std::chrono::year_month_day_last::year_month_day_last(3)

NAME
std::chrono::year_month_day_last::year_month_day_last - std::chrono::year_month_day_last::year_month_day_last

Synopsis
   constexpr year_month_day_last( const std::chrono::year& y,
                        const std::chrono::month_day_last& mdl (since C++20)
   ) noexcept;
   Constructs a year_month_day_last object storing the year y and the month
   mdl.month(). The constructed object represents the last day of that year and month.

Notes
   A year_month_day_last can also be created by combining a std::chrono::year_month
   with std::chrono::last using operator/.

Example
// Run this code
 #include <chrono>
 #include <iostream>
 int main()
 {
     std::cout << "All last days of months of a given year:\n";
     constexpr std::chrono::year year{2021};
     for (int i{1}; i <= 12; ++i)
     {
         const std::chrono::month_day_last mdl{std::chrono::month(i) / std::chrono::last};
         const std::chrono::year_month_day_last ymdl{year, mdl};
         std::cout << ymdl << " day: " << ymdl.day() << '\n';
     }
 }

Possible output:
 All last days of months of a given year:
 2021/Jan/last day: 31
 2021/Feb/last day: 28
 2021/Mar/last day: 31
 2021/Apr/last day: 30
 2021/May/last day: 31
 2021/Jun/last day: 30
 2021/Jul/last day: 31
 2021/Aug/last day: 31
 2021/Sep/last day: 30
 2021/Oct/last day: 31
 2021/Nov/last day: 30
 2021/Dec/last day: 31

See also
   operator/ conventional syntax for Gregorian calendar date creation
   (C++20) (function)