std::chrono::weekday_indexed - cppreference.com

From cppreference.com


`class weekday_indexed;`		(since C++20)

The class weekday_indexed combines a weekday, representing a day of the week in the proleptic Gregorian calendar, with a small index n in the range [1, 5]. It represents the first, second, third, fourth, or fifth weekday of some month.

weekday_indexed is a TriviallyCopyable StandardLayoutType.

Member functions

Nonmember functions

Helper classes

Example

#include <chrono>
#include <iostream>

int main()
{
    using namespace std::chrono;
    
    constexpr weekday_indexed wi = Friday[2];
    
    // Indexed weekday can be used at any place where chrono::day can be used:
    constexpr year_month_weekday ymwd = 2021y / August / wi;
    static_assert(ymwd == August / wi / 2021y &&
                  ymwd == wi / August / 2021y);
    std::cout << ymwd << '\n';
    
    constexpr year_month_day ymd{ymwd}; // a conversion
    static_assert(ymd == 2021y / 8 / 13);
    std::cout << ymd << '\n';
}

Possible output:

2021/Aug/Fri[2]
2021-08-13