1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>basic_stream::async_connect (4 of 5 overloads)</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="../../../../index.html" title="Chapter 1. Boost.Beast"> 8<link rel="up" href="../async_connect.html" title="basic_stream::async_connect"> 9<link rel="prev" href="overload3.html" title="basic_stream::async_connect (3 of 5 overloads)"> 10<link rel="next" href="overload5.html" title="basic_stream::async_connect (5 of 5 overloads)"> 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="overload3.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_connect.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload5.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h6 class="title"> 27<a name="beast.ref.boost__beast__basic_stream.async_connect.overload4"></a><a class="link" href="overload4.html" title="basic_stream::async_connect (4 of 5 overloads)">basic_stream::async_connect 28 (4 of 5 overloads)</a> 29</h6></div></div></div> 30<p> 31 Establishes a connection by trying each endpoint in a sequence asynchronously. 32 </p> 33<h7><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.h0"></a> 34 <span class="phrase"><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.synopsis"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__basic_stream.async_connect.overload4.synopsis">Synopsis</a> 35 </h7><pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 36 <span class="keyword">class</span> <span class="identifier">Iterator</span><span class="special">,</span> 37 <span class="keyword">class</span> <a href="../../../../../../../../doc/html/boost_asio/reference/IteratorConnectHandler.html" target="_top"><span class="emphasis"><em>IteratorConnectHandler</em></span></a> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special"><</span><a class="link" href="../executor_type.html" title="basic_stream::executor_type">executor_type</a><span class="special">>></span> 38<a href="../../../../../../../../doc/html/boost_asio/reference/asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type" target="_top"><span class="emphasis"><em>DEDUCED</em></span></a> 39<span class="identifier">async_connect</span><span class="special">(</span> 40 <span class="identifier">Iterator</span> <span class="identifier">begin</span><span class="special">,</span> 41 <span class="identifier">Iterator</span> <span class="identifier">end</span><span class="special">,</span> 42 <span class="identifier">IteratorConnectHandler</span><span class="special">&&</span> <span class="identifier">handler</span> <span class="special">=</span> <span class="identifier">net</span><span class="special">::</span><span class="identifier">default_completion_token_t</span><span class="special"><</span> <a class="link" href="../executor_type.html" title="basic_stream::executor_type">executor_type</a> <span class="special">>{});</span> 43</pre> 44<h7><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.h1"></a> 45 <span class="phrase"><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.description"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__basic_stream.async_connect.overload4.description">Description</a> 46 </h7><p> 47 This function attempts to connect the stream to one of a sequence of 48 endpoints by trying each endpoint until a connection is successfully 49 established. The underlying socket is automatically opened if needed. 50 An automatically opened socket is not returned to the closed state upon 51 failure. The algorithm, known as a <span class="emphasis"><em>composed asynchronous operation</em></span>, 52 is implemented in terms of calls to the underlying socket's <code class="computeroutput"><span class="identifier">async_connect</span></code> function. If the timeout 53 timer expires while the operation is outstanding, the current connection 54 attempt will be canceled and the completion handler will be invoked with 55 the error <a class="link" href="../../boost__beast__error.html" title="error"><code class="computeroutput"><span class="identifier">error</span><span class="special">::</span><span class="identifier">timeout</span></code></a>. 56 </p> 57<h7><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.h2"></a> 58 <span class="phrase"><a name="beast.ref.boost__beast__basic_stream.async_connect.overload4.parameters"></a></span><a class="link" href="overload4.html#beast.ref.boost__beast__basic_stream.async_connect.overload4.parameters">Parameters</a> 59 </h7><div class="informaltable"><table class="table"> 60<colgroup> 61<col> 62<col> 63</colgroup> 64<thead><tr> 65<th> 66 <p> 67 Name 68 </p> 69 </th> 70<th> 71 <p> 72 Description 73 </p> 74 </th> 75</tr></thead> 76<tbody> 77<tr> 78<td> 79 <p> 80 <code class="computeroutput"><span class="identifier">begin</span></code> 81 </p> 82 </td> 83<td> 84 <p> 85 An iterator pointing to the start of a sequence of endpoints. 86 </p> 87 </td> 88</tr> 89<tr> 90<td> 91 <p> 92 <code class="computeroutput"><span class="identifier">end</span></code> 93 </p> 94 </td> 95<td> 96 <p> 97 An iterator pointing to the end of a sequence of endpoints. 98 </p> 99 </td> 100</tr> 101<tr> 102<td> 103 <p> 104 <code class="computeroutput"><span class="identifier">handler</span></code> 105 </p> 106 </td> 107<td> 108 <p> 109 The completion handler to invoke when the operation completes. 110 The implementation takes ownership of the handler by performing 111 a decay-copy. The equivalent function signature of the handler 112 must be: 113 </p> 114<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span> 115 <span class="comment">// Result of operation. if the sequence is empty, set to</span> 116 <span class="comment">// net::error::not_found. Otherwise, contains the</span> 117 <span class="comment">// error from the last connection attempt.</span> 118 <span class="identifier">error_code</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">error</span><span class="special">,</span> 119 120 <span class="comment">// On success, an iterator denoting the successfully</span> 121 <span class="comment">// connected endpoint. Otherwise, the end iterator.</span> 122 <span class="identifier">Iterator</span> <span class="identifier">iterator</span> 123<span class="special">);</span> 124</pre> 125 <p> 126 Regardless of whether the asynchronous operation completes 127 immediately or not, the handler will not be invoked from within 128 this function. Invocation of the handler will be performed 129 in a manner equivalent to using <code class="computeroutput"><span class="identifier">net</span><span class="special">::</span><span class="identifier">post</span></code>. 130 </p> 131 </td> 132</tr> 133</tbody> 134</table></div> 135</div> 136<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 137<td align="left"></td> 138<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Vinnie 139 Falco<p> 140 Distributed under the Boost Software License, Version 1.0. (See accompanying 141 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>) 142 </p> 143</div></td> 144</tr></table> 145<hr> 146<div class="spirit-nav"> 147<a accesskey="p" href="overload3.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../async_connect.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="overload5.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 148</div> 149</body> 150</html> 151
