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>Class template microsec_clock</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="../../date_time/doxy.html#header.boost.date_time.microsec_time_clock_hpp" title="Header <boost/date_time/microsec_time_clock.hpp>"> 10<link rel="prev" href="us_dst_trait.html" title="Struct template us_dst_trait"> 11<link rel="next" href="ymd_order_spec.html" title="Type ymd_order_spec"> 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" 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name="boost.date_time.microsec_clock"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class template microsec_clock</span></h2> 30<p>boost::date_time::microsec_clock — A clock providing microsecond level resolution. </p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../date_time/doxy.html#header.boost.date_time.microsec_time_clock_hpp" title="Header <boost/date_time/microsec_time_clock.hpp>">boost/date_time/microsec_time_clock.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> time_type<span class="special">></span> 36<span class="keyword">class</span> <a class="link" href="microsec_clock.html" title="Class template microsec_clock">microsec_clock</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// types</span> 39 <span class="keyword">typedef</span> <span class="identifier">time_type</span><span class="special">::</span><span class="identifier">date_type</span> <a name="boost.date_time.microsec_clock.date_type"></a><span class="identifier">date_type</span><span class="special">;</span> 40 <span class="keyword">typedef</span> <span class="identifier">time_type</span><span class="special">::</span><span class="identifier">time_duration_type</span> <a name="boost.date_time.microsec_clock.time_duration_type"></a><span class="identifier">time_duration_type</span><span class="special">;</span> 41 <span class="keyword">typedef</span> <span class="identifier">time_duration_type</span><span class="special">::</span><span class="identifier">rep_type</span> <a name="boost.date_time.microsec_clock.resolution_traits_type"></a><span class="identifier">resolution_traits_type</span><span class="special">;</span> 42 43 <span class="comment">// <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_7-bb">public static functions</a></span> 44 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> time_zone_type<span class="special">></span> 45 <span class="keyword">static</span> <span class="identifier">time_type</span> <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_7_1-bb"><span class="identifier">local_time</span></a><span class="special">(</span><span class="identifier">shared_ptr</span><span class="special"><</span> <span class="identifier">time_zone_type</span> <span class="special">></span><span class="special">)</span><span class="special">;</span> 46 <span class="keyword">static</span> <span class="identifier">time_type</span> <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_7_2-bb"><span class="identifier">local_time</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 47 <span class="keyword">static</span> <span class="identifier">time_type</span> <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_7_3-bb"><span class="identifier">universal_time</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 48 49 <span class="comment">// <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_8-bb">private static functions</a></span> 50 <span class="keyword">static</span> <span class="identifier">time_type</span> <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_8_1-bb"><span class="identifier">create_time</span></a><span class="special">(</span><span class="identifier">time_converter</span><span class="special">)</span><span class="special">;</span> 51 <span class="keyword">static</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span> 52 <a class="link" href="microsec_clock.html#id-1_3_14_15_3_34_2_1_1_8_2-bb"><span class="identifier">file_time_to_microseconds</span></a><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">winapi</span><span class="special">::</span><span class="identifier">FILETIME_</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 53<span class="special">}</span><span class="special">;</span></pre></div> 54<div class="refsect1"> 55<a name="id-1.3.14.15.3.33.4.4"></a><h2>Description</h2> 56<p>A high precision clock that measures the local time at a resolution up to microseconds and adjusts to the resolution of the time system. For example, for the a library configuration with nano second resolution, the last 3 places of the fractional seconds will always be 000 since there are 1000 nano-seconds in a micro second. </p> 57<div class="refsect2"> 58<a name="id-1.3.14.15.3.33.4.4.3"></a><h3> 59<a name="id-1_3_14_15_3_34_2_1_1_7-bb"></a><code class="computeroutput">microsec_clock</code> public static functions</h3> 60<div class="orderedlist"><ol class="orderedlist" type="1"> 61<li class="listitem"> 62<pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> time_zone_type<span class="special">></span> 63 <span class="keyword">static</span> <span class="identifier">time_type</span> <a name="id-1_3_14_15_3_34_2_1_1_7_1-bb"></a><span class="identifier">local_time</span><span class="special">(</span><span class="identifier">shared_ptr</span><span class="special"><</span> <span class="identifier">time_zone_type</span> <span class="special">></span> tz_ptr<span class="special">)</span><span class="special">;</span></pre>return a local time object for the given zone, based on computer clock </li> 64<li class="listitem"> 65<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">time_type</span> <a name="id-1_3_14_15_3_34_2_1_1_7_2-bb"></a><span class="identifier">local_time</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Returns the local time based on computer clock settings. </li> 66<li class="listitem"> 67<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">time_type</span> <a name="id-1_3_14_15_3_34_2_1_1_7_3-bb"></a><span class="identifier">universal_time</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Returns the UTC time based on computer settings. </li> 68</ol></div> 69</div> 70<div class="refsect2"> 71<a name="id-1.3.14.15.3.33.4.4.4"></a><h3> 72<a name="id-1_3_14_15_3_34_2_1_1_8-bb"></a><code class="computeroutput">microsec_clock</code> private static functions</h3> 73<div class="orderedlist"><ol class="orderedlist" type="1"> 74<li class="listitem"><pre class="literallayout"><span class="keyword">static</span> <span class="identifier">time_type</span> <a name="id-1_3_14_15_3_34_2_1_1_8_1-bb"></a><span class="identifier">create_time</span><span class="special">(</span><span class="identifier">time_converter</span> converter<span class="special">)</span><span class="special">;</span></pre></li> 75<li class="listitem"> 76<pre class="literallayout"><span class="keyword">static</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">uint64_t</span> 77<a name="id-1_3_14_15_3_34_2_1_1_8_2-bb"></a><span class="identifier">file_time_to_microseconds</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">winapi</span><span class="special">::</span><span class="identifier">FILETIME_</span> <span class="keyword">const</span> <span class="special">&</span> ft<span class="special">)</span><span class="special">;</span></pre> 78<p>The function converts file_time into number of microseconds elapsed since 1970-Jan-01</p> 79<div class="note"><table border="0" summary="Note"> 80<tr> 81<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../doc/src/images/note.png"></td> 82<th align="left">Note</th> 83</tr> 84<tr><td align="left" valign="top"><p>Only dates after 1970-Jan-01 are supported. Dates before will be wrapped. </p></td></tr> 85</table></div> 86<p> 87</p> 88</li> 89</ol></div> 90</div> 91</div> 92</div> 93<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 94<td align="left"></td> 95<td align="right"><div class="copyright-footer">Copyright © 2001-2005 CrystalClear Software, Inc<p>Subject to the Boost Software License, Version 1.0. (See accompanying file 96 <code class="filename">LICENSE_1_0.txt</code> 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> 97</div></td> 98</tr></table> 99<hr> 100<div class="spirit-nav"> 101<a accesskey="p" href="us_dst_trait.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../date_time/doxy.html#header.boost.date_time.microsec_time_clock_hpp"><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="ymd_order_spec.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 102</div> 103</body> 104</html> 105
