1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>io_context::wrap</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="../io_context.html" title="io_context"> 9<link rel="prev" href="use_service/overload2.html" title="io_context::use_service (2 of 2 overloads)"> 10<link rel="next" href="_io_context.html" title="io_context::~io_context"> 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="use_service/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_context.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="_io_context.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.io_context.wrap"></a><a class="link" href="wrap.html" title="io_context::wrap">io_context::wrap</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.io_context.wrap"></a> 31(Deprecated: Use <a class="link" href="../bind_executor.html" title="bind_executor"><code class="computeroutput">bind_executor</code></a>.) 32 Create a new handler that automatically dispatches the wrapped handler 33 on the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a>. 34 </p> 35<pre class="programlisting">template< 36 typename <a class="link" href="../Handler.html" title="Handlers">Handler</a>> 37unspecified wrap( 38 Handler handler); 39</pre> 40<p> 41 This function is used to create a new handler function object that, when 42 invoked, will automatically pass the wrapped handler to the <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 43 object's dispatch function. 44 </p> 45<h6> 46<a name="boost_asio.reference.io_context.wrap.h0"></a> 47 <span class="phrase"><a name="boost_asio.reference.io_context.wrap.parameters"></a></span><a class="link" href="wrap.html#boost_asio.reference.io_context.wrap.parameters">Parameters</a> 48 </h6> 49<div class="variablelist"> 50<p class="title"><b></b></p> 51<dl class="variablelist"> 52<dt><span class="term">handler</span></dt> 53<dd> 54<p> 55 The handler to be wrapped. The <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 56 will make a copy of the handler object as required. The function 57 signature of the handler must be: 58</p> 59<pre class="programlisting">void handler(A1 a1, ... An an); 60</pre> 61<p> 62 </p> 63</dd> 64</dl> 65</div> 66<h6> 67<a name="boost_asio.reference.io_context.wrap.h1"></a> 68 <span class="phrase"><a name="boost_asio.reference.io_context.wrap.return_value"></a></span><a class="link" href="wrap.html#boost_asio.reference.io_context.wrap.return_value">Return 69 Value</a> 70 </h6> 71<p> 72 A function object that, when invoked, passes the wrapped handler to the 73 <a class="link" href="../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 74 object's dispatch function. Given a function object with the signature: 75 </p> 76<pre class="programlisting">R f(A1 a1, ... An an); 77</pre> 78<p> 79 If this function object is passed to the wrap function like so: 80 </p> 81<pre class="programlisting">io_context.wrap(f); 82</pre> 83<p> 84 then the return value is a function object with the signature 85 </p> 86<pre class="programlisting">void g(A1 a1, ... An an); 87</pre> 88<p> 89 that, when invoked, executes code equivalent to: 90 </p> 91<pre class="programlisting">io_context.dispatch(boost::bind(f, a1, ... an)); 92</pre> 93</div> 94<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 95<td align="left"></td> 96<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 97 Kohlhoff<p> 98 Distributed under the Boost Software License, Version 1.0. (See accompanying 99 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>) 100 </p> 101</div></td> 102</tr></table> 103<hr> 104<div class="spirit-nav"> 105<a accesskey="p" href="use_service/overload2.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../io_context.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="_io_context.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 106</div> 107</body> 108</html> 109
