public static member function
<chrono>
std::chrono::system_clock::from_time_t
static time_point from_time_t (time_t t) noexcept;
Convert from time_t
Converts t into its equivalent of member type time_point.
Example
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| // system_clock::from_time_t #include <iostream> #include <ctime> #include <ratio> #include <chrono> int main () { using namespace std::chrono; // create tm with 1/1/2000: std::tm timeinfo = std::tm(); timeinfo.tm_year = 100; // year: 2000 timeinfo.tm_mon = 0; // month: january timeinfo.tm_mday = 1; // day: 1st std::time_t tt = std::mktime (&timeinfo); system_clock::time_point tp = system_clock::from_time_t (tt); system_clock::duration d = system_clock::now() - tp; // convert to number of days: typedef duration<int,std::ratio<60*60*24>> days_type; days_type ndays = duration_cast<days_type> (d); // display result: std::cout << ndays.count() << " days have passed since 1/1/2000"; std::cout << std::endl; return 0; }
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Possible output:
4533 days have passed since 1/1/2000 |