<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Chrono</title> <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> <link rel="up" href="../cpp2011.html" title="C++ 2011 Support"> <link rel="prev" href="shared_ptr.html" title="Shared Pointers"> <link rel="next" href="futures.html" title="Futures"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> <td align="center"><a href="../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="shared_ptr.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../cpp2011.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="futures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="boost_asio.overview.cpp2011.chrono"></a><a class="link" href="chrono.html" title="Chrono">Chrono</a> </h4></div></div></div> <p> Boost.Asio provides timers based on the <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span></code> facilities via the <a class="link" href="../../reference/basic_waitable_timer.html" title="basic_waitable_timer">basic_waitable_timer</a> class template. The typedefs <a class="link" href="../../reference/system_timer.html" title="system_timer">system_timer</a>, <a class="link" href="../../reference/steady_timer.html" title="steady_timer">steady_timer</a> and <a class="link" href="../../reference/high_resolution_timer.html" title="high_resolution_timer">high_resolution_timer</a> utilise the standard clocks <code class="computeroutput"><span class="identifier">system_clock</span></code>, <code class="computeroutput"><span class="identifier">steady_clock</span></code> and <code class="computeroutput"><span class="identifier">high_resolution_clock</span></code> respectively. </p> <p> Support for the <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">chrono</span></code> facilities is automatically enabled for <code class="literal">g++</code> 4.6 and later, when the <code class="literal">-std=c++0x</code> or <code class="literal">-std=gnu++0x</code> compiler options are used. (Note that, for <code class="literal">g++</code>, the draft-standard <code class="computeroutput"><span class="identifier">monotonic_clock</span></code> is used in place of <code class="computeroutput"><span class="identifier">steady_clock</span></code>.) Support may be disabled by defining <code class="computeroutput"><span class="identifier">BOOST_ASIO_DISABLE_STD_CHRONO</span></code>, or explicitly enabled for other compilers by defining <code class="computeroutput"><span class="identifier">BOOST_ASIO_HAS_STD_CHRONO</span></code>. </p> <p> When standard <code class="computeroutput"><span class="identifier">chrono</span></code> is unavailable, Boost.Asio will otherwise use the Boost.Chrono library. The <a class="link" href="../../reference/basic_waitable_timer.html" title="basic_waitable_timer">basic_waitable_timer</a> class template may be used with either. </p> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2003-2015 Christopher M. Kohlhoff<p> Distributed under the Boost Software License, Version 1.0. (See accompanying 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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="shared_ptr.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../cpp2011.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="futures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>