>shall</ins> be default constructible, and that
 construction <del>must</del> <ins>shall</ins> not throw an exception. <tt>D</tt> <del>must</del> <ins>shall</ins> not be a
 reference type <ins>or pointer type (diagnostic required)</ins>.
 </p>
 </blockquote>
 <pre>unique_ptr(<del>T*</del> <ins>pointer</ins> p);</pre>
 <blockquote>
 <p>
 <i>Requires:</i>  The expression <tt>D()(p)</tt> <del>must</del> <ins>shall</ins> be well formed.
 The default constructor of <tt>D</tt> <del>must</del> <ins>shall</ins> not throw an exception.
 <tt>D</tt> <del>must</del> <ins>shall</ins> not be a reference type <ins>or pointer type (diagnostic
 required)</ins>.
 </p>
 </blockquote>
 </blockquote>

 </li>

 </ul>


 <hr>
 <h3><a name="674"></a>674. <tt>shared_ptr</tt> interface changes for consistency with N1856</h3>
 <p><b>Section:</b> 20.7.12.2 [util.smartptr.shared] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2007-05-05</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#util.smartptr.shared">active issues</a> in [util.smartptr.shared].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared">issues</a> in [util.smartptr.shared].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1856.html">N1856</a> does not propose
 any changes to <tt>shared_ptr</tt>. It needs to be updated to use a rvalue reference where appropriate
 and to interoperate with <tt>unique_ptr</tt> as it does with <tt>auto_ptr</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>

 <p>
 Change 20.7.12.2 [util.smartptr.shared] as follows:
 </p>

 <blockquote>
 <pre>template&lt;class Y&gt; explicit shared_ptr(auto_ptr&lt;Y&gt;<del>&amp;</del><ins>&amp;&amp;</ins> r);
 <ins>template&lt;class Y, class D&gt; explicit shared_ptr(const unique_ptr&lt;Y,D&gt;&amp; r) = delete;
 template&lt;class Y, class D&gt; explicit shared_ptr(unique_ptr&lt;Y,D&gt;&amp;&amp; r);</ins>
 ...
 template&lt;class Y&gt; shared_ptr&amp; operator=(auto_ptr&lt;Y&gt;<del>&amp;</del><ins>&amp;&amp;</ins> r);
 <ins>template&lt;class Y, class D&gt; shared_ptr&amp; operator=(const unique_ptr&lt;Y,D&gt;&amp; r) = delete;
 template&lt;class Y, class D&gt; shared_ptr&amp; operator=(unique_ptr&lt;Y,D&gt;&amp;&amp; r);</ins></pre>
 </blockquote>

 <p>
 Change 20.7.12.2.1 [util.smartptr.shared.const] as follows:
 </p>

 <blockquote>
 <pre><ins>template&lt;class Y&gt; shared_ptr(auto_ptr&lt;Y&gt;<del>&amp;</del><ins>&amp;&amp;</ins> r);</ins></pre>
 </blockquote>

 <p>
 Add to 20.7.12.2.1 [util.smartptr.shared.const]:
 </p>

 <blockquote>
 <pre><ins>template&lt;class Y, class D&gt; shared_ptr(unique_ptr&lt;Y, D&gt;&amp;&amp; r);</ins></pre>
 <blockquote>

 <p><ins>
 <i>Effects:</i> Equivalent to <tt>shared_ptr( r.release(), r.get_deleter() )</tt> when <tt>D</tt> is
           not a reference type, <tt>shared_ptr( r.release(), ref( r.get_deleter() ) )</tt>
           otherwise.
 </ins></p>

 <p><ins>
 <i>Exception safety:</i> If an exception is thrown, the constructor has no effect.
 </ins></p>
 </blockquote>

 </blockquote>

 <p>
 Change 20.7.12.2.3 [util.smartptr.shared.assign] as follows:
 </p>

 <blockquote>
 <pre>template&lt;class Y&gt; shared_ptr&amp; operator=(auto_ptr&lt;Y&gt;<del>&amp;</del><ins>&amp;&amp;</ins> r);</pre>
 </blockquote>

 <p>
 Add to 20.7.12.2.3 [util.smartptr.shared.assign]:
 </p>

 <blockquote>
 <pre><ins>template&lt;class Y, class D&gt; shared_ptr&amp; operator=(unique_ptr&lt;Y,D&gt;&amp;&amp; r);</ins></pre>

 <blockquote>
 <p><ins>
 -4- <i>Effects:</i> Equivalent to <tt>shared_ptr(std::move(r)).swap(*this)</tt>.
 </ins></p>
 <p><ins>
 -5- <i>Returns:</i> <tt>*this</tt>.
 </ins></p>
 </blockquote>

 </blockquote>


 <p><i>[
 Kona (2007): We may need to open an issue (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>) to deal with the question of
 whether <tt>shared_ptr</tt> needs an rvalue <tt>swap</tt>.
 ]</i></p>


 <hr>
 <h3><a name="677"></a>677. Weaknesses in seed_seq::randomize [rand.util.seedseq]</h3>
 <p><b>Section:</b> 26.4.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Charles Karney <b>Date:</b> 2007-05-15</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.util.seedseq">active issues</a> in [rand.util.seedseq].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>seed_seq::randomize</tt> provides a mechanism for initializing random number
 engines which ideally would yield "distant" states when given "close"
 seeds.  The algorithm for <tt>seed_seq::randomize</tt> given in the current
 Working Draft for C++,
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2284.pdf">N2284</a>
 (2007-05-08), has 3 weaknesses
 </p>

 <ol>
 <li>
 <p> Collisions in state.  Because of the way the state is initialized,
     seeds of different lengths may result in the same state.  The
     current version of seed_seq has the following properties:</p>
 <ul>
 <li>  For a given <tt>s &lt;= n</tt>, each of the 2^(32s) seed vectors results in a
       distinct state.</li>
 </ul>
 <p>
     The proposed algorithm (below) has the considerably stronger
     properties:</p>
 <ul>
 <li>   All of the <tt>(2^(32n)-1)/(2^32-1)</tt> seed vectors of lengths <tt>s &lt; n</tt>
       result in distinct states.
 </li>
 <li>  All of the <tt>2^(32n)</tt> seed vectors of length <tt>s == n</tt> result in
       distinct states.
 </li>
 </ul>
 </li>
 <li>
 <p> Poor mixing of <tt>v'</tt>s entropy into the state.  Consider <tt>v.size() == n</tt>
     and hold <tt>v[n/2]</tt> thru <tt>v[n-1]</tt> fixed while varying <tt>v[0]</tt> thru <tt>v[n/2-1]</tt>,
     a total of <tt>2^(16n)</tt> possibilities.  Because of the simple recursion
     used in <tt>seed_seq</tt>, <tt>begin[n/2]</tt> thru <tt>begin[n-1]</tt> can take on only 2^64
     possible states.</p>

 <p> The proposed algorithm uses a more complex recursion which results
     in much better mixing.</p>
 </li>
 <li> <tt>seed_seq::randomize</tt> is undefined for <tt>v.size() == 0</tt>.  The proposed
     algorithm remedies this.
 </li>
 </ol>
 <p>
 The current algorithm for <tt>seed_seq::randomize</tt> is adapted by me from the
 initialization procedure for the Mersenne Twister by Makoto Matsumoto
 and Takuji Nishimura.  The weakness (2) given above was communicated to
 me by Matsumoto last year.
 </p>
 <p>
 The proposed replacement for <tt>seed_seq::randomize</tt> is due to Mutsuo Saito,
 a student of Matsumoto, and is given in the implementation of the
 SIMD-oriented Fast Mersenne Twister random number generator SFMT.
 <a href="http://www.math.sci.hiroshima-u.ac.jp/%7Em-mat/MT/SFMT/index.html">http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html</a>
 <a href="http://www.math.sci.hiroshima-u.ac.jp/%7Em-mat/MT/SFMT/SFMT-src-1.2.tar.gz">http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/SFMT-src-1.2.tar.gz</a>
 </p>
 <p>
 See
 Mutsuo Saito,
 An Application of Finite Field: Design and Implementation of 128-bit
 Instruction-Based Fast Pseudorandom Number Generator,
 Master's Thesis, Dept. of Math., Hiroshima University (Feb. 2007)
 <a href="http://www.math.sci.hiroshima-u.ac.jp/%7Em-mat/MT/SFMT/M062821.pdf">http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/M062821.pdf</a>
 </p>
 <p>
 One change has been made here, namely to treat the case of small <tt>n</tt>
 (setting <tt>t = (n-1)/2</tt> for <tt>n &lt; 7</tt>).
 </p>
 <p>
 Since <tt>seed_seq</tt> was introduced relatively recently there is little cost
 in making this incompatible improvement to it.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="678"></a>678. Changes for [rand.req.eng]</h3>
 <p><b>Section:</b> 26.4.1.3 [rand.req.eng] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Charles Karney <b>Date:</b> 2007-05-15</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.req.eng">issues</a> in [rand.req.eng].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Section 26.4.1.3 [rand.req.eng] Random number engine requirements:
 </p>

 <p>
 This change follows naturally from the proposed change to
 <tt>seed_seq::randomize</tt> in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>.
 </p>

 <p>
 In table 104 the description of <tt>X(q)</tt> contains a special treatment of
 the case <tt>q.size() == 0</tt>.  This is undesirable for 4 reasons:
 </p>

 <ol>
 <li>It replicates the functionality provided by <tt>X()</tt>.</li>
 <li>It leads to the possibility of a collision in the state provided
     by some other <tt>X(q)</tt> with <tt>q.size() &gt; 0</tt>.</li>
 <li>It is inconsistent with the description of the <tt>X(q)</tt> in
 paragraphs 26.4.3.1 [rand.eng.lcong] p5, 26.4.3.2 [rand.eng.mers] p8, and 26.4.3.3 [rand.eng.sub] p10 where
 there is no special treatment of <tt>q.size() == 0</tt>.</li>
 <li>The proposed replacement for <tt>seed_seq::randomize</tt> given above
     allows for the case <tt>q.size() == 0</tt>.</li>
 </ol>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="679"></a>679. resize parameter by value</h3>
 <p><b>Section:</b> 23.2 [sequences] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-06-11</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The C++98 standard specifies that one member function alone of the containers
 passes its parameter (<tt>T</tt>) by value instead of by const reference:
 </p>

 <blockquote><pre>void resize(size_type sz, T c = T());
 </pre></blockquote>

 <p>
 This fact has been discussed / debated repeatedly over the years, the first time
 being even before C++98 was ratified.  The rationale for passing this parameter by
 value has been:
 </p>

 <blockquote>
 <p>
 So that self referencing statements are guaranteed to work, for example:
 </p>
 <blockquote><pre>v.resize(v.size() + 1, v[0]);
 </pre></blockquote>
 </blockquote>

 <p>
 However this rationale is not convincing as the signature for <tt>push_back</tt> is:
 </p>

 <blockquote><pre>void push_back(const T&amp; x);
 </pre></blockquote>

 <p>
 And <tt>push_back</tt> has similar semantics to <tt>resize</tt> (append).
 And <tt>push_back</tt> must also work in the self referencing case:
 </p>

 <blockquote><pre>v.push_back(v[0]);  // must work
 </pre></blockquote>

 <p>
 The problem with passing <tt>T</tt> by value is that it can be significantly more
 expensive than passing by reference.  The converse is also true, however when it is
 true it is usually far less dramatic (e.g. for scalar types).
 </p>

 <p>
 Even with move semantics available, passing this parameter by value can be expensive.
 Consider for example <tt>vector&lt;vector&lt;int&gt;&gt;</tt>:
 </p>

 <blockquote><pre>std::vector&lt;int&gt; x(1000);
 std::vector&lt;std::vector&lt;int&gt;&gt; v;
 ...
 v.resize(v.size()+1, x);
 </pre></blockquote>

 <p>
 In the pass-by-value case, <tt>x</tt> is copied once to the parameter of
 <tt>resize</tt>.  And then internally, since the code can not know at compile
 time by how much <tt>resize</tt> is growing the <tt>vector</tt>, <tt>x</tt> is
 usually copied (not moved) a second time from <tt>resize</tt>'s parameter into its proper place
 within the <tt>vector</tt>.
 </p>

 <p>
 With pass-by-const-reference, the <tt>x</tt> in the above example need be copied
 only once.  In this case, <tt>x</tt> has an expensive copy constructor and so any
 copies that can be saved represents a significant savings.
 </p>

 <p>
 If we can be efficient for <tt>push_back</tt>, we should be efficient for <tt>resize</tt>
 as well.  The resize taking a reference parameter has been coded and shipped in the
 CodeWarrior library with no reports of problems which I am aware of.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 23.2.2 [deque], p2:
 </p>

 <blockquote><pre>class deque {
    ...
    void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>

 <p>
 Change 23.2.2.2 [deque.capacity], p3:
 </p>

 <blockquote><pre>void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>

 <p>
 Change 23.2.4 [list], p2:
 </p>

 <blockquote><pre>class list {
    ...
    void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>

 <p>
 Change 23.2.4.2 [list.capacity], p3:
 </p>

 <blockquote><pre>void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>

 <p>
 Change 23.2.6 [vector], p2:
 </p>

 <blockquote><pre>class vector {
    ...
    void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>

 <p>
 Change 23.2.6.2 [vector.capacity], p11:
 </p>

 <blockquote><pre>void resize(size_type sz, <ins>const </ins>T<ins>&amp;</ins> c);
 </pre></blockquote>


