#include <iostream>
using namespace std;

class Base{
 public:
 	class iImplement{
 	 public:
 		virtual int func() = 0;
 	};

 	Base(iImplement *impl): impl(impl) {}

 	bool func2(){
 		return func() < 5;
 	}

 private:
 	iImplement *impl;

 	int func(){
 		return impl->func();
 	}
};

class Derived: public Base{
 public:
 	class DerivedImplement: public iImplement{
 	 public:
 		int func() final {
 			// sugoi syori
 			return 10;
 		}
 	};

 	Derived(iImplement *impl=new DerivedImplement()): Base(impl) {}
};

class TestSuite{
 public:
 	class TestImplement: public Base::iImplement{
 	 public:
 	 	int func_value;

 		int func() final {
 			// stub
 			return func_value;
 		}
 	};

 	TestSuite(): t(new TestImplement), d(t){}

 	void run_test(){
 		func2_test();
 	}
 private:
 	TestImplement *t;
	Derived d;

 	void func2_test(){
 		t->func_value = 10;
 		cout << d.func2() << endl;

 		t->func_value = 0;
 		cout << d.func2() << endl;
 	}
};

int main(){
	TestSuite test;
	test.run_test();

	return 0;
}