Namespaces
Variants

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

From cppreference.net
< cpp ‎ | chrono ‎ | day
C++
Date and time library
std::chrono::day
헤더 파일에 정의됨 <chrono>
constexpr bool operator == ( const std:: chrono :: day & x,
const std:: chrono :: day & y ) noexcept ;
(1) (C++20부터)
constexpr std:: strong_ordering operator <=> ( const std:: chrono :: day & x,
const std:: chrono :: day & y ) noexcept ;
(2) (C++20부터)

두 std::chrono::day x 와 y 를 비교합니다.

< , <= , > , >= , 그리고 != 연산자들은 각각 합성됩니다 operator <=> 와 operator == 로부터.

반환값

1) unsigned ( x ) == unsigned ( y )
2) unsigned ( x ) <=> unsigned ( y )

예제

이 코드 실행 
#include <chrono>
#include <iostream>
int main()
{
    constexpr std::chrono::day x{13}, y{31};
    static_assert(x != y);
    if constexpr (constexpr auto res = x <=> y; res < 0)
        std::cout << "x is less than y\n";
    else if constexpr (res > 0)
        std::cout << "x is greater than y\n";
    else
        std::cout << "x and y are equal\n";
    using namespace std::literals::chrono_literals;
    static_assert
    (
        (6d < 9d) && (6d == 6d) && (6d <= 9d) &&
        (9d > 6d) && (9d != 6d) && (9d >= 6d)
    );
}

출력: 

x is less than y