std::literals::chrono_literals::operator""us (3) - Linux Manuals

std::literals::chrono_literals::operator""us: std::literals::chrono_literals::operator""us


std::literals::chrono_literals::operator""us - std::literals::chrono_literals::operator""us


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

Forms a std::chrono::duration literal representing microseconds.
1) integer literal, returns exactly std::chrono::microseconds(us)
2) floating-point literal, returns a floating-point duration equivalent to std::chrono::microseconds


us - the number of microseconds

Return value

The std::chrono::duration literal.

Possible implementation

  constexpr std::chrono::microseconds operator ""us(unsigned long long us)
      return std::chrono::microseconds(us);
  constexpr std::chrono::duration<long double, std::micro> operator ""us(long double us)
      return std::chrono::duration<long double, std::micro>(us);


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 = 250us;
      std::chrono::microseconds d2 = 1ms;
      std::cout << "250us = " << d1.count() << " microseconds\n"
                << "1ms = " << d2.count() << " microseconds\n";


  250us = 250 microseconds
  1ms = 1000 microseconds

See also

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