112 lines
8.1 KiB
HTML
112 lines
8.1 KiB
HTML
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
|
|
<title>buffer_copy</title>
|
|
<link rel="stylesheet" href="../../boostbook.css" type="text/css">
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
|
|
<link rel="home" href="../../index.html" title="Asio">
|
|
<link rel="up" href="../reference.html" title="Reference">
|
|
<link rel="prev" href="buffer_cast/overload2.html" title="buffer_cast (2 of 2 overloads)">
|
|
<link rel="next" href="buffer_copy/overload1.html" title="buffer_copy (1 of 2 overloads)">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|
</head>
|
|
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
|
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table>
|
|
<hr>
|
|
<div class="spirit-nav">
|
|
<a accesskey="p" href="buffer_cast/overload2.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="buffer_copy/overload1.html"><img src="../../next.png" alt="Next"></a>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="asio.reference.buffer_copy"></a><a class="link" href="buffer_copy.html" title="buffer_copy">buffer_copy</a>
|
|
</h3></div></div></div>
|
|
<p>
|
|
<a class="indexterm" name="asio.indexterm.buffer_copy"></a>
|
|
</p>
|
|
<p>
|
|
The <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer_copy</span></code> function is used to copy bytes
|
|
from a source buffer (or buffer sequence) to a target buffer (or buffer sequence).
|
|
</p>
|
|
<p>
|
|
Copies bytes from a source buffer sequence to a target buffer sequence.
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span>
|
|
<span class="keyword">typename</span> <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a><span class="special">,</span>
|
|
<span class="keyword">typename</span> <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a><span class="special">></span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="buffer_copy/overload1.html" title="buffer_copy (1 of 2 overloads)">buffer_copy</a><span class="special">(</span>
|
|
<span class="keyword">const</span> <span class="identifier">MutableBufferSequence</span> <span class="special">&</span> <span class="identifier">target</span><span class="special">,</span>
|
|
<span class="keyword">const</span> <span class="identifier">ConstBufferSequence</span> <span class="special">&</span> <span class="identifier">source</span><span class="special">);</span>
|
|
<span class="emphasis"><em>» <a class="link" href="buffer_copy/overload1.html" title="buffer_copy (1 of 2 overloads)">more...</a></em></span>
|
|
</pre>
|
|
<p>
|
|
Copies a limited number of bytes from a source buffer sequence to a target
|
|
buffer sequence.
|
|
</p>
|
|
<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span>
|
|
<span class="keyword">typename</span> <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a><span class="special">,</span>
|
|
<span class="keyword">typename</span> <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a><span class="special">></span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="buffer_copy/overload2.html" title="buffer_copy (2 of 2 overloads)">buffer_copy</a><span class="special">(</span>
|
|
<span class="keyword">const</span> <span class="identifier">MutableBufferSequence</span> <span class="special">&</span> <span class="identifier">target</span><span class="special">,</span>
|
|
<span class="keyword">const</span> <span class="identifier">ConstBufferSequence</span> <span class="special">&</span> <span class="identifier">source</span><span class="special">,</span>
|
|
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">max_bytes_to_copy</span><span class="special">);</span>
|
|
<span class="emphasis"><em>» <a class="link" href="buffer_copy/overload2.html" title="buffer_copy (2 of 2 overloads)">more...</a></em></span>
|
|
</pre>
|
|
<p>
|
|
The <code class="computeroutput"><span class="identifier">buffer_copy</span></code> function
|
|
is available in two forms:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
|
|
<li class="listitem">
|
|
A 2-argument form: <code class="computeroutput"><span class="identifier">buffer_copy</span><span class="special">(</span><span class="identifier">target</span><span class="special">,</span> <span class="identifier">source</span><span class="special">)</span></code>
|
|
</li>
|
|
<li class="listitem">
|
|
A 3-argument form: <code class="computeroutput"><span class="identifier">buffer_copy</span><span class="special">(</span><span class="identifier">target</span><span class="special">,</span> <span class="identifier">source</span><span class="special">,</span> <span class="identifier">max_bytes_to_copy</span><span class="special">)</span></code>
|
|
</li>
|
|
</ul></div>
|
|
<p>
|
|
Both forms return the number of bytes actually copied. The number of bytes
|
|
copied is the lesser of:
|
|
</p>
|
|
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
|
|
<li class="listitem">
|
|
<code class="computeroutput"><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">target</span><span class="special">)</span></code>
|
|
</li>
|
|
<li class="listitem">
|
|
<code class="computeroutput"><span class="identifier">buffer_size</span><span class="special">(</span><span class="identifier">source</span><span class="special">)</span></code>
|
|
</li>
|
|
<li class="listitem">
|
|
<code class="computeroutput"><span class="identifier">If</span></code> specified, <code class="computeroutput"><span class="identifier">max_bytes_to_copy</span></code>.
|
|
</li>
|
|
</ul></div>
|
|
<p>
|
|
This prevents buffer overflow, regardless of the buffer sizes used in the
|
|
copy operation.
|
|
</p>
|
|
<p>
|
|
Note that <a class="link" href="buffer_copy.html" title="buffer_copy"><code class="computeroutput"><span class="identifier">buffer_copy</span></code></a>
|
|
is implemented in terms of <code class="computeroutput"><span class="identifier">memcpy</span></code>,
|
|
and consequently it cannot be used to copy between overlapping memory regions.
|
|
</p>
|
|
<h5>
|
|
<a name="asio.reference.buffer_copy.h0"></a>
|
|
<span><a name="asio.reference.buffer_copy.requirements"></a></span><a class="link" href="buffer_copy.html#asio.reference.buffer_copy.requirements">Requirements</a>
|
|
</h5>
|
|
<p>
|
|
<span class="emphasis"><em>Header: </em></span><code class="literal">asio/buffer.hpp</code>
|
|
</p>
|
|
<p>
|
|
<span class="emphasis"><em>Convenience header: </em></span><code class="literal">asio.hpp</code>
|
|
</p>
|
|
</div>
|
|
<div class="copyright-footer">Copyright © 2003-2023 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>
|
|
<hr>
|
|
<div class="spirit-nav">
|
|
<a accesskey="p" href="buffer_cast/overload2.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="buffer_copy/overload1.html"><img src="../../next.png" alt="Next"></a>
|
|
</div>
|
|
</body>
|
|
</html>
|