std::chrono::year::is_leap

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< cpp‎ | chrono‎ | year
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std::chrono::year
constexpr bool is_leap( ) const noexcept ;
(since C++20)

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

*this represents a leap year if the stored year value

  • is divisible by 4 and not divisible by 100; or
  • is divisible by 400.

Return value

true if *this represents a leap year, otherwise false

Example

Run this code
#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";
    }
}

Output: 

2020 is a leap year because it is divisible by 4 and not divisible by 100
2021 is not a leap year
2000 is a leap year because it is divisible by 400
3000 is not a leap year
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