Process.cpp

#include "Process.hpp"

Process::Process() {

}

Process::~Process() {

}

void Process::execute() {
	this->init();
}

Process.hpp

#ifndef PROCESS_HPP_
#define PROCESS_HPP_

class Process {
public:
	Process();
	virtual ~Process();
	void execute();
	virtual void init() = 0;
};

#endif /* PROCESS_HPP_ */

Screen.cpp

#include <iostream>

#include "Screen.hpp"

Screen::Screen() {
	Screen(320);
}

Screen::Screen(unsigned int w) : width(w) {
	std::cout << "Screen(): " << this->width << std::endl;
}

Screen::~Screen() {

}

void Screen::init() {
	std::cout << "Screen::init(): " << this->width << std::endl;
}

Screen.hpp

#ifndef SCREEN_HPP_
#define SCREEN_HPP_

#include "Process.hpp"

class Screen : public Process {
public:
	Screen();
	Screen(unsigned int);
	virtual ~Screen();
	void init();

	unsigned int width;
};

#endif /* SCREEN_HPP_ */

System.cpp

#include <iostream>

#include "System.hpp"

System::System() {
	std::cout << "System(): " << this->s.width << std::endl;
}

System::~System() {

}

void System::init() {
	std::cout << "System::init(): " << this->s.width << std::endl;
	this->s.execute();
}

int main(int argc, char **argv) {
	System s;
	s.execute();
	return 0;
}

System.hpp

#ifndef SYSTEM_HPP_
#define SYSTEM_HPP_

#include "Process.hpp"
#include "Screen.hpp"

class System : public Process {
public:
	System();
	virtual ~System();
	void init();

	Screen s;
};

#endif /* SYSTEM_HPP_ */