 <hr>
 <h3><a name="680"></a>680. move_iterator operator-&gt; return</h3>
 <p><b>Section:</b> 24.4.3.1 [move.iterator] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-06-11</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>move_iterator</tt>'s <tt>operator-&gt;</tt> return type <tt>pointer</tt>
 does not consistently match the type which is returned in the description
 in 24.4.3.3.5 [move.iter.op.ref].
 </p>

 <blockquote><pre>template &lt;class Iterator&gt;
 class move_iterator {
 public:
     ...
     typedef typename iterator_traits&lt;Iterator&gt;::pointer pointer;
     ...
     pointer operator-&gt;() const {return current;}
     ...
 private:
     Iterator current; // exposition only
 };
 </pre></blockquote>


 <p>
 There are two possible fixes.
 </p>

 <ol>
 <li><tt>pointer operator-&gt;() const {return &amp;*current;}</tt></li>
 <li><tt>typedef Iterator pointer;</tt></li>
 </ol>

 <p>
 The first solution is the one chosen by <tt>reverse_iterator</tt>.  A potential
 disadvantage of this is it may not work well with iterators which return a
 proxy on dereference and that proxy has overloaded <tt>operator&amp;()</tt>.  Proxy
 references often need to overloaad <tt>operator&amp;()</tt> to return a proxy
 pointer.  That proxy pointer may or may not be the same type as the iterator's
 <tt>pointer</tt> type.
 </p>

 <p>
 By simply returning the <tt>Iterator</tt> and taking advantage of the fact that
 the language forwards calls to <tt>operator-&gt;</tt> automatically until it
 finds a non-class type, the second solution avoids the issue of an overloaded
 <tt>operator&amp;()</tt> entirely.
 </p>

 <p><b>Proposed resolution:</b></p>
 <p>
 Change the synopsis in 24.4.3.1 [move.iterator]:
 </p>

 <blockquote><pre>typedef <del>typename iterator_traits&lt;</del>Iterator<del>&gt;::pointer</del> pointer;
 </pre></blockquote>


 <hr>
 <h3><a name="681"></a>681. Operator functions impossible to compare are defined in [re.submatch.op]</h3>
 <p><b>Section:</b> 28.9.2 [re.submatch.op] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Nozomu Katoo <b>Date:</b> 2007-05-27</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In 28.9.2 [re.submatch.op] of N2284,
 operator functions numbered 31-42 seem impossible to compare. &nbsp;E.g.:
 </p>

 <blockquote>
 <pre>template &lt;class BiIter&gt;
 &nbsp; &nbsp; bool operator==(typename iterator_traits&lt;BiIter&gt;::value_type const&amp; lhs,
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; const sub_match&lt;BiIter&gt;&amp; rhs);
 </pre>
 <blockquote>
 <p>
 -31- <i>Returns:</i> <tt>lhs == rhs.str()</tt>.
 </p>
 </blockquote>
 </blockquote>

 <p>
 When <tt>char*</tt> is used as <tt>BiIter</tt>, <tt>iterator_traits&lt;BiIter&gt;::value_type</tt> would be
 <tt>char</tt>, so that <tt>lhs == rhs.str()</tt> ends up comparing a <tt>char</tt> value and an object
 of <tt>std::basic_string&lt;char&gt;</tt>. &nbsp;However, the behaviour of comparison between
 these two types is not defined in 21.3.8 [string.nonmembers] of N2284.
 &nbsp;This applies when <tt>wchar_t*</tt> is used as <tt>BiIter</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2409.pdf">N2409</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="682"></a>682. basic_regex ctor takes InputIterator or ForwardIterator?</h3>
 <p><b>Section:</b> 28.8.2 [re.regex.construct] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Eric Niebler <b>Date:</b> 2007-06-03</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Looking at N2284, 28.8 [re.regex], p3 <tt>basic_regex</tt> class template synopsis shows this
 constructor:
 </p>
 <blockquote><pre>template &lt;class InputIterator&gt;
 &nbsp; &nbsp; &nbsp;basic_regex(InputIterator first, InputIterator last,
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;flag_type f = regex_constants::ECMAScript);
 </pre></blockquote>

 <p>
 In 28.8.2 [re.regex.construct], p15, the constructor appears with this signature:
 </p>

 <blockquote><pre>template &lt;class ForwardIterator&gt;
 &nbsp; &nbsp; &nbsp;basic_regex(ForwardIterator first, ForwardIterator last,
 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;flag_type f = regex_constants::ECMAScript);
 </pre></blockquote>

 <p>
 <tt>ForwardIterator</tt> is probably correct, so the synopsis is wrong.
 </p>

 <p><i>[
 John adds:
 ]</i></p>


 <blockquote>
 <p>
 I think either could be implemented? &nbsp;Although an input iterator would
 probably require an internal copy of the string being made.
 </p>
 <p>
 I have no strong feelings either way, although I think my original intent
 was <tt>InputIterator</tt>.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2409.pdf">N2409</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2409 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="685"></a>685. reverse_iterator/move_iterator difference has invalid signatures</h3>
 <p><b>Section:</b> 24.4.1.3.19 [reverse.iter.opdiff], 24.4.3.3.14 [move.iter.nonmember] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Bo Persson <b>Date:</b> 2007-06-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In C++03 the difference between two <tt>reverse_iterators</tt>
 </p>
 <blockquote><pre>ri1 - ri2
 </pre></blockquote>
 <p>
 is possible to compute only if both iterators have the same base
 iterator. The result type is the <tt>difference_type</tt> of the base iterator.
 </p>
 <p>
 In the current draft, the operator is defined as 24.4.1.3.19 [reverse.iter.opdiff]
 </p>
 <blockquote><pre>template&lt;class Iterator1, class Iterator2&gt;
 typename reverse_iterator&lt;Iterator&gt;::difference_type
    operator-(const reverse_iterator&lt;Iterator1&gt;&amp; x,
                     const reverse_iterator&lt;Iterator2&gt;&amp; y);
 </pre></blockquote>
 <p>
 The return type is the same as the C++03 one, based on the no longer
 present <tt>Iterator</tt> template parameter.
 </p>
 <p>
 Besides being slightly invalid, should this operator work only when
 <tt>Iterator1</tt> and <tt>Iterator2</tt> has the same <tt>difference_type</tt>? Or should the
 implementation choose one of them? Which one?
 </p>
 <p>
 The same problem now also appears in <tt>operator-()</tt> for <tt>move_iterator</tt>
 24.4.3.3.14 [move.iter.nonmember].
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the synopsis in 24.4.1.1 [reverse.iterator]:
 </p>

 <blockquote>
 <pre>template &lt;class Iterator1, class Iterator2&gt;
   <del>typename reverse_iterator&lt;Iterator&gt;::difference_type</del> <ins>auto</ins> operator-(
     const reverse_iterator&lt;Iterator1&gt;&amp; x,
     const reverse_iterator&lt;Iterator2&gt;&amp; y)<ins> -&gt; decltype(y.current - x.current)</ins>;
 </pre>
 </blockquote>

 <p>
 Change 24.4.1.3.19 [reverse.iter.opdiff]:
 </p>

 <blockquote>
 <pre>template &lt;class Iterator1, class Iterator2&gt;
   <del>typename reverse_iterator&lt;Iterator&gt;::difference_type</del> <ins>auto</ins> operator-(
     const reverse_iterator&lt;Iterator1&gt;&amp; x,
     const reverse_iterator&lt;Iterator2&gt;&amp; y)<ins> -&gt; decltype(y.current - x.current)</ins>;
 </pre>
 <blockquote>
 <p>
 <i>Returns:</i> <tt>y.current - x.current</tt>.
 </p>
 </blockquote>
 </blockquote>


 <p>
 Change the synopsis in 24.4.3.1 [move.iterator]:
 </p>

 <blockquote>
 <pre>template &lt;class Iterator1, class Iterator2&gt;
   <del>typename move_iterator&lt;Iterator&gt;::difference_type</del> <ins>auto</ins> operator-(
     const move_iterator&lt;Iterator1&gt;&amp; x,
     const move_iterator&lt;Iterator2&gt;&amp; y)<ins> -&gt; decltype(x.base() - y.base())</ins>;
 </pre>
 </blockquote>

 <p>
 Change 24.4.3.3.14 [move.iter.nonmember]:
 </p>

 <blockquote>
 <pre>template &lt;class Iterator1, class Iterator2&gt;
   <del>typename move_iterator&lt;Iterator&gt;::difference_type</del> <ins>auto</ins> operator-(
     const move_iterator&lt;Iterator1&gt;&amp; x,
     const move_iterator&lt;Iterator2&gt;&amp; y)<ins> -&gt; decltype(x.base() - y.base())</ins>;
 </pre>
 <blockquote>
 <p>
 <i>Returns:</i> <tt>x.base() - y.base()</tt>.
 </p>
 </blockquote>
 </blockquote>

 <p><i>[
 Pre Bellevue:  This issue needs to wait until the <tt>auto -&gt; return</tt> language feature
 goes in.
 ]</i></p>


 <hr>
 <h3><a name="687"></a>687. shared_ptr conversion constructor not constrained</h3>
 <p><b>Section:</b> 20.7.12.2.1 [util.smartptr.shared.const], 20.7.12.3.1 [util.smartptr.weak.const] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2007-05-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared.const">issues</a> in [util.smartptr.shared.const].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Since all conversions from <tt>shared_ptr&lt;T&gt;</tt> to <tt>shared_ptr&lt;U&gt;</tt> have the same
 rank regardless of the relationship between <tt>T</tt> and <tt>U</tt>, reasonable user
 code that works with raw pointers fails with <tt>shared_ptr</tt>:
 </p>

 <blockquote><pre>void f( shared_ptr&lt;void&gt; );
 void f( shared_ptr&lt;int&gt; );

 int main()
 {
 &nbsp;&nbsp;f( shared_ptr&lt;double&gt;() ); // ambiguous
 }
 </pre></blockquote>

 <p>
 Now that we officially have <tt>enable_if</tt>, we can constrain the constructor
 and the corresponding assignment operator to only participate in the
 overload resolution when the pointer types are compatible.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 20.7.12.2.1 [util.smartptr.shared.const], change:
 </p>

 <blockquote><p>
 -14- <i>Requires:</i> <del>For the second constructor</del> <ins>The
 second constructor shall not participate in the overload resolution
 unless</ins> <tt>Y*</tt> <del>shall be</del> <ins>is implicitly</ins> convertible
 to <tt>T*</tt>.
 </p></blockquote>

 <p>
 In 20.7.12.3.1 [util.smartptr.weak.const], change:
 </p>

 <blockquote>
 <pre><del>template&lt;class Y&gt; weak_ptr(shared_ptr&lt;Y&gt; const&amp; r);</del>
 <del>weak_ptr(weak_ptr const&amp; r);</del>
 <del>template&lt;class Y&gt; weak_ptr(weak_ptr&lt;Y&gt; const&amp; r);</del>
 <ins>weak_ptr(weak_ptr const&amp; r);</ins>
 <ins>template&lt;class Y&gt; weak_ptr(weak_ptr&lt;Y&gt; const&amp; r);</ins>
 <ins>template&lt;class Y&gt; weak_ptr(shared_ptr&lt;Y&gt; const&amp; r);</ins>
 </pre>
 <blockquote><p>
 -4- <i>Requires:</i> <del>For</del> <del>t</del><ins>T</ins>he second and
 third constructors<del>,</del> <ins>shall not participate in the
 overload resolution unless</ins> <tt>Y*</tt> <del>shall be</del>
 <ins>is implicitly</ins> convertible to <tt>T*</tt>.
 </p></blockquote>
 </blockquote>


 <hr>
 <h3><a name="689"></a>689. reference_wrapper constructor overly constrained</h3>
 <p><b>Section:</b> 20.6.5.1 [refwrap.const] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2007-05-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#refwrap.const">issues</a> in [refwrap.const].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The constructor of <tt>reference_wrapper</tt> is currently <tt>explicit</tt>. The primary
 motivation behind this is the safety problem with respect to rvalues,
 which is addressed by the proposed resolution of the previous issue.
 Therefore we should consider relaxing the requirements on the
 constructor since requests for the implicit conversion keep resurfacing.
 </p>
 <p>
 Also please see the thread starting at c++std-lib-17398 for some good discussion on this subject.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Remove the <tt>explicit</tt> from the constructor of <tt>reference_wrapper</tt>. If the
 proposed resolution of the previous issue is accepted, remove the
 <tt>explicit</tt> from the <tt>T&amp;&amp;</tt> constructor as well to keep them in sync.
 </p>


 <hr>
 <h3><a name="693"></a>693. <code>std::bitset::all()</code> missing</h3>
 <p><b>Section:</b> 23.3.5 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-06-22</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The  <code>bitset</code> class template  provides the  member function
 <code>any()</code> to determine whether an  object of the type has any
 bits  set, and  the member  function <code>none()</code>  to determine
 whether all of an object's  bits are clear. However, the template does
 not   provide  a   corresponding  function   to  discover   whether  a
 <code>bitset</code>  object  has  all  its  bits  set.   While  it  is
 possible,  even easy,  to  obtain this  information  by comparing  the
 result of <code>count()</code>  with the result of <code>size()</code>
 for  equality  (i.e.,  via  <code>b.count()  ==  b.size()</code>)  the
 operation  is   less  efficient   than  a  member   function  designed
 specifically  for that purpose  could be.   (<code>count()</code> must
 count  all non-zero bits  in a  <code>bitset</code> a  word at  a time
 while <code>all()</code> could stop counting as soon as it encountered
 the first word with a zero bit).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add  a declaration of the new  member function <code>all()</code> to the
 defintion of the <code>bitset</code> template in 23.3.5 [template.bitset], p1,
 right above the declaration of <code>any()</code> as shown below:
 </p>

