菱形继承+虚继承

菱形继承的概念：

两个派生类继承同一个基类；又有某个类同时继承两个派生类；这种继承被称为菱形继承，或者钻石继承

带来的问题：子类继承两份相同的数据，导致资源浪费。

虚继承：解决菱形继承带来的问题

class Animal
{
public:
	int m_Age;
};

//继承前加virtual关键字后，变为虚继承
//此时公共的父类Animal称为虚基类
class Sheep : virtual public Animal {};
class Tuo   : virtual public Animal {};
class SheepTuo : public Sheep, public Tuo {};

void test01()
{
	SheepTuo st;
	st.Sheep::m_Age = 100;
	st.Tuo::m_Age = 200;

	cout << "st.Sheep::m_Age = " << st.Sheep::m_Age << endl;
	cout << "st.Tuo::m_Age = " <<  st.Tuo::m_Age << endl;
	cout << "st.m_Age = " << st.m_Age << endl;
}


int main() {

	test01();

	system("pause");

	return 0;
}