//xxxcopy.cpp
#include <iostream>
using namespace std;
class Cat {
    int a;
   public:  Cat(int x) { a = x; cout << " born " << a << endl;}
   friend ostream& operator<<(ostream&, const Cat&);
/***/
   Cat(const Cat& cc) {  // copy constructor
       cout << " you give me " << cc.a << endl;
        a = 456;
        cout << " you give me " << cc.a << endl;
        cout << " ..copy constructor.. ";
    }
/***********/
};
int main( ) {
   Cat x(123);
   Cat y = x;
   cout << "x=" << x << endl;
   cout << "y=" << y << endl;
}
ostream& operator<<(ostream& river, const Cat& aaa) {
    river << aaa.a;
    return river;
}