<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Convertible to const buffer requirements</title> <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../boost_asio.html" title="Boost.Asio"> <link rel="up" href="../reference.html" title="Reference"> <link rel="prev" href="ConstBufferSequence.html" title="Constant buffer sequence requirements"> <link rel="next" href="ConvertibleToMutableBuffer.html" title="Convertible to mutable buffer 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 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="ConstBufferSequence.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="ConvertibleToMutableBuffer.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_asio.reference.ConvertibleToConstBuffer"></a><a class="link" href="ConvertibleToConstBuffer.html" title="Convertible to const buffer requirements">Convertible to const buffer requirements</a> </h3></div></div></div> <p> A type that meets the requirements for convertibility to a const buffer must meet the requirements of <code class="computeroutput"><span class="identifier">CopyConstructible</span></code> types (C++ Std, 20.1.3), and the requirements of <code class="computeroutput"><span class="identifier">Assignable</span></code> types (C++ Std, 23.1). </p> <p> In the table below, <code class="computeroutput"><span class="identifier">X</span></code> denotes a class meeting the requirements for convertibility to a const buffer, <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code> denote values of type <code class="computeroutput"><span class="identifier">X</span></code>, and <code class="computeroutput"><span class="identifier">u</span></code>, <code class="computeroutput"><span class="identifier">v</span></code> and <code class="computeroutput"><span class="identifier">w</span></code> denote identifiers. </p> <div class="table"> <a name="boost_asio.reference.ConvertibleToConstBuffer.t0"></a><p class="title"><b>Table 6. ConvertibleToConstBuffer requirements</b></p> <div class="table-contents"><table class="table" summary="ConvertibleToConstBuffer requirements"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> expression </p> </th> <th> <p> postcondition </p> </th> </tr></thead> <tbody> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">const_buffer</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">const_buffer</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">const_buffer</span> <span class="identifier">v</span><span class="special">;</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="keyword">const</span> <span class="identifier">X</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span> <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">w</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">X</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">w</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">X</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span> <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">w</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span> </pre> <p> </p> </td> </tr> <tr> <td> <p> </p> <pre class="programlisting"><span class="identifier">const_buffer</span> <span class="identifier">u</span><span class="special">(</span><span class="identifier">a</span><span class="special">);</span> <span class="identifier">X</span> <span class="identifier">v</span><span class="special">(</span><span class="identifier">b</span><span class="special">);</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">a</span><span class="special">;</span> <span class="identifier">const_buffer</span> <span class="identifier">w</span><span class="special">(</span><span class="identifier">v</span><span class="special">);</span> </pre> <p> </p> </td> <td> <p> </p> <pre class="programlisting"><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">void</span><span class="special">*>(</span><span class="identifier">w</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">u</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">w</span><span class="special">)</span> </pre> <p> </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 © 2003-2015 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="ConstBufferSequence.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="ConvertibleToMutableBuffer.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>