1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>basic_waitable_timer::cancel (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="../cancel.html" title="basic_waitable_timer::cancel"> 9<link rel="prev" href="overload1.html" title="basic_waitable_timer::cancel (1 of 2 overloads)"> 10<link rel="next" href="../cancel_one.html" title="basic_waitable_timer::cancel_one"> 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="../cancel.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="../cancel_one.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.basic_waitable_timer.cancel.overload2"></a><a class="link" href="overload2.html" title="basic_waitable_timer::cancel (2 of 2 overloads)">basic_waitable_timer::cancel 28 (2 of 2 overloads)</a> 29</h5></div></div></div> 30<p> 31 (Deprecated: Use non-error_code overload.) Cancel any asynchronous operations 32 that are waiting on the timer. 33 </p> 34<pre class="programlisting">std::size_t cancel( 35 boost::system::error_code & ec); 36</pre> 37<p> 38 This function forces the completion of any pending asynchronous wait 39 operations against the timer. The handler for each cancelled operation 40 will be invoked with the <code class="computeroutput">boost::asio::error::operation_aborted</code> 41 error code. 42 </p> 43<p> 44 Cancelling the timer does not change the expiry time. 45 </p> 46<h6> 47<a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.h0"></a> 48 <span class="phrase"><a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.basic_waitable_timer.cancel.overload2.parameters">Parameters</a> 49 </h6> 50<div class="variablelist"> 51<p class="title"><b></b></p> 52<dl class="variablelist"> 53<dt><span class="term">ec</span></dt> 54<dd><p> 55 Set to indicate what error occurred, if any. 56 </p></dd> 57</dl> 58</div> 59<h6> 60<a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.h1"></a> 61 <span class="phrase"><a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.return_value"></a></span><a class="link" href="overload2.html#boost_asio.reference.basic_waitable_timer.cancel.overload2.return_value">Return 62 Value</a> 63 </h6> 64<p> 65 The number of asynchronous operations that were cancelled. 66 </p> 67<h6> 68<a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.h2"></a> 69 <span class="phrase"><a name="boost_asio.reference.basic_waitable_timer.cancel.overload2.remarks"></a></span><a class="link" href="overload2.html#boost_asio.reference.basic_waitable_timer.cancel.overload2.remarks">Remarks</a> 70 </h6> 71<p> 72 If the timer has already expired when <code class="computeroutput">cancel()</code> is called, 73 then the handlers for asynchronous wait operations will: 74 </p> 75<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 76<li class="listitem"> 77 have already been invoked; or 78 </li> 79<li class="listitem"> 80 have been queued for invocation in the near future. 81 </li> 82</ul></div> 83<p> 84 These handlers can no longer be cancelled, and therefore are passed an 85 error code that indicates the successful completion of the wait operation. 86 </p> 87</div> 88<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 89<td align="left"></td> 90<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 91 Kohlhoff<p> 92 Distributed under the Boost Software License, Version 1.0. (See accompanying 93 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>) 94 </p> 95</div></td> 96</tr></table> 97<hr> 98<div class="spirit-nav"> 99<a accesskey="p" href="overload1.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../cancel.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="../cancel_one.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> 100</div> 101</body> 102</html> 103
