operators (std::chrono::duration)

template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(1)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(2)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator<(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(3)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(4)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator>(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(5)
template <class Rep1, class Period1, class Rep2, class Period2> constexpr bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);	(6)

Compares two durations.

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.

Parameters

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

Return value

Assuming that CT = std::common_type<std::chrono::duration<Rep1, Period1>, std::chrono::duration<Rep2, Period2>>::type, then:

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).

Example

#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";
 
}

Output:

2 s == 2000 ms
61 s > 1 min

Links:

http://en.cppreference.com/w/cpp/chrono/duration/operator_cmp

doc_CPP

2016-10-11 09:59:32

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