12.3. protected Members

Chapter 3 introduced access specifiers public and private. A base class’s public members are accessible within its body and anywhere that the program has a handle (i.e., a name, reference or pointer) to an object of that class or one of its derived classes. A base class’s private members are accessible only within its body and to the friends of that base class. In this section, we introduce the access specifier protected.

Using protected access offers an intermediate level of protection between public and private access. A base class’s protected members can be accessed within the body of that base class, by members and friends of that base class, and by members and friends of any classes derived from that base class.