In C++, describe the implications of using public, protected, and private inheritance.
In C++, inheritance access modifiers (public, protected, and private) determine the accessibility of base class members in derived classes. Public inheritance implies that public members remain public, protected members stay protected, and private members are inaccessible. Protected inheritance downgrades public members to protected status while keeping protected members unchanged; private members remain inaccessible. Private inheritance makes both public and protected members private, with private members still being inaccessible.
Public inheritance models “is-a” relationships, maintaining the original access levels for base class members. It is commonly used when implementing polymorphism and adhering to the Liskov Substitution Principle.
Protected inheritance is less common but can be useful when creating a new class that should only expose certain inherited functionality to its subclasses, not to external users.
Private inheritance models “has-a” or “implemented-in-terms-of” relationships, hiding all inherited members from external access. This approach is suitable when reusing code without exposing the base class interface, effectively treating the base class as an implementation detail.
