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

constexpr bool operator==( const std::chrono::year_month_day& x,
                           const std::chrono::year_month_day& y ) noexcept;

constexpr std::strong_ordering
    operator<=>( const std::chrono::year_month_day& x,
                 const std::chrono::year_month_day& y ) noexcept;

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

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

Return value

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

#include <iostream>
#include <chrono>
 
int main()
{
    constexpr auto ymd1 {std::chrono::day(1)/7/2021};
    constexpr auto ymd2 {std::chrono::year(2021)/7/1};
    std::cout << std::boolalpha << (ymd1 == ymd2) << '\n';
 
    static_assert(ymd1 <= ymd2);
}

true