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

From cppreference.com
< cpp‎ | 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

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";

    }

Output:

    2 s == 2000 ms
    61 s > 1 min

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/duration/operator_cmp&oldid=49375"