not_sure_if_this_is_visitor.cpp

class A : class Base {
public:
	void doSomething(Visitor& v) {
		v.visit(this);
	}	
};

class B : class Base {
public:
	void doSomething(Visitor& v) {
		v.visit(this);
	}
};

// Visitors hierarchy
class Visitor {
public:
	virtual void visit(A* a) = 0;
	virtual void visit(B* b) = 0;
};

class Visitor1 : public Visitor {
public:
	void visit(A* a) {
		cout << "behavior of A + Visitor1" << endl;	
	}

	void visit(B* b) {
		cout << "behavior of B + Visitor1" << endl;
	}
};

class Visitor2 : public Visitor {
public:
	void visit(A* a) {
		cout << "behavior of A + Visitor2" << endl;	
	}

	void visit(B* b) {
		cout << "behavior of B + Visitor2" << endl;
	}
};


// ------------------------------------------------
// client code

Visitor1 v1;
Visitor1 v2;
A a;
B b;

a.doSomething(v1);
b.doSomething(v1);
a.doSomething(v2);
b.doSomething(v2);


// ------------------------------------------------