 <blockquote><pre>bool operator!=(const bitset&lt;N&gt;&amp; rhs) const;
 bool test(size_t pos) const;
 <ins>bool all() const;</ins>
 bool any() const;
 bool none() const;
 </pre></blockquote>

 <p>
 Add a description of the new member function to the end of 23.3.5.2 [bitset.members] with the following text:
 </p>
 <blockquote><p>
 <code>bool all() const;</code>
 </p>
 <blockquote>
 <i>Returns</i>: <code>count() == size()</code>.
 </blockquote>
 </blockquote>

 <p>
 In  addition,   change  the  description   of  <code>any()</code>  and
 <code>none()</code>   for  consistency   with   <code>all()</code>  as
 follows:
 </p>
 <blockquote><p>
 <code>bool any() const;</code>
 </p>
 <blockquote>
 <p>
 <i>Returns</i>: <del><code>true</code> if any bit in <code>*this</code>
 is one</del><ins><code>count() != 0</code></ins>.
 </p>
 </blockquote>
 <p>
 <code>bool none() const;</code>
 </p>
 <blockquote>
 <p>
 <i>Returns</i>: <del><code>true</code> if no bit in <code>*this</code>
 is one</del><ins><code>count() == 0</code></ins>.
 </p>
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="694"></a>694. <code>std::bitset</code> and <code>long long</code></h3>
 <p><b>Section:</b> 23.3.5 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-06-22</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Objects of the  <code>bitset</code> class template specializations can
 be constructed from  and explicitly converted to values  of the widest
 C++ integer  type, <code>unsigned long</code>.   With the introduction
 of  <code>long long</code> into  the language  the template  should be
 enhanced to make it possible  to interoperate with values of this type
 as well, or  perhaps <code>uintmax_t</code>.  See c++std-lib-18274 for
 a brief discussion in support of this change.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 For simplicity,  instead of  adding overloads for  <code>unsigned long
 long</code> and dealing with possible ambiguities in the spec, replace
 the <code>bitset</code> ctor  that takes an <code>unsigned long</code>
 argument  with  one  taking  <code>unsigned long  long</code>  in  the
 definition  of the  template as  shown below.   (The  standard permits
 implementations  to add  overloads on  other integer  types  or employ
 template tricks to  achieve the same effect provided  they don't cause
 ambiguities or changes in behavior.)
 </p>
 <blockquote>
 <pre>// [bitset.cons] constructors:
 bitset();
 bitset(unsigned <ins>long</ins> long val);
 template&lt;class charT, class traits, class Allocator&gt;
 explicit bitset(
                 const basic_string&lt;charT,traits,Allocator&gt;&amp; str,
                 typename basic_string&lt;charT,traits,Allocator&gt;::size_type pos = 0,
                 typename basic_string&lt;charT,traits,Allocator&gt;::size_type n =
                     basic_string&lt;charT,traits,Allocator&gt;::npos);
 </pre>
 </blockquote>
 <p>
 Make a corresponding change in 23.3.5.1 [bitset.cons], p2:
 </p>
 <blockquote>
 <p>
 <code>bitset(unsigned <ins>long</ins> long val);</code>
 </p>
 <blockquote>
 <i>Effects</i>:  Constructs   an  object  of   class  bitset&lt;N&gt;,
 initializing  the  first <code><i>M</i></code>  bit  positions to  the
 corresponding      bit     values      in     <code><i>val</i></code>.
 <code><i>M</i></code> is the  smaller of <code><i>N</i></code> and the
 number of bits in  the value representation (section [basic.types]) of
 <code>unsigned  <ins> long</ins> long</code>.   If  <code><i>M</i> &lt;
 <i>N</i></code>  <ins>is  <code>true</code></ins>,  the remaining  bit
 positions are initialized to zero.
 </blockquote>
 </blockquote>

 <p>
 Additionally, introduce a new member function <code>to_ullong()</code>
 to make  it possible to  convert <code>bitset</code> to values  of the
 new  type. Add  the following  declaration  to the  definition of  the
 template, immediate  after the declaration  of <code>to_ulong()</code>
 in 23.3.5 [template.bitset], p1, as shown below:
 </p>
 <blockquote>
 <pre>// element access:
 bool operator[](size_t pos) const; // for b[i];
 reference operator[](size_t pos); // for b[i];
 unsigned long to_ulong() const;
 <ins>unsigned long long to_ullong() const;</ins>
 template &lt;class charT, class traits, class Allocator&gt;
 basic_string&lt;charT, traits, Allocator&gt; to_string() const;
 </pre>
 </blockquote>
 <p>
 And add a description of  the new member function to 23.3.5.2 [bitset.members],
 below  the  description of  the  existing <code>to_ulong()</code>  (if
 possible), with the following text:
 </p>
 <blockquote>
 <p>
 <code>unsigned long long to_ullong() const;</code>
 </p>
 <blockquote>
 <i>Throws</i>:  <code>overflow_error</code>   if  the  integral  value
 <code><i>x</i></code> corresponding to  the bits in <code>*this</code>
 cannot be represented as type <code>unsigned long long</code>.
 </blockquote>
 <blockquote>
 <i>Returns:</i> <code><i>x</i></code>.
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="695"></a>695. ctype&lt;char&gt;::classic_table() not accessible</h3>
 <p><b>Section:</b> 22.2.1.3 [facet.ctype.special] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Martin Sebor <b>Date:</b> 2007-06-22</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The   <code>ctype&lt;char&gt;::classic_table()</code>   static  member
 function    returns    a    pointer    to   an    array    of    const
 <code>ctype_base::mask</code>    objects    (enums)   that    contains
 <code>ctype&lt;char&gt;::table_size</code>    elements.    The   table
 describes the properties of the character set in the "C" locale (i.e.,
 whether a  character at an index  given by its value  is alpha, digit,
 punct,   etc.),   and   is    typically   used   to   initialize   the
 <code>ctype&lt;char&gt;</code>  facet in the  classic "C"  locale (the
 protected      <code>ctype&lt;char&gt;</code>      member     function
 <code>table()</code>    then    returns     the    same    value    as
 <code>classic_table()</code>).
 </p>
 <p>
 However, while <code>ctype&lt;char&gt;::table_size</code> (the size of
 the   table)    is   a   public    static   const   member    of   the
 <code>ctype&lt;char&gt;</code>           specialization,           the
 <code>classic_table()</code> static member function is protected. That
 makes getting at the classic  data less than convenient (i.e., one has
 to create  a whole derived class just  to get at the  masks array). It
 makes  little sense  to expose  the size  of the  table in  the public
 interface while making the table itself protected, especially when the
 table is a constant object.
 </p>
 <p>
 The  same argument  can be  made for  the non-static  protected member
 function <code>table()</code>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Make     the    <code>ctype&lt;char&gt;::classic_table()</code>    and
 <code>ctype&lt;char&gt;::table()</code>  member  functions  public  by
 moving their declarations into the public section of the definition of
 specialization in 22.2.1.3 [facet.ctype.special] as shown below:
 </p>
 <blockquote>
 <pre>  static locale::id id;
   static const size_t table_size = IMPLEMENTATION_DEFINED;
 <del>protected:</del>
   const mask* table() const throw();
   static const mask* classic_table() throw();
 <ins>protected:</ins>

 ~ctype(); // virtual
 virtual char do_toupper(char c) const;
 </pre>
 </blockquote>


 <hr>
 <h3><a name="699"></a>699. N2111 changes min/max</h3>
 <p><b>Section:</b> 26.4 [rand] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger <b>Date:</b> 2007-07-01</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand">issues</a> in [rand].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2111.pdf">N2111</a>
 changes <tt>min/max</tt> in several places in random from member
 functions to static data members. I believe this introduces
 a needless backward compatibility problem between C++0X and
 TR1. I'd like us to find new names for the static data members,
 or perhaps change <tt>min/max</tt> to <tt>constexpr</tt>s in C++0X.
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="700"></a>700. N1856 defines struct <tt>identity</tt></h3>
 <p><b>Section:</b> 20.2.2 [forward] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger <b>Date:</b> 2007-07-01</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#forward">active issues</a> in [forward].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#forward">issues</a> in [forward].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1856.html">N1856</a>
 defines struct <tt>identity</tt> in <tt>&lt;utility&gt;</tt> which clashes with
 the traditional definition of struct <tt>identity</tt> in <tt>&lt;functional&gt;</tt>
 (not standard, but a common extension from old STL). Be nice
 if we could avoid this name clash for backward compatibility.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 20.2.2 [forward]:
 </p>

 <blockquote>
 <pre>template &lt;class T&gt; struct identity
 {
     typedef T type;
     <ins>const T&amp; operator()(const T&amp; x) const;</ins>
 };
 </pre>
 <blockquote>
 <pre><ins>const T&amp; operator()(const T&amp; x) const;</ins>
 </pre>
 <blockquote>
 <p>
 <ins><i>Returns:</i> <tt>x</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 </blockquote>


 <hr>
 <h3><a name="703"></a>703. <tt>map::at()</tt> need a complexity specification</h3>
 <p><b>Section:</b> 23.3.1.2 [map.access] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Joe Gottman <b>Date:</b> 2007-07-03</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#map.access">issues</a> in [map.access].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>map::at()</tt> need a complexity specification.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the following to the specification of <tt>map::at()</tt>, 23.3.1.2 [map.access]:
 </p>
 <blockquote>
 <p>
 <i>Complexity:</i> logarithmic.
 </p>
 </blockquote>


 <hr>
 <h3><a name="705"></a>705. type-trait <tt>decay</tt> incompletely specified</h3>
 <p><b>Section:</b> 20.5.7 [meta.trans.other] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thorsten Ottosen <b>Date:</b> 2007-07-08</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#meta.trans.other">active issues</a> in [meta.trans.other].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.trans.other">issues</a> in [meta.trans.other].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current working draft has a type-trait <tt>decay</tt> in 20.5.7 [meta.trans.other].
 </p>

 <p>
 Its use is to turn C++03 pass-by-value parameters into efficient C++0x
 pass-by-rvalue-reference parameters. However, the current definition
 introduces an incompatible change where the cv-qualification of the
 parameter type is retained. The deduced type should loose such
 cv-qualification, as pass-by-value does.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 20.5.7 [meta.trans.other] change the last sentence:
 </p>

 <blockquote><p>
 Otherwise the  member typedef <tt>type</tt> equals <tt><ins>remove_cv&lt;</ins>U<ins>&gt;::type</ins></tt>.
 </p></blockquote>

 <p>
 In 20.4.1.3 [tuple.creation]/1 change:
 </p>

 <blockquote><p>
 <del>where each <tt>Vi</tt> in <tt>VTypes</tt> is <tt>X&amp;</tt> if, for the
 corresponding type <tt>Ti</tt> in <tt>Types</tt>,
 <tt>remove_cv&lt;remove_reference&lt;Ti&gt;::type&gt;::type</tt> equals
 <tt>reference_wrapper&lt;X&gt;</tt>, otherwise <tt>Vi</tt> is
 <tt>decay&lt;Ti&gt;::type</tt>.</del>
 <ins>Let <tt>Ui</tt> be <tt>decay&lt;Ti&gt;::type</tt> for each
 <tt>Ti</tt> in <tt>Types</tt>. Then each <tt>Vi</tt> in <tt>VTypes</tt>
 is <tt>X&amp;</tt> if <tt>Ui</tt> equals
 <tt>reference_wrapper&lt;X&gt;</tt>, otherwise <tt>Vi</tt> is
 <tt>Ui</tt>.</ins>
 </p></blockquote>


 <hr>
 <h3><a name="706"></a>706. <tt>make_pair()</tt> should behave as <tt>make_tuple()</tt> wrt. <tt>reference_wrapper()</tt></h3>
 <p><b>Section:</b> 20.2.3 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thorsten Ottosen <b>Date:</b> 2007-07-08</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current draft has <tt>make_pair()</tt> in 20.2.3 [pairs]/16
 and <tt>make_tuple()</tt> in 20.4.1.3 [tuple.creation].
 <tt>make_tuple()</tt> detects the presence of
 <tt>reference_wrapper&lt;X&gt;</tt> arguments and "unwraps" the reference in
 such cases. <tt>make_pair()</tt> would OTOH create a
 <tt>reference_wrapper&lt;X&gt;</tt> member. I suggest that the two
 functions are made to behave similar in this respect to minimize
 confusion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 20.2 [utility] change the synopsis for make_pair() to read
 </p>

 <blockquote><pre>template &lt;class T1, class T2&gt;
   pair&lt;<del>typename decay&lt;T1&gt;::type</del> <ins>V1</ins>, <del>typename decay&lt;T2&gt;::type</del> <ins>V2</ins>&gt; make_pair(T1&amp;&amp;, T2&amp;&amp;);
 </pre></blockquote>

 <p>
 In 20.2.3 [pairs]/16 change the declaration to match the above synopsis.
 Then change the 20.2.3 [pairs]/17 to:
 </p>

