1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Chapter 7. Boost.Chrono 2.0.8</title> 6<link rel="stylesheet" href="../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="libraries.html" title="Part I. The Boost C++ Libraries (BoostBook Subset)"> 10<link rel="prev" href="atomic/porting.html" title="Porting"> 11<link rel="next" href="chrono/users_guide.html" title="User's Guide"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../boost.png"></td> 16<td align="center"><a href="../../index.html">Home</a></td> 17<td align="center"><a href="../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="atomic/porting.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="chrono/users_guide.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="chapter"> 27<div class="titlepage"><div> 28<div><h2 class="title"> 29<a name="chrono"></a>Chapter 7. Boost.Chrono 2.0.8</h2></div> 30<div><div class="author"><h3 class="author"> 31<span class="firstname">Howard</span> <span class="surname">Hinnant</span> 32</h3></div></div> 33<div><div class="author"><h3 class="author"> 34<span class="firstname">Beman</span> <span class="surname">Dawes</span> 35</h3></div></div> 36<div><div class="author"><h3 class="author"> 37<span class="firstname">Vicente J.</span> <span class="surname">Botet Escriba</span> 38</h3></div></div> 39<div><p class="copyright">Copyright © 2008 Howard Hinnant</p></div> 40<div><p class="copyright">Copyright © 2006, 2008 Beman Dawes</p></div> 41<div><p class="copyright">Copyright © 2009-2013 Vicente J. Botet Escriba</p></div> 42<div><div class="legalnotice"> 43<a name="chrono.legal"></a><p> 44 Distributed under the Boost Software License, Version 1.0. (See accompanying 45 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>) 46 </p> 47</div></div> 48</div></div> 49<div class="toc"> 50<p><b>Table of Contents</b></p> 51<dl class="toc"> 52<dt><span class="section"><a href="chrono.html#chrono.overview">Overview</a></span></dt> 53<dd><dl> 54<dt><span class="section"><a href="chrono.html#chrono.overview.motivation">Motivation</a></span></dt> 55<dt><span class="section"><a href="chrono.html#chrono.overview.description">Description</a></span></dt> 56</dl></dd> 57<dt><span class="section"><a href="chrono/users_guide.html">User's Guide</a></span></dt> 58<dd><dl> 59<dt><span class="section"><a href="chrono/users_guide.html#chrono.users_guide.getting_started">Getting Started</a></span></dt> 60<dt><span class="section"><a href="chrono/users_guide.html#chrono.users_guide.tutorial">Tutorial</a></span></dt> 61<dt><span class="section"><a href="chrono/users_guide.html#chrono.users_guide.examples">Examples</a></span></dt> 62<dt><span class="section"><a href="chrono/users_guide.html#chrono.users_guide.ext_references">External Resources</a></span></dt> 63</dl></dd> 64<dt><span class="section"><a href="chrono/reference.html">Reference </a></span></dt> 65<dd><dl> 66<dt><span class="section"><a href="chrono/reference.html#chrono.reference.chrono_include_hpp">Header <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">chrono</span><span class="special">/</span><span class="identifier">include</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code></a></span></dt> 67<dt><span class="section"><a href="chrono/reference.html#chrono.reference.cpp0x">Included on the C++11 Recommendation</a></span></dt> 68<dt><span class="section"><a href="chrono/reference.html#chrono.reference.io_v1">Chrono I/O V1</a></span></dt> 69<dt><span class="section"><a href="chrono/reference.html#chrono.reference.io">Chrono I/O V2</a></span></dt> 70<dt><span class="section"><a href="chrono/reference.html#chrono.reference.round">Chrono Rounding Utilities</a></span></dt> 71<dt><span class="section"><a href="chrono/reference.html#chrono.reference.other_clocks">Other Clocks</a></span></dt> 72</dl></dd> 73<dt><span class="section"><a href="chrono/appendices.html">Appendices</a></span></dt> 74<dd><dl> 75<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.history">Appendix: History</a></span></dt> 76<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.rationale">Appendix: Rationale</a></span></dt> 77<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.implementation">Appendix: Implementation 78 Notes</a></span></dt> 79<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.faq">Appendix: