c++ 输入输出流关联

#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
using namespace std;
int main()
{

  cout << cin.tie()  << endl;  //打印cin的关联流的地址
  cout << &cout << endl;    //打印cout的地址
  cout << &cin << endl;      //打印地址
  cout << cout.tie() << endl;   //打印关联流地址

  cout <<"tie the cerr to cout " << endl;
  cout.tie(&cerr);            //把cerr关联到cout
  cout << cout.tie() << endl;    //打印cout的关联流，即打印cerr的地址
  cout << &cerr <<endl;