(一)boost库之日期、时间

（一）boost库之日期、时间一、计时器计时器，通常在一个项目中统计一个函数的执行时间是非常实用的。

#include <boost/timer.hpp>void PrintUserTime(){boost::timer t; //定义一个计时类，开始计时std::cout << "可度量的最大时间:" <<t.elapsed_max()/3600 << "h" << std::endl;std::cout << "可度量的最大时间:" <<t.elapsed_min() << "s" << std::endl;std::cout << "使用时间为：" << t.elapsed() << std::endl;}二、获取当前日期date d(day_clock::local_day());三、将字符串转换成日期date fmtdt1 = from_string("2013-04-21");date fmtdt2 = date_from_iso_string("20140320");date fmtdt3 = from_us_string("1-25-2003")四、日期转换成字符串to_iso_stringto_simple_string五、日期长度，以天为单位date_duration dur = end - beg;cout << dur.days() << endl;六、日期区间接收两个时间点，用于判断时间区间的交集、并集、间隔、区间平移等关于区间的操作date_period p(beg, end);七、日期运算提供days、months、years三个时间类，可与日期类进行混合运算months m(1);date end = d + m;八、日期、日期与字符串转换、日期加减运算#include <boost/date_time/gregorian/gregorian.hpp> void PrintDate(){using namespace boost::gregorian;using namespace std;//获取当前时间date d(day_clock::local_day());//日期类支持IO流输出cout << d << endl;//将日期转换成字符串20140320cout << to_iso_string(d) << endl;//将字符串中转换成日期date fmtdt1 = from_string("2013-04-21");date fmtdt2 = from_string("2013/04/21");cout << fmtdt1 << " " << fmtdt2 << endl;//日期的运算,days day(1);months m(1);years y(1);date beg = d + day - y;date end = d + m;cout << (beg < end ? "Yes" : "No") << endl;//特别地，date - date = date_duration ，同时也支持date +/- date_duration//日期长度date_duration dur = end - beg;cout << dur.days() << endl;//日期区间date_period p(beg, dur);cout << p << endl;}九、时间、时间与字符串转换、时间加减运算和日期大同小异，也提供时间长度：time_duration，时间区间：time_period,及时间操作类hours、minutes、seconds、milliseconds、microseconds#include<boost/date_time/posix_time/posix_time.hpp>void PrintTime(){using namespace boost::posix_time;using namespace std;using namespace boost::gregorian;//获取本地时间ptime t1(second_clock::local_time());//获取UTC时间ptime t2(second_clock::universal_time());cout << t1 << t2 << endl;//时间8：30time_duration dur(8,30,0);hours h(1);minutes m(1);seconds s(1);milliseconds mi(1); //毫秒microseconds mic(1); //微秒//nanoseconds na(1); //纳秒需要系统的支持ptime t3(date(2013,4,20));ptime t4(date(2013,4,20), dur);ptime t5(date(2013,4,20), mic);cout << to_simple_string(t3) <<" " << to_simple_string(t5) << endl;//时间的运算，与日期差不多，非常简单cout << t2 - t1 << endl;}十、格式化时间主要用来两个类，输入：date_input_facet，输出：date_facet时间格式化类为：time_input_facet time_facet boost::posix_time::time_facet *timeFmt = newboost::posix_time::time_facet("%Y-%m-%d %H:%M:%S"); #include <boost/date_time/gregorian/gregorian.hpp> void FormatDateTime(){using namespace boost::gregorian;using namespace std;//输入date d;std::string teststring = "140320";boost::gregorian::date_input_facet *fmt = new boost::gregorian::date_input_facet("%y%m%d");std::stringstream ss1(teststring);ss1.imbue(locale(ss1.getloc(), fmt));ss1 >> d;cout << d << endl;//输出boost::gregorian::date d2(2009, 1, 7);boost::gregorian::date_facet *fmt2 = newboost::gregorian::date_facet("%A, %d %B %Y");std::cout.imbue(std::locale(std::cout.getloc(), fmt2));std::cout << d2 << std::endl;//定制std::locale::global(std::locale("German"));std::string months[12] = { "Januar", "Februar", "M?rz", "April", "Mai", "Juni", "Juli", "August", "September", "Oktober", "November", "Dezember" };std::string weekdays[7] = { "Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samstag" };boost::gregorian::date d3(2009, 1, 7);boost::gregorian::date_facet *df = newboost::gregorian::date_facet("%A, %d. %B %Y");df->long_month_names(std::vector<std::string>(months, months + 12));df->long_weekday_names(std::vector<std::string>( weekdays, weekdays + 7));std::cout.imbue(std::locale(std::cout.getloc(), df));std::cout << d3 << std::endl;}。