std::chrono::operator==,<=>(std::chrono::year_month)
来自cppreference.com
< cpp | chrono | year month
定义于头文件 <chrono>
|
||
constexpr bool operator==( const std::chrono::year_month& x, const std::chrono::year_month& y ) noexcept; |
(1) | (C++20 起) |
constexpr std::strong_ordering operator<=>( const std::chrono::year_month& x, const std::chrono::year_month& y ) noexcept; |
(2) | (C++20 起) |
比较二个 year_month
值 x
与 y
。
<
、 <=
、 >
、 >=
及 !=
运算符分别从 operator<=>
与 operator==
合成。
返回值
1) x.year() == y.year() && x.month() == y.month()
2) x.year() <=> y.year() != 0 ? x.year() <=> y.year() : x.month() <=> y.month()
示例
运行此代码
#include <iostream> #include <chrono> int main() { using namespace std::chrono; constexpr year_month ym1 {year(2021), month(7)}; constexpr year_month ym2 {year(2021)/7}; std::cout << std::boolalpha << (ym1 == ym2) << '\n'; static_assert( (2020y/1 < 2020y/2) && (2020y/2 == 2020y/2) && (2020y/3 <= 2021y/3) && (2023y/1 > 2020y/2) && (3020y/2 != 2020y/2) && (2020y/3 >= 2020y/3) ); }
输出:
true