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

 

C++

Compiler support

Freestanding and hosted

Language

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros (C++20) Dynamic memory management Program utilities Coroutine support (C++20) Variadic functions is_constant_evaluated (C++20) launder (C++17) initializer_list (C++11) source_location (C++20) Three-way comparison (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)    is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

General utilities Date and time Function objects Formatting library (C++20) bitset hash (C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator> rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)    cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) Elementary string conversions to_chars (C++17) from_chars (C++17) chars_format (C++17)

 

Date and time utilities

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) high_resolution_clock (C++11)	is_clock (C++20) utc_clock (C++20) tai_clock (C++20)	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)
Calendars
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)
Time zones
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)
chrono I/O
parse (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)

 

template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator==(const std::chrono::duration<Rep1, Period1>& lhs,                           const std::chrono::duration<Rep2, Period2>& rhs);	(1)	(since C++11)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator!=(const std::chrono::duration<Rep1, Period1>& lhs,                           const std::chrono::duration<Rep2, Period2>& rhs);	(2)	(since C++11) (until C++20)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator<(const std::chrono::duration<Rep1, Period1>& lhs,                          const std::chrono::duration<Rep2, Period2>& rhs);	(3)	(since C++11)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator<=(const std::chrono::duration<Rep1, Period1>& lhs,                           const std::chrono::duration<Rep2, Period2>& rhs);	(4)	(since C++11)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator>(const std::chrono::duration<Rep1, Period1>& lhs,                          const std::chrono::duration<Rep2, Period2>& rhs);	(5)	(since C++11)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator>=(const std::chrono::duration<Rep1, Period1>& lhs,                           const std::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>> constexpr auto operator<=>(const std::chrono::duration<Rep1, Period1>& lhs,                            const std::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()
{
    if(std::chrono::seconds(2) == std::chrono::milliseconds(2000))
        std::cout <<  "2 s == 2000 ms\n";
    else
        std::cout <<  "2 s != 2000 ms\n";
 
    if(std::chrono::seconds(61) > std::chrono::minutes(1))
        std::cout <<  "61 s > 1 min\n";
    else
        std::cout <<  "61 s <= 1 min\n";
 
 
    using namespace 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:

2 s == 2000 ms
61 s > 1 min