overload5.html
7.22 KB
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
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>async_connect (5 of 6 overloads)</title>
<link rel="stylesheet" href="../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../index.html" title="Asio">
<link rel="up" href="../async_connect.html" title="async_connect">
<link rel="prev" href="overload4.html" title="async_connect (4 of 6 overloads)">
<link rel="next" href="overload6.html" title="async_connect (6 of 6 overloads)">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../../asio.png"></td></tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="overload4.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../async_connect.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload6.html"><img src="../../../next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.async_connect.overload5"></a><a class="link" href="overload5.html" title="async_connect (5 of 6 overloads)">async_connect
(5 of 6 overloads)</a>
</h4></div></div></div>
<p>
(Deprecated: Use range overload.) Asynchronously establishes a socket connection
by trying each endpoint in a sequence.
</p>
<pre class="programlisting">template<
typename <a class="link" href="../Protocol.html" title="Protocol requirements">Protocol</a>,
typename <a class="link" href="../Executor1.html" title="Executor requirements">Executor</a>,
typename Iterator,
typename <a class="link" href="../ConnectCondition.html" title="Connect condition requirements">ConnectCondition</a>,
typename <a class="link" href="../IteratorConnectHandler.html" title="Iterator connect handler requirements">IteratorConnectHandler</a> = <a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>>
<a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_connect(
basic_socket< Protocol, Executor > & s,
Iterator begin,
ConnectCondition connect_condition,
IteratorConnectHandler && handler = <a class="link" href="../asynchronous_operations.html#asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>,
typename enable_if<!is_endpoint_sequence< Iterator >::value >::type * = 0);
</pre>
<p>
This function attempts to connect a socket to one of a sequence of endpoints.
It does this by repeated calls to the socket's <code class="computeroutput">async_connect</code>
member function, once for each endpoint in the sequence, until a connection
is successfully established.
</p>
<h6>
<a name="asio.reference.async_connect.overload5.h0"></a>
<span><a name="asio.reference.async_connect.overload5.parameters"></a></span><a class="link" href="overload5.html#asio.reference.async_connect.overload5.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">s</span></dt>
<dd><p>
The socket to be connected. If the socket is already open, it will
be closed.
</p></dd>
<dt><span class="term">begin</span></dt>
<dd><p>
An iterator pointing to the start of a sequence of endpoints.
</p></dd>
<dt><span class="term">connect_condition</span></dt>
<dd>
<p>
A function object that is called prior to each connection attempt.
The signature of the function object must be:
</p>
<pre class="programlisting">bool connect_condition(
const asio::error_code& ec,
const typename Protocol::endpoint& next);
</pre>
<p>
The <code class="computeroutput">ec</code> parameter contains the result from the most recent
connect operation. Before the first connection attempt, <code class="computeroutput">ec</code>
is always set to indicate success. The <code class="computeroutput">next</code> parameter
is the next endpoint to be tried. The function object should return
true if the next endpoint should be tried, and false if it should
be skipped.
</p>
</dd>
<dt><span class="term">handler</span></dt>
<dd>
<p>
The handler to be called when the connect operation completes. Copies
will be made of the handler as required. The function signature of
the handler must be:
</p>
<pre class="programlisting">void handler(
// Result of operation. if the sequence is empty, set to
// asio::error::not_found. Otherwise, contains the
// error from the last connection attempt.
const asio::error_code& error,
// On success, an iterator denoting the successfully
// connected endpoint. Otherwise, the end iterator.
Iterator iterator
);
</pre>
<p>
Regardless of whether the asynchronous operation completes immediately
or not, the handler will not be invoked from within this function.
On immediate completion, invocation of the handler will be performed
in a manner equivalent to using <a class="link" href="../post.html" title="post"><code class="computeroutput">post</code></a>.
</p>
</dd>
</dl>
</div>
<h6>
<a name="asio.reference.async_connect.overload5.h1"></a>
<span><a name="asio.reference.async_connect.overload5.remarks"></a></span><a class="link" href="overload5.html#asio.reference.async_connect.overload5.remarks">Remarks</a>
</h6>
<p>
This overload assumes that a default constructed object of type <code class="computeroutput">Iterator</code>
represents the end of the sequence. This is a valid assumption for iterator
types such as <code class="computeroutput">asio::ip::tcp::resolver::iterator</code>.
</p>
</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 © 2003-2020 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="overload4.html"><img src="../../../prev.png" alt="Prev"></a><a accesskey="u" href="../async_connect.html"><img src="../../../up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../home.png" alt="Home"></a><a accesskey="n" href="overload6.html"><img src="../../../next.png" alt="Next"></a>
</div>
</body>
</html>