C++ 对象的内存布局

 1 class Parent {
 2 public:
 3     LL iparent;
 4     Parent ():iparent (10) {}
 5     virtual void f() { cout << " 1 " << endl; }
 6     virtual void g() { cout << " 2 " << endl; }
 7     virtual void h() { cout << " 3 " << endl; }
 8  
 9 };
10  
11 class Child : public Parent {
12 public:
13     LL ichild;
14     Child():ichild(100) {}
15     virtual void f() { cout << " 11 " << endl; }
16     virtual void g_child() { cout << " 4 " << endl; }
17     virtual void h_child() { cout << " 5 " << endl; }
18 };
19  
20 class GrandChild : public Child{
21 public:
22     LL igrandchild;
23     GrandChild():igrandchild(1000) {}
24     virtual void f() { cout << " 111 " << endl; }
25     virtual void g_child() { cout << " 44 " << endl; }
26     virtual void h_grandchild() { cout << " 6 " << endl; }
27 };
28 int main(void)
29 {
30     typedef void(*Fun)(void);
31     GrandChild gc;
32  
33     LL** pVtab = (LL**)&gc;
34     Fun pFun=NULL;
35 
36     cout << "[0] GrandChild::_vptr->" << endl;
37     for (int i=0; i<6; i++){
38         pFun = (Fun)pVtab[0][i];
39         cout << "    ["<<i<<"] ";
40         pFun();
41     }
42     LL *p=(LL*)&gc;
43     cout << "[1] Parent.iparent = " <<*(p+1)<< endl;
44     cout << "[2] Child.ichild = " << *(p+2)<< endl;
45     cout << "[3] GrandChild.igrandchild = " << *(p+3)<< endl;
46     
47     cout<<"对象gc的大小："<<sizeof(gc)<<endl;    
48  
49     return 0;
50 }