1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>execution::start</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="../reference.html" title="Reference"> 9<link rel="prev" href="execution__set_value.html" title="execution::set_value"> 10<link rel="next" href="execution__submit.html" title="execution::submit"> 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="execution__set_value.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="execution__submit.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h3 class="title"> 27<a name="boost_asio.reference.execution__start"></a><a class="link" href="execution__start.html" title="execution::start">execution::start</a> 28</h3></div></div></div> 29<p> 30 <a class="indexterm" name="boost_asio.indexterm.execution__start"></a> 31A customisation point 32 that notifies an operation state object to start its associated operation. 33 </p> 34<pre class="programlisting">constexpr unspecified start = unspecified; 35</pre> 36<p> 37 The name <code class="computeroutput">execution::start</code> denotes a customisation point object. 38 The expression <code class="computeroutput">execution::start(R)</code> for some subexpression <code class="computeroutput">R</code> 39 is expression-equivalent to: 40 </p> 41<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 42<li class="listitem"> 43 <code class="computeroutput">R.start()</code>, if that expression is valid. 44 </li> 45<li class="listitem"> 46 Otherwise, <code class="computeroutput">start(R)</code>, if that expression is valid, with overload 47 resolution performed in a context that includes the declaration <code class="computeroutput">void 48 start();</code> and that does not include a declaration of <code class="computeroutput">execution::start</code>. 49 </li> 50<li class="listitem"> 51 Otherwise, <code class="computeroutput">execution::start(R)</code> is ill-formed. 52 </li> 53</ul></div> 54<h5> 55<a name="boost_asio.reference.execution__start.h0"></a> 56 <span class="phrase"><a name="boost_asio.reference.execution__start.requirements"></a></span><a class="link" href="execution__start.html#boost_asio.reference.execution__start.requirements">Requirements</a> 57 </h5> 58<p> 59 <span class="emphasis"><em>Header: </em></span><code class="literal">boost/asio/execution/start.hpp</code> 60 </p> 61<p> 62 <span class="emphasis"><em>Convenience header: </em></span><code class="literal">boost/asio/execution.hpp</code> 63 </p> 64</div> 65<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 66<td align="left"></td> 67<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 68 Kohlhoff<p> 69 Distributed under the Boost Software License, Version 1.0. (See accompanying 70 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>) 71 </p> 72</div></td> 73</tr></table> 74<hr> 75<div class="spirit-nav"> 76<a accesskey="p" href="execution__set_value.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="execution__submit.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 77</div> 78</body> 79</html> 80
