<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Buffer-oriented synchronous random-access write device requirements</title> <link rel="stylesheet" href="../../boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../../boost_asio.html" title="Boost.Asio"> <link rel="up" href="../reference.html" title="Reference"> <link rel="prev" href="SyncRandomAccessReadDevice.html" title="Buffer-oriented synchronous random-access read device requirements"> <link rel="next" href="SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements"> </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 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class="link" href="SyncRandomAccessWriteDevice.html" title="Buffer-oriented synchronous random-access write device requirements"> Buffer-oriented synchronous random-access write device requirements</a> </h3></div></div></div> <p> In the table below, <code class="computeroutput"><span class="identifier">a</span></code> denotes a synchronous random-access write device object, <code class="computeroutput"><span class="identifier">o</span></code> denotes an offset of type <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span></code>, <code class="computeroutput"><span class="identifier">cb</span></code> denotes an object satisfying <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">constant buffer sequence</a> requirements, and <code class="computeroutput"><span class="identifier">ec</span></code> denotes an object of type <code class="computeroutput"><span class="identifier">error_code</span></code>. </p> <div class="table"> <a name="id656376"></a><p class="title"><b>Table 32. Buffer-oriented synchronous random-access write device requirements</b></p> <div class="table-contents"><table class="table" summary="Buffer-oriented synchronous random-access write device requirements"> <colgroup> <col> <col> <col> </colgroup> <thead><tr> <th> <p> operation </p> </th> <th> <p> type </p> </th> <th> <p> semantics, pre/post-conditions </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">write_some_at</span><span class="special">(</span><span class="identifier">o</span><span class="special">,</span> <span class="identifier">cb</span><span class="special">);</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">size_t</span></code> </p> </td> <td> <p> Equivalent to: </p> <pre class="programlisting"><span class="identifier">error_code</span> <span class="identifier">ec</span><span class="special">;</span> <span class="identifier">size_t</span> <span class="identifier">s</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">.</span><span class="identifier">write_some</span><span class="special">(</span><span class="identifier">o</span><span class="special">,</span> <span class="identifier">cb</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span> <span class="keyword">if</span> <span class="special">(</span><span class="identifier">ec</span><span class="special">)</span> <span class="keyword">throw</span> <span class="identifier">system_error</span><span class="special">(</span><span class="identifier">ec</span><span class="special">);</span> <span class="keyword">return</span> <span class="identifier">s</span><span class="special">;</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">write_some_at</span><span class="special">(</span><span class="identifier">o</span><span class="special">,</span> <span class="identifier">cb</span><span class="special">,</span> <span class="identifier">ec</span><span class="special">);</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">size_t</span></code> </p> </td> <td> <p> Writes one or more bytes of data to the device <code class="computeroutput"><span class="identifier">a</span></code> at offset <code class="computeroutput"><span class="identifier">o</span></code>.<br> <br> The constant buffer sequence <code class="computeroutput"><span class="identifier">cb</span></code> specifies memory where the data to be written is located. The <code class="computeroutput"><span class="identifier">write_some_at</span></code> operation shall always write a buffer in the sequence completely before proceeding to the next.<br> <br> If successful, returns the number of bytes written and sets <code class="computeroutput"><span class="identifier">ec</span></code> such that <code class="computeroutput"><span class="special">!</span><span class="identifier">ec</span></code> is true. If an error occurred, returns <code class="computeroutput"><span class="number">0</span></code> and sets <code class="computeroutput"><span class="identifier">ec</span></code> such that <code class="computeroutput"><span class="special">!!</span><span class="identifier">ec</span></code> is true.<br> <br> If the total size of all buffers in the sequence <code class="computeroutput"><span class="identifier">cb</span></code> is <code class="computeroutput"><span class="number">0</span></code>, the function shall return <code class="computeroutput"><span class="number">0</span></code> immediately. </p> </td> </tr> </tbody> </table></div> </div> <br class="table-break"> </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 - 2010 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="SyncRandomAccessReadDevice.html"><img src="../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../boost_asio.html"><img src="../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="SyncReadStream.html"><img src="../../../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>