1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>buffer_copy (2 of 2 overloads)</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="../buffer_copy.html" title="buffer_copy"> 9<link rel="prev" href="overload1.html" title="buffer_copy (1 of 2 overloads)"> 10<link rel="next" href="../buffer_sequence_begin.html" title="buffer_sequence_begin"> 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 href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="overload1.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../buffer_copy.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_sequence_begin.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_asio.reference.buffer_copy.overload2"></a><a class="link" href="overload2.html" title="buffer_copy (2 of 2 overloads)">buffer_copy 28 (2 of 2 overloads)</a> 29</h4></div></div></div> 30<p> 31 Copies a limited number of bytes from a source buffer sequence to a target 32 buffer sequence. 33 </p> 34<pre class="programlisting">template< 35 typename <a class="link" href="../MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>, 36 typename <a class="link" href="../ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>> 37std::size_t buffer_copy( 38 const MutableBufferSequence & target, 39 const ConstBufferSequence & source, 40 std::size_t max_bytes_to_copy); 41</pre> 42<h6> 43<a name="boost_asio.reference.buffer_copy.overload2.h0"></a> 44 <span class="phrase"><a name="boost_asio.reference.buffer_copy.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.buffer_copy.overload2.parameters">Parameters</a> 45 </h6> 46<div class="variablelist"> 47<p class="title"><b></b></p> 48<dl class="variablelist"> 49<dt><span class="term">target</span></dt> 50<dd><p> 51 A modifiable buffer sequence representing the memory regions to which 52 the bytes will be copied. 53 </p></dd> 54<dt><span class="term">source</span></dt> 55<dd><p> 56 A non-modifiable buffer sequence representing the memory regions 57 from which the bytes will be copied. 58 </p></dd> 59<dt><span class="term">max_bytes_to_copy</span></dt> 60<dd><p> 61 The maximum number of bytes to be copied. 62 </p></dd> 63</dl> 64</div> 65<h6> 66<a name="boost_asio.reference.buffer_copy.overload2.h1"></a> 67 <span class="phrase"><a name="boost_asio.reference.buffer_copy.overload2.return_value"></a></span><a class="link" href="overload2.html#boost_asio.reference.buffer_copy.overload2.return_value">Return 68 Value</a> 69 </h6> 70<p> 71 The number of bytes copied. 72 </p> 73<h6> 74<a name="boost_asio.reference.buffer_copy.overload2.h2"></a> 75 <span class="phrase"><a name="boost_asio.reference.buffer_copy.overload2.remarks"></a></span><a class="link" href="overload2.html#boost_asio.reference.buffer_copy.overload2.remarks">Remarks</a> 76 </h6> 77<p> 78 The number of bytes copied is the lesser of: 79 </p> 80<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 81<li class="listitem"> 82 <code class="computeroutput">buffer_size(target)</code> 83 </li> 84<li class="listitem"> 85 <code class="computeroutput">buffer_size(source)</code> 86 </li> 87<li class="listitem"> 88 <code class="computeroutput">max_bytes_to_copy</code> 89 </li> 90</ul></div> 91<p> 92 This function is implemented in terms of <code class="computeroutput">memcpy</code>, and consequently 93 it cannot be used to copy between overlapping memory regions. 94 </p> 95</div> 96<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 97<td align="left"></td> 98<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 99 Kohlhoff<p> 100 Distributed under the Boost Software License, Version 1.0. (See accompanying 101 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>) 102 </p> 103</div></td> 104</tr></table> 105<hr> 106<div class="spirit-nav"> 107<a accesskey="p" href="overload1.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../buffer_copy.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_sequence_begin.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 108</div> 109</body> 110</html> 111
