| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>write_at (4 of 8 overloads)</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="../../../boost_asio.html" title="Boost.Asio"> |
| <link rel="up" href="../write_at.html" title="write_at"> |
| <link rel="prev" href="overload3.html" title="write_at (3 of 8 overloads)"> |
| <link rel="next" href="overload5.html" title="write_at (5 of 8 overloads)"> |
| </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="overload3.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../write_at.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload5.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="boost_asio.reference.write_at.overload4"></a><a class="link" href="overload4.html" title="write_at (4 of 8 overloads)">write_at (4 |
| of 8 overloads)</a> |
| </h4></div></div></div> |
| <p> |
| Write a certain amount of data at a specified offset before returning. |
| </p> |
| <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> |
| <span class="keyword">typename</span> <a class="link" href="../SyncRandomAccessWriteDevice.html" title="Buffer-oriented synchronous random-access write device requirements">SyncRandomAccessWriteDevice</a><span class="special">,</span> |
| <span class="keyword">typename</span> <a class="link" href="../ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a><span class="special">,</span> |
| <span class="keyword">typename</span> <span class="identifier">CompletionCondition</span><span class="special">></span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">write_at</span><span class="special">(</span> |
| <span class="identifier">SyncRandomAccessWriteDevice</span> <span class="special">&</span> <span class="identifier">d</span><span class="special">,</span> |
| <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span> <span class="identifier">offset</span><span class="special">,</span> |
| <span class="keyword">const</span> <span class="identifier">ConstBufferSequence</span> <span class="special">&</span> <span class="identifier">buffers</span><span class="special">,</span> |
| <span class="identifier">CompletionCondition</span> <span class="identifier">completion_condition</span><span class="special">,</span> |
| <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span> <span class="special">&</span> <span class="identifier">ec</span><span class="special">);</span> |
| </pre> |
| <p> |
| This function is used to write a certain number of bytes of data to a random |
| access device at a specified offset. The call will block until one of the |
| following conditions is true: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| All of the data in the supplied buffers has been written. That is, |
| the bytes transferred is equal to the sum of the buffer sizes. |
| </li> |
| <li class="listitem"> |
| The completion_condition function object returns 0. |
| </li> |
| </ul></div> |
| <p> |
| This operation is implemented in terms of zero or more calls to the device's |
| write_some_at function. |
| </p> |
| <a name="boost_asio.reference.write_at.overload4.parameters"></a><h6> |
| <a name="boost_asio.reference.write_at.overload4.parameters-heading"></a> |
| <a class="link" href="overload4.html#boost_asio.reference.write_at.overload4.parameters">Parameters</a> |
| </h6> |
| <div class="variablelist"> |
| <p class="title"><b></b></p> |
| <dl> |
| <dt><span class="term">d</span></dt> |
| <dd><p> |
| The device to which the data is to be written. The type must support |
| the SyncRandomAccessWriteDevice concept. |
| </p></dd> |
| <dt><span class="term">offset</span></dt> |
| <dd><p> |
| The offset at which the data will be written. |
| </p></dd> |
| <dt><span class="term">buffers</span></dt> |
| <dd><p> |
| One or more buffers containing the data to be written. The sum of |
| the buffer sizes indicates the maximum number of bytes to write to |
| the device. |
| </p></dd> |
| <dt><span class="term">completion_condition</span></dt> |
| <dd> |
| <p> |
| The function object to be called to determine whether the write operation |
| is complete. The signature of the function object must be: |
| </p> |
| <pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">completion_condition</span><span class="special">(</span> |
| <span class="comment">// Result of latest write_some_at operation.</span> |
| <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">error</span><span class="special">,</span> |
| |
| <span class="comment">// Number of bytes transferred so far.</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">bytes_transferred</span> |
| <span class="special">);</span> |
| </pre> |
| <p> |
| A return value of 0 indicates that the write operation is complete. |
| A non-zero return value indicates the maximum number of bytes to |
| be written on the next call to the device's write_some_at function. |
| </p> |
| </dd> |
| <dt><span class="term">ec</span></dt> |
| <dd><p> |
| Set to indicate what error occurred, if any. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="boost_asio.reference.write_at.overload4.return_value"></a><h6> |
| <a name="boost_asio.reference.write_at.overload4.return_value-heading"></a> |
| <a class="link" href="overload4.html#boost_asio.reference.write_at.overload4.return_value">Return |
| Value</a> |
| </h6> |
| <p> |
| The number of bytes written. If an error occurs, returns the total number |
| of bytes successfully transferred prior to the error. |
| </p> |
| </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 © 2003-2011 Christopher |
| M. Kohlhoff<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="overload3.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../write_at.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload5.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |