1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>const_buffer</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../reference.html" title="Reference"> 9<link rel="prev" href="connect/overload12.html" title="connect (12 of 12 overloads)"> 10<link rel="next" href="const_buffer/const_buffer.html" title="const_buffer::const_buffer"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 15<td align="center"><a href="../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a 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32<pre class="programlisting">class const_buffer 33</pre> 34<h5> 35<a name="boost_asio.reference.const_buffer.h0"></a> 36 <span class="phrase"><a name="boost_asio.reference.const_buffer.member_functions"></a></span><a class="link" href="const_buffer.html#boost_asio.reference.const_buffer.member_functions">Member 37 Functions</a> 38 </h5> 39<div class="informaltable"><table class="table"> 40<colgroup> 41<col> 42<col> 43</colgroup> 44<thead><tr> 45<th> 46 <p> 47 Name 48 </p> 49 </th> 50<th> 51 <p> 52 Description 53 </p> 54 </th> 55</tr></thead> 56<tbody> 57<tr> 58<td> 59 <p> 60 <a class="link" href="const_buffer/const_buffer.html" title="const_buffer::const_buffer"><span class="bold"><strong>const_buffer</strong></span></a> <span class="silver">[constructor]</span> 61 </p> 62 </td> 63<td> 64 <p> 65 Construct an empty buffer. <br> <span class="silver"> —</span><br> Construct a buffer to 66 represent a given memory range. <br> <span class="silver"> —</span><br> Construct a non-modifiable 67 buffer from a modifiable one. 68 </p> 69 </td> 70</tr> 71<tr> 72<td> 73 <p> 74 <a class="link" href="const_buffer/data.html" title="const_buffer::data"><span class="bold"><strong>data</strong></span></a> 75 </p> 76 </td> 77<td> 78 <p> 79 Get a pointer to the beginning of the memory range. 80 </p> 81 </td> 82</tr> 83<tr> 84<td> 85 <p> 86 <a class="link" href="const_buffer/operator_plus__eq_.html" title="const_buffer::operator+="><span class="bold"><strong>operator+=</strong></span></a> 87 </p> 88 </td> 89<td> 90 <p> 91 Move the start of the buffer by the specified number of bytes. 92 </p> 93 </td> 94</tr> 95<tr> 96<td> 97 <p> 98 <a class="link" href="const_buffer/size.html" title="const_buffer::size"><span class="bold"><strong>size</strong></span></a> 99 </p> 100 </td> 101<td> 102 <p> 103 Get the size of the memory range. 104 </p> 105 </td> 106</tr> 107</tbody> 108</table></div> 109<h5> 110<a name="boost_asio.reference.const_buffer.h1"></a> 111 <span class="phrase"><a name="boost_asio.reference.const_buffer.related_functions"></a></span><a class="link" href="const_buffer.html#boost_asio.reference.const_buffer.related_functions">Related 112 Functions</a> 113 </h5> 114<div class="informaltable"><table class="table"> 115<colgroup> 116<col> 117<col> 118</colgroup> 119<thead><tr> 120<th> 121 <p> 122 Name 123 </p> 124 </th> 125<th> 126 <p> 127 Description 128 </p> 129 </th> 130</tr></thead> 131<tbody><tr> 132<td> 133 <p> 134 <a class="link" href="const_buffer/operator_plus_.html" title="const_buffer::operator+"><span class="bold"><strong>operator+</strong></span></a> 135 </p> 136 </td> 137<td> 138 <p> 139 Create a new non-modifiable buffer that is offset from the start 140 of another. 141 </p> 142 </td> 143</tr></tbody> 144</table></div> 145<p> 146 The <a class="link" href="const_buffer.html" title="const_buffer"><code class="computeroutput">const_buffer</code></a> 147 class provides a safe representation of a buffer that cannot be modified. 148 It does not own the underlying data, and so is cheap to copy or assign. 149 </p> 150<h5> 151<a name="boost_asio.reference.const_buffer.h2"></a> 152 <span class="phrase"><a name="boost_asio.reference.const_buffer.accessing_buffer_contents"></a></span><a class="link" href="const_buffer.html#boost_asio.reference.const_buffer.accessing_buffer_contents">Accessing 153 Buffer Contents</a> 154 </h5> 155<p> 156 The contents of a buffer may be accessed using the <code class="computeroutput">data()</code> and 157 <code class="computeroutput">size()</code> member functions: 158 </p> 159<pre class="programlisting">boost::asio::const_buffer b1 = ...; 160std::size_t s1 = b1.size(); 161const unsigned char* p1 = static_cast<const unsigned char*>(b1.data()); 162</pre> 163<p> 164 The <code class="computeroutput">data()</code> member function permits violations of type safety, 165 so uses of it in application code should be carefully considered. 166 </p> 167<h5> 168<a name="boost_asio.reference.const_buffer.h3"></a> 169 <span class="phrase"><a name="boost_asio.reference.const_buffer.requirements"></a></span><a class="link" href="const_buffer.html#boost_asio.reference.const_buffer.requirements">Requirements</a> 170 </h5> 171<p> 172 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/buffer.hpp</code> 173 </p> 174<p> 175 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 176 </p> 177</div> 178<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 179<td align="left"></td> 180<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 181 Kohlhoff<p> 182 Distributed under the Boost Software License, Version 1.0. (See accompanying 183 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>) 184 </p> 185</div></td> 186</tr></table> 187<hr> 188<div class="spirit-nav"> 189<a accesskey="p" href="connect/overload12.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="const_buffer/const_buffer.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 190</div> 191</body> 192</html> 193
