< cpp‎ | chrono
Defined in header <chrono>
constexpr std::chrono::milliseconds operator "" ms(unsigned long long ms);
(1) (since C++14)
constexpr std::chrono::duration</*unspecified*/,
                           std::milli> operator "" ms(long double ms);
(2) (since C++14)

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

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


[edit] Parameters

ms - the number of milliseconds

[edit] Return value

The std::chrono::duration literal.

[edit] Possible implementation

constexpr std::chrono::milliseconds operator ""ms(unsigned long long ms)
    return chrono::milliseconds(ms);
constexpr std::chrono::duration<long double, std::milli> operator ""ms(long double ms)
    return std::chrono::duration<long double, std::milli>(ms);

[edit] Notes

These operators are declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces. Access to these operators can be gained with using namespace std::literals, using namespace std::chrono_literals, and 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 duration classes, the duration literal operators become visible as well.

[edit] Example

#include <iostream>
#include <chrono>
int main()
    using namespace std::chrono_literals;
    auto d1 = 250ms;
    std::chrono::milliseconds d2 = 1s;
    std::cout << "250ms = " << d1.count() << " milliseconds\n"
              << "1s = " << d2.count() << " milliseconds\n";


250ms = 250 milliseconds
1s = 1000 milliseconds

[edit] See also

constructs new duration
(public member function of std::chrono::duration)