1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>basic_socket::async_connect</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="../basic_socket.html" title="basic_socket"> 9<link rel="prev" href="assign/overload2.html" title="basic_socket::assign (2 of 2 overloads)"> 10<link rel="next" href="async_wait.html" title="basic_socket::async_wait"> 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="assign/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../basic_socket.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="async_wait.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.basic_socket.async_connect"></a><a class="link" href="async_connect.html" title="basic_socket::async_connect">basic_socket::async_connect</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.basic_socket.async_connect"></a> 31Start 32 an asynchronous connect. 33 </p> 34<pre class="programlisting">template< 35 typename <a class="link" href="../ConnectHandler.html" title="Connect handler requirements">ConnectHandler</a> = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>> 36<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_connect( 37 const endpoint_type & peer_endpoint, 38 ConnectHandler && handler = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>); 39</pre> 40<p> 41 This function is used to asynchronously connect a socket to the specified 42 remote endpoint. The function call always returns immediately. 43 </p> 44<p> 45 The socket is automatically opened if it is not already open. If the connect 46 fails, and the socket was automatically opened, the socket is not returned 47 to the closed state. 48 </p> 49<h6> 50<a name="boost_asio.reference.basic_socket.async_connect.h0"></a> 51 <span class="phrase"><a name="boost_asio.reference.basic_socket.async_connect.parameters"></a></span><a class="link" href="async_connect.html#boost_asio.reference.basic_socket.async_connect.parameters">Parameters</a> 52 </h6> 53<div class="variablelist"> 54<p class="title"><b></b></p> 55<dl class="variablelist"> 56<dt><span class="term">peer_endpoint</span></dt> 57<dd><p> 58 The remote endpoint to which the socket will be connected. Copies 59 will be made of the endpoint object as required. 60 </p></dd> 61<dt><span class="term">handler</span></dt> 62<dd> 63<p> 64 The handler to be called when the connection operation completes. 65 Copies will be made of the handler as required. The function signature 66 of the handler must be: 67</p> 68<pre class="programlisting">void handler( 69 const boost::system::error_code& error // Result of operation 70); 71</pre> 72<p> 73 Regardless of whether the asynchronous operation completes immediately 74 or not, the handler will not be invoked from within this function. 75 On immediate completion, invocation of the handler will be performed 76 in a manner equivalent to using <a class="link" href="../post.html" title="post"><code class="computeroutput">post</code></a>. 77 </p> 78</dd> 79</dl> 80</div> 81<h6> 82<a name="boost_asio.reference.basic_socket.async_connect.h1"></a> 83 <span class="phrase"><a name="boost_asio.reference.basic_socket.async_connect.example"></a></span><a class="link" href="async_connect.html#boost_asio.reference.basic_socket.async_connect.example">Example</a> 84 </h6> 85<pre class="programlisting">void connect_handler(const boost::system::error_code& error) 86{ 87 if (!error) 88 { 89 // Connect succeeded. 90 } 91} 92 93... 94 95boost::asio::ip::tcp::socket socket(my_context); 96boost::asio::ip::tcp::endpoint endpoint( 97 boost::asio::ip::address::from_string("1.2.3.4"), 12345); 98socket.async_connect(endpoint, connect_handler); 99</pre> 100</div> 101<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 102<td align="left"></td> 103<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 104 Kohlhoff<p> 105 Distributed under the Boost Software License, Version 1.0. (See accompanying 106 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>) 107 </p> 108</div></td> 109</tr></table> 110<hr> 111<div class="spirit-nav"> 112<a accesskey="p" href="assign/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../basic_socket.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="async_wait.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 113</div> 114</body> 115</html> 116