FAQ</a></span></dt> 80<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.acknowledgements">Appendix: Acknowledgements</a></span></dt> 81<dt><span class="section"><a href="chrono/appendices.html#chrono.appendices.todo">Appendix: Future plans</a></span></dt> 82</dl></dd> 83</dl> 84</div> 85<p> 86 ] 87 </p> 88<p> 89 ] 90 </p> 91<div class="section"> 92<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 93<a name="chrono.overview"></a><a class="link" href="chrono.html#chrono.overview" title="Overview">Overview</a> 94</h2></div></div></div> 95<div class="toc"><dl class="toc"> 96<dt><span class="section"><a href="chrono.html#chrono.overview.motivation">Motivation</a></span></dt> 97<dt><span class="section"><a href="chrono.html#chrono.overview.description">Description</a></span></dt> 98</dl></div> 99<div class="blockquote"><blockquote class="blockquote"><p> 100 <span class="quote">“<span class="quote">What is time, then? If nobody asks me, I know; if I have to explain 101 it to someone who has asked me, I do not know."</span>”</span> 102 </p></blockquote></div> 103<div class="blockquote"><blockquote class="blockquote"><p> 104 <span class="bold"><strong><span class="emphasis"><em>-- Augustine </em></span></strong></span> 105 </p></blockquote></div> 106<h4> 107<a name="chrono.overview.h0"></a> 108 <span class="phrase"><a name="chrono.overview.how_to_use_this_documentation"></a></span><a class="link" href="chrono.html#chrono.overview.how_to_use_this_documentation">How 109 to Use This Documentation</a> 110 </h4> 111<p> 112 This documentation makes use of the following naming and formatting conventions. 113 </p> 114<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 115<li class="listitem"> 116 Code is in <code class="computeroutput"><span class="identifier">fixed</span> <span class="identifier">width</span> 117 <span class="identifier">font</span></code> and is syntax-highlighted. 118 </li> 119<li class="listitem"> 120 Replaceable text that you will need to supply is in <em class="replaceable"><code>italics</code></em>. 121 </li> 122<li class="listitem"> 123 Free functions are rendered in the code font followed by <code class="computeroutput"><span class="special">()</span></code>, as in <code class="computeroutput"><span class="identifier">free_function</span><span class="special">()</span></code>. 124 </li> 125<li class="listitem"> 126 If a name refers to a class template, it is specified like this: <code class="computeroutput"><span class="identifier">class_template</span><span class="special"><></span></code>; 127 that is, it is in code font and its name is followed by <code class="computeroutput"><span class="special"><></span></code> 128 to indicate that it is a class template. 129 </li> 130<li class="listitem"> 131 If a name refers to a function-like macro, it is specified like this: 132 <code class="computeroutput"><span class="identifier">MACRO</span><span class="special">()</span></code>; 133 that is, it is uppercase in code font and its name is followed by <code class="computeroutput"><span class="special">()</span></code> to indicate that it is a function-like 134 macro. Object-like macros appear without the trailing <code class="computeroutput"><span class="special">()</span></code>. 135 </li> 136<li class="listitem"> 137 Names that refer to <span class="emphasis"><em>concepts</em></span> in the generic programming 138 sense are specified in CamelCase. 139 </li> 140</ul></div> 141<div class="note"><table border="0" summary="Note"> 142<tr> 143<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../doc/src/images/note.png"></td> 144<th align="left">Note</th> 145</tr> 146<tr><td align="left" valign="top"><p> 147 In addition, notes such as this one specify non-essential information that 148 provides additional background or rationale. 