std::chrono::abs(std::chrono::duration)

 

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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)

 

定义于头文件 <chrono>
template <class Rep, class Period> constexpr std::chrono::duration<Rep, Period> abs( std::chrono::duration<Rep, Period> d );		(C++17 起)

返回时期 d 的绝对值。具体而言，若 d >= d.zero() ，则返回 d ，否则返回 -d 。

该函数不参与重载决议，除非 std::numeric_limits<Rep>::is_signed 为 true 。

参数

d

-

时期

返回值

d 的绝对值

可能的实现

template <class Rep, class Period, class = std::enable_if_t< std::chrono::duration<Rep, Period>::min() < std::chrono::duration<Rep, Period>::zero()>> constexpr std::chrono::duration<Rep, Period> abs(std::chrono::duration<Rep, Period> d) { return d >= d.zero() ? d : -d; }

示例

运行此代码

#include <iostream>
#include <chrono>
 
int main()
{
    using namespace std::chrono;
 
    static_assert(abs(-42s) == std::chrono::abs(42s));
 
    std::cout << "abs(+3min) = " << abs(3min).count() << '\n'
              << "abs(-3min) = " << abs(-3min).count() << '\n';
}

输出：

abs(+3min) = 3
abs(-3min) = 3

参阅

operator+operator-	实现一元 + 和一元 - (公开成员函数)
abs(int)labsllabs (C++11)	计算整数值的绝对值（ \(\small{|x|}\)|x| ） (函数)