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# std::chrono::time_point::time_point

From cppreference.com
< cpp‎ | chrono‎ | time point

| (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`.

### [edit] Parameters

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

### [edit] 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

### [edit] See also

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

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