1 Factory Method 工厂方法

class Abstract {
	virtual void DoSomething() = 0;
	virtual ~Abstract(){}
};

class AbstractFactory {
	virtual Abstract* CreateAbstract() = 0;
	virtual ~AbstractFactory(){}
};

class User {
private:
	AbstractFactory* m_AbstractFactory;
public:
	User(AbstractFactory* abstractFactory) : m_AbstractFactory(abstractFactory) {
		Abstract* abstract = m_AbstractFactory->CreateAbstract();
	}
};