| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>Local Variables</title> |
| <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> |
| <link rel="home" href="../../../index.html" title="Chapter 1. Phoenix 3.0"> |
| <link rel="up" href="../scope.html" title="Scope"> |
| <link rel="prev" href="../scope.html" title="Scope"> |
| <link rel="next" href="let.html" title="let"> |
| </head> |
| <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> |
| <table cellpadding="2" width="100%"><tr> |
| <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> |
| <td align="center"><a href="../../../../../../../index.html">Home</a></td> |
| <td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> |
| <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> |
| <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> |
| <td align="center"><a href="../../../../../../../more/index.htm">More</a></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="../scope.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../scope.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="let.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h4 class="title"> |
| <a name="phoenix.modules.scope.local_variables"></a><a class="link" href="local_variables.html" title="Local Variables">Local Variables</a> |
| </h4></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">scope</span><span class="special">/</span><span class="identifier">local_variable</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| We use an instance of: |
| </p> |
| <pre class="programlisting"><span class="identifier">expression</span><span class="special">::</span><span class="identifier">local_variable</span><span class="special"><</span><span class="identifier">Key</span><span class="special">>::</span><span class="identifier">type</span> |
| </pre> |
| <p> |
| to represent a local variable. The local variable acts as an imaginary |
| data-bin where a local, stack based data will be placed. <code class="computeroutput"><span class="identifier">Key</span></code> is an arbitrary type that is used |
| to identify the local variable. Example: |
| </p> |
| <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">size_key</span><span class="special">;</span> |
| <span class="identifier">expression</span><span class="special">::</span><span class="identifier">local_variable</span><span class="special"><</span><span class="identifier">size_key</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">size</span><span class="special">;</span> |
| </pre> |
| <p> |
| <span class="bold"><strong>Predefined Local Variables</strong></span> |
| </p> |
| <p> |
| There are a few predefined instances of <code class="computeroutput"><span class="identifier">expression</span><span class="special">::</span><span class="identifier">local_variable</span><span class="special"><</span><span class="identifier">Key</span><span class="special">>::</span><span class="identifier">type</span></code> |
| named <code class="computeroutput"><span class="identifier">_a</span></code>..<code class="computeroutput"><span class="identifier">_z</span></code> that you can already use. To make |
| use of them, simply use the <code class="computeroutput"><span class="keyword">namespace</span> |
| <span class="identifier">boost</span><span class="special">::</span><span class="identifier">phoenix</span><span class="special">::</span><span class="identifier">local_names</span></code>: |
| </p> |
| <pre class="programlisting"><span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">phoenix</span><span class="special">::</span><span class="identifier">local_names</span><span class="special">;</span> |
| </pre> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2002-2005, 2010 Joel de Guzman, Dan Marsden, Thomas Heller<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
| </div></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="../scope.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../scope.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="let.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
