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

 

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std::chrono::year_month

成员函数

year_month::year_month

year_month::yearyear_month::month

year_month::operator+=year_month::operator-=

year_month::ok

非成员函数

operator==operator<=>

operator+operator-

operator<<

from_stream

辅助类

formatter<std::chrono::year_month>

hash<std::chrono::year_month> (C++26)

 

在标头 <chrono> 定义
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)

比较两个 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 <chrono>
#include <iostream>
 
int main()
{
    using namespace std::chrono;
 
    constexpr year_month ym1{year(2021), month(7)};
    constexpr year_month ym2{year(2021)/7};
    static_assert(ym1 == ym2);
    std::cout << ym1 << '\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：

2021/Jul