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

std::literals::chrono_literals::operator""s: std::literals::chrono_literals::operator""s

NAME

std::literals::chrono_literals::operator""s - std::literals::chrono_literals::operator""s

Synopsis

Defined in header <chrono>
constexpr chrono::seconds operator "" s(unsigned long long secs); (1) (since C++14)
constexpr chrono::duration</*unspecified*/> operator "" s(long double secs); (2) (since C++14)

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

Parameters

secs - the number of seconds

Return value

The std::chrono::duration literal.

Possible implementation

  constexpr std::chrono::seconds operator ""s(unsigned long long s)
  {
      return std::chrono::seconds(s);
  }
  constexpr std::chrono::duration<long double> operator ""s(long double s)
  {
      return std::chrono::duration<long double>(s);
  }

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.
std::string also defines operator""s, to represent literal objects of type std::string, but it is a string literal: 10s is ten seconds, but "10"s is a two-character string.

Example

// Run this code

  #include <iostream>
  #include <chrono>

  int main()
  {
      using namespace std::chrono_literals;
      auto halfmin = 30s;
      std::cout << "half a minute is " << halfmin.count() << " seconds\n"
                << "a minute and a second is " << (1min + 1s).count() << " seconds\n";
  }

Output:

  half a minute is 30 seconds
  a minute and a second is 61 seconds