In summary, the effect of protected and private derivation is to elevate the effective status of member variables and member functions of the base class as viewed from the derived class:
The following table reflects the same points:
Public | Protected | Private\ | derivation | derivation | derivation\ Public member function | remains public | becomes protected | becomes private\ Protected member function | remains protected | remains protected | becomes private\ Private member function | remains private | remains private | remains private\ |