std::chrono::operator==,<=>(std::chrono::year_month_day_last)

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std::chrono::year_month_day_last
 
Defined in header <chrono>
constexpr bool operator==( const std::chrono::year_month_day_last& x,
                           const std::chrono::year_month_day_last& y ) noexcept;
 (1) (since C++20)
constexpr std::strong_ordering

    operator<=>( const std::chrono::year_month_day_last& x,

                 const std::chrono::year_month_day_last& y ) noexcept;
 (2) (since C++20)

Compares the two year_month_day_last values x and y. This is a lexicographical comparison: the year() is compared first, then month().

The <, <=, >, >=, and != operators are synthesized from operator<=> and operator== respectively.

Return value

1) x.year() == y.year() && x.month() == y.month()
2) x.year() <=> y.year() != 0 ? x.year() <=> y.year() : x.month() <=> y.month()

Notes

If both x and y represent valid dates (x.ok() && y.ok() == true), the result of the lexicographical comparison is consistent with the calendar order.

Example

Run this code
#include <iostream>
#include <chrono>
 
int main()
{
    std::cout << std::boolalpha;
 
    auto ymdl1 {11/std::chrono::last/2020};
    auto mdl {std::chrono::last/std::chrono::November};
    auto ymdl2 {mdl/2020};
    std::cout << (ymdl1 == ymdl2) << ' ';
    ymdl1 -= std::chrono::months{2};
    ymdl2 -= std::chrono::months{1};
    std::cout << (ymdl1 < ymdl2) << '\n';
}

Output: 

true true
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