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

From cppreference.com
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.

[edit] Parameters

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

[edit] 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)

[edit] 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