C++下标[]运算符重载

#include <iostream>
using namespace std;
const int SIZE = 10;

class safearay {
   private:
      int arr[SIZE];

   public:
      safearay() {
         register int i;
         for(i = 0; i < SIZE; i++) {
           arr[i] = i;
         }
      }

      int &operator[](int i) {
         if( i > SIZE ) {
            cout << "Index out of bounds" <<endl; 
            // return first element.
            return arr[0];
         }

         return arr[i];
      }
};

int main() {
   safearay A;

   cout << "Value of A[2] : " << A[2] <<endl;
   cout << "Value of A[5] : " << A[5]<<endl;
   cout << "Value of A[12] : " << A[12]<<endl;

   return 0;
}