operator==,!=,<,<=,>,>=(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 =, then:
 std::common_type<std::chrono::duration<Rep1, Period1>,
 std::chrono::duration<Rep2, Period2>>::type
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
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