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      std::chrono::floor(std::chrono::duration)

      From cppreference.com
      <cpp‎ |chrono‎ |duration
       
       
      Date and time library
       
      std::chrono::duration
       
      Defined in header<chrono>
      template<class ToDuration,class Rep,class Period>
      constexpr ToDuration floor(conststd::chrono::duration<Rep, Period>& d);
      (since C++17)

      Returns the greatest durationt representable inToDuration that is less or equal tod.

      The function does not participate in the overload resolution unlessToDuration is a specialization ofstd::chrono::duration.

      Contents

      [edit]Parameters

      d - duration to convert

      [edit]Return value

      d rounded down to a duration of typeToDuration.

      [edit]Possible implementation

      namespace detail{template<class>inlineconstexprbool is_duration_v=false;template<class Rep,class Period>inlineconstexprbool is_duration_v<std::chrono::duration<Rep, Period>>=true;} template<class To,class Rep,class Period,class=std::enable_if_t<detail::is_duration_v<To>>>constexpr To floor(const duration<Rep, Period>& d){    To t=std::chrono::duration_cast<To>(d);if(t> d)return t- To{1};return t;}

      [edit]Example

      Run this code
      #include <chrono>#include <iomanip>#include <iostream> int main(){usingnamespace std::chrono_literals;std::cout<<"Duration\tFloor\tRound\tCeil\n";for(using Sec=std::chrono::seconds;autoconst d:{+4999ms,+5000ms,+5001ms,+5499ms,+5500ms,+5999ms,-4999ms,-5000ms,-5001ms,-5499ms,-5500ms,-5999ms})std::cout<<std::showpos<< d<<"\t\t"<< std::chrono::floor<Sec>(d)<<'\t'<<std::chrono::round<Sec>(d)<<'\t'<<std::chrono::ceil<Sec>(d)<<'\n';}

      Output:

      DurationFloorRoundCeil+4999ms+4s+5s+5s+5000ms+5s+5s+5s+5001ms+5s+5s+6s+5499ms+5s+5s+6s+5500ms+5s+6s+6s+5999ms+5s+6s+6s-4999ms-5s-5s-4s-5000ms-5s-5s-5s-5001ms-6s-5s-5s-5499ms-6s-5s-5s-5500ms-6s-6s-5s-5999ms-6s-6s-5s

      [edit]See also

      converts a duration to another, with a different tick interval
      (function template)[edit]
      converts a duration to another, rounding up
      (function template)[edit]
      converts a duration to another, rounding to nearest, ties to even
      (function template)[edit]
      converts a time_point to another, rounding down
      (function template)[edit]
      (C++11)(C++11)
      nearest integer not greater than the given value
      (function)[edit]
      Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/duration/floor&oldid=157075"

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