Question

Taken from here: http://www.cplusplus.com/doc/tutorial/inheritance/

What is inherited from the base class?
In principle, a derived class inherits every member of a base class except:

its constructor and its destructor
its operator=() members
its friends

My question is, what are operator=() members?

Answer 1

You can define any kind of operator=(). Even very useless ones. But non of them will be inherited to the child class. From your link site I changed the example a little to make it more clear. This example won’t compile because of the mentioned errors.

class mother {
public:
    mother ()
    { cout << "mother: no parameters\n"; }
    explicit mother (int a):m_int(a)
    { cout << "mother: int parameter\n"; }

    mother& operator=(mother const& rhs)
    {
        if(&rhs != this)
        {
            m_int = rhs.m_int;
        }
        return *this;
    }

    mother& operator=(int i)
    {
        m_int = i;
        return *this;
    }
private:
    int m_int;
};

class son : public mother {
public:
    explicit  son (int a) : mother (a)
    { cout << "son: int parameter\n\n"; }
};
int main()
{
    mother mom(2);
    son daniel(0);
    mom = 3;
    daniel = 4; // compile error
    daniel = mom; // also error
}