1 overload a operator of a class, you can only use one para., this pointer is automatically used.
class Rational
{
public:
//not correct since this ponit would be used automatically.
//Rational operator+ (const Rational& lhs, const Rational& rhs);
//correct
Rational operator+ (const Rational& rhs);
}
2 outside the class two para are allowed
Rational operator+(const Rational& lhs, const Rational& rhs))