1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Move accept handler requirements</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="LegacyCompletionHandler.html" title="Legacy completion handler requirements"> 10<link rel="next" href="MutableBufferSequence.html" title="Mutable buffer sequence requirements"> 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="LegacyCompletionHandler.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="MutableBufferSequence.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="boost_asio.reference.MoveAcceptHandler"></a><a class="link" href="MoveAcceptHandler.html" title="Move accept handler requirements">Move accept handler 28 requirements</a> 29</h3></div></div></div> 30<p> 31 A move accept handler must meet the requirements for a <a class="link" href="Handler.html" title="Handlers">handler</a>. 32 A value <code class="computeroutput">h</code> of a move accept handler class should work correctly 33 in the expression <code class="computeroutput">h(ec, s)</code>, where <code class="computeroutput">ec</code> is an lvalue 34 of type <code class="computeroutput">const error_code</code> and <code class="computeroutput">s</code> is an lvalue of 35 the nested type <code class="computeroutput">Protocol::socket</code> for the type <code class="computeroutput">Protocol</code> 36 of the socket class template. 37 </p> 38<h5> 39<a name="boost_asio.reference.MoveAcceptHandler.h0"></a> 40 <span class="phrase"><a name="boost_asio.reference.MoveAcceptHandler.examples"></a></span><a class="link" href="MoveAcceptHandler.html#boost_asio.reference.MoveAcceptHandler.examples">Examples</a> 41 </h5> 42<p> 43 A free function as a move accept handler: 44 </p> 45<pre class="programlisting">void accept_handler( 46 const boost::system::error_code& ec, boost::asio::ip::tcp::socket s) 47{ 48 ... 49} 50</pre> 51<p> 52 A move accept handler function object: 53 </p> 54<pre class="programlisting">struct accept_handler 55{ 56 ... 57 void operator()( 58 const boost::system::error_code& ec, boost::asio::ip::tcp::socket s) 59 { 60 ... 61 } 62 ... 63}; 64</pre> 65<p> 66 A lambda as a move accept handler: 67 </p> 68<pre class="programlisting">acceptor.async_accept(..., 69 [](const boost::system::error_code& ec, boost::asio::ip::tcp::socket s) 70 { 71 ... 72 }); 73</pre> 74<p> 75 A non-static class member function adapted to a move accept handler using 76 <code class="computeroutput">std::bind()</code>: 77 </p> 78<pre class="programlisting">void my_class::accept_handler( 79 const boost::system::error_code& ec, boost::asio::ip::tcp::socket socket) 80{ 81 ... 82} 83... 84boost::asio::async_accept(..., 85 std::bind(&my_class::accept_handler, 86 this, std::placeholders::_1, 87 std::placeholders::_2)); 88</pre> 89</div> 90<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 91<td align="left"></td> 92<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 93 Kohlhoff<p> 94 Distributed under the Boost Software License, Version 1.0. (See accompanying 95 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>) 96 </p> 97</div></td> 98</tr></table> 99<hr> 100<div class="spirit-nav"> 101<a accesskey="p" href="LegacyCompletionHandler.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="MutableBufferSequence.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 102</div> 103</body> 104</html> 105