149 </p></td></tr> 150</table></div> 151<p> 152 Finally, you can mentally add the following to any code fragments in this document: 153 </p> 154<pre class="programlisting"><span class="comment">// Include all of Chrono files</span> 155<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">chrono</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 156</pre> 157<div class="section"> 158<div class="titlepage"><div><div><h3 class="title"> 159<a name="chrono.overview.motivation"></a><a class="link" href="chrono.html#chrono.overview.motivation" title="Motivation">Motivation</a> 160</h3></div></div></div> 161<h5> 162<a name="chrono.overview.motivation.h0"></a> 163 <span class="phrase"><a name="chrono.overview.motivation.time"></a></span><a class="link" href="chrono.html#chrono.overview.motivation.time">Time</a> 164 </h5> 165<p> 166 We all deal with time every day of our lives. We've intuitively known it 167 since birth. Thus we are all very familiar with it and believe it to be a 168 simple matter. The modeling of time in computer programs should be similarly 169 simple. The unfortunate truth is that this perceived simplicity is only skin 170 deep. Fortunately, we do not need a terribly complicated solution to meet 171 the bulk of our needs. However, overly simplistic solutions can be dangerous 172 and inefficient, and won't adapt as the computer industry evolves. 173 </p> 174<p> 175 <span class="bold"><strong>Boost.Chrono</strong></span> implements the new time facilities 176 in C++11, as proposed in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2661.htm" target="_top"><span class="bold"><strong>N2661 - A Foundation to Sleep On</strong></span></a>. That document 177 provides background and motivation for key design decisions and is the source 178 of a good deal of information in this documentation. 179 </p> 180<p> 181 In addition to the clocks provided by the standard proposal, <span class="bold"><strong>Boost.Chrono</strong></span> 182 provides specific process and thread clocks. 183 </p> 184<h5> 185<a name="chrono.overview.motivation.h1"></a> 186 <span class="phrase"><a name="chrono.overview.motivation.wall_clock_versus_system_and_user_time"></a></span><a class="link" href="chrono.html#chrono.overview.motivation.wall_clock_versus_system_and_user_time">Wall 187 clock versus system and user time</a> 188 </h5> 189<p> 190 To make the timing facilities of Boost.Chrono more generally useful, the 191 library provides a number of clocks that are thin wrappers around the operating 192 system's process time API, thereby allowing the extraction of wall clock 193 time, user CPU time, and system CPU time of the process. Wall clock time 194 is the sum of CPU time and system CPU time. (On POSIX-like systems, this 195 relies on <code class="computeroutput"><span class="identifier">times</span><span class="special">()</span></code>. 196 On Windows, it relies on <code class="computeroutput"><span class="identifier">GetProcessTimes</span><span class="special">()</span></code>.) 197 </p> 198</div> 199<div class="section"> 200<div class="titlepage"><div><div><h3 class="title"> 201<a name="chrono.overview.description"></a><a class="link" href="chrono.html#chrono.overview.description" title="Description">Description</a> 202</h3></div></div></div> 203<p> 204 The <span class="bold"><strong>Boost.Chrono</strong></span> library provides: 205 </p> 206<h5> 207<a name="chrono.overview.description.h0"></a> 208 <span class="phrase"><a name="chrono.overview.description.standard"></a></span><a class="link" href="chrono.html#chrono.overview.description.standard">Standard</a> 209 </h5> 210<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 211<li class="listitem"> 212 A means to represent time durations: managed by the generic <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a> class . Examples of 213 time durations include days, <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration_typedefs" title="duration typedefs"><code class="computeroutput"><span class="identifier">minutes</span></code></a>, <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration_typedefs" title="duration typedefs"><code class="computeroutput"><span class="identifier">seconds</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration_typedefs" title="duration typedefs"><code class="computeroutput"><span class="identifier">nanoseconds</span></code></a>, which can be represented 214 with a fixed number of clock ticks per unit. All of these units of time 215 duration are united with a generic interface by the <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a> facility. 