std::chrono::last_spec

 

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Defined in header <chrono>
struct last_spec {     explicit last_spec() = default; };		(since C++20)
inline constexpr last_spec last{};		(since C++20)

last_spec is an empty tag type that is used in conjunction with other calendar types to indicate the last thing in a sequence. Depending on context, it may indicate the last day of a month (as in 2018y/February/last, for last day of February 2018, i.e., 2018-02-28) or the last day of the week in a month (as in 2018/February/Sunday[last], for last Sunday of February 2018, i.e., 2018-02-25).

Example

Run this code

#include <iostream>
#include <chrono>
 
int main()
{
    std::cout << std::boolalpha;
 
    constexpr auto mdl {std::chrono::June/std::chrono::last};
    std::cout << (mdl == std::chrono::month_day_last(std::chrono::month(6))) << ' ';
 
    constexpr auto ymwdl {std::chrono::year(2023)/
                          std::chrono::December/
                          std::chrono::Tuesday[std::chrono::last]
                         };
    std::cout << (ymwdl == std::chrono::year_month_weekday_last(
                           std::chrono::year(2023), 
                           std::chrono::month(12),
                           std::chrono::weekday_last(std::chrono::Tuesday))
                           ) << '\n';
}

Output:

true true