C++ Primer Plus, Fourth Edition

Member Dereferencing Operators

C++ lets you define pointers to members of a class. These pointers involve special notations to declare them and to dereference them. To see what's involved, let's start with a sample class:

class Example
{
private:
    int feet;
    int inches;
public:
    Example();
    Example(int ft);
    ~Example();
    void show_in() const;
    void show_ft() const;
    void use_ptr() const;
} ;

Consider the inches member. Without a specific object, inches is a label. That is, the class defines inches as a member identifier, but you need an object before you actually have memory allocated:

Example ob;  // now ob.inches exists

Thus, you specify an actual memory location by using the identifier inches in conjunction with a specific object. (In a member ...