Question

Possible Duplicate:
How to overload unary minus operator in C++?

I have a class C that overloads a number of operators:

class C
{
  ...
  C& operator-=(const C& other) {...}
  const C operator-(const C& other) {...}
}
inline const C operator*(const double& lhs, const C& rhs)

Now I wanted to invert an object of type C

c = -c;

And gcc gives me the following error:

no match for >>operator-<< in >>-d<<
candidate is: const C C::operator-(const C&)

Using c = -1*c works, but I’d like to be able to shorten that. What’s missing in my class?

---

Solved: added the unary operator-:

C operator-() const {...}

as a member of C.

Answer 1

You overloaded the binary – operator. What you also need is to overload the unary – operator

See

How to overload unary minus operator in C++?

for how to overload the unary – operator