Friends

friend class-name;

friend function-declarator;

In some circumstances, it is more convenient to grant member-level access to functions that are not members of a class or to all functions in a separate class. The friend keyword allows a function or class to gain access to the private and protected members of a class. You can declare friend functions or friend classes to access not only public members but also protected and private class members.

See Also

Friend Declarations, Defining Friend Functions in Class Declarations