e26fd2ed98
* Synchronize each miscrosec test to the next second (#109) * Synchronize each miscrosec test to the next second The aim is to avoid false positives in test_microsec when the seconds, minutes or hours change during time read between the second_clock and the microsec_clock. * Improved readability of the microcec_time_clock test * Improve performance of adding and subtracting time durations from a ptime. (#99) Modifying ptime objects by adding and subtracting time durations was inefficient because it extracted the date and time of day and then re-constructed a ptime using the date and modified time of day. This can be avoided by using the existing time_system utilities which perform the operation by adjusting the number of ticks. Performance is improved by a factor of 48 on my system. * Update CI Scripts * Add time_duration helper functions: (#113) 1. is_positive() - Return boolean value to indicate whether or not time duration is positive. 2. is_zero() - Return boolean value to indicate whether or not time duration is zero. 3. abs() - Return a time_duration which is the absolute value of time duration. Added documentation for these helper functions and improved existing documentation to indicate constness, return values or static functions. * Cease dependence on MPL (#115)
622 lines
23 KiB
XML
622 lines
23 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
|
|
<!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
|
|
"../../../tools/boostbook/dtd/boostbook.dtd">
|
|
|
|
<!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
|
|
Subject to the Boost Software License, Version 1.0.
|
|
(See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
|
|
-->
|
|
|
|
<section id="date_time.posix_time.time_duration">
|
|
<title>Time Duration</title>
|
|
|
|
<link linkend="time_duration_intro">Introduction</link> --
|
|
<link linkend="time_duration_header">Header</link> --
|
|
<link linkend="time_duration_constr">Construction</link> --
|
|
<link linkend="time_duration_count_constr">Count Based Construction</link> --
|
|
<link linkend="time_duration_from_string">Construct from String</link> --
|
|
<link linkend="time_duration_accessors">Accessors</link> --
|
|
<link linkend="time_duration_to_string">Conversion To String</link> --
|
|
<link linkend="time_duration_operators">Operators</link> --
|
|
<link linkend="time_duration_struct_tm">Struct tm Functions</link>
|
|
|
|
<anchor id="time_duration_intro" />
|
|
<bridgehead renderas="sect3">Introduction</bridgehead>
|
|
<para>
|
|
The class boost::posix_time::time_duration the base type responsible for representing a length of time. A duration can be either positive or negative. The general time_duration class provides a constructor that takes a count of the number of hours, minutes, seconds, and fractional seconds count as shown in the code fragment below. The resolution of the time_duration is configure able at compile time. See <link linkend="date_time.buildinfo">Build-Compiler Information</link> for more information.
|
|
</para>
|
|
<para>
|
|
<programlisting>using namespace boost::posix_time;
|
|
time_duration td(1,2,3,4); //01:02:03.000000004 when resolution is nano seconds
|
|
time_duration td(1,2,3,4); //01:02:03.000004 when resolution is micro seconds</programlisting>
|
|
</para>
|
|
<para>
|
|
Several small helper classes that derive from a base time_duration, as shown below, to adjust for different resolutions. These classes can shorten code and make the intent clearer.
|
|
</para>
|
|
<imagedata fileref="../../libs/date_time/doc/time_duration_inherit.png" />
|
|
<para>
|
|
As an example:
|
|
<programlisting>using namespace boost::posix_time;
|
|
|
|
time_duration td = hours(1) + seconds(10); //01:00:10
|
|
td = hours(1) + nanoseconds(5); //01:00:00.000000005</programlisting>
|
|
Note that the existence of the higher resolution classes (eg: nanoseconds) depends on the installation of the library. See <link linkend="date_time.buildinfo">Build-Compiler Information</link> for more information.
|
|
</para>
|
|
|
|
<para>
|
|
Another way to handle this is to utilize the ticks_per_second() method of time_duration to
|
|
write code that is portable no matter how the library is compiled. The general equation
|
|
for calculating a resolution independent count is as follows:
|
|
|
|
<programlisting>
|
|
count*(time_duration_ticks_per_second / count_ticks_per_second)
|
|
</programlisting>
|
|
|
|
For example, let's suppose we want to construct using a count that represents tenths
|
|
of a second. That is, each tick is 0.1 second.
