buffer_copy.html
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<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>
The <code class="computeroutput">asio::buffer_copy</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">template<
typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>,
typename <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>>
std::size_t <a class="link" href="buffer_copy/overload1.html" title="buffer_copy (1 of 2 overloads)">buffer_copy</a>(
const MutableBufferSequence & target,
const ConstBufferSequence & source);
<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">template<
typename <a class="link" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements">MutableBufferSequence</a>,
typename <a class="link" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>>
std::size_t <a class="link" href="buffer_copy/overload2.html" title="buffer_copy (2 of 2 overloads)">buffer_copy</a>(
const MutableBufferSequence & target,
const ConstBufferSequence & source,
std::size_t max_bytes_to_copy);
<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">buffer_copy</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">buffer_copy(target, source)</code>
</li>
<li class="listitem">
A 3-argument form: <code class="computeroutput">buffer_copy(target, source, max_bytes_to_copy)</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">buffer_size(target)</code>
</li>
<li class="listitem">
<code class="computeroutput">buffer_size(source)</code>
</li>
<li class="listitem">
<code class="computeroutput">If</code> specified, <code class="computeroutput">max_bytes_to_copy</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">buffer_copy</code></a>
is implemented in terms of <code class="computeroutput">memcpy</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>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2020 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>)
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