The Actor Class

    enum Role { Person = 0 , Student, Employer, Final };
    
    class actor {                      
 defines the repertoire


    public:
    
    actor() {  } 
    
    virtual	void walk()  { if (exists()) self()->walk();  }
    virtual	void talk()  { if (exists()) self()->talk();  } 
    virtual	void think() { if (exists()) self()->think(); }
    virtual void act()   { if (exists()) self()->act();   }
    
    virtual void become(Role) { }               
 only for a person


    virtual void become(actor*) { }
    
    virtual actor* self() { return this; }         
 an empty self


    int exists() { return self() != this; }         
 who ami


    };