doc/html/boost_asio/reference/ConnectHandler.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Connect handler requirements</title>
<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../../boost_asio.html" title="Boost.Asio">
<link rel="up" href="../reference.html" title="Reference">
<link rel="prev" href="ConnectCondition.html" title="Connect condition requirements">
<link rel="next" href="ConstBufferSequence.html" title="Constant buffer sequence requirements">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td>
<td align="center"><a href="../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="ConnectCondition.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="ConstBufferSequence.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_asio.reference.ConnectHandler"></a><a class="link" href="ConnectHandler.html" title="Connect handler requirements">Connect handler
      requirements</a>
</h3></div></div></div>
<p>
        A connect 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 connect handler class should work correctly in
        the expression <code class="computeroutput">h(ec)</code>, where <code class="computeroutput">ec</code> is an lvalue of
        type <code class="computeroutput">const error_code</code>.
      </p>
<h5>
<a name="boost_asio.reference.ConnectHandler.h0"></a>
        <span class="phrase"><a name="boost_asio.reference.ConnectHandler.examples"></a></span><a class="link" href="ConnectHandler.html#boost_asio.reference.ConnectHandler.examples">Examples</a>
      </h5>
<p>
        A free function as a connect handler:
      </p>
<pre class="programlisting">void connect_handler(
    const boost::system::error_code&amp; ec)
{
  ...
}
</pre>
<p>
        A connect handler function object:
      </p>
<pre class="programlisting">struct connect_handler
{
  ...
  void operator()(
      const boost::system::error_code&amp; ec)
  {
    ...
  }
  ...
};
</pre>
<p>
        A lambda as a connect handler:
      </p>
<pre class="programlisting">socket.async_connect(...,
    [](const boost::system::error_code&amp; ec)
    {
      ...
    });
</pre>
<p>
        A non-static class member function adapted to a connect handler using <code class="computeroutput">std::bind()</code>:
      </p>
<pre class="programlisting">void my_class::connect_handler(
    const boost::system::error_code&amp; ec)
{
  ...
}
...
socket.async_connect(...,
    std::bind(&amp;my_class::connect_handler,
      this, std::placeholders::_1));
</pre>
<p>
        A non-static class member function adapted to a connect handler using <code class="computeroutput">boost::bind()</code>:
      </p>
<pre class="programlisting">void my_class::connect_handler(
    const boost::system::error_code&amp; ec)
{
  ...
}
...
socket.async_connect(...,
    boost::bind(&amp;my_class::connect_handler,
      this, boost::asio::placeholders::error));
</pre>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2019 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>)
      </p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="ConnectCondition.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="ConstBufferSequence.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>