[C++] 虚指针，虚表，虚函数地址打印

#include <iostream>using namespace std;class Base{public :int base_data;Base() { base_data = 1; }virtual void func1() { cout << "base_func1" << endl; }virtual void func2() { cout << "base_func2" << endl; }virtual void func3() { cout << "base_func3" << endl; }};class Derive : public Base{public :int derive_data;Derive() { derive_data = 2; }virtual void func1() { cout << "derive_func1" << endl; }virtual void func2() { cout << "derive_func2" << endl; }};typedef void (*func)();int main(){Base base;cout << "&base: " << &base << endl;cout << "&base.base_data: " << &base.base_data << endl;cout << "----------------------------------------" << endl;Derive derive;cout << "&derive: " << &derive << endl;cout << "&derive.base_data: " << &derive.base_data << endl;cout << "&derive.derive_data: " << &derive.derive_data << endl;cout << "----------------------------------------" << endl;for(int i=0; i<3; i++){// &base : base首地址// (unsigned long*)&base : base的首地址，vptr的地址// (*(unsigned long*)&base) : vptr的内容，即vtable的地址，指向第一个虚函数的slot的地址// (unsigned long*)(*(unsigned long*)&base) : vtable的地址，指向第一个虚函数的slot的地址// vtbl : 指向虚函数slot的地址// *vtbl : 虚函数的地址unsigned long* vtbl = (unsigned long*)(*(unsigned long*)&base) + i;cout << "slot address: " << vtbl << endl;cout << "func address: " << *vtbl << endl;func pfunc = (func)*(vtbl);pfunc();}cout << "----------------------------------------" << endl;for(i=0; i<3; i++){unsigned long* vtbl = (unsigned long*)(*(unsigned long*)&derive) + i;cout << "slot address: " << vtbl << endl;cout << "func address: " << *vtbl << endl;func pfunc = (func)*(vtbl);pfunc();}cout << "----------------------------------------" << endl;return 1;}