std::chrono::time_point<Clock,Duration>::time_since_epoch
From cppreference.com
< cpp | chrono | time point
duration time_since_epoch() const; |
(since C++11) (until C++14) |
|
constexpr duration time_since_epoch() const; |
(since C++14) | |
Returns a duration representing the amount of time between *this and the clock
's epoch.
Parameters
(none)
Return value
The amount of time between this time_point
and the clock
's epoch
Example
Run this code
#include <iostream> #include <chrono> #include <ctime> int main() { const auto p0 = std::chrono::time_point<std::chrono::system_clock>{}; const auto p1 = std::chrono::system_clock::now(); const auto p2 = p1 - std::chrono::hours(24); std::time_t epoch_time = std::chrono::system_clock::to_time_t(p0); std::cout << "epoch: " << std::ctime(&epoch_time); std::time_t today_time = std::chrono::system_clock::to_time_t(p1); std::cout << "today: " << std::ctime(&today_time); std::cout << "hours since epoch: " << std::chrono::duration_cast<std::chrono::hours>( p1.time_since_epoch()).count() << '\n'; std::cout << "yesterday, hours since epoch: " << std::chrono::duration_cast<std::chrono::hours>( p2.time_since_epoch()).count() << '\n'; }
Possible output:
epoch: Thu Jan 1 00:00:00 1970 today: Fri Jun 30 10:44:11 2017 hours since epoch: 416338 yesterday, hours since epoch: 416314