Defined in header <chrono> | ||
|---|---|---|
template <class ToDuration, class Clock, class Duration>
std::chrono::time_point<Clock, ToDuration>
time_point_cast(const std::chrono::time_point<Clock, Duration> &t);
| (since C++11) (until C++14) | |
template <class ToDuration, class Clock, class Duration>
constexpr std::chrono::time_point<Clock, ToDuration>
time_point_cast(const std::chrono::time_point<Clock, Duration> &t);
| (since C++14) |
Converts a std::chrono::time_point from one duration to another.
time_point_cast participates in overload resolution only if ToDuration is a specialization of std::chrono::duration.
| t | - | time_point to convert from |
std::chrono::time_point<Clock, ToDuration>(.
std::chrono::duration_cast<ToDuration>(t.time_since_epoch()))
#include <iostream>
#include <chrono>
using namespace std::chrono_literals;
using Clock = std::chrono::high_resolution_clock;
using Ms = std::chrono::milliseconds;
using Sec = std::chrono::seconds;
template<class Duration>
using TimePoint = std::chrono::time_point<Clock, Duration>;
inline void print_ms(const TimePoint<Ms>& time_point)
{
std::cout << time_point.time_since_epoch().count() << " ms\n";
}
int main()
{
TimePoint<Sec> time_point_sec{4s};
// implicit cast, no precision loss
TimePoint<Ms> time_point_ms{time_point_sec};
print_ms(time_point_ms); // 4000 ms
time_point_ms = TimePoint<Ms>{5756ms};
print_ms(time_point_ms); // 5756 ms
// explicit cast, need when precision loss may happen
// 5756 truncated to 5000
time_point_sec = std::chrono::time_point_cast<Sec>(time_point_ms);
print_ms(time_point_sec); // 5000 ms
}Output:
4000 ms 5756 ms 5000 ms
|
(C++17) | converts a time_point to another, rounding down (function template) |
|
(C++17) | converts a time_point to another, rounding up (function template) |
|
(C++17) | converts a time_point to another, rounding to nearest, ties to even (function template) |
|
(C++11) | converts a duration to another, with a different tick interval (function template) |
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