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一、計時(shí)器
計時(shí)器，通常在一個(gè)項目中統計一個(gè)函數的執行時(shí)間是非常實(shí)用的。

#include <boost/timer.hpp>
void PrintUserTime()
{
    boost::timer t;  //定義一個(gè)計時(shí)類(lèi)，開(kāi)始計時(shí)
    std::cout << "可度量的最大時(shí)間:" << t.elapsed_max()/3600 << "h" << std::endl;
    std::cout << "可度量的最大時(shí)間:" << t.elapsed_min() << "s" << std::endl;
    std::cout << "使用時(shí)間為：" <<  t.elapsed() << std::endl;
}

二、獲取當前日期

date d(day_clock::local_day());

三、將字符串轉換成日期

date fmtdt1 = from_string("2013-04-21");
date fmtdt2 = date_from_iso_string("20140320");
date fmtdt3 = from_us_string("1-25-2003")

四、日期轉換成字符串

to_iso_string
to_simple_string

五、日期長(cháng)度，以天為單位

date_duration dur = end - beg;    
cout << dur.days() << endl;

六、日期區間

接收兩個(gè)時(shí)間點(diǎn)，用于判斷時(shí)間區間的交集、并集、間隔、區間平移等關(guān)于區間的操作

date_period p(beg, end);

七、日期運算

提供days、months、years三個(gè)時(shí)間類(lèi)，可與日期類(lèi)進(jìn)行混合運算

months m(1);
date end = d + m;

八、日期、日期與字符串轉換、日期加減運算

#include <boost/date_time/gregorian/gregorian.hpp>
void PrintDate()
{
    using namespace boost::gregorian;
    using namespace std;
    //獲取當前時(shí)間
    date d(day_clock::local_day());
    //日期類(lèi)支持IO流輸出
    cout << d << endl;
    //將日期轉換成字符串  20140320
    cout << to_iso_string(d) << endl;
    //將字符串中轉換成日期
    date fmtdt1 = from_string("2013-04-21");
    date fmtdt2 = from_string("2013/04/21");
    cout << fmtdt1 << " " << fmtdt2 << endl;
    //日期的運算, 
    days day(1);
    months m(1);
    years y(1);
    date beg = d + day - y;
    date end = d + m;
    cout << (beg < end ? "Yes" : "No") << endl;
    //特別地， date - date = date_duration ， 同時(shí)也支持date +/- date_duration
    //日期長(cháng)度
    date_duration dur = end - beg;    
    cout << dur.days() << endl;
    //日期區間
    date_period p(beg, dur);
    cout << p << endl;
}

九、時(shí)間、時(shí)間與字符串轉換、時(shí)間加減運算

和日期大同小異，也提供時(shí)間長(cháng)度：time_duration，時(shí)間區間：time_period,及時(shí)間操作類(lèi)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;
    //獲取本地時(shí)間
    ptime t1(second_clock::local_time());
    //獲取UTC時(shí)間
    ptime t2(second_clock::universal_time());
    cout << t1 << t2 << endl;
    //時(shí)間8：30
    time_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);    //納秒   需要系統的支持
    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;
    
    //時(shí)間的運算，與日期差不多，非常簡(jiǎn)單
    cout << t2 - t1 << endl;
}

十、格式化時(shí)間

主要用來(lái)兩個(gè)類(lèi)，輸入：date_input_facet， 輸出：date_facet
時(shí)間格式化類(lèi)為：time_input_facet   time_facet  boost::posix_time::time_facet *timeFmt = new boost::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;
    
    //輸入
    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;
    //輸出
    boost::gregorian::date d2(2009, 1, 7); 
    boost::gregorian::date_facet *fmt2 = new boost::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 = new boost::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; 
}