|
|
<programlisting>
|
|
int number_of_tenths = 5;
|
|
//create a resolution independent count -- divide by 10 since there are
|
|
//10 tenths in a second.
|
|
int count = number_of_tenths*(time_duration::ticks_per_second()/10);
|
|
time_duration td(1,2,3,count); //01:02:03.5 //no matter the resolution settings
|
|
</programlisting>
|
|
</para>
|
|
|
|
<anchor id="time_duration_header" />
|
|
<bridgehead renderas="sect3">Header</bridgehead>
|
|
<para>
|
|
<programlisting>#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
|
|
or
|
|
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types</programlisting>
|
|
</para>
|
|
|
|
<anchor id="time_duration_constr" />
|
|
<bridgehead renderas="sect3">Construction</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration(hours,
|
|
minutes,
|
|
seconds,
|
|
fractional_seconds)</screen></entry>
|
|
<entry>Construct a duration from the counts. The fractional_second parameter is a number of units and is therefore affected by the resolution the application is compiled with (see <link linkend="compile_options">Build-Compiler Information</link>). If the fractional_seconds argument exceeds the limit of the compiled precision, the excess value will be "carried over" into the seconds field. See above for techniques to creating a resolution independent count.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3,9);
|
|
//1 hr 2 min 3 sec 9 nanoseconds
|
|
time_duration td2(1,2,3,123456789);
|
|
time_duration td3(1,2,3,1000);
|
|
// with microsecond resolution (6 digits)
|
|
// td2 => "01:04:06.456789"
|
|
// td3 => "01:02:03.001000"
|
|
// with nanosecond resolution (9 digits)
|
|
// td2 => "01:02:03.123456789"
|
|
// td3 => "01:02:03.000001000"</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top"><screen>time_duration(special_value sv)</screen></entry>
|
|
<entry>Special values constructor. <emphasis role="strong">Important note</emphasis>: When a time_duration is a special value, either by construction or other means, the following accessor functions will give unpredictable results: <screen>hours(), minutes(), seconds(), ticks(),
|
|
fractional_seconds(), total_nanoseconds(),
|
|
total_microseconds(), total_milliseconds(),
|
|
total_seconds()</screen>The remaining accessor functions will work as expected.</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
|
|
<anchor id="time_duration_count_constr" />
|
|
<bridgehead renderas="sect3">Count Based Construction</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>hours(long)</screen></entry>
|
|
<entry>Number of hours</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = hours(3);</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>minutes(long)</screen></entry>
|
|
<entry>Number of minutes</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = minutes(3);</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>seconds(long)</screen></entry>
|
|
<entry> Number of seconds</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = seconds(3);</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>milliseconds(long)</screen></entry>
|
|
<entry>Number of milliseconds.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = milliseconds(3);</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>microseconds(long)</screen></entry>
|
|
<entry>Number of microseconds.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = microseconds(3);</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>nanoseconds(long)</screen></entry>
|
|
<entry>Number of nanoseconds.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td = nanoseconds(3);</screen></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
|
|
<anchor id="time_duration_from_string" />
|
|
<bridgehead renderas="sect3">Construct from String</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration duration_from_string(std::string)</screen></entry>
|
|
<entry>From delimited string. NOTE: Excess digits in fractional seconds will be dropped. Ex: "1:02:03.123456999" => 1:02:03.123456. This behavior is affected by the precision the library is compiled with (see <link linkend="date_time.buildinfo">Build-Compiler Information</link>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>std::string ts("23:59:59.000");
|
|
time_duration td(duration_from_string(ts));</screen>
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
|
|
<anchor id="time_duration_accessors" />
|
|
<bridgehead renderas="sect3">Accessors</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t hours()</screen></entry>
|
|
<entry>Get the number of normalized hours (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3);
|
|
time_duration neg_td(-1,2,3);
|
|
td.hours(); // --> 1
|
|
neg_td.hours(); // --> -1</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t minutes()</screen></entry>
|
|
<entry>Get the number of minutes normalized +/-(0..59) (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3);
|
|
time_duration neg_td(-1,2,3);
|
|
td.minutes(); // --> 2
|
|
neg_td.minutes(); // --> -2</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t seconds() const</screen></entry>
|
|
