Std::literals::chrono_literals::operator""ms (3) Linux Manual Page

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

Synopsis

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

Parameters

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);
  }

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

Example

// 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";
}

Output:

250ms = 250 milliseconds
1s = 1000 milliseconds

std::literals::chrono_literals::operator””ms (3) Linux Manual Page