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

来自cppreference.com
< cpp‎ | chrono‎ | year month
 
 
工具库
通用工具
格式化库 (C++20)
(C++11)
关系运算符 (C++20 中弃用)
整数比较函数
(C++20)(C++20)(C++20)
(C++20)
swap 与类型运算
(C++14)
(C++11)
(C++11)
(C++11)
(C++17)
常用词汇类型
(C++11)
(C++17)
(C++17)
(C++17)
(C++11)
(C++17)

初等字符串转换
(C++17)
(C++17)
栈踪
 
 
 
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_monthxy

<<=>>=!= 运算符分别从 operator<=>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

#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