std::literals::chrono_literals::operator""s
<chrono>
operator""s( unsigned long long secs );
operator""s( long double secs );
Forms a std::chrono::duration literal representing seconds.
[edit] Parameters
[edit] Return value
The std::chrono::duration literal.
[edit] 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); }
[edit] Notes
This operator is declared in the namespace std::literals::chrono_literals, where both literals and chrono_literals are inline namespaces. Access to this operator can be gained with:
- using namespace std::literals,
- using namespace std::chrono_literals, or
- 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.
[edit] Example
#include <chrono> #include <iostream> int main() { using namespace std::chrono_literals; std::chrono::seconds halfmin = 30s; std::cout << "Half a minute is " << halfmin.count() << " seconds" " (" << halfmin << ").\n" "A minute and a second is " << (1min + 1s).count() << " seconds.\n"; std::chrono::duration moment = 0.1s; std::cout << "A moment is " << moment.count() << " seconds" " (" << moment << ").\n" "And thrice as much is " << (moment + 0.2s).count() << " seconds.\n"; }
Output:
Half a minute is 30 seconds (30s). A minute and a second is 61 seconds. A moment is 0.1 seconds (0.1s). And thrice as much is 0.3 seconds.