doc/html/boost_asio/reference/ComposedConnectHandler.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>Composed connect handler requirements</title>
   5 <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
   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="CompletionHandler.html" title="Completion handler requirements">
  10 <link rel="next" href="ConnectHandler.html" title="Connect handler 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="CompletionHandler.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="ConnectHandler.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.ComposedConnectHandler"></a><a class="link" href="ComposedConnectHandler.html" title="Composed connect handler requirements">Composed
  28       connect handler requirements</a>
  29 </h3></div></div></div>
  30 <p>
  31         A composed connect handler must meet the requirements for a <a class="link" href="Handler.html" title="Handlers">handler</a>.
  32         A value <code class="computeroutput"><span class="identifier">h</span></code> of a composed connect
  33         handler class should work correctly in the expression <code class="computeroutput"><span class="identifier">h</span><span class="special">(</span><span class="identifier">ec</span><span class="special">,</span>
  34         <span class="identifier">i</span><span class="special">)</span></code>,
  35         where <code class="computeroutput"><span class="identifier">ec</span></code> is an lvalue of
  36         type <code class="computeroutput"><span class="keyword">const</span> <span class="identifier">error_code</span></code>
  37         and <code class="computeroutput"><span class="identifier">i</span></code> is an lvalue of the
  38         type <code class="computeroutput"><span class="identifier">Iterator</span></code> used in the
  39         corresponding <code class="computeroutput"><span class="identifier">connect</span><span class="special">()</span></code>
  40         or async_connect()` function.
  41       </p>
  42 <h5>
  43 <a name="boost_asio.reference.ComposedConnectHandler.h0"></a>
  44         <span class="phrase"><a name="boost_asio.reference.ComposedConnectHandler.examples"></a></span><a class="link" href="ComposedConnectHandler.html#boost_asio.reference.ComposedConnectHandler.examples">Examples</a>
  45       </h5>
  46 <p>
  47         A free function as a composed connect handler:
  48       </p>
  49 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">connect_handler</span><span class="special">(</span>
  50     <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">ec</span><span class="special">,</span>
  51     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">iterator</span><span class="special">)</span>
  52 <span class="special">{</span>
  53   <span class="special">...</span>
  54 <span class="special">}</span>
  55 </pre>
  56 <p>
  57         A composed connect handler function object:
  58       </p>
  59 <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">connect_handler</span>
  60 <span class="special">{</span>
  61   <span class="special">...</span>
  62   <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Iterator</span><span class="special">&gt;</span>
  63   <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()(</span>
  64       <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">ec</span><span class="special">,</span>
  65       <span class="identifier">Iterator</span> <span class="identifier">iterator</span><span class="special">)</span>
  66   <span class="special">{</span>
  67     <span class="special">...</span>
  68   <span class="special">}</span>
  69   <span class="special">...</span>
  70 <span class="special">};</span>
  71 </pre>
  72 <p>
  73         A non-static class member function adapted to a composed connect handler
  74         using <code class="computeroutput"><span class="identifier">bind</span><span class="special">()</span></code>:
  75       </p>
  76 <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">my_class</span><span class="special">::</span><span class="identifier">connect_handler</span><span class="special">(</span>
  77     <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">system</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&amp;</span> <span class="identifier">ec</span><span class="special">,</span>
  78     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">ip</span><span class="special">::</span><span class="identifier">tcp</span><span class="special">::</span><span class="identifier">resolver</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">iterator</span><span class="special">)</span>
  79 <span class="special">{</span>
  80   <span class="special">...</span>
  81 <span class="special">}</span>
  82 <span class="special">...</span>
  83 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">async_connect</span><span class="special">(...,</span>
  84     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">bind</span><span class="special">(&amp;</span><span class="identifier">my_class</span><span class="special">::</span><span class="identifier">connect_handler</span><span class="special">,</span>
  85       <span class="keyword">this</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">placeholders</span><span class="special">::</span><span class="identifier">error</span><span class="special">,</span>
  86       <span class="identifier">boost</span><span class="special">::</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">placeholders</span><span class="special">::</span><span class="identifier">iterator</span><span class="special">));</span>
  87 </pre>
  88 </div>
  89 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  90 <td align="left"></td>
  91 <td align="right"><div class="copyright-footer">Copyright &#169; 2003-2014 Christopher M. Kohlhoff<p>
  92         Distributed under the Boost Software License, Version 1.0. (See accompanying
  93         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>)
  94       </p>
  95 </div></td>
  96 </tr></table>
  97 <hr>
  98 <div class="spirit-nav">
  99 <a accesskey="p" href="CompletionHandler.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="ConnectHandler.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
 100 </div>
 101 </body>
 102 </html>