 <blockquote>
 <p>
 <i>Returns:</i> <tt>pair&lt;<del>typename decay&lt;T1&gt;::type</del> <ins>V1</ins>,<del>typename decay&lt;T2&gt;::type</del> <ins>V2</ins>&gt;(forward&lt;T1&gt;(x),forward&lt;T2&gt;(y))</tt> <ins>where <tt>V1</tt> and
 <tt>V2</tt> are determined as follows: Let <tt>Ui</tt> be
 <tt>decay&lt;Ti&gt;::type</tt> for each <tt>Ti</tt>. Then each
 <tt>Vi</tt> is <tt>X&amp;</tt> if <tt>Ui</tt> equals
 <tt>reference_wrapper&lt;X&gt;</tt>, otherwise <tt>Vi</tt> is
 <tt>Ui</tt>.</ins>
 </p>
 </blockquote>


 <hr>
 <h3><a name="710"></a>710. Missing postconditions</h3>
 <p><b>Section:</b> 20.7.12.2 [util.smartptr.shared] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Peter Dimov <b>Date:</b> 2007-08-24</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#util.smartptr.shared">active issues</a> in [util.smartptr.shared].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared">issues</a> in [util.smartptr.shared].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 A discussion on
 <a href="http://groups.google.com/group/comp.std.c++/browse_frm/thread/8e89dceb35cd7971">comp.std.c++</a>
 has identified a contradiction in the <tt>shared_ptr</tt> specification.
 The <tt>shared_ptr</tt> move constructor and the cast functions are
 missing postconditions for the <tt>get()</tt> accessor.
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 Move to "ready", adopting the first (Peter's) proposed resolution.
 </p>
 <p>
 Note to the project editor: there is an editorial issue here. The
 wording for the postconditions of the casts is slightly awkward, and the
 editor should consider rewording "If w is the return value...", e. g. as
 "For a return value w...".
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add to 20.7.12.2.1 [util.smartptr.shared.const]:
 </p>

 <blockquote>
 <pre>shared_ptr(shared_ptr&amp;&amp; r);
 template&lt;class Y&gt; shared_ptr(shared_ptr&lt;Y&gt;&amp;&amp; r);
 </pre>
 <blockquote>
 <p>
 <i>Postconditions:</i>  <tt>*this</tt> shall contain the old value of <tt>r</tt>. <tt>r</tt>
 shall be empty. <ins><tt>r.get() == 0</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 <p>
 Add to 20.7.12.2.10 [util.smartptr.shared.cast]:
 </p>

 <blockquote>
 <pre>template&lt;class T, class U&gt; shared_ptr&lt;T&gt; static_pointer_cast(shared_ptr&lt;U&gt; const&amp; r);
 </pre>
 <blockquote>
 <p>
 <ins><i>Postconditions:</i> If <tt>w</tt> is the return value,
 <tt>w.get() == static_cast&lt;T*&gt;(r.get()) &amp;&amp; w.use_count() == r.use_count()</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 <blockquote>
 <pre>template&lt;class T, class U&gt; shared_ptr&lt;T&gt; dynamic_pointer_cast(shared_ptr&lt;U&gt; const&amp; r);
 </pre>
 <blockquote>
 <p>
 <ins><i>Postconditions:</i> If <tt>w</tt> is the return value, <tt>w.get() == dynamic_cast&lt;T*&gt;(r.get())</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 <blockquote>
 <pre>template&lt;class T, class U&gt; shared_ptr&lt;T&gt; const_pointer_cast(shared_ptr&lt;U&gt; const&amp; r);
 </pre>
 <blockquote>
 <p>
 <ins><i>Postconditions:</i> If <tt>w</tt> is the return value,
 <tt>w.get() == const_cast&lt;T*&gt;(r.get()) &amp;&amp; w.use_count() == r.use_count()</tt>.</ins>
 </p>
 </blockquote>
 </blockquote>

 <p>
 Alberto Ganesh Barbati has written an
 <a href="http://barbati.net/c++/shared_ptr.pdf">alternative proposal</a>
 where he suggests (among other things) that the casts be respecified in terms of
 the aliasing constructor as follows:
 </p>

 <p>
 Change 20.7.12.2.10 [util.smartptr.shared.cast]:
 </p>

 <blockquote>
 <p>
 -2- <i>Returns:</i> <del>If <tt>r</tt> is empty, an <tt>empty
 shared_ptr&lt;T&gt;;</tt> otherwise, a <tt>shared_ptr&lt;T&gt;</tt>
 object that stores <tt>static_cast&lt;T*&gt;(r.get())</tt> and shares ownership with
 <tt>r</tt>.</del> <ins><tt>shared_ptr&lt;T&gt;(r, static_cast&lt;T*&gt;(r.get())</tt>.</ins>
 </p>
 </blockquote>

 <blockquote>
 <p>
 -6- <i>Returns:</i>
 </p>
 <ul>
 <li><del>When <tt>dynamic_cast&lt;T*&gt;(r.get())</tt> returns a nonzero value,
 a <tt>shared_ptr&lt;T&gt;</tt> object that stores a copy
 of it and <i>shares ownership</i> with <tt>r</tt>;</del></li>
 <li><del>Otherwise, an <i>empty</i> <tt>shared_ptr&lt;T&gt;</tt> object.</del></li>
 <li><ins>If <tt>p = dynamic_cast&lt;T*&gt;(r.get())</tt> is a non-null pointer, <tt>shared_ptr&lt;T&gt;(r, p);</tt></ins></li>
 <li><ins>Otherwise, <tt>shared_ptr&lt;T&gt;()</tt>.</ins></li>
 </ul>
 </blockquote>

 <blockquote>
 <p>
 -10- <i>Returns:</i> <del>If <tt>r</tt> is empty, an <tt>empty
 shared_ptr&lt;T&gt;;</tt> otherwise, a <tt>shared_ptr&lt;T&gt;</tt>
 object that stores <tt>const_cast&lt;T*&gt;(r.get())</tt> and shares ownership with
 <tt>r</tt>.</del> <ins><tt>shared_ptr&lt;T&gt;(r, const_cast&lt;T*&gt;(r.get())</tt>.</ins>
 </p>
 </blockquote>

 <p>
 This takes care of the missing postconditions for the casts by bringing
 in the aliasing constructor postcondition "by reference".
 </p>


 <hr>
 <h3><a name="712"></a>712. <tt>seed_seq::size</tt> no longer useful</h3>
 <p><b>Section:</b> 26.4.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Marc Paterno <b>Date:</b> 2007-08-25</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.util.seedseq">active issues</a> in [rand.util.seedseq].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 One of the motivations for incorporating <tt>seed_seq::size()</tt>
 was to simplify the wording
 in other parts of 26.4 [rand].
 As a side effect of resolving related issues,
 all such references
 to <tt>seed_seq::size()</tt> will have been excised.
 More importantly,
 the present specification is contradictory,
 as "The number of 32-bit units the object can deliver"
 is not the same as "the result of <tt>v.size()</tt>."
 </p>

 <p>
 See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2391.pdf">N2391</a> and
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>
 for some further discussion.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Adopt the proposed resolution in
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2423.pdf">N2423</a>.
 </p>


 <p><i>[
 Kona (2007): The LWG adopted the proposed resolution of N2423 for this issue.
 The LWG voted to accelerate this issue to Ready status to be voted into the WP at Kona.
 ]</i></p>


 <hr>
 <h3><a name="715"></a>715. <tt>minmax_element</tt> complexity is too lax</h3>
 <p><b>Section:</b> 25.3.7 [alg.min.max] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Matt Austern <b>Date:</b> 2007-08-30</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.min.max">issues</a> in [alg.min.max].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The complexity for <tt>minmax_element</tt> (25.3.7 [alg.min.max] par 16) says "At most <tt>max(2 *
 (last - first ) - 2, 0)</tt> applications of the corresponding comparisons",
 i.e. the worst case complexity is no better than calling <tt>min_element</tt> and
 <tt>max_element</tt> separately. This is gratuitously inefficient. There is a
 well known technique that does better: see section 9.1 of CLRS
 (Introduction to Algorithms, by Cormen, Leiserson, Rivest, and Stein).
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 25.3.7 [alg.min.max] to:
 </p>

 <blockquote>
 <pre>template&lt;class ForwardIterator&gt;
   pair&lt;ForwardIterator, ForwardIterator&gt;
     minmax_element(ForwardIterator first , ForwardIterator last);
 template&lt;class ForwardIterator, class Compare&gt;
   pair&lt;ForwardIterator, ForwardIterator&gt;
     minmax_element(ForwardIterator first , ForwardIterator last , Compare comp);
 </pre>
 <blockquote>
 <p>
 <i>Returns:</i> <tt>make_pair(m, M)</tt>, where <tt>m</tt> is
 <del><tt>min_element(first, last)</tt> or <tt>min_element(first, last,
 comp)</tt></del> <ins>the first iterator in <tt>[first,
 last)</tt> such that no iterator in the range refers to a smaller element,</ins> and
 <ins>where</ins> <tt>M</tt> is <del><tt>max_element(first, last)</tt> or
 <tt>max_element(first, last, comp)</tt></del> <ins>the last iterator
 in <tt>[first, last)</tt> such that no iterator in the range refers to a larger element</ins>.
 </p>
 <p>
 <i>Complexity:</i> At most <del><tt>max(2 * (last - first ) - 2, 0)</tt></del>
 <ins><tt>max(&#8970;(3/2) (N-1)&#8971;, 0)</tt></ins> applications of the
 corresponding <del>comparisons</del> <ins>predicate, where <tt>N</tt> is <tt>distance(first, last)</tt></ins>.
 </p>
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="722"></a>722. Missing [c.math] functions <tt>nanf</tt> and <tt>nanl</tt></h3>
 <p><b>Section:</b> 26.7 [c.math] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2007-08-27</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#c.math">issues</a> in [c.math].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 In the listing of 26.7 [c.math], table 108: Header <tt>&lt;cmath&gt;</tt> synopsis I miss
 the following C99 functions (from 7.12.11.2):
 </p>

 <blockquote><pre>float nanf(const char *tagp);
 long double nanl(const char *tagp);
 </pre></blockquote>

 <p>
 (Note: These functions cannot be overloaded and they are also not
 listed anywhere else)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 26.7 [c.math], table 108, section "Functions", add <tt>nanf</tt> and <tt>nanl</tt>
 just after the existing entry <tt>nan</tt>.
 </p>


 <hr>
 <h3><a name="740"></a>740. Please remove <tt>*_ptr&lt;T[N]&gt;</tt></h3>
 <p><b>Section:</b> 20.7.11.4 [unique.ptr.compiletime] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Herb Sutter <b>Date:</b> 2007-10-04</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Please don't provide <tt>*_ptr&lt;T[N]&gt;</tt>. It doesn't enable any useful
 bounds-checking (e.g., you could imagine that doing <tt>op++</tt> on a
 <tt>shared_ptr&lt;T[N]&gt;</tt> yields a <tt>shared_ptr&lt;T[N-1]&gt;</tt>, but that promising path
 immediately falters on <tt>op--</tt> which can't reliably dereference because we
 don't know the lower bound). Also, most buffers you'd want to point to
 don't have a compile-time known size.
 </p>

 <p>
 To enable any bounds-checking would require run-time information, with
 the usual triplet: base (lower bound), current offset, and max offset
 (upper  bound). And I can sympathize with the point of view that you
 wouldn't want to require this on <tt>*_ptr</tt> itself. But please let's not
 follow the <tt>&lt;T[N]&gt;</tt> path, especially not with additional functions to
 query the bounds etc., because this sets wrong user expectations by
 embarking on a path that doesn't go all the way to bounds checking as it
 seems to imply.
 </p>

 <p>
 If bounds checking is desired, consider a <tt>checked_*_ptr</tt> instead (e.g.,
 <tt>checked_shared_ptr</tt>). And make the interfaces otherwise identical so that
 user code could easily <tt>#define/typedef</tt> between prepending <tt>checked_</tt> on
 debug builds and not doing so on release builds (for example).
 </p>

 <p>
 Note that some may object that <tt>checked_*_ptr</tt> may seem to make the smart
 pointer more like <tt>vector</tt>, and we don't want two ways to spell <tt>vector</tt>. I
 don't agree, but if that were true that would be another reason to
 remove <tt>*_ptr&lt;T[N]&gt;</tt> which equally makes the smart pointer more like
 <tt>std::array.</tt> :-)
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>Suggestion that fixed-size array instantiations are going to fail at
 compile time anyway (if we remove specialization) due to pointer decay,
 at least that appears to be result from available compilers.
 </p>
 <p>
 So concerns about about requiring static_assert seem unfounded.
 </p>
 <p>After a little more experimentation with compiler, it appears that
 fixed size arrays would only work at all if we supply these explicit
 specialization. So removing them appears less breaking than originally
 thought.
 </p>
 <p>
 straw poll unanimous move to Ready.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the synopsis under 20.7.11 [unique.ptr] p2:
 </p>

 <blockquote><pre>...
 template&lt;class T&gt; struct default_delete;
 template&lt;class T&gt; struct default_delete&lt;T[]&gt;;
 <del>template&lt;class T, size_t N&gt; struct default_delete&lt;T[N]&gt;;</del>

 template&lt;class T, class D = default_delete&lt;T&gt;&gt; class unique_ptr;
 template&lt;class T, class D&gt; class unique_ptr&lt;T[], D&gt;;
 <del>template&lt;class T, class D, size_t N&gt; class unique_ptr&lt;T[N], D&gt;;</del>
 ...
 </pre></blockquote>

 <p>
 Remove the entire section 20.7.11.1.3 [unique.ptr.dltr.dflt2] <b><tt>default_delete&lt;T[N]&gt;</tt></b>.
 </p>

