std::chrono::duration<Rep,Period>::operator+(unary),std::chrono::duration<Rep,Period>::operator-(unary) (3) - Linux Manuals

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

NAME

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

Synopsis

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

Implements unary plus and unary minus for the durations.
If rep_ is a member variable holding the number of ticks in a duration object, and D is the return type,
1) Equivalent to return D(*this);
2) Equivalent to return D(-rep_);

Parameters

(none)

Return value

1) a copy of this duration object
2) a copy of this duration object, with the number of ticks negated

Example

// Run this code

  #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";
  }

Output:

  negated 10 seconds are -10 seconds