[面经] 访问C++虚函数表

#include <cstdio>

class A
{
public:
virtual void a(void)
{
printf("A:a(%p)\n", this);
}

private:
virtual void b(void)
{
printf("A:b(%p)\n", this);
}
};

class B : public A
{
public:
virtual void c(void)
{
printf("B:c(%p)\n", this);
}

private:
virtual void d(void)
{
printf("B:d(%p)\n", this);
}
};

class C : public B
{
public:
virtual void e(void)
{
printf("C:e(%p)\n", this);
}

private:
virtual void f(void)
{
printf("C:f(%p)\n", this);
}
};

int main(void)
{
A a;
B b;
C c;
// void ***ppp_avf = (void ***)&a;
void ***ppp_bvf = (void ***)&b;
void ***ppp_cvf = (void ***)&c;

printf("a, b, c: %p, %p, %p\n", &a, &b, &c);

// for (int i = 0; NULL != (*ppp_avf)[i]; ++i) {
//     ((void (*)(void))(*ppp_avf)[i])();
// }
// printf("\n");

for (int i = 0; NULL != (*ppp_bvf)[i]; ++i) {
((void (*)(void *))(*ppp_bvf)[i])(&b);
}
printf("\n");

for (int i = 0; NULL != (*ppp_cvf)[i]; ++i) {
((void (*)(void *))(*ppp_cvf)[i])(&c);
}
printf("\n");

return 0;
}