<entry>Get the normalized number of second +/-(0..59) (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3);
|
|
time_duration neg_td(-1,2,3);
|
|
td.seconds(); // --> 3
|
|
neg_td.seconds(); // --> -3</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t total_seconds() const</screen></entry>
|
|
<entry>Get the total number of seconds truncating any fractional seconds (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3,10);
|
|
td.total_seconds();
|
|
// --> (1*3600) + (2*60) + 3 == 3723</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t total_milliseconds() const</screen></entry>
|
|
<entry>Get the total number of milliseconds truncating any remaining digits (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3,123456789);
|
|
td.total_milliseconds();
|
|
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
|
|
// milliseconds is 3 decimal places
|
|
// (3723 * 1000) + 123 == 3723123</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t total_microseconds() const</screen></entry>
|
|
<entry>Get the total number of microseconds truncating any remaining digits (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3,123456789);
|
|
td.total_microseconds();
|
|
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
|
|
// microseconds is 6 decimal places
|
|
// (3723 * 1000000) + 123456 == 3723123456</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t total_nanoseconds() const</screen></entry>
|
|
<entry>Get the total number of nanoseconds truncating any remaining digits (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3,123456789);
|
|
td.total_nanoseconds();
|
|
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
|
|
// nanoseconds is 9 decimal places
|
|
// (3723 * 1000000000) + 123456789
|
|
// == 3723123456789</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t fractional_seconds() const</screen></entry>
|
|
<entry>Get the number of fractional seconds (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3, 1000);
|
|
td.fractional_seconds(); // --> 1000</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_negative() const</screen></entry>
|
|
<entry>True if and only if duration is negative.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(-1,0,0);
|
|
td.is_negative(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_zero() const</screen></entry>
|
|
<entry>True if and only if duration is zero.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(0,0,0);
|
|
td.is_zero(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_positive() const</screen></entry>
|
|
<entry>True if and only if duration is positive.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,0,0);
|
|
td.is_positive(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration invert_sign() const</screen></entry>
|
|
<entry>Generate a new duration with the sign inverted.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(-1,0,0);
|
|
td.invert_sign(); // --> 01:00:00</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration abs() const</screen></entry>
|
|
<entry>Generate a new duration with the absolute value of the time duration.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(-1,0,0);
|
|
td.abs(); // --> 01:00:00</screen></entry>
|
|
<entry><screen>time_duration td(+1,0,0);
|
|
td.abs(); // --> 01:00:00</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>date_time::time_resolutions time_duration::resolution()</screen></entry>
|
|
<entry>Describes the resolution capability of the time_duration class. time_resolutions is an enum of resolution possibilities ranging from seconds to nanoseconds.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration::resolution() --> nano</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>unsigned short time_duration::num_fractional_digits()</screen></entry>
|
|
<entry>Returns the number of fractional digits the time resolution has.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>unsigned short secs;
|
|
secs = time_duration::num_fractional_digits();
|
|
// 9 for nano, 6 for micro, etc.</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t time_duration::ticks_per_second()</screen></entry>
|
|
<entry>Return the number of ticks in a second. For example, if the duration supports nanoseconds then the returned result will be 1,000,000,000 (1e+9).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>std::cout << time_duration::ticks_per_second();</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>boost::int64_t ticks()</screen></entry>
|
|
<entry>Return the raw count of the duration type (will give unpredictable results if calling <code>time_duration</code> is a <code>special_value</code>).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(0,0,0, 1000);
|
|
td.ticks() // --> 1000</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration time_duration::unit()</screen></entry>
|
|
<entry>Return smallest possible unit of duration type (1 nanosecond).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration::unit() --> time_duration(0,0,0,1)</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_neg_infinity() const</screen></entry>
|
|