 <p>
 Remove the entire section 20.7.11.4 [unique.ptr.compiletime] <b><tt>unique_ptr</tt> for array objects with a compile time length</b>
 and its subsections: 20.7.11.4.1 [unique.ptr.compiletime.dtor], 20.7.11.4.2 [unique.ptr.compiletime.observers],
 20.7.11.4.3 [unique.ptr.compiletime.modifiers].
 </p>


 <hr>
 <h3><a name="743"></a>743. rvalue <tt>swap</tt> for <tt>shared_ptr</tt></h3>
 <p><b>Section:</b> 20.7.12.2.9 [util.smartptr.shared.spec] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Howard Hinnant <b>Date:</b> 2007-10-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 When the LWG looked at <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a> in Kona the following note was made:
 </p>

 <blockquote><p>
 We may need to open an issue to deal with the question of
 whether <tt>shared_ptr</tt> needs an rvalue <tt>swap</tt>.
 </p></blockquote>

 <p>
 This issue was opened in response to that note.
 </p>

 <p>
 I believe allowing rvalue <tt>shared_ptr</tt>s to <tt>swap</tt> is both
 appropriate, and consistent with how other library components are currently specified.
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 Concern that the three signatures for swap is needlessly complicated,
 but this issue merely brings shared_ptr into equal complexity with the
 rest of the library. Will open a new issue for concern about triplicate
 signatures.
 </p>
 <p>
 Adopt issue as written.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the synopsis in 20.7.12.2 [util.smartptr.shared]:
 </p>

 <blockquote><pre>void swap(shared_ptr&amp;<ins>&amp;</ins> r);
 ...
 template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp; a, shared_ptr&lt;T&gt;&amp; b);
 <ins>template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp;&amp; a, shared_ptr&lt;T&gt;&amp; b);
 template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp; a, shared_ptr&lt;T&gt;&amp;&amp; b);</ins>
 </pre></blockquote>

 <p>
 Change 20.7.12.2.4 [util.smartptr.shared.mod]:
 </p>

 <blockquote><pre>void swap(shared_ptr&amp;<ins>&amp;</ins> r);
 </pre></blockquote>

 <p>
 Change 20.7.12.2.9 [util.smartptr.shared.spec]:
 </p>

 <blockquote><pre>template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp; a, shared_ptr&lt;T&gt;&amp; b);
 <ins>template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp;&amp; a, shared_ptr&lt;T&gt;&amp; b);
 template&lt;class T&gt; void swap(shared_ptr&lt;T&gt;&amp; a, shared_ptr&lt;T&gt;&amp;&amp; b);</ins>
 </pre></blockquote>


 <hr>
 <h3><a name="744"></a>744. What is the lifetime of an exception pointed to by an exception_ptr?</h3>
 <p><b>Section:</b> 18.7.5 [propagation] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alisdair Meredith <b>Date:</b> 2007-10-10</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#propagation">active issues</a> in [propagation].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#propagation">issues</a> in [propagation].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Without some lifetime guarantee, it is hard to know how this type can be
 used.  Very specifically, I don't see how the current wording would
 guarantee and exception_ptr caught at the end of one thread could be safely
 stored and rethrown in another thread - the original motivation for this
 API.
 </p>
 <p>
 (Peter Dimov agreed it should be clearer, maybe a non-normative note to
 explain?)
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 Agree the issue is real.
 </p>
 <p>
 Intent is lifetime is similar to a shared_ptr (and we might even want to
 consider explicitly saying that it is a shared_ptr&lt; unspecified type &gt;).
 </p>
 <p>
 We expect that most implementations will use shared_ptr, and the
 standard should be clear that the exception_ptr type is intended to be
 something whose semantics are smart-pointer-like so that the user does
 not need to worry about lifetime management. We still need someone to
 draught those words - suggest emailing Peter Dimov.
 </p>
 <p>
 Move to Open.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 18.7.5 [propagation]/7:
 </p>

 <blockquote>
 -7- Returns: An <tt>exception_ptr</tt> object that refers to the currently
 handled exception or a copy of the currently handled exception, or a
 null <tt>exception_ptr</tt> object if no exception is being handled.
 <ins>The referenced object remains valid at least as long as there is an
 <tt>exception_ptr</tt> that refers to it.</ins>
 If the function needs to allocate memory and the attempt
 fails, it returns an <tt>exception_ptr</tt> object that refers to an instance of
 <tt>bad_alloc</tt>. It is unspecified whether the return values of two successive
 calls to <tt>current_exception</tt> refer to the same exception object. [<i>Note:</i>
 that is, it is unspecified whether <tt>current_exception</tt> creates a new copy
 each time it is called. <i>--end note</i>]
 </blockquote>


 <hr>
 <h3><a name="746"></a>746. current_exception may fail with bad_alloc</h3>
 <p><b>Section:</b> 18.7.5 [propagation] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alisdair Meredith <b>Date:</b> 2007-10-10</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#propagation">active issues</a> in [propagation].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#propagation">issues</a> in [propagation].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 I understand that the attempt to copy an exception may run out of memory,
 but I believe this is the only part of the standard that mandates failure
 with specifically <tt>bad_alloc</tt>, as opposed to allowing an
 implementation-defined type derived from <tt>bad_alloc</tt>.  For instance, the Core
 language for a failed new expression is:
 </p>
 <blockquote>
 <p>
 Any other allocation function that fails to allocate storage shall indicate
 failure only by throwing an exception of a type that would match a handler
 (15.3) of type <tt>std::bad_alloc</tt> (18.5.2.1).
 </p>
 </blockquote>
 <p>
 I think we should allow similar freedom here (or add a blanket
 compatible-exception freedom paragraph in 17)
 </p>
 <p>
 I prefer the clause 17 approach myself, and maybe clean up any outstanding
 wording that could also rely on it.
 </p>
 <p>
 Although filed against a specific case, this issue is a problem throughout
 the library.
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 Is issue bigger than library?
 </p>
 <p>
 No - Core are already very clear about their wording, which is inspiration for the issue.
 </p>
 <p>
 While not sold on the original 18.7.5 use case, the generalised 17.4.4.8 wording is the real issue.
 </p>
 <p>
 Accept the broad view and move to ready
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the following exemption clause to 17.4.4.9 [res.on.exception.handling]:
 </p>

 <blockquote>
 A function may throw a type not listed in its <i>Throws</i> clause so long as it is
 derived from a class named in the <i>Throws</i> clause, and would be caught by an
 exception handler for the base type.
 </blockquote>


 <hr>
 <h3><a name="749"></a>749. Currently <tt>has_nothrow_copy_constructor&lt;T&gt;::value</tt> is true if T has 'a' nothrow copy constructor.</h3>
 <p><b>Section:</b> 20.5.4.3 [meta.unary.prop] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alisdair Meredith <b>Date:</b> 2007-10-10</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.unary.prop">issues</a> in [meta.unary.prop].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Unfortunately a class can have multiple copy constructors, and I believe to
 be useful this trait should only return true is ALL copy constructors are
 no-throw.
 </p>
 <p>
 For instance:
 </p>
 <blockquote>
 <pre>struct awkward {
  awkward( const awkward &amp; ) throw() {}
  awkward( awkward &amp; ) { throw "oops"; } };
 </pre>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 20.5.4.3 [meta.unary.prop]:
 </p>

 <blockquote>
 <pre>has_trivial_copy_constructor</pre>
 <blockquote>
 <tt>T</tt> is a trivial type (3.9) or a reference type or a class type <del>with a trivial copy constructor</del>
 <ins>where all copy constructors are trivial</ins> (12.8).
 </blockquote>
 </blockquote>

 <blockquote>
 <pre>has_trivial_assign</pre>
 <blockquote>
 <tt>T</tt> is neither <tt>const</tt> nor a reference type, and <tt>T</tt> is a trivial type (3.9)
 or a class type <del>with a trivial copy assignment operator</del> <ins>where all copy assignment operators are trivial</ins> (12.8).
 </blockquote>
 </blockquote>

 <blockquote>
 <pre>has_nothrow_copy_constructor</pre>
 <blockquote>
 <tt>has_trivial_copy_constructor&lt;T&gt;::value</tt> is <tt>true</tt> or <tt>T</tt> is a class type <del>with
 a</del> <ins>where all</ins> copy constructor<ins>s</ins> <del>that is</del> <ins>are</ins>
 known not to throw any exceptions or <tt>T</tt> is an
 array of such a class type
 </blockquote>
 </blockquote>

 <blockquote>
 <pre>has_nothrow_assign</pre>
 <blockquote>
 <tt>T</tt> is neither <tt>const</tt> nor a reference type, and
 <tt>has_trivial_assign&lt;T&gt;::value</tt> is <tt>true</tt> or <tt>T</tt> is a class type <del>with a</del>
 <ins>where all</ins> copy
 assignment operator<ins>s</ins> tak<ins>e</ins><del>ing</del> an lvalue of type <tt>T</tt> that is known not to
 throw any exceptions or <tt>T</tt> is an array of such a class type.
 </blockquote>
 </blockquote>


 <hr>
 <h3><a name="755"></a>755. <tt>std::vector</tt> and <tt>std:string</tt> lack explicit shrink-to-fit operations</h3>
 <p><b>Section:</b> 23.2.6.2 [vector.capacity], 21.3.4 [string.capacity] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Beman Dawes <b>Date:</b> 2007-10-31</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.capacity">issues</a> in [vector.capacity].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 A <tt>std::vector</tt> can be shrunk-to-fit via the swap idiom:
 </p>

 <blockquote><pre>vector&lt;int&gt; v;
 ...
 v.swap(vector&lt;int&gt;(v));  // shrink to fit
 </pre>
 <blockquote><p>
 or:
 </p></blockquote>
 <pre>vector&lt;int&gt;(v).swap(v);  // shrink to fit
 </pre>
 <blockquote><p>
 or:
 </p></blockquote>
 <pre>swap(v, vector&lt;int&gt;(v));  // shrink to fit
 </pre>
 </blockquote>

 <p>
 A non-binding request for shrink-to-fit can be made to a <tt>std::string</tt> via:
 </p>

 <blockquote><pre>string s;
 ...
 s.reserve(0);
 </pre></blockquote>

 <p>
 Neither of these is at all obvious to beginners, and even some
 experienced C++ programmers are not aware that shrink-to-fit is
 trivially available.
 </p>
 <p>
 Lack of explicit functions to perform these commonly requested
 operations makes vector and string less usable for non-experts. Because
 the idioms are somewhat obscure, code readability is impaired. It is
 also unfortunate that two similar vector-like containers use different
 syntax for the same operation.
 </p>
 <p>
 The proposed resolution addresses these concerns. The proposed function
 takes no arguments to keep the solution simple and focused.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 To Class template basic_string 21.3 [basic.string] synopsis,
 Class template vector 23.2.6 [vector] synopsis, and Class
 vector&lt;bool&gt; 23.2.7 [vector.bool] synopsis, add:
 </p>

 <blockquote><pre>
 void shrink_to_fit();
 </pre></blockquote>

 <p>
 To basic_string capacity 21.3.4 [string.capacity] and vector
 capacity 23.2.6.2 [vector.capacity], add:
 </p>

 <blockquote>
 <pre>void shrink_to_fit();
 </pre>
 <blockquote>
 <i>Remarks:</i> <tt>shrink_to_fit</tt> is a non-binding request to reduce
 <tt>capacity()</tt> to <tt>size()</tt>. [<i>Note:</i> The request is non-binding to
 allow latitude for implementation-specific optimizations.
 <i>-- end note</i>]
 </blockquote>
 </blockquote>

 <p><i>[
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#850">850</a> has been added to deal with this issue with respect to <tt>deque</tt>.
 ]</i></p>


 <hr>
 <h3><a name="759"></a>759. A reference is not an object</h3>
 <p><b>Section:</b> 23.1 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Jens Maurer <b>Date:</b> 2007-11-06</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 23.1 [container.requirements] says:
 </p>

 <blockquote>
 -12- Objects passed to member functions of a container as rvalue references shall not be elements of that container. No
 diagnostic required.
 </blockquote>

 <p>
 A reference is not an object, but this sentence appears to claim so.
 </p>

 <p>
 What is probably meant here:
 </p>
 <blockquote>
 An object bound to an rvalue
 reference parameter of a member function of a container shall not be
 an element of that container; no diagnostic required.
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 23.1 [container.requirements]:
 </p>

 <blockquote>
 -12- <del>Objects passed to member functions of a container as rvalue references shall not be elements</del>
 <ins>An object bound to an rvalue
 reference parameter of a member function of a container shall not be
 an element</ins>
 of that container<del>.</del><ins>;</ins> <del>N</del><ins>n</ins>o
 diagnostic required.
 </blockquote>


 <hr>
 <h3><a name="761"></a>761. <tt>unordered_map</tt> needs an <tt>at()</tt> member function</h3>
 <p><b>Section:</b> 23.4.1.2 [unord.map.elem] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Joe Gottman <b>Date:</b> 2007-11-15</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The new member function <tt>at()</tt> was recently added to <tt>std::map()</tt>.  It acts
 like <tt>operator[]()</tt>, except it throws an exception when the input key is
 not found.  It is useful when the <tt>map</tt> is <tt>const</tt>, the <tt>value_type</tt> of the
 key doesn't have  a default constructor, it is an error if the key is
 not found, or the user wants to avoid accidentally adding an element to
 the map.  For exactly these same reasons, <tt>at()</tt> would be equally useful
 in <tt>std::unordered_map</tt>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the following functions to the definition of <tt>unordered_map</tt> under "lookup" (23.4.1 [unord.map]):
 </p>

