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<div class="titlepage"><div><div><h3 class="title">
<a name="boost_asio.reference.WriteHandler"></a><a class="link" href="WriteHandler.html" title="Write handler requirements">Write handler requirements</a>
</h3></div></div></div>
<p>
A write handler must meet the requirements for a <a class="link" href="Handler.html" title="Handlers">handler</a>.
A value <code class="computeroutput">h</code> of a write handler class should work correctly in
the expression <code class="computeroutput">h(ec, s)</code>, where <code class="computeroutput">ec</code> is an lvalue
of type <code class="computeroutput">const error_code</code> and <code class="computeroutput">s</code> is an lvalue of
type <code class="computeroutput">const size_t</code>.
</p>
<h5>
<a name="boost_asio.reference.WriteHandler.h0"></a>
<span class="phrase"><a name="boost_asio.reference.WriteHandler.examples"></a></span><a class="link" href="WriteHandler.html#boost_asio.reference.WriteHandler.examples">Examples</a>
</h5>
<p>
A free function as a write handler:
</p>
<pre class="programlisting">void write_handler(
const boost::system::error_code& ec,
std::size_t bytes_transferred)
{
...
}
</pre>
<p>
A write handler function object:
</p>
<pre class="programlisting">struct write_handler
{
...
void operator()(
const boost::system::error_code& ec,
std::size_t bytes_transferred)
{
...
}
...
};
</pre>
<p>
A lambda as a write handler:
</p>
<pre class="programlisting">socket.async_write(...
[](const boost::system::error_code& ec,
std::size_t bytes_transferred)
{
...
});
</pre>
<p>
A non-static class member function adapted to a write handler using <code class="computeroutput">std::bind()</code>:
</p>
<pre class="programlisting">void my_class::write_handler(
const boost::system::error_code& ec,
std::size_t bytes_transferred)
{
...
}
...
socket.async_write(...,
std::bind(&my_class::write_handler,
this, std::placeholders::_1,
std::placeholders::_2));
</pre>
<p>
A non-static class member function adapted to a write handler using <code class="computeroutput">boost::bind()</code>:
</p>
<pre class="programlisting">void my_class::write_handler(
const boost::system::error_code& ec,
std::size_t bytes_transferred)
{
...
}
...
socket.async_write(...,
boost::bind(&my_class::write_handler,
this, boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
</pre>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2017 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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