1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>execution_context::has_service</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="../execution_context.html" title="execution_context"> 9<link rel="prev" href="fork_event.html" title="execution_context::fork_event"> 10<link rel="next" href="make_service.html" title="execution_context::make_service"> 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="fork_event.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../execution_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="make_service.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.execution_context.has_service"></a><a class="link" href="has_service.html" title="execution_context::has_service">execution_context::has_service</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.execution_context.has_service"></a> 31Determine 32 if an <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a> 33 contains a specified service type. 34 </p> 35<pre class="programlisting">template< 36 typename <a class="link" href="../Service.html" title="Service requirements">Service</a>> 37friend bool has_service( 38 execution_context & e); 39</pre> 40<p> 41 This function is used to determine whether the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a> 42 contains a service object corresponding to the given service type. 43 </p> 44<h6> 45<a name="boost_asio.reference.execution_context.has_service.h0"></a> 46 <span class="phrase"><a name="boost_asio.reference.execution_context.has_service.parameters"></a></span><a class="link" href="has_service.html#boost_asio.reference.execution_context.has_service.parameters">Parameters</a> 47 </h6> 48<div class="variablelist"> 49<p class="title"><b></b></p> 50<dl class="variablelist"> 51<dt><span class="term">e</span></dt> 52<dd><p> 53 The <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a> 54 object that owns the service. 55 </p></dd> 56</dl> 57</div> 58<h6> 59<a name="boost_asio.reference.execution_context.has_service.h1"></a> 60 <span class="phrase"><a name="boost_asio.reference.execution_context.has_service.return_value"></a></span><a class="link" href="has_service.html#boost_asio.reference.execution_context.has_service.return_value">Return 61 Value</a> 62 </h6> 63<p> 64 A boolean indicating whether the <a class="link" href="../execution_context.html" title="execution_context"><code class="computeroutput">execution_context</code></a> 65 contains the service. 66 </p> 67<h6> 68<a name="boost_asio.reference.execution_context.has_service.h2"></a> 69 <span class="phrase"><a name="boost_asio.reference.execution_context.has_service.requirements"></a></span><a class="link" href="has_service.html#boost_asio.reference.execution_context.has_service.requirements">Requirements</a> 70 </h6> 71<p> 72 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/execution_context.hpp</code> 73 </p> 74<p> 75 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio/execution.hpp</code> 76 </p> 77</div> 78<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 79<td align="left"></td> 80<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 81 Kohlhoff<p> 82 Distributed under the Boost Software License, Version 1.0. (See accompanying 83 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>) 84 </p> 85</div></td> 86</tr></table> 87<hr> 88<div class="spirit-nav"> 89<a accesskey="p" href="fork_event.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../execution_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="make_service.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 90</div> 91</body> 92</html> 93
