std::chrono::floor(std::chrono::time_point)

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< cpplrm; | chronolrm; | time point
Date and time utilities
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Calendars
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Time zones
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C-style date and time
Defined in header <chrono>
template <class ToDuration, class Clock, class Duration>
constexpr time_point<Clock, ToDuration> floor(const time_point<Clock, Duration>& tp);
(since C++17)

Returns the largest time point t representable in ToDuration that is smaller or equal to tp.

The function does not participate in the overload resolution unless ToDuration is an specialization of std::chrono::duration.

Parameters

tp - time point to round down

Return value

d rounded down to a the next time point using duration of type ToDuration.

Possible implementation

template <class T> struct is_duration : std::false_type {};
template <class Rep, class Period> struct is_duration<
    std::chrono::duration<Rep, Period>> : std::true_type {};

template <class To, class Clock, class FromDuration,
          class = std::enable_if_t<is_duration<To>{}>>
constexpr std::chrono::time_point<Clock, To>
    floor(const std::chrono::time_point<Clock, FromDuration>& tp)
{
    return std::chrono::time_point<Clock, To>{
        std::chrono::floor<To>(tp.time_since_epoch())};
}

Example

See also

converts a time point to another time point on the same clock, with a different duration
(function template)
converts a time_point to another, rounding up
(function template)
converts a time_point to another, rounding to nearest, ties to even
(function template)
converts a duration to another, rounding down
(function template)
nearest integer not greater than the given value
(function)