? FRIEND function
             ? OVERLOADed function
         
   class Mysomething {
      int kk;
     public:
      float x,y;
      void talk(int);
     private:
      float z;
      friend void modifyme(int);
      friend void modifyme(float);
   };
   void modifyme(int m){
      Mysomething you;
      you.kk = m*10;
      // ...
   }
   void modifyme(int m,int n){
      Mysomething you;
      you.kk = m+n;    // ERROR !
      // ...
   }
   void modifyme(float m){
      Mysomething you;
      you.z = m;
      you.x = m;
      // ...
   }