Defined in header <chrono>
constexpr chrono::minutes operator ""min( unsigned long long mins );
(1) (since C++14)
constexpr chrono::duration</*unspecified*/, ratio<60,1>>
                          operator ""min( long double mins );
(2) (since C++14)

Forms a std::chrono::duration literal representing minutes.

1) integer literal, returns exactly std::chrono::minutes(mins)
2) floating-point literal, returns a floating-point duration equivalent to std::chrono::minutes


mins - the number of minutes

Return value

The std::chrono::duration literal.

Possible implementation

constexpr std::chrono::minutes operator ""min(unsigned long long m)
    return std::chrono::minutes(m);
constexpr std::chrono::duration<long double,
                                std::ratio<60,1>> operator ""min(long double m)
    return std::chrono::duration<long double, ratio<60,1>> (m);


This operator is declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces. Access to this operator can be gained with:

  • using namespace std::literals,
  • using namespace std::chrono_literals, or
  • using namespace std::literals::chrono_literals.

In addition, within the namespace std::chrono, the directive using namespace literals::chrono_literals; is provided by the standard library, so that if a programmer uses using namespace std::chrono; to gain access to the classes in the chrono library, the corresponding literal operators become visible as well.


#include <iostream>
#include <chrono>
int main()
    using namespace std::chrono_literals;
    auto lesson = 45min;
    auto halfmin = 0.5min;
    std::cout << "one lesson is " << lesson.count() << " minutes\n"
              << "half a minute is " << halfmin.count() << " minutes\n";


one lesson is 45 minutes
half a minute is 0.5 minutes

See also

constructs new duration
(public member function of std::chrono::duration<Rep,Period>)

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