operator==,!=,<,<=,>,>=,<=>(std::chrono::duration)

 

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Feature test macros(C++20)

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Date and time library

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Date and time library

Time point time_point (C++11) clock_time_conversion (C++20)   clock_cast (C++20) Duration duration (C++11) Clocks system_clock (C++11) steady_clock (C++11) is_clock (C++20) utc_clock (C++20) tai_clock (C++20) high_resolution_clock (C++11) gps_clock (C++20) file_clock (C++20) local_t (C++20) Time of day is_amis_pm (C++20)(C++20) make12make24 (C++20)(C++20) hh_mm_ss (C++20)

Calendar day (C++20) month (C++20) year (C++20) weekday (C++20) operator/ (C++20) year_month_day (C++20) year_month_day_last (C++20) year_month_weekday (C++20) year_month_weekday_last (C++20)   weekday_indexed (C++20) weekday_last (C++20) month_day (C++20) month_day_last (C++20) month_weekday (C++20) month_weekday_last (C++20) year_month (C++20) last_speclast (C++20)(C++20) chrono I/O parse (C++20)

Time zone tzdb (C++20) tzdb_list (C++20) get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20) sys_info (C++20) local_info (C++20) nonexistent_local_time (C++20) ambiguous_local_time (C++20) locate_zone (C++20) current_zone (C++20) time_zone (C++20) choose (C++20) zoned_traits (C++20) zoned_time (C++20) time_zone_link (C++20) leap_second (C++20) leap_second_info (C++20) get_leap_second_info (C++20) C-style date and time

 

std::chrono::duration

Member functions
duration::duration duration::operator= duration::count duration::zero duration::min duration::max duration::operator+duration::operator-	duration::operator++duration::operator-- duration::operator+=duration::operator-=duration::operator*=duration::operator/=duration::operator%=
Non-member functions
operator+operator-operator*operator/operator% operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(C++20) operator<< (C++20)	duration_cast floor (C++17) ceil (C++17) round (C++17) abs (C++17) operator""h (C++14) operator""min (C++14) operator""s (C++14) operator""ms (C++14) operator""us (C++14) operator""ns (C++14) from_stream (C++20)
Helper classes
common_type treat_as_floating_point      duration_values	formatter<std::chrono::duration> (C++20) hash<std::chrono::duration> (C++26)

 

template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator==(conststd::chrono::duration<Rep1, Period1>& lhs,                            conststd::chrono::duration<Rep2, Period2>& rhs );	(1)	(since C++11)
template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator!=(conststd::chrono::duration<Rep1, Period1>& lhs,                            conststd::chrono::duration<Rep2, Period2>& rhs );	(2)	(since C++11) (until C++20)
template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator<(conststd::chrono::duration<Rep1, Period1>& lhs,                           conststd::chrono::duration<Rep2, Period2>& rhs );	(3)	(since C++11)
template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator<=(conststd::chrono::duration<Rep1, Period1>& lhs,                            conststd::chrono::duration<Rep2, Period2>& rhs );	(4)	(since C++11)
template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator>(conststd::chrono::duration<Rep1, Period1>& lhs,                           conststd::chrono::duration<Rep2, Period2>& rhs );	(5)	(since C++11)
template<class Rep1, class Period1, class Rep2, class Period2 > constexprbool operator>=(conststd::chrono::duration<Rep1, Period1>& lhs,                            conststd::chrono::duration<Rep2, Period2>& rhs );	(6)	(since C++11)
template<class Rep1, class Period1, class Rep2, class Period2 >     requires std::three_way_comparable<std::common_type_t<Rep1, Rep2>> constexprauto operator<=>(conststd::chrono::duration<Rep1, Period1>& lhs,                             conststd::chrono::duration<Rep2, Period2>& rhs );	(7)	(since C++20)

Compares two durations. Let CT be std::common_type<std::chrono::duration<Rep1, Period1>, std::chrono::duration<Rep2, Period2>>::type:

1,2) Checks if lhs and rhs are equal, i.e. the number of ticks for the type common to both durations are equal.

3-6) Compares lhs to rhs, i.e. compares the number of ticks for the type common to both durations.

7) Compares lhs to rhs, i.e. compares the number of ticks for the type common to both durations. The return type is deduced from CT(lhs).count()<=> CT(rhs).count().

The != operator is synthesized from operator==.

(since C++20)

Parameters

lhs	-	duration on the left-hand side of the operator
rhs	-	duration on the right-hand side of the operator

Return value

1)CT(lhs).count()== CT(rhs).count()

2)!(lhs == rhs)

3)CT(lhs).count()< CT(rhs).count()

4)!(rhs < lhs)

5)rhs < lhs

6)!(lhs < rhs)

7)CT(lhs).count()<=> CT(rhs).count()

Example

Run this code

#include <chrono>#include <iostream>   int main(){constexprauto t1 =std::chrono::seconds(2);constexprauto t2 =std::chrono::milliseconds(2000);   ifconstexpr(t1 == t2)std::cout<< t1 <<" == "<< t2 <<'\n';elsestd::cout<< t1 <<" != "<< t2 <<'\n';   constexprauto t3 =std::chrono::seconds(61);constexprauto t4 =std::chrono::minutes(1);   ifconstexpr(t3 > t4)std::cout<< t3 <<" > "<< t4 <<'\n';elsestd::cout<< t3 <<" <= "<< t4 <<'\n';   usingnamespace std::chrono_literals;   static_assert(1h == 60min); static_assert(1min == 60s); static_assert(1s ==1'000ms); static_assert(1ms == 1'000us); static_assert(1us ==1'000ns); }

Output:

2s == 2000ms 61s > 1min