间接修改指针的地址
代码：
// test for a pointer.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
using namespace std;
typedef struct
{
int *p;
}Test;
int main( )
{
int *p;
// p[0] = 4;
// p[1] = 3;
Test test;
p = (int *)&test;
p[0] = 1;
cout << "p[0] = " << p[0] << endl;
cout << "test.i = " << test.p << endl;
return 0;
}