private inheritance

Question

I dont completely understand this:

class Base
{
    public:
    Base()
    {
        cout<<\"Base\" << endl;
    }

    virtual void call()
    {         


        

Answer 1

Because private means "implementation detail", which makes the fact that Derived derives from Base an implementation detail.

Private inheritance is not interface inheritance, but implementation inheritance. It doesn't implement an "Is-A" relationship, but an "Is-Implemented-Using" relationship. Derived isn't a Base as far as users of the classes are concerned, it just happens to (currently) be implemented using it.