std::chrono::floor(std::chrono::duration)
From cppreference.com
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Date and time library
(C++11)
(C++20)
(C++20)
(C++11)
(C++11)
(C++11)
(C++20)
(C++20)
(C++20)
(C++11)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)(C++20)(C++20)(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
std::chrono::duration
Member functions
Non-member functions
(until C++20)(C++20)
(C++20)
floor
(C++17)
(C++17)
(C++17)
(C++17)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++14)
(C++20)
Helper classes
Defined in header
<chrono>
template< class ToDuration, class Rep, class Period >
constexpr ToDuration floor( const std::chrono::duration <Rep, Period>& d );
(since C++17)
constexpr ToDuration floor( const std::chrono::duration <Rep, Period>& d );
Returns the greatest duration t representable in ToDuration that is less or equal to d.
The function does not participate in the overload resolution unless ToDuration is a specialization of std::chrono::duration .
[edit] Parameters
d
-
duration to convert
[edit] Return value
d rounded down to a duration of type ToDuration.
[edit] Possible implementation
namespace detail { template<class> inline constexpr bool is_duration_v = false; template<class Rep, class Period> inline constexpr bool 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() { using namespace std::chrono_literals; std::cout << "Duration\tFloor\tRound\tCeil\n"; for (using Sec = std::chrono::seconds ; auto const 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:
Duration Floor Round Ceil +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
(C++17)
(function template) [edit]