std::chrono::time_point::time_point

 

C++

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Technical Specifications

 

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Date and time utilities

time_point (C++11)

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C-style date and time

 

std::chrono::time_point

Member functions

time_point::time_point

time_point::time_since_epoch

time_point::operator+time_point::operator-

time_point::min

time_point::max

Non-member functions

common_type

operator+operator-

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time_point_cast

floor (C++17)

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	(1)
time_point();			(since C++11) (until C++14)
constexpr time_point();			(since C++14)
		(2)
explicit time_point( const duration& d );				(since C++11) (until C++14)
constexpr explicit time_point( const duration& d );				(since C++14)
			(3)
template< class Duration2 > time_point( const time_point<Clock,Duration2>& t );					(since C++11) (until C++14)
template< class Duration2 > constexpr time_point( const time_point<Clock,Duration2>& t );					(since C++14)

Constructs a new time_point from one of several optional data sources.

1) Default constructor, creates a time_point with a value of Clock's epoch.

2) Constructs a time_point at Clock's epoch plus d.

3) Constructs a time_point by converting t to duration. This constructor only participates in overload resolution if Duration2 is implicitly convertible to duration.

Parameters

d	-	a duration to copy from
t	-	a time_point to convert from

Example

Run this code

#include <chrono>
#include <iostream>
 
using Clock = std::chrono::high_resolution_clock;
using TimePoint = std::chrono::time_point<Clock>;
 
void print_ms(const TimePoint& point) 
{
    using Ms = std::chrono::milliseconds;
    const Clock::duration since_epoch = point.time_since_epoch();
    std::cout << std::chrono::duration_cast<Ms>(since_epoch).count() << " ms\n";
}
 
int main() 
{
    const TimePoint default_value = TimePoint(); // (1)
    print_ms(default_value); // 0 ms
 
    const Clock::duration duration_4_seconds = std::chrono::seconds(4);
    const TimePoint time_point_4_seconds(duration_4_seconds); // (2)
      // 4 seconds from start of epoch
    print_ms(time_point_4_seconds); // 4000 ms
 
    const TimePoint time_point_now = Clock::now(); // (3)
    print_ms(time_point_now); // 43098276 ms
}

Possible output:

0 ms
4000 ms
43098276 ms

See also

(constructor)	constructs new duration (public member function of std::chrono::duration)
duration_cast	converts a duration to another, with a different tick interval (function template)