60 lines
6.4 KiB
XML
60 lines
6.4 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) 2001-2004 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.examples.days_alive">
|
|
<title>Days Alive</title>
|
|
|
|
<para>
|
|
Calculate the number of days you have been living using durations and dates.
|
|
</para>
|
|
<programlisting>
|
|
<literal>
|
|
<phrase role="comment">/* Short example that calculates the number of days since user was born.
|
|
* Demonstrates comparisons of durations, use of the day_clock,
|
|
* and parsing a date from a string.
|
|
*/</phrase><phrase role="preprocessor">
|
|
|
|
#include</phrase><phrase role="string"> "boost/date_time/gregorian/gregorian.hpp"</phrase><phrase role="preprocessor">
|
|
#include</phrase><phrase role="special"> <</phrase><phrase role="identifier">iostream</phrase><phrase role="special">></phrase><phrase role="keyword">
|
|
|
|
int</phrase><phrase role="identifier">
|
|
main</phrase><phrase role="special">()</phrase><phrase role="special">
|
|
{</phrase><phrase role="keyword">
|
|
|
|
using</phrase><phrase role="keyword"> namespace</phrase><phrase role="identifier"> boost</phrase><phrase role="special">::</phrase><phrase role="identifier">gregorian</phrase><phrase role="special">;</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">string</phrase><phrase role="identifier"> s</phrase><phrase role="special">;</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> <<</phrase><phrase role="string"> "Enter birth day YYYY-MM-DD (eg: 2002-02-01): "</phrase><phrase role="special">;</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cin</phrase><phrase role="special"> >></phrase><phrase role="identifier"> s</phrase><phrase role="special">;</phrase><phrase role="keyword">
|
|
try</phrase><phrase role="special"> {</phrase><phrase role="identifier">
|
|
date</phrase><phrase role="identifier"> birthday</phrase><phrase role="special">(</phrase><phrase role="identifier">from_simple_string</phrase><phrase role="special">(</phrase><phrase role="identifier">s</phrase><phrase role="special">));</phrase><phrase role="identifier">
|
|
date</phrase><phrase role="identifier"> today</phrase><phrase role="special"> =</phrase><phrase role="identifier"> day_clock</phrase><phrase role="special">::</phrase><phrase role="identifier">local_day</phrase><phrase role="special">();</phrase><phrase role="identifier">
|
|
days</phrase><phrase role="identifier"> days_alive</phrase><phrase role="special"> =</phrase><phrase role="identifier"> today</phrase><phrase role="special"> -</phrase><phrase role="identifier"> birthday</phrase><phrase role="special">;</phrase><phrase role="identifier">
|
|
days</phrase><phrase role="identifier"> one_day</phrase><phrase role="special">(</phrase><phrase role="number">1</phrase><phrase role="special">);</phrase><phrase role="keyword">
|
|
if</phrase><phrase role="special"> (</phrase><phrase role="identifier">days_alive</phrase><phrase role="special"> ==</phrase><phrase role="identifier"> one_day</phrase><phrase role="special">)</phrase><phrase role="special"> {</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> <<</phrase><phrase role="string"> "Born yesterday, very funny"</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="special">
|
|
}</phrase><phrase role="keyword">
|
|
else</phrase><phrase role="keyword"> if</phrase><phrase role="special"> (</phrase><phrase role="identifier">days_alive</phrase><phrase role="special"> <</phrase><phrase role="identifier"> days</phrase><phrase role="special">(</phrase><phrase role="number">0</phrase><phrase role="special">))</phrase><phrase role="special"> {</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> <<</phrase><phrase role="string"> "Not born yet, hmm: "</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> days_alive</phrase><phrase role="special">.</phrase><phrase role="identifier">days</phrase><phrase role="special">()</phrase><phrase role="special">
|
|
<<</phrase><phrase role="string"> " days"</phrase><phrase role="special"> <<</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="special">
|
|
}</phrase><phrase role="keyword">
|
|
else</phrase><phrase role="special"> {</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> <<</phrase><phrase role="string"> "Days alive: "</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> days_alive</phrase><phrase role="special">.</phrase><phrase role="identifier">days</phrase><phrase role="special">()</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="special">
|
|
}</phrase><phrase role="special">
|
|
|
|
}</phrase><phrase role="keyword">
|
|
catch</phrase><phrase role="special">(...)</phrase><phrase role="special"> {</phrase><phrase role="identifier">
|
|
std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> <<</phrase><phrase role="string"> "Bad date entered: "</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> s</phrase><phrase role="special"> <<</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="special">
|
|
}</phrase><phrase role="keyword">
|
|
return</phrase><phrase role="number"> 0</phrase><phrase role="special">;</phrase><phrase role="special">
|
|
}</phrase>
|
|
</literal>
|
|
</programlisting>
|
|
|
|
</section>
|