216 </li> 217<li class="listitem"> 218 A type for representing points in time: <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a>. A <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> represents an epoch 219 plus or minus a <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a>. The library leaves 220 epochs unspecified. A <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> is associated with 221 a <span class="emphasis"><em>clock</em></span>. 222 </li> 223<li class="listitem"> 224 Several clocks, some of which may not be available on a particular platform: 225 <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.system_clocks_hpp.system_clock" title="Class system_clock"><code class="computeroutput"><span class="identifier">system_clock</span></code></a>, <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.system_clocks_hpp.steady_clock" title="Class steady_clock"><code class="computeroutput"><span class="identifier">steady_clock</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.system_clocks_hpp.high_resolution_clock" title="Class high_resolution_clock"><code class="computeroutput"><span class="identifier">high_resolution_clock</span></code></a>. A clock 226 is a pairing of a <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a>, and a function which 227 returns a <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> representing <span class="emphasis"><em>now</em></span>. 228 </li> 229</ul></div> 230<h5> 231<a name="chrono.overview.description.h1"></a> 232 <span class="phrase"><a name="chrono.overview.description.other_clocks"></a></span><a class="link" href="chrono.html#chrono.overview.description.other_clocks">Other 233 clocks</a> 234 </h5> 235<p> 236 To make the timing facilities more generally useful, <span class="bold"><strong>Boost.Chrono</strong></span> 237 provides a number of clocks that are thin wrappers around the operating system's 238 time APIs, thereby allowing the extraction of wall clock time, user CPU time, 239 system CPU time spent by the process, 240 </p> 241<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 242<li class="listitem"> 243 <a class="link" href="chrono/reference.html#chrono.reference.other_clocks.process_cpu_clocks_hpp.process_real_cpu_clock" title="Class process_real_cpu_clock"><code class="computeroutput"><span class="identifier">process_real_cpu_clock</span></code></a>, captures 244 wall clock CPU time spent by the current process. 245 </li> 246<li class="listitem"> 247 <a class="link" href="chrono/reference.html#chrono.reference.other_clocks.process_cpu_clocks_hpp.process_user_cpu_clock" title="Class process_user_cpu_clock"><code class="computeroutput"><span class="identifier">process_user_cpu_clock</span></code></a>, captures 248 user-CPU time spent by the current process. 249 </li> 250<li class="listitem"> 251 <a class="link" href="chrono/reference.html#chrono.reference.other_clocks.process_cpu_clocks_hpp.process_system_cpu_clock" title="Class process_system_cpu_clock"><code class="computeroutput"><span class="identifier">process_system_cpu_clock</span></code></a>, captures 252 system-CPU time spent by the current process. 253 </li> 254<li class="listitem"> 255 A tuple-like class <a class="link" href="chrono/reference.html#chrono.reference.other_clocks.process_cpu_clocks_hpp.process_cpu_clock" title="Class process_cpu_clock"><code class="computeroutput"><span class="identifier">process_cpu_clock</span></code></a>, that captures 256 real, user-CPU, and system-CPU process times together. 257 </li> 258<li class="listitem"> 259 A <a class="link" href="chrono/reference.html#chrono.reference.other_clocks.thread_clock_hpp.thread_clock" title="Class thread_clock"><code class="computeroutput"><span class="identifier">thread_clock</span></code></a> thread steady clock 260 giving the time spent by the current thread (when supported by a platform). 261 </li> 262</ul></div> 263<p> 264 Lastly, <span class="bold"><strong>Boost.Chrono</strong></span> includes <a href="http://www.boost.org/libs/typeof" target="_top">typeof</a> 265 registration for <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> to permit using emulated 266 auto with C++03 compilers. 267 </p> 268<h5> 269<a name="chrono.overview.description.h2"></a> 270 <span class="phrase"><a name="chrono.overview.description.i_o"></a></span><a class="link" href="chrono.html#chrono.overview.description.i_o">I/O</a> 271 </h5> 272<p> 273 It provides I/O for <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a>. This I/O makes use of 274 these types much more convenient. In following the "you only pay for 275 what you use" philosophy, this extra functionality is located in a header 276 separate from <boost/chrono/chrono.hpp>, namely <boost/chrono/chrono_io.hpp>. 