std::literals::chrono_literals::operator""ms (3) - Linux Man Pages

std::literals::chrono_literals::operator""ms: std::literals::chrono_literals::operator""ms


std::literals::chrono_literals::operator""ms - std::literals::chrono_literals::operator""ms


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

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


ms - the number of milliseconds

Return value

The std::chrono::duration literal.

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);


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 classes in the chrono library, the corresponding literal operators become visible as well.


// Run this code

  #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

See also

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