<entry>Returns true if time_duration is negative infinity</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(neg_infin);
|
|
td.is_neg_infinity(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_pos_infinity() const</screen></entry>
|
|
<entry>Returns true if time_duration is positive infinity</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(pos_infin);
|
|
td.is_pos_infinity(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_not_a_date_time() const</screen></entry>
|
|
<entry>Returns true if value is not a time</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(not_a_date_time);
|
|
td.is_not_a_date_time(); // --> true</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>bool is_special() const</screen></entry>
|
|
<entry>Returns true if time_duration is any <code>special_value</code></entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(pos_infin);
|
|
time_duration td2(not_a_date_time);
|
|
time_duration td3(2,5,10);
|
|
td.is_special(); // --> true
|
|
td2.is_special(); // --> true
|
|
td3.is_special(); // --> false</screen></entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
|
|
<anchor id="time_duration_to_string" />
|
|
<bridgehead renderas="sect3">Conversion To String</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>std::string to_simple_string(time_duration)</screen></entry>
|
|
<entry>To <code>HH:MM:SS.fffffffff</code> were <code>fff</code> is fractional seconds that are only included if non-zero.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>10:00:01.123456789</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>std::string to_iso_string(time_duration)</screen></entry>
|
|
<entry>Convert to form <code>HHMMSS,fffffffff</code>.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>100001,123456789</screen></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
|
|
<anchor id="time_duration_operators" />
|
|
<bridgehead renderas="sect3">Operators</bridgehead>
|
|
<para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>operator<<, operator>></screen></entry>
|
|
<entry>Streaming operators. <emphasis role="strong">Note:</emphasis> As of version 1.33, streaming operations have been greatly improved. See <link linkend="date_time.date_time_io">Date Time IO System</link> for more details (including exceptions and error conditions).</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(0,0,0);
|
|
stringstream ss("14:23:11.345678");
|
|
ss >> td;
|
|
std::cout << td; // "14:23:11.345678"
|
|
</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>operator==, operator!=,
|
|
operator>, operator<,
|
|
operator>=, operator<=</screen>
|
|
</entry>
|
|
<entry>A full complement of comparison operators</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>dd1 == dd2, etc</screen></entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration operator+(time_duration)</screen></entry>
|
|
<entry>Add durations.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td1(hours(1)+minutes(2));
|
|
time_duration td2(seconds(10));
|
|
time_duration td3 = td1 + td2;</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration operator-(time_duration)</screen></entry>
|
|
<entry>Subtract durations.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td1(hours(1)+nanoseconds(2));
|
|
time_duration td2 = td1 - minutes(1);</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration operator/(int)</screen></entry>
|
|
<entry>Divide the length of a duration by an integer value. Discards any remainder.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>hours(3)/2 == time_duration(1,30,0);
|
|
nanosecond(3)/2 == nanosecond(1);</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>time_duration operator*(int)</screen></entry>
|
|
<entry>Multiply the length of a duration by an integer value.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>hours(3)*2 == hours(6);</screen></entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
</para>
|
|
|
|
<anchor id="time_duration_struct_tm" />
|
|
<bridgehead renderas="sect3">Struct tm, time_t, and FILETIME Functions</bridgehead>
|
|
<para>Function for converting a time_duration to a <code>tm</code> struct is provided.</para>
|
|
<informaltable frame="all">
|
|
<tgroup cols="2">
|
|
<thead>
|
|
<row>
|
|
<entry valign="top" morerows="1">Syntax</entry>
|
|
<entry>Description</entry>
|
|
</row>
|
|
<row>
|
|
<entry>Example</entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry valign="top" morerows="1"><screen>tm to_tm(time_duration)</screen></entry>
|
|
<entry>A function for converting a <code>time_duration</code> object to a <code>tm</code> struct. The fields: <code>tm_year</code>, <code>tm_mon</code>, <code>tm_mday</code>, <code>tm_wday</code>, <code>tm_yday</code> are set to zero. The <code>tm_isdst</code> field is set to -1.</entry>
|
|
</row>
|
|
<row>
|
|
<entry><screen>time_duration td(1,2,3);
|
|
tm td_tm = to_tm(td);
|
|
/* tm_year => 0
|
|
tm_mon => 0
|
|
tm_mday => 0
|
|
tm_wday => 0
|
|
tm_yday => 0
|
|
tm_hour => 1
|
|
tm_min => 2
|
|
tm_sec => 3
|
|
tm_isddst => -1 */</screen>
|
|
</entry>
|
|
</row>
|
|
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
|
|
</section>
|