关于vs下多态虚表中存储的地址和实际成员函数地址不一样的原因

以如下代码为例：

class Base1

{

public:

        virtual void func1() { cout << "Base1::func1" << endl; }

        virtual void func2() { cout << "Base1::func2" << endl; }

private:

        int b1;

};

class Base2

{

public:

        virtual void func1() { cout << "Base2::func1" << endl; }

        virtual void func2() { cout << "Base2::func2" << endl; }

private:

               int b2;

};

class Derive : public Base1, public Base2

{

public:

        virtual void func1() { cout << "Derive::func1" << endl; }

        virtual void func3() { cout << "Derive::func3" << endl; }

private:

        int d1;

};

typedef void (*func)();

void print(func a[])

{

        for (size_t i = 0; a[i] != nullptr; ++i)

        {

               printf("[%d]:%p\n", i, a[i]);

               a[i]();

        }

}

int main()

{

        Derive d;

        func* v1 = (func*)(*(int*)&d);

        PrintVTable(v1);

        func* v2 = (func*)*(int*)((char*)&d + sizeof(Base1));

         //&d得到的是Derive*类型的，+1会跳过sizeof(Derive)个字节，所以&d要强转为char*类型，