std::literals::chrono_literals::operator""d
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std::chrono::day
Member functions
Nonmember functions
operator""d
Helper classes
(C++26)
Defined in header
<chrono>
constexpr std::chrono::day operator ""d( unsigned long long d ) noexcept;
(since C++20)
Forms a std::chrono::day literal representing a day of the month in the calendar.
[edit] Parameters
d
-
the day value
[edit] Return value
A std::chrono::day storing d. If d > 255, the stored value is unspecified.
[edit] Possible implementation
constexpr std::chrono::day operator ""d(unsigned long long d) noexcept { return std::chrono::day (d); }
[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.
[edit] Example
Run this code
#include <chrono> #include <iostream> int main() { using namespace std::literals::chrono_literals; std::cout << static_cast<unsigned>(42d) << '\t' << 42d << '\n' << static_cast<unsigned>(256d) << '\t' << 256d << '\n' // unspecified << static_cast<unsigned>(298d) << '\t' << 298d << '\n'; // unspecified }
Possible output:
42 42 is not a valid day 0 00 is not a valid day 42 42 is not a valid day