std::chrono::operator==,<=>(std::chrono::year_month_day)
Defined in header <chrono> |
||
|---|---|---|
constexpr bool operator==( const std::chrono::year_month_day& x,
const std::chrono::year_month_day& y ) noexcept; |
(1) | (since C++20) |
constexpr std::strong_ordering
operator<=>( const std::chrono::year_month_day& x,
const std::chrono::year_month_day& y ) noexcept; |
(2) | (since C++20) |
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
1)
x.year() == y.year() && x.month() == y.month() && x.day() == y.day()
2) If
x.year() <=> y.year != 0,
x.year() <=> y.year; otherwise if
x.month() <=> y.month() != 0,
x.month() <=> y.month(); otherwise
x.day() <=> y.day()
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);
}
Output:
true
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