我有一个“人类可读”变量hours
,minutes
,seconds
,day
,month
,{{ 1}}包含与其名称相对应的值(假设我year
的结构为SYSTEMTIME
)。
我发现创建<windows.h>
的唯一方法是:
chrono::time_point
首先,我从SYSTEMTIME sysTime = ...; // Came from some source (file, network, etc. )
tm t;
t.tm_sec = sysTime.wSecond;
t.tm_min = sysTime.wMinute;
t.tm_hour = sysTime.wHour;
t.tm_mday = sysTime.wDay;
t.tm_mon = sysTime.wMonth - 1;
t.tm_year = sysTime.wYear - 1900;
t.tm_isdst = 0;
std::chrono::system_clock::time_point dateTime =
std::chrono::system_clock::from_time_t( mktime( & t ) );
丢失了一毫秒
第二,(mmm ......)我不喜欢这种转换))
你能以更优雅的方式解决这个问题吗?
答案 0 :(得分:7)
使用this open source, header-only library,我可以:
#include "date.h"
#include <iostream>
struct SYSTEMTIME
{
int wMilliseconds;
int wSecond;
int wMinute;
int wHour;
int wDay;
int wMonth;
int wYear;
};
int
main()
{
SYSTEMTIME sysTime = {123, 38, 9, 10, 8, 7, 2015};
std::chrono::system_clock::time_point dateTime =
date::sys_days(date::year(sysTime.wYear)
/date::month(sysTime.wMonth)
/date::day(sysTime.wDay))
+ std::chrono::hours(sysTime.wHour)
+ std::chrono::minutes(sysTime.wMinute)
+ std::chrono::seconds(sysTime.wSecond)
+ std::chrono::milliseconds(sysTime.wMilliseconds);
std::cout << dateTime << '\n';
}
输出:
2015-07-08 10:09:38.123000
在&#34; date.h&#34;中,您可能需要使用这些宏来编译VS.:
# define CONSTDATA const
# define CONSTCD11
# define CONSTCD14
使用符合标准的C ++ 14编译器,这些宏应设置为:
# define CONSTDATA constexpr
# define CONSTCD11 constexpr
# define CONSTCD14 constexpr