NAME¶

std::literals::chrono_literals::operator""d - std::literals::chrono_literals::operator""d

Synopsis¶

Defined in header <chrono>
constexpr std::chrono::day operator ""d( unsigned long long d ) (since C++20)
noexcept;

Forms a std::chrono::day literal representing a day of the month in the calendar.

Parameters¶

d - the day value

Return value¶

A std::chrono::day storing d. If d > 255, the stored value is unspecified.

Possible implementation¶

constexpr std::chrono::day operator ""d(unsigned long long d) noexcept
{
return std::chrono::day(d);
}

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.

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

See also¶

constructor constructs a day
(public member function of std::chrono::day)
operator unsigned retrieves the stored day value
(public member function of std::chrono::day)