含有虛函數菱形的虛擬繼承(沒有對虛函數進行重寫)

含有虛函數菱形的虛擬繼承(沒有對虛函數進行重寫)

在VS2013編程，調試

問題 : 菱形繼承會引來，二義性

1.源代碼

#include 
using namespace std;

class Base


{
public:
	virtual void  FunTest()
	{
		cout << "Base::FunTest () " << endl;
	}
	virtual void  FunTest1()
	{
		cout << "Base::FunTest1 () " << endl;
	}
};

class C1 :virtual public Base
{
public:
	virtual void  FunTest2()
	{
		cout << "C1::FunTest2 () " << endl;
	}
};

class C2 :virtual public Base
{
public:
	virtual void  FunTest3()
	{
		cout << "C2::FunTest3 () " << endl;
	}
};

class Der : public C1, public C2
{
public:
	virtual void  FunTest4()
	{
		cout << "Der::FunTest4 () " << endl;
	}
	virtual void  FunTest5()
	{
		cout << "Der::FunTest5 () " << endl;
	}
	virtual void  FunTest6()
	{
		cout << "Der::FunTest6 () " << endl;
	}
};

typedef void(*vftab) ();

void Test()
{
	Der  d;
	cout << sizeof(d) << endl;
	cout << "-------C1---- " << endl;
	int *vfpt = (int *)(*(int *)&d);
	vftab vft = (vftab)(*(int *)vfpt);

	while (vft != 0)
	{
		vft();
		vfpt++;
		vft = (vftab)(*vfpt);
	}
	cout << endl;

	cout << "-------C2---- " << endl;
	vfpt = (int *)(*((int *)&d + 2));
	vft = (vftab)(*(int *)vfpt);

	while (vft != 0)
	{
		vft();
		vfpt++;
		vft = (vftab)(*vfpt);
	}
	cout << endl;

	cout << "-------Base---- " << endl;
	vfpt = (int *)(*((int *)&d + 4));
	vft = (vftab)(*(int *)vfpt);


	while (vft != 0)
	{
		vft();
		vfpt++;
		vft = (vftab)(*vfpt);
	}

}

int main()
{
	Test();

	getchar();
	return 0;
}