Category 

C++-Specific Keywords 

Syntax  

protected: <declarations>

Description 

Access to protected class members is restricted to member functions within the class, member functions of derived classes, and to friend classes. 

Structure (struct) and union members are public by default. You can override the default access specifier for structures, but not for unions. 

Friend declarations can be placed anywhere in the class declaration; friends are not affected by access control specifiers.