c++primer 2.5 const 有感想

 

#include<iostream>

using namespace std;

int main()
{
 //example 1
 int i = 123;
 int & cpy1_i = i, &cpy2_i = cpy1_i;
 cpy2_i = 321;
 cout <<"After changing the reference number i is " << i << endl;
 cout << "The addrs are : " << &i <<" " << &cpy1_i <<  " " << &cpy2_i << endl;

 //example 2
 //double dval = 3.14;    //1) int temp = dval;
 //const int & ri = dval;   //2) const int & ri = temp;
 signed int dval = -2;
 unsigned int & ri = dval;   //===error here====, if const unsigned int & ri = dval, right
 
 cout <<"Does dval changed ? " << dval << endl;
 cout <<"The value ri is " << ri << endl;

 printf("The addr of dval is %p\n", &dval);
 printf("The addr of ri is %p\n", &ri);
 return 0;
}