#include <string>
#include <iostream>


class SceneGraph;

class Entity {
  public:
	virtual void deleteE(SceneGraph* e);
};

using namespace std;

class Entity;

class SceneGraph {
  public:
	void deleteE(Entity* e);
	void print(string s);
};

class SpecialEntity: public Entity {
  public:
	virtual void deleteE(SceneGraph* e);
};

void Entity::deleteE(SceneGraph* graph) {
	graph->print("entity::delete()");
}



void SceneGraph::deleteE(Entity* e) {
	e->deleteE(this);
}

void SceneGraph::print(string s) {
	cout << s << "\n";
}



void SpecialEntity::deleteE(SceneGraph* graph) {
	graph->print("SpecialEntity::delete()");
}


int main() {
	Entity e;
	SpecialEntity f;
	SceneGraph* graph = new SceneGraph();

	graph->deleteE(&e);
	graph->deleteE(&f);
}