 <blockquote><pre>mapped_type&amp; at(const key_type&amp; k);
 const mapped_type &amp;at(const key_type &amp;k) const;
 </pre></blockquote>

 <p>
 Add the following definitions to 23.4.1.2 [unord.map.elem]:
 </p>

 <blockquote>
 <pre>mapped_type&amp; at(const key_type&amp; k);
 const mapped_type &amp;at(const key_type &amp;k) const;
 </pre>
 <blockquote>
 <p>
 <i>Returns:</i> A reference to <tt>x.second</tt>, where <tt>x</tt> is the (unique) element
 whose key is equivalent to <tt>k</tt>.
 </p>
 <p>
 <i>Throws:</i> An exception object of type <tt>out_of_range</tt> if no such element
 is present.
 </p>
 </blockquote>
 </blockquote>

 <p><i>[
 Bellevue:  Editorial note: the "(unique)" differs from map.
 ]</i></p>


 <hr>
 <h3><a name="766"></a>766. Inconsistent exception guarantees between ordered and unordered associative containers</h3>
 <p><b>Section:</b> 23.1 [container.requirements], 23.1.5.1 [unord.req.except] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Ion Gaztañaga <b>Date:</b> 2007-12-22</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 23.1 [container.requirements]p10 states:
 </p>

 <blockquote>
 <p>
 Unless otherwise specified (see 23.2.2.3 and 23.2.5.4) all container types defined in this clause meet the following
 additional requirements:
 </p>
 <ul>

 <li>[...]</li>

 <li>no <tt>erase()</tt>, <tt>pop_back()</tt> or <tt>pop_front()</tt> function throws an exception.</li>

 </ul>
 </blockquote>

 <p>
 23.2.2.3 [deque.modifiers] and 23.2.6.4 [vector.modifiers] offer
 additional guarantees for <tt>deque</tt>/<tt>vector insert()</tt> and
 <tt>erase()</tt> members. However, 23.1 [container.requirements]p10
 does not mention 23.1.5.1 [unord.req.except] that specifies exception
 safety guarantees
 for unordered containers. In addition, 23.1.5.1 [unord.req.except]p1
 offers the following guaratee for
 <tt>erase()</tt>:
 </p>

 <blockquote>
 No <tt>erase()</tt> function throws an exception unless that exception
 is thrown by the container's Hash or Pred object (if any).
 </blockquote>

 <p>
 Summary:
 </p>

 <p>
 According to 23.1 [container.requirements]p10 no
 <tt>erase()</tt> function should throw an exception unless otherwise
 specified. Although does not explicitly mention 23.1.5.1 [unord.req.except], this section offers additional guarantees
 for unordered containers, allowing <tt>erase()</tt> to throw if
 predicate or hash function throws.
 </p>

 <p>
 In contrast, associative containers have no exception safety guarantees
 section so no <tt>erase()</tt> function should throw, <em>including
 <tt>erase(k)</tt></em> that needs to use the predicate function to
 perform its work. This means that the predicate of an associative
 container is not allowed to throw.
 </p>

 <p>
 So:
 </p>

 <ol>
 <li>
 <tt>erase(k)</tt> for associative containers is not allowed to throw. On
 the other hand, <tt>erase(k)</tt> for unordered associative containers
 is allowed to throw.
 </li>
 <li>
 <tt>erase(q)</tt> for associative containers is not allowed to throw. On
 the other hand, <tt>erase(q)</tt> for unordered associative containers
 is allowed to throw if it uses the hash or predicate.
 </li>
 <li>
 To fulfill 1), predicates of associative containers are not allowed to throw.
 Predicates of unordered associative containers are allowed to throw.
 </li>
 <li>
 2) breaks a widely used programming pattern (flyweight pattern) for
 unordered containers, where objects are registered in a global map in
 their constructors and unregistered in their destructors. If <tt>erase(q)</tt> is
 allowed to throw, the destructor of the object would need to rethrow the
 exception or swallow it, leaving the object registered.
 </li>
 </ol>


 <p><b>Proposed resolution:</b></p>
 <p>
 Create a new sub-section of 23.1.4 [associative.reqmts] (perhaps [associative.req.except]) titled "Exception
 safety guarantees".
 </p>

 <blockquote>
 <p>
 1 For associative containers, no <tt>clear()</tt> function throws an exception.
 <tt>erase(k)</tt> does not throw an exception unless that exception is thrown by
 the container's Pred object (if any).
 </p>

 <p>
 2 For associative containers, if an exception is thrown by any operation
 from within an <tt>insert()</tt> function inserting a single element, the
 <tt>insert()</tt> function has no effect.
 </p>

 <p>
 3 For associative containers, no <tt>swap</tt> function throws an exception
 unless that exception is thrown by the copy constructor or copy
 assignment operator of the container's Pred object (if any).
 </p>
 </blockquote>

 <p>
 Change 23.1.5.1 [unord.req.except]p1:
 </p>

 <blockquote>
 For unordered associative containers, no <tt>clear()</tt> function
 throws an exception. <del>No</del> <tt>erase(<ins>k</ins>)</tt>
 <del>function</del> <ins>does not</ins> throw<del>s</del> an exception
 unless that exception is thrown by the container's Hash or Pred object
 (if any).
 </blockquote>

 <p>
 Change 23.1 [container.requirements]p10 to add references to new sections:
 </p>

 <blockquote>
 Unless otherwise specified (see [deque.modifiers]<ins>,</ins>
 <del>and</del> [vector.modifiers]<ins>, [associative.req.except],
 [unord.req.except]</ins>) all container types defined in this clause meet
 the following additional requirements:
 </blockquote>

 <p>
 Change 23.1 [container.requirements]p10 referring to <tt>swap</tt>:
 </p>

 <blockquote>
 <ul>
 <li>
 no <tt>swap()</tt> function throws an exception<del> unless that exception is thrown
 by the copy constructor or assignment operator of the container's
 Compare object (if any; see [associative.reqmts])</del>.
 </li>
 </ul>
 </blockquote>


 <hr>
 <h3><a name="768"></a>768. Typos in [atomics]?</h3>
 <p><b>Section:</b> 29.3.3 [atomics.types.generic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alberto Ganesh Barbati <b>Date:</b> 2007-12-28</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 in the latest publicly available draft, paper
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2461.pdf">N2641</a>,
 in section 29.3.3 [atomics.types.generic], the following specialization of the template
 <tt>atomic&lt;&gt;</tt> is provided for pointers:
 </p>

 <blockquote><pre>template &lt;class T&gt; struct atomic&lt;T*&gt; : atomic_address {
   T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile;
   T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile;

   atomic() = default;
   constexpr explicit atomic(T);
   atomic(const atomic&amp;) = delete;
   atomic&amp; operator=(const atomic&amp;) = delete;

   T* operator=(T*) volatile;
   T* operator++(int) volatile;
   T* operator--(int) volatile;
   T* operator++() volatile;
   T* operator--() volatile;
   T* operator+=(ptrdiff_t) volatile;
   T* operator-=(ptrdiff_t) volatile;
 };
 </pre></blockquote>

 <p>
 First of all, there is a typo in the non-default constructor which
 should take a <tt>T*</tt> rather than a <tt>T</tt>.
 </p>

 <p>
 As you can see, the specialization redefine and therefore hide a few
 methods from the base class <tt>atomic_address</tt>, namely <tt>fetch_add</tt>, <tt>fetch_sub</tt>,
 <tt>operator=</tt>, <tt>operator+=</tt> and <tt>operator-=</tt>. That's good, but... what happened
 to the other methods, in particular these ones:
 </p>

 <blockquote><pre>void store(T*, memory_order = memory_order_seq_cst) volatile;
 T* load( memory_order = memory_order_seq_cst ) volatile;
 T* swap( T*, memory_order = memory_order_seq_cst ) volatile;
 bool compare_swap( T*&amp;, T*, memory_order, memory_order ) volatile;
 bool compare_swap( T*&amp;, T*, memory_order = memory_order_seq_cst ) volatile;
 </pre></blockquote>

 <p>
 By reading paper
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html">N2427 "C++ Atomic Types and Operations"</a>,
 I see that the
 definition of the specialization <tt>atomic&lt;T*&gt;</tt> matches the one in the
 draft, but in the example implementation the methods <tt>load()</tt>, <tt>swap()</tt>
 and <tt>compare_swap()</tt> are indeed present.
 </p>

 <p>
 Strangely, the example implementation does not redefine the method
 <tt>store()</tt>. It's true that a <tt>T*</tt> is always convertible to <tt>void*</tt>, but not
 hiding the <tt>void*</tt> signature from the base class makes the class
 error-prone to say the least: it lets you assign pointers of any type to
 a <tt>T*</tt>, without any hint from the compiler.
 </p>

 <p>
 Is there a true intent to remove them from the specialization or are
 they just missing from the definition because of a mistake?
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 The proposed revisions are accepted.
 </p>
 <p>
 Further discussion: why is the ctor labeled "constexpr"? Lawrence said
 this permits the object to be statically initialized, and that's
 important because otherwise there would be a race condition on
 initialization.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change the synopsis in 29.3.3 [atomics.types.generic]:
 </p>

 <blockquote><pre>template &lt;class T&gt; struct atomic&lt;T*&gt; : atomic_address {
   <ins>void store(T*, memory_order = memory_order_seq_cst) volatile;</ins>
   <ins>T* load( memory_order = memory_order_seq_cst ) volatile;</ins>
   <ins>T* swap( T*, memory_order = memory_order_seq_cst ) volatile;</ins>
   <ins>bool compare_swap( T*&amp;, T*, memory_order, memory_order ) volatile;</ins>
   <ins>bool compare_swap( T*&amp;, T*, memory_order = memory_order_seq_cst ) volatile;</ins>

   T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile;
   T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile;

   atomic() = default;
   constexpr explicit atomic(T<ins>*</ins>);
   atomic(const atomic&amp;) = delete;
   atomic&amp; operator=(const atomic&amp;) = delete;

   T* operator=(T*) volatile;
   T* operator++(int) volatile;
   T* operator--(int) volatile;
   T* operator++() volatile;
   T* operator--() volatile;
   T* operator+=(ptrdiff_t) volatile;
   T* operator-=(ptrdiff_t) volatile;
 };
 </pre></blockquote>


 <hr>
 <h3><a name="770"></a>770. std::function should use rvalue swap</h3>
 <p><b>Section:</b> 20.6.15 [func.wrap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2008-01-10</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 It is expected that typical implementations of <tt>std::function</tt> will
 use dynamic memory allocations at least under given conditions,
 so it seems appropriate to change the current lvalue swappabilty of
 this class to rvalue swappability.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 20.6 [function.objects], header <tt>&lt;functional&gt;</tt> synopsis, just below of
 </p>

 <blockquote><pre>template&lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;, function&lt;R(ArgTypes...)&gt;&amp;);
 <ins>template&lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;&amp;, function&lt;R(ArgTypes...)&gt;&amp;);
 template&lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;, function&lt;R(ArgTypes...)&gt;&amp;&amp;);</ins>
 </pre></blockquote>

 <p>
 In 20.6.15.2 [func.wrap.func] class <tt>function</tt> definition, change
 </p>

 <blockquote><pre>void swap(function&amp;<ins>&amp;</ins>);
 </pre></blockquote>

 <p>
 In 20.6.15.2 [func.wrap.func], just below of
 </p>

 <blockquote><pre>template &lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;, function&lt;R(ArgTypes...)&gt;&amp;);
 <ins>template &lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;&amp;, function&lt;R(ArgTypes...)&gt;&amp;);
 template &lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;, function&lt;R(ArgTypes...)&gt;&amp;&amp;);</ins>
 </pre></blockquote>

 <p>
 In 20.6.15.2.2 [func.wrap.func.mod] change
 </p>

 <blockquote><pre>void swap(function&amp;<ins>&amp;</ins> other);
 </pre></blockquote>

 <p>
 In 20.6.15.2.7 [func.wrap.func.alg] add the two overloads
 </p>

 <blockquote><pre><ins>template&lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp;&amp; f1, function&lt;R(ArgTypes...)&gt;&amp; f2);
 template&lt;class R, class... ArgTypes&gt;
   void swap(function&lt;R(ArgTypes...)&gt;&amp; f1, function&lt;R(ArgTypes...)&gt;&amp;&amp; f2);</ins>
 </pre></blockquote>


 <hr>
 <h3><a name="775"></a>775. Tuple indexing should be unsigned?</h3>
 <p><b>Section:</b> 20.4.1.4 [tuple.helper] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Alisdair Meredith <b>Date:</b> 2008-01-16</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The tuple element access API identifies the element in the sequence
 using signed integers, and then goes on to enforce the requirement that
 I be &gt;= 0.  There is a much easier way to do this - declare I as
 <tt>unsigned</tt>.
 </p>
 <p>
 In fact the proposal is to use <code>std::size_t</code>, matching the type used in the <tt>tuple_size</tt> API.
 </p>
 <p>
 A second suggestion is that it is hard to imagine an API that deduces
 and index at compile time and returns a reference throwing an exception.
 Add a specific <em>Throws:</em> Nothing paragraph to each element
 access API.
 </p>
 <p>
 In addition to <code>tuple</code>, update the API applies to
 <code>pair</code> and <code>array</code>, and should be updated
 accordingly.
 </p>

