# std::chrono::duration<Rep,Period>::zero

From cppreference.com
< cpp‎ | chrono‎ | duration

static constexpr duration zero(); |  | (until C++20)
static constexpr duration zero() noexcept; |  | (since C++20)

Returns a zero-length duration.

If the representation `rep` of the duration requires some other implementation to return a zero-length duration, std::chrono::duration_values can be specialized to return the desired value.

### Parameters

(none)

### Return value

returns duration(std::chrono::duration_values<rep>::zero())

### Example

Run this code

    #include <chrono>
    #include <ratio>
    int main() {
        static_assert((std::chrono::hours::zero() == std::chrono::nanoseconds::zero()) &&
                      (std::chrono::duration<short, std::nano>::zero() ==
                       std::chrono::duration<int, std::deci>::zero()) &&
                      (std::chrono::duration<short, std::deca>::zero() ==
                       std::chrono::duration<long, std::exa>::zero()) &&
                      (std::chrono::duration<long, std::atto>::zero().count() ==
                       std::chrono::duration<float, std::exa>::zero().count()));
    }

### See also

min [static] | returns the special duration value min (public static member function)
max [static] | returns the special duration value max (public static member function)

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