std::chrono::duration<Rep,Period>::operator+(unary), std::chrono::duration<Rep,Period>::operator-(unary)

 

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std::chrono::duration

成员函数
duration::duration duration::operator= duration::count duration::zero duration::min duration::max duration::operator+duration::operator-	duration::operator++duration::operator-- duration::operator+=duration::operator-=duration::operator*=duration::operator/=duration::operator%=
非成员函数
operator+operator-operator*operator/operator% operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20 前)(C++20) operator<< (C++20)	duration_cast floor (C++17) ceil (C++17) round (C++17) abs (C++17) operator""h (C++14) operator""min (C++14) operator""s (C++14) operator""ms (C++14) operator""us (C++14) operator""ns (C++14) from_stream (C++20)
辅助类
common_type treat_as_floating_point      duration_values	formatter<std::chrono::duration> (C++20) hash<std::chrono::duration> (C++26)

 

	(1)
constexpr duration operator+() const;			(C++17 前)
constexpr std::common_type_t<duration> operator+() const;			(C++17 起)
		(2)
constexpr duration operator-() const;				(C++17 前)
constexpr std::common_type_t<duration> operator-() const;				(C++17 起)

实现 duration 的一元加和一元减。

若 rep_ 为 duration 对象中保有计次数的成员变量，而 D 是返回类型，则

1) 等价于 return D(*this);

2) 等价于 return D(-rep_);

参数

（无）

返回值

1) 此 duration 对象的副本

2) 此 duration 对象的副本，对其计次数取反

示例

运行此代码

#include <chrono>
#include <iostream>
 
int main()
{
    std::chrono::seconds s1(10);
    std::chrono::seconds s2 = -s1;
 
    std::cout << "negated 10 seconds are " << s2.count() << " seconds\n";
}

输出：

negated 10 seconds are -10 seconds

参阅

operator++operator++(int)operator--operator--(int)	递增或递减滴答计数 (公开成员函数)
operator+operator-operator*operator/operator% (C++11)	实现以时长为实参的算术运算 (函数模板)