 <p>
 A third observation is that the return type of the <code>get</code>
 functions for <code>std::pair</code> is pseudo-code, but it is not
 clearly marked as such.  There is actually no need for pseudo-code as
 the return type can be specified precisely with a call to
 <code>tuple_element</code>.  This is already done for
 <code>std::tuple</code>, and <code>std::array</code> does not have a
 problem as all elements are of type <code>T</code>.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Update header &lt;utility&gt; synopsis in 20.2 [utility]
 </p>
 <pre><em>// 20.2.3, tuple-like access to pair:</em>
 template &lt;class T&gt; class tuple_size;
 template &lt;<del>int</del><ins>size_t</ins> I, class T&gt; class tuple_element;

 template &lt;class T1, class T2&gt; struct tuple_size&lt;std::pair&lt;T1, T2&gt; &gt;;
 template &lt;class T1, class T2&gt; struct tuple_element&lt;0, std::pair&lt;T1, T2&gt; &gt;;
 template &lt;class T1, class T2&gt; struct tuple_element&lt;1, std::pair&lt;T1, T2&gt; &gt;;

 template&lt;<del>int</del><ins>size_t</ins> I, class T1, class T2&gt;
   <del>P</del><ins>typename tuple_element&lt;I, std::pair&lt;T1, T2&gt; &gt;::type </ins>&amp; get(std::pair&lt;T1, T2&gt;&amp;);
 template&lt;<del>int</del><ins>size_t</ins> I, class T1, class T2&gt;
   const <del>P</del><ins>typename tuple_element&lt;I, std::pair&lt;T1, T2&gt; &gt;::type </ins>&amp; get(const std::pair&lt;T1, T2&gt;&amp;);
 </pre>
 <p>
 Update <strong>20.2.3 [pairs] Pairs</strong>
 </p>
 <pre>template&lt;<del>int</del><ins>size_t</ins> I, class T1, class T2&gt;
   <del>P</del><ins>typename tuple_element&lt;I, std::pair&lt;T1, T2&gt; &gt;::type </ins>&amp; get(pair&lt;T1, T2&gt;&amp;);
 template&lt;<del>int</del><ins>size_t</ins> I, class T1, class T2&gt;
   const <del>P</del><ins>typename tuple_element&lt;I, std::pair&lt;T1, T2&gt; &gt;::type </ins>&amp; get(const pair&lt;T1, T2&gt;&amp;);
 </pre>
 <p>
 <del>24 <em>Return type:</em> If <code>I == 0</code> then <code>P</code> is <code>T1</code>, if <code>I == 1</code> then <code>P</code> is <code>T2</code>, and otherwise the program is ill-formed.</del>
 </p>
 <p>
 25 <em>Returns:</em> If <code>I == 0</code> returns <code>p.first</code>, <del>otherwise</del> <ins>if <code>I == 1</code></ins> returns <code>p.second</code><ins>, and otherwise the program is ill-formed</ins>.
 </p>
 <p>
 <ins><em>Throws:</em> Nothing.</ins>
 </p>


 <p>
 Update header &lt;tuple&gt; synopsis in 20.4 [tuple] with a APIs as below:
 </p>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class T&gt; class tuple_element; <em>// undefined</em>
 template &lt;<del>int</del><ins>size_t</ins> I, class... Types&gt; class tuple_element&lt;I, tuple&lt;Types...&gt; &gt;;

 <em>// 20.3.1.4, element access:</em>
 template &lt;<del>int</del><ins>size_t</ins> I, class... Types&gt;
   typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type&amp; get(tuple&lt;Types...&gt;&amp;);
 template &lt;<del>int</del><ins>size_t</ins> I, class ... types&gt;
   typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type const&amp; get(const tuple&lt;Types...&gt;&amp;);
 </pre>

 <p>
 Update <strong>20.4.1.4 [tuple.helper] Tuple helper classes</strong>
 </p>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class... Types&gt;
 class tuple_element&lt;I, tuple&lt;Types...&gt; &gt; {
 public:
   typedef TI type;
 };</pre>
 <p>
 1 <em>Requires:</em> <code><del>0 &lt;= I and </del>I &lt; sizeof...(Types)</code>. The program is ill-formed if <code>I</code> is out of bounds.
 </p>
 <p>
 2 <em>Type:</em> <code>TI</code> is the type of the <code>I</code>th element of <code>Types</code>, where indexing is zero-based.
 </p>
 <p>
 Update <strong>20.4.1.5 [tuple.elem] Element access</strong>
 </p>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class... types &gt;
 typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type&amp; get(tuple&lt;Types...&gt;&amp; t);
 </pre>
 1 <em>Requires:</em> <code><del>0 &lt;= I and </del>I &lt; sizeof...(Types)</code>. The program is ill-formed if <code>I</code> is out of bounds.
 <p>
 2 <em>Returns:</em> A reference to the <code>I</code>th element of <code>t</code>, where indexing is zero-based.
 </p>
 <ins><em>Throws:</em> Nothing.</ins>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class... types&gt;
 typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type const&amp; get(const tuple&lt;Types...&gt;&amp; t);
 </pre>
 <p>
 3 <em>Requires:</em> <code><del>0 &lt;= I and </del>I &lt; sizeof...(Types)</code>. The program is ill-formed if <code>I</code> is out of bounds.
 </p>
 <p>
 4 <em>Returns:</em> A const reference to the <code>I</code>th element of <code>t</code>, where indexing is zero-based.
 </p>
 <p>
 <ins><em>Throws:</em> Nothing.</ins>
 </p>


 <p>
 Update header &lt;array&gt; synopsis in 20.2 [utility]
 </p>
 <pre>template &lt;class T&gt; class tuple_size; <em>// forward declaration</em>
 template &lt;<del>int</del><ins>size_t</ins> I, class T&gt; class tuple_element; <em>// forward declaration</em>
 template &lt;class T, size_t N&gt;
   struct tuple_size&lt;array&lt;T, N&gt; &gt;;
 template &lt;<del>int</del><ins>size_t</ins> I, class T, size_t N&gt;
   struct tuple_element&lt;I, array&lt;T, N&gt; &gt;;
 template &lt;<del>int</del><ins>size_t</ins> I, class T, size_t N&gt;
   T&amp; get(array&lt;T, N&gt;&amp;);
 template &lt;<del>int</del><ins>size_t</ins> I, class T, size_t N&gt;
   const T&amp; get(const array&lt;T, N&gt;&amp;);
 </pre>

 <p>
 Update <strong>23.2.1.6 [array.tuple] Tuple interface to class template array</strong>
 </p>
 <pre>tuple_element&lt;<ins>size_t </ins>I, array&lt;T, N&gt; &gt;::type
 </pre>
 <p>
 3 <em>Requires:</em> <code><del>0 &lt;= </del>I &lt; N.</code> The program is ill-formed if <code>I</code> is out of bounds.
 </p>
 <p>
 4 <em>Value:</em> The type <code>T</code>.
 </p>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class T, size_t N&gt; T&amp; get(array&lt;T, N&gt;&amp; a);
 </pre>
 <p>
 5 <em>Requires:</em> <code><del>0 &lt;= </del>I &lt; N</code>. The program is ill-formed if <code>I</code> is out of bounds.
 </p>
 <p>
 <em>Returns:</em> A reference to the <code>I</code>th element of <code>a</code>, where indexing is zero-based.
 </p>
 <p>
 <ins><em>Throws:</em> Nothing.</ins>
 </p>
 <pre>template &lt;<del>int</del><ins>size_t</ins> I, class T, size_t N&gt; const T&amp; get(const array&lt;T, N&gt;&amp; a);
 </pre>
 <p>
 6 <em>Requires:</em> <code><del>0 &lt;= </del>I &lt; N</code>. The program is ill-formed if <code>I</code> is out of bounds.
 </p>
 <p>
 7 <em>Returns:</em> A const reference to the <code>I</code>th element of <code>a</code>, where indexing is zero-based.
 </p>
 <p>
 <ins><em>Throws:</em> Nothing.</ins>
 </p>


 <p><i>[
 Bellevue: Note also that the phrase "The program is ill-formed if I is
 out of bounds" in the requires clauses are probably unnecessary, and
 could be removed at the editor's discretion. Also std:: qualification
 for pair is also unnecessary.
 ]</i></p>


 <hr>
 <h3><a name="777"></a>777. Atomics Library Issue</h3>
 <p><b>Section:</b> 29.4 [atomics.types.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Lawrence Crowl <b>Date:</b> 2008-01-21</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#atomics.types.operations">issues</a> in [atomics.types.operations].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The load functions are defined as
 </p>

 <blockquote><pre>C atomic_load(volatile A* object);
 C atomic_load_explicit(volatile A* object, memory_order);
 C A::load(memory_order order = memory_order_seq_cst) volatile;
 </pre></blockquote>

 <p>
 which prevents their use in <tt>const</tt> contexts.
 </p>

 <p><i>[
 post Bellevue Peter adds:
 ]</i></p>


 <blockquote>
 <p>
 Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a> suggests making <tt>atomic_load</tt> operate on <tt>const</tt> objects. There is a
 subtle point here. Atomic loads do not generally write to the object, except
 potentially for the <tt>memory_order_seq_cst</tt> constraint. Depending on the
 architecture, a dummy write with the same value may be required to be issued
 by the atomic load to maintain sequential consistency. This, in turn, may
 make the following code:
 </p>

 <blockquote><pre>const atomic_int x{};

 int main()
 {
   x.load();
 }
 </pre></blockquote>

 <p>
 dump core under a straightforward implementation that puts const objects in
 a read-only section.
 </p>
 <p>
 There are ways to sidestep the problem, but it needs to be considered.
 </p>
 <p>
 The tradeoff is between making the data member of the atomic types
 mutable and requiring the user to explicitly mark atomic members as
 mutable, as is already the case with mutexes.
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add the <tt>const</tt> qualifier to <tt>*object</tt> and <tt>*this</tt>.
 </p>

 <blockquote><pre>C atomic_load(<ins>const</ins> volatile A* object);
 C atomic_load_explicit(<ins>const</ins> volatile A* object, memory_order);
 C A::load(memory_order order = memory_order_seq_cst) <ins>const</ins> volatile;
 </pre></blockquote>


 <hr>
 <h3><a name="778"></a>778. std::bitset does not have any constructor taking a string literal</h3>
 <p><b>Section:</b> 23.3.5.1 [bitset.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Thorsten Ottosen <b>Date:</b> 2008-01-24</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bitset.cons">issues</a> in [bitset.cons].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#116">116</a></p>
 <p><b>Discussion:</b></p>
 <p>
 A small issue with <tt>std::bitset</tt>: it does not have any constructor
 taking a string literal, which is clumsy and looks like an oversigt when
 we tried to enable uniform use of <tt>string</tt> and <tt>const char*</tt> in the library.
 </p>

 <p>
 Suggestion: Add
 </p>

 <blockquote><pre>explicit bitset( const char* str );
 </pre></blockquote>

 <p>
 to std::bitset.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add to synopsis in 23.3.5 [template.bitset]
 </p>

 <blockquote><pre>explicit bitset( const char* str );
 </pre></blockquote>

 <p>
 Add to synopsis in 23.3.5.1 [bitset.cons]
 </p>

 <blockquote><pre>explicit bitset( const char* str );
 </pre>
 <p>
 <i>Effects:</i> Constructs a <tt>bitset</tt> as if <tt>bitset(string(str))</tt>.
 </p>
 </blockquote>


 <hr>
 <h3><a name="781"></a>781. <tt>std::complex</tt> should add missing C99 functions</h3>
 <p><b>Section:</b> 26.3.7 [complex.value.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2008-01-26</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.value.ops">issues</a> in [complex.value.ops].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 A comparision of the N2461 header <tt>&lt;complex&gt;</tt> synopsis ([complex.synopsis])
 with the C99 standard (ISO 9899, 2nd edition and the two corrigenda) show
 some complex functions that are missing in C++. These are:
 </p>

 <ol>
 <li>
 7.3.9.4: (required elements of the C99 library)<br>
 The <tt>cproj</tt> functions
 </li>
 <li>
 7.26.1: (optional elements of the C99 library)<br>
 <pre>cerf    cerfc    cexp2
 cexpm1  clog10   clog1p
 clog2   clgamma  ctgamma
 </pre>
 </li>
 </ol>

 <p>
 I propose that at least the required <tt>cproj</tt> overloads are provided as equivalent
 C++ functions. This addition is easy to do in one sentence (delegation to C99
 function).
 </p>

 <p>
 Please note also that the current entry <tt>polar</tt>
 in 26.3.9 [cmplx.over]/1
 should be removed from the mentioned overload list. It does not make sense to require that a
 function already expecting <em>scalar</em> arguments
 should cast these arguments into corresponding
 <tt>complex&lt;T&gt;</tt> arguments, which are not accepted by
 this function.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 In 26.3.1 [complex.synopsis] add just between the declaration of <tt>conj</tt> and <tt>fabs</tt>:
 </p>

 <blockquote><pre>template&lt;class T&gt; complex&lt;T&gt; conj(const complex&lt;T&gt;&amp;);
 <ins>template&lt;class T&gt; complex&lt;T&gt; proj(const complex&lt;T&gt;&amp;);</ins>
 template&lt;class T&gt; complex&lt;T&gt; fabs(const complex&lt;T&gt;&amp;);
 </pre></blockquote>

 <p>
 In 26.3.7 [complex.value.ops] just after p.6 (return clause of <tt>conj</tt>) add:
 </p>

 <blockquote>
 <pre>template&lt;class T&gt; complex&lt;T&gt; proj(const complex&lt;T&gt;&amp; x);
 </pre>
 <blockquote>

 <i>Effects:</i> Behaves the same as C99 function <tt>cproj</tt>, defined in
 subclause 7.3.9.4."
 </blockquote>
 </blockquote>

