std::chrono::abs(std::chrono::duration)(3)

NAME
std::chrono::abs(std::chrono::duration) - std::chrono::abs(std::chrono::duration)

Synopsis
   Defined in header <chrono>
   template< class Rep, class Period >
   constexpr std::chrono::duration<Rep, Period> abs( (since C++17)
   std::chrono::duration<Rep, Period> d );
   Returns the absolute value of the duration d. Specifically, if d >= d.zero(), return
   d, otherwise return -d.
   The function does not participate in the overload resolution unless
   std::numeric_limits<Rep>::is_signed is true.

Parameters
   d - duration

Return value
   Absolute value of d.

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

Example
// Run this code
 #include <chrono>
 #include <iostream>
 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';
 }

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

See also
   operator+ implements unary + and unary -
   operator- (public member function)
   abs(int)
   labs computes absolute value of an integral value (\(\small{|x|}\)|x|)
   llabs (function)
   (C++11)