多继承中多态的实现

#include <iostream>using namespace std;class A{private:virtual void Func1(){cout << "class A Func1" << endl;}virtual void Func2(){cout << "class A Func2" << endl;}};class B : public A{public:virtual void Func1(){cout << "class B Func1" << endl;}void Func2(){cout << "class B Func2" << endl;}virtual void Func3(){cout << "class B Func3" << endl;}};class C {public:virtual void Func1(){cout << "class C Func1" << endl;}virtual void Func3(){cout << "class C Func3" << endl;}virtual void Func4(){cout << "class C Func4" << endl;}};class D : public B, public C{public:virtual void Func1(){cout << "class D Func1" << endl;}virtual void Func5(){cout << "class D Func5" << endl;}};int* GetFuncAddr(void* p, int offer){int* v_ptrAdrs = *((int**)p);// void* pp = p;// __asm mov ecx, pp;return *((int**)v_ptrAdrs + offer);}typedef void (*gFUNC)();void AFunc1Helper(A *p){//直接调用虚函数(*(gFUNC)GetFuncAddr(p, 0))();}void AFunc2Helper(A *p){        (*(gFUNC)GetFuncAddr(p, 1))();}//B类中的虚表列表void BFunc1Helper(B *p){(*(gFUNC)GetFuncAddr(p, 0))();}void BFunc2Helper(B *p){(*(gFUNC)GetFuncAddr(p, 1))();}void BFunc3Helper(B *p){(*(gFUNC)GetFuncAddr(p, 2))();}void CFunc1Helper(C *p){(*(gFUNC)GetFuncAddr(p, 0))();}void CFunc4Helper(C *p){(*(gFUNC)GetFuncAddr(p, 1))();}//此处，D和B公用一个虚函数表，C单独使用一个虚函数表void DFunc1Helper(D *p){(*(gFUNC)GetFuncAddr(p, 0))();}void DFunc2Helper(D *p){(*(gFUNC)GetFuncAddr(p, 1))();}void DFunc3Helper(D *p){(*(gFUNC)GetFuncAddr(p, 2))();}void DFunc5Helper(D *p){(*(gFUNC)GetFuncAddr(p, 3))();}//C单独使用一个虚函数表void DCFunc1Helper(D *p){  //此处为第二个虚函数表int *ptr = (int*)p + 1;(*(gFUNC)GetFuncAddr(ptr, 0))();}void DCFunc3Helper(D *p){        int *ptr = (int*)p + 1;(*(gFUNC)GetFuncAddr(ptr, 1))();}void DCFunc4Helper(D *p){        int *ptr = (int*)p + 1;(*(gFUNC)GetFuncAddr(ptr, 2))();}int _tmain(int argc, _TCHAR* argv[]){C *pc = new C;D *pd = new D;A *pa = new D;//pa->Func1();AFunc1Helper(pa);//pa->Func2();AFunc2Helper(pa);//pc->Func1();CFunc1Helper(pc);//pc->Func4();CFunc4Helper(pc);cout << sizeof(D) << endl;pd->Func1();DFunc1Helper(pd);DFunc2Helper(pd);pd->C::Func3();DFunc3Helper(pd);DFunc5Helper(pd);DCFunc4Helper(pd);return 0;}