<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>buffer_cast</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="buffer/overload28.html" title="buffer (28 of 28 overloads)"> <link rel="next" href="buffer_cast/overload1.html" title="buffer_cast (1 of 2 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 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class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span></code> function is used to obtain a pointer to the underlying memory region associated with a buffer. </p> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">PointerToPodType</span><span class="special">></span> <span class="identifier">PointerToPodType</span> <a class="link" href="buffer_cast/overload1.html" title="buffer_cast (1 of 2 overloads)">buffer_cast</a><span class="special">(</span> <span class="keyword">const</span> <span class="identifier">mutable_buffer</span> <span class="special">&</span> <span class="identifier">b</span><span class="special">);</span> <span class="emphasis"><em>» <a class="link" href="buffer_cast/overload1.html" title="buffer_cast (1 of 2 overloads)">more...</a></em></span> <span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">PointerToPodType</span><span class="special">></span> <span class="identifier">PointerToPodType</span> <a class="link" href="buffer_cast/overload2.html" title="buffer_cast (2 of 2 overloads)">buffer_cast</a><span class="special">(</span> <span class="keyword">const</span> <span class="identifier">const_buffer</span> <span class="special">&</span> <span class="identifier">b</span><span class="special">);</span> <span class="emphasis"><em>» <a class="link" href="buffer_cast/overload2.html" title="buffer_cast (2 of 2 overloads)">more...</a></em></span> </pre> <h5> <a name="boost_asio.reference.buffer_cast.h0"></a> <span class="phrase"><a name="boost_asio.reference.buffer_cast.examples_"></a></span><a class="link" href="buffer_cast.html#boost_asio.reference.buffer_cast.examples_">Examples:</a> </h5> <p> To access the memory of a non-modifiable buffer, use: </p> <pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">const_buffer</span> <span class="identifier">b1</span> <span class="special">=</span> <span class="special">...;</span> <span class="keyword">const</span> <span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">p1</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">const</span> <span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*>(</span><span class="identifier">b1</span><span class="special">);</span> </pre> <p> To access the memory of a modifiable buffer, use: </p> <pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">mutable_buffer</span> <span class="identifier">b2</span> <span class="special">=</span> <span class="special">...;</span> <span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">p2</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span><span class="special"><</span><span class="keyword">unsigned</span> <span class="keyword">char</span><span class="special">*>(</span><span class="identifier">b2</span><span class="special">);</span> </pre> <p> The <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_cast</span></code> function permits violations of type safety, so uses of it in application code should be carefully considered. </p> <h5> <a name="boost_asio.reference.buffer_cast.h1"></a> <span class="phrase"><a name="boost_asio.reference.buffer_cast.requirements"></a></span><a class="link" href="buffer_cast.html#boost_asio.reference.buffer_cast.requirements">Requirements</a> </h5> <p> <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/buffer.hpp</code> </p> <p> <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> </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 © 2003-2015 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="buffer/overload28.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="buffer_cast/overload1.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>