277 </p> 278<p> 279 It builds on <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">ratio</span><span class="special">/</span><span class="identifier">ratio_io</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 280 to provide readable and flexible formatting and parsing for types in <code class="computeroutput"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">chrono</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code>. 281 This textural representation uses <a href="http://en.wikipedia.org/wiki/SI_prefix#List_of_SI_prefixes" target="_top">SI 282 prefixes</a> whenever possible. This makes it easy for <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">milliseconds</span></code> to be represented by the text 283 "milliseconds", or a hypothetical meter class to print out "millimeter". 284 The <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.duration_hpp.duration" title="Class Template duration<>"><code class="computeroutput"><span class="identifier">duration</span></code></a> and the <a class="link" href="chrono/reference.html#chrono.reference.cpp0x.time_point_hpp.time_point" title="Class template time_point<>"><code class="computeroutput"><span class="identifier">time_point</span></code></a> i/o can be customized 285 through the new facets: <a class="link" href="chrono/reference.html#chrono.reference.io.duration_units_hpp.duration_units" title="Template Class duration_units"><code class="computeroutput"><span class="identifier">duration_units</span></code></a> and <a class="link" href="chrono/reference.html#chrono.reference.io.time_point_units_hpp.time_point_units" title="Template Class time_point_units"><code class="computeroutput"><span class="identifier">time_point_units</span></code></a>. The user can specialize 286 these facets so that the chrono i/o could be localizable. However Boost.Chrono 287 doesn't provides a complete locale solution. 288 </p> 289<p> 290 <code class="computeroutput"><span class="identifier">system_clock</span><span class="special">::</span><span class="identifier">time_point</span></code> I/O is proposed in terms of 291 UTC timepoints, strongly guided by ISO 9899:1999, Programming languages - 292 C, ISO 9945:2003, Information Technology - Portable Operating System Interface 293 (POSIX) and ISO 8601:2004, Data elements and interchange formats - Information 294 interchange - Representation of dates and times. 295 </p> 296<h5> 297<a name="chrono.overview.description.h3"></a> 298 <span class="phrase"><a name="chrono.overview.description.rounding_utilities"></a></span><a class="link" href="chrono.html#chrono.overview.description.rounding_utilities">Rounding 299 utilities</a> 300 </h5> 301<p> 302 A few simple rounding utility functions for working with durations. 303 </p> 304<h5> 305<a name="chrono.overview.description.h4"></a> 306 <span class="phrase"><a name="chrono.overview.description.caveat_emptor"></a></span><a class="link" href="chrono.html#chrono.overview.description.caveat_emptor">Caveat 307 Emptor</a> 308 </h5> 309<p> 310 The underlying clocks provided by operating systems are subject to many seemingly 311 arbitrary policies and implementation irregularities. That's a polite way 312 of saying they tend to be flakey, and each operating system or even each 313 clock has its own cruel and unusual forms of flakiness. Don't bet the farm 314 on their accuracy, unless you have become deeply familiar with exactly what 315 the specific operating system is guaranteeing, which is often very little. 316 </p> 317</div> 318</div> 319</div> 320<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 321<td align="left"><p><small>Last revised: August 11, 2020 at 15:03:48 GMT</small></p></td> 322<td align="right"><div class="copyright-footer"></div></td> 323</tr></table> 324<hr> 325<div class="spirit-nav"> 326<a accesskey="p" href="atomic/porting.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="libraries.html"><img src="../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="chrono/users_guide.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 327</div> 328</body> 329</html> 330