 <p>
 In 26.3.9 [cmplx.over]/1, add one further entry <tt>proj</tt> to
 the overload list.
 </p>

 <blockquote>
 <p>
 The following function templates shall have additional overloads:
 </p>
 <blockquote><pre>arg           norm
 conj          <del>polar</del> <ins>proj</ins>
 imag          real
 </pre></blockquote>
 </blockquote>


 <hr>
 <h3><a name="782"></a>782. Extended <tt>seed_seq</tt> constructor is useless</h3>
 <p><b>Section:</b> 26.4.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2008-01-27</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.util.seedseq">active issues</a> in [rand.util.seedseq].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 Part of the resolution of n2423, issue 8 was the proposal to
 extend the <tt>seed_seq</tt> constructor accepting an input range
 as follows (which is now part of N2461):
 </p>

 <blockquote><pre>template&lt;class InputIterator,
 size_t u = numeric_limits&lt;iterator_traits&lt;InputIterator&gt;::value_type&gt;::digits&gt;
 seed_seq(InputIterator begin, InputIterator end);
 </pre></blockquote>

 <p>
 First, the expression <tt>iterator_traits&lt;InputIterator&gt;::value_type</tt>
 is invalid due to missing <tt>typename</tt> keyword, which is easy to
 fix.
 </p>

 <p>
 Second (and worse), while the language now supports default
 template arguments of function templates, this customization
 point via the second <tt>size_t</tt> template parameter is of no advantage,
 because <tt>u</tt> can never be deduced, and worse - because it is a
 constructor function template - it can also never be explicitly
 provided (14.8.1 [temp.arg.explicit]/7).
 </p>

 <p>
 The question arises, which advantages result from a compile-time
 knowledge of <tt>u</tt> versus a run time knowledge? If run time knowledge
 suffices, this parameter should be provided as normal function
 default argument [Resolution marked (A)], if compile-time knowledge
 is important, this could be done via a tagging template or more
 user-friendly via a standardized helper generator function
 (<tt>make_seed_seq</tt>), which allows this [Resolution marked (B)].
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 <p>
 Fermilab does not have a strong opinion. Would prefer to go with
 solution A. Bill agrees that solution A is a lot simpler and does the
 job.
 </p>
 <p>
 Proposed Resolution: Accept Solution A.
 </p>
 </blockquote>

 <p>
 Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#803">803</a> claims to make this issue moot.
 </p>


 <p><b>Proposed resolution:</b></p>
 <ol type="A">
 <li>
 <p>
 In 26.4.7.1 [rand.util.seedseq]/2, class <tt>seed_seq</tt> synopsis replace:
 </p>

 <blockquote><pre>class seed_seq
 {
 public:
    ...
    template&lt;class InputIterator<del>,
       size_t u = numeric_limits&lt;iterator_traits&lt;InputIterator&gt;::value_type&gt;::digits</del>&gt;
           seed_seq(InputIterator begin, InputIterator end<ins>,
           size_t u = numeric_limits&lt;typename iterator_traits&lt;InputIterator&gt;::value_type&gt;::digits</ins>);
    ...
 };
 </pre></blockquote>

 <p>
 and do a similar replacement in the member description between
 p.3 and p.4.
 </p>
 </li>

 <li>
 <p>
 In 26.4.7.1 [rand.util.seedseq]/2, class <tt>seed_seq</tt> synopsis <em>and</em> in the
 member description between p.3 and p.4 replace:
 </p>

 <blockquote><pre>template&lt;class InputIterator<del>,
   size_t u = numeric_limits&lt;iterator_traits&lt;InputIterator&gt;::value_type&gt;::digits</del>&gt;
 	  seed_seq(InputIterator begin, InputIterator end);
 <ins>template&lt;class InputIterator, size_t u&gt;
 seed_seq(InputIterator begin, InputIterator end, <i>implementation-defined</i> s);</ins>
 </pre></blockquote>

 <p>
 In 26.4.2 [rand.synopsis], header <tt>&lt;random&gt;</tt> synopsis, immediately after the
 class <tt>seed_seq</tt> declaration <em>and</em> in 26.4.7.1 [rand.util.seedseq]/2, immediately
 after the class <tt>seed_seq</tt> definition add:
 </p>

 <blockquote><pre>template&lt;size_t u, class InputIterator&gt;
   seed_seq make_seed_seq(InputIterator begin, InputIterator end);
 </pre></blockquote>

 <p>
 In 26.4.7.1 [rand.util.seedseq], just before p.5 insert two paragraphs:
 </p>

 <blockquote>
 <p>
 The first constructor behaves as if it would provide an
 integral constant expression <tt>u</tt> of type <tt>size_t</tt> of value
 <tt>numeric_limits&lt;typename iterator_traits&lt;InputIterator&gt;::value_type&gt;::digits</tt>.
 </p>
 <p>
 The second constructor uses an implementation-defined mechanism
 to provide an integral constant expression <tt>u</tt> of type <tt>size_t</tt> and
 is called by the function <tt>make_seed_seq</tt>.
 </p>
 </blockquote>

 <p>
 In 26.4.7.1 [rand.util.seedseq], just after the last paragraph add:
 </p>

 <blockquote>
 <pre>template&lt;size_t u, class InputIterator&gt;
    seed_seq make_seed_seq(InputIterator begin, InputIterator end);
 </pre>
 <blockquote>
 <p>
 where <tt>u</tt> is used to construct an object <tt>s</tt> of implementation-defined type.
 </p>
 <p>
 <i>Returns:</i> <tt>seed_seq(begin, end, s)</tt>;
 </p>
 </blockquote>
 </blockquote>

 </li>
 </ol>


 <hr>
 <h3><a name="783"></a>783. <tt>thread::id</tt> reuse</h3>
 <p><b>Section:</b> 30.2.1.1 [thread.thread.id] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Hans Boehm <b>Date:</b> 2008-02-01</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 The current working paper
 (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2497.html">N2497</a>,
 integrated just before Bellevue) is
 not completely clear whether a given <tt>thread::id</tt> value may be reused once
 a thread has exited and has been joined or detached.  Posix allows
 thread ids (<tt>pthread_t</tt> values) to be reused in this case.  Although it is
 not completely clear whether this originally was the right decision, it
 is clearly the established practice, and we believe it was always the
 intent of the C++ threads API to follow Posix and allow this.  Howard
 Hinnant's example implementation implicitly relies on allowing reuse
 of ids, since it uses Posix thread ids directly.
 </p>

 <p>
 It is important to be clear on this point, since it the reuse of thread
 ids often requires extra care in client code, which would not be
 necessary if thread ids were unique across all time.  For example, a
 hash table indexed by thread id may have to be careful not to associate
 data values from an old thread with a new one that happens to reuse the
 id.  Simply removing the old entry after joining a thread may not be
 sufficient, if it creates a visible window between the join and removal
 during which a new thread with the same id could have been created and
 added to the table.
 </p>

 <p><i>[
 post Bellevue Peter adds:
 ]</i></p>


 <blockquote>
 <p>
 There is a real issue with <tt>thread::id</tt> reuse, but I urge the LWG to
 reconsider fixing this by disallowing reuse, rather than explicitly allowing
 it. Dealing with thread id reuse is an incredibly painful exercise that
 would just force the world to reimplement a non-conflicting <tt>thread::id</tt> over
 and over.
 </p>
 <p>
 In addition, it would be nice if a <tt>thread::id</tt> could be manipulated
 atomically in a lock-free manner, as motivated by the recursive lock
 example:
 </p>

 <p>
 <a href="http://www.decadentplace.org.uk/pipermail/cpp-threads/2006-August/001091.html">http://www.decadentplace.org.uk/pipermail/cpp-threads/2006-August/001091.html</a>
 </p>
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Add a sentence to 30.2.1.1 [thread.thread.id]/p1:
 </p>

 <blockquote>
 <p>
 An object of type <code>thread::id</code> provides
 a unique identifier for each thread of execution
 and a single distinct value for all thread objects
 that do not represent a thread of execution ([thread.threads.class]).
 Each thread of execution has a <code>thread::id</code>
 that is not equal to the <code>thread::id</code>
 of other threads of execution
 and that is not equal to
 the <code>thread::id</code> of <code>std::thread</code> objects
 that do not represent threads of execution.
 <ins>The library may reuse the value of a <code>thread::id</code> of a
 terminated thread that can no longer be joined.</ins>
 </p>
 </blockquote>


 <hr>
 <h3><a name="789"></a>789. <tt>xor_combine_engine(result_type)</tt> should be explicit</h3>
 <p><b>Section:</b> 26.4.4.4 [rand.adapt.xor] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger <b>Date:</b> 2008-02-09</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.adapt.xor">issues</a> in [rand.adapt.xor].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>xor_combine_engine(result_type)</tt> should be <tt>explicit</tt>. (Obvious oversight.)
 </p>

 <p><i>[
 Bellevue:
 ]</i></p>


 <blockquote>
 Non-controversial. Bill is right, but Fermilab believes that this is
 easy to use badly and hard to use right, and so it should be removed
 entirely. Got into TR1 by well defined route, do we have permission to
 remove stuff? Should probably check with Jens, as it is believed he is
 the originator. Broad consensus that this is not a robust engine
 adapter.
 </blockquote>


 <p><b>Proposed resolution:</b></p>
 <p>
 Remove xor_combine_engine from synopsis of 26.4.2 [rand.synopsis].
 </p>
 <p>
 Remove 26.4.4.4 [rand.adapt.xor] <tt>xor_combine_engine</tt>.
 </p>


 <hr>
 <h3><a name="792"></a>792. <tt>piecewise_constant_distribution</tt> is undefined for a range with just one endpoint</h3>
 <p><b>Section:</b> 26.4.8.5.2 [rand.dist.samp.pconst] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> P.J. Plauger <b>Date:</b> 2008-02-09</p>
 <p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#rand.dist.samp.pconst">active issues</a> in [rand.dist.samp.pconst].</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.dist.samp.pconst">issues</a> in [rand.dist.samp.pconst].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <tt>piecewise_constant_distribution</tt> is undefined for a range with just one
 endpoint. (Probably should be the same as an empty range.)
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change 26.4.8.5.2 [rand.dist.samp.pconst] paragraph 3b:
 </p>

 <blockquote>
 b) If <tt>firstB == lastB</tt> <ins>or the sequence <tt>w</tt> has the length zero</ins>,
 </blockquote>


 <hr>
 <h3><a name="798"></a>798. Refactoring of binders lead to interface breakage</h3>
 <p><b>Section:</b> D.8 [depr.lib.binders] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#WP">WP</a>
  <b>Submitter:</b> Daniel Krügler <b>Date:</b> 2008-02-14</p>
 <p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#depr.lib.binders">issues</a> in [depr.lib.binders].</p>
 <p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#WP">WP</a> status.</p>
 <p><b>Discussion:</b></p>
 <p>
 <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2521.pdf">N2521</a>
 and its earlier predecessors have moved the old binders from
 [lib.binders] to D.8 [depr.lib.binders] thereby introducing some renaming
 of the template parameter names (<tt>Operation -&gt; Fn</tt>). During this
 renaming process the <em>protected</em> data member <tt>op</tt> was also renamed to
 <tt>fn</tt>, which seems as an unnecessary interface breakage to me - even if
 this user access point is probably rarely used.
 </p>


 <p><b>Proposed resolution:</b></p>
 <p>
 Change D.8.1 [depr.lib.binder.1st]:
 </p>

 <blockquote>
 <pre>template &lt;class Fn&gt;
 class binder1st
   : public unary_function&lt;typename Fn::second_argument_type,
                           typename Fn::result_type&gt; {
 protected:
   Fn <del>fn</del> <ins>op</ins>;
   typename Fn::first_argument_type value;
 public:
   binder1st(const Fn&amp; x,
             const typename Fn::first_argument_type&amp; y);
   typename Fn::result_type
     operator()(const typename Fn::second_argument_type&amp; x) const;
   typename Fn::result_type
     operator()(typename Fn::second_argument_type&amp; x) const;
 };
 </pre>

 <blockquote>
 <p>
 -1- The constructor initializes <del><tt>fn</tt></del> <ins><tt>op</tt></ins> with <tt>x</tt> and <tt>value</tt> with <tt>y</tt>.
 </p>
 <p>
 -2- <tt>operator()</tt> returns <tt><del>fn</del><ins>op</ins>(value,x)</tt>.
 </p>
 </blockquote>
 </blockquote>

 <p>
 Change D.8.3 [depr.lib.binder.2nd]:
 </p>

 <blockquote>
 <pre>template &lt;class Fn&gt;
 class binder2nd
   : public unary_function&lt;typename Fn::first_argument_type,
                           typename Fn::result_type&gt; {
 protected:
   Fn <del>fn</del> <ins>op</ins>;
   typename Fn::second_argument_type value;
 public:
   binder2nd(const Fn&amp; x,
             const typename Fn::second_argument_type&amp; y);
   typename Fn::result_type
     operator()(const typename Fn::first_argument_type&amp; x) const;
   typename Fn::result_type
     operator()(typename Fn::first_argument_type&amp; x) const;
 };
 </pre>

 <blockquote>
 <p>
 -1- The constructor initializes <del><tt>fn</tt></del> <ins><tt>op</tt></ins> with <tt>x</tt> and <tt>value</tt> with <tt>y</tt>.
 </p>
 <p>
 -2- <tt>operator()</tt> returns <tt><del>fn</del><ins>op</ins>(value,x)</tt>.
 </p>
 </blockquote>
 </blockquote>


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