1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>system_context::use_service (2 of 2 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="../../../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../use_service.html" title="system_context::use_service"> 9<link rel="prev" href="overload1.html" title="system_context::use_service (1 of 2 overloads)"> 10<link rel="next" href="../_system_context.html" title="system_context::~system_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="overload1.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../use_service.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="../_system_context.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="boost_asio.reference.system_context.use_service.overload2"></a><a class="link" href="overload2.html" title="system_context::use_service (2 of 2 overloads)">system_context::use_service 28 (2 of 2 overloads)</a> 29</h5></div></div></div> 30<p> 31 <span class="emphasis"><em>Inherited from execution_context.</em></span> 32 </p> 33<p> 34 Obtain the service object corresponding to the given type. 35 </p> 36<pre class="programlisting">template< 37 typename <a class="link" href="../../Service.html" title="Service requirements">Service</a>> 38friend Service & use_service( 39 io_context & ioc); 40</pre> 41<p> 42 This function is used to locate a service object that corresponds to 43 the given service type. If there is no existing implementation of the 44 service, then the <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 45 will create a new instance of the service. 46 </p> 47<h6> 48<a name="boost_asio.reference.system_context.use_service.overload2.h0"></a> 49 <span class="phrase"><a name="boost_asio.reference.system_context.use_service.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.system_context.use_service.overload2.parameters">Parameters</a> 50 </h6> 51<div class="variablelist"> 52<p class="title"><b></b></p> 53<dl class="variablelist"> 54<dt><span class="term">ioc</span></dt> 55<dd><p> 56 The <a class="link" href="../../io_context.html" title="io_context"><code class="computeroutput">io_context</code></a> 57 object that owns the service. 58 </p></dd> 59</dl> 60</div> 61<h6> 62<a name="boost_asio.reference.system_context.use_service.overload2.h1"></a> 63 <span class="phrase"><a name="boost_asio.reference.system_context.use_service.overload2.return_value"></a></span><a class="link" href="overload2.html#boost_asio.reference.system_context.use_service.overload2.return_value">Return 64 Value</a> 65 </h6> 66<p> 67 The service interface implementing the specified service type. Ownership 68 of the service interface is not transferred to the caller. 69 </p> 70<h6> 71<a name="boost_asio.reference.system_context.use_service.overload2.h2"></a> 72 <span class="phrase"><a name="boost_asio.reference.system_context.use_service.overload2.remarks"></a></span><a class="link" href="overload2.html#boost_asio.reference.system_context.use_service.overload2.remarks">Remarks</a> 73 </h6> 74<p> 75 This overload is preserved for backwards compatibility with services 76 that inherit from <a class="link" href="../../io_context__service.html" title="io_context::service"><code class="computeroutput">io_context::service</code></a>. 77 </p> 78<h6> 79<a name="boost_asio.reference.system_context.use_service.overload2.h3"></a> 80 <span class="phrase"><a name="boost_asio.reference.system_context.use_service.overload2.requirements"></a></span><a class="link" href="overload2.html#boost_asio.reference.system_context.use_service.overload2.requirements">Requirements</a> 81 </h6> 82<p> 83 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/system_context.hpp</code> 84 </p> 85<p> 86 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio.hpp</code> 87 </p> 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 © 2003-2020 Christopher M. 92 Kohlhoff<p> 93 Distributed under the Boost Software License, Version 1.0. (See accompanying 94 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>) 95 </p> 96</div></td> 97</tr></table> 98<hr> 99<div class="spirit-nav"> 100<a accesskey="p" href="overload1.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../use_service.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="../_system_context.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 101</div> 102</body> 103</html> 104
