std::chrono::year::is_leap

Since C++20

Determines if *this represents a leap year in the proleptic Gregorian calendar.

# Declarations

constexpr bool is_leap() const noexcept;

(since C++20)

# Return value

true if *this represents a leap year, otherwise false.

# Example

#include <chrono>
#include <iostream>
 
int main()
{
    using namespace std::chrono_literals;
    for (const std::chrono::year y : {2020y, 2021y, 2000y, 3000y})
    {
        if (const int iy{static_cast<int>(y)}; y.is_leap())
            std::cout << iy << " is a leap year because it is divisible by "
                      << (iy % 400 == 0 ? "400\n" : "4 and not divisible by 100\n");
        else
            std::cout << iy << " is not a leap year\n";
    }
}