The std::chrono::system_clock class provides a means of
obtaining the current wall-clock time from the system-wide real-time clock.
The current time can be obtained by calling std::chrono::system_clock::now(). Instances of std::chrono::system_clock::time_point
can be converted to and from time_t
with the std::chrono::system_clock::to_time_t()
and std::chrono::system_clock::from_time_t()
functions. They system clock is not steady, so a subsequent
call to std::chrono::system_clock::now()
may return an earlier time than a previous call (e.g. if the operating
system clock is manually adjusted, or synchronized with an external clock).
std::chrono::system_clock::to_time_point()
is the old name for std::chrono::system_clock::from_time_t(), and is provided for backwards compatibility
only. It will be removed in some future release.
class system_clock { public: typedef unspecified-integral-type rep; typedef std::ratio< unspecified,unspecified> period; typedef std::chrono::duration<rep,period> duration; typedef std::chrono::time_point<system_clock> time_point; static const bool is_steady=false; static time_point now() noexcept; static time_t to_time_t(const time_point& t) noexcept; static time_point from_time_t(time_t t) noexcept; // for backwards compatibility only static time_point to_time_point(time_t t) noexcept; static const bool is_monotonic=false; };
Header
#include <chrono>