智能指针

#include
using namespace std;

class U_Ptr {
      friend class Has_Ptr;
      int *ip;
      size_t use;
      U_Ptr(int *p): ip(p),use(1) {}
      ~U_Ptr() { delete ip; }
};

class Has_Ptr {
      public:
             Has_Ptr(int *p,int i): ptr(new U_Ptr(p)),val(i) {}
             Has_Ptr(const Has_Ptr &rptr):ptr(rptr.ptr), val(rptr.val)
             {
                ptr->use++;
             }
             Has_Ptr& operator=(const Has_Ptr &rptr)
             {
                if (&rptr != this) {
                   if(--ptr->use == 0)
                      delete ptr;       
               
                   val=rptr.val;
                   ptr=rptr.ptr;
                   ptr->use++;
                }
                return *this;
             }
             ~Has_Ptr() {
                        if (--ptr->use == 0)
                           delete ptr;
             }
                
                
             int *get_ptr()  const { return ptr->ip;}
             int get_int()  const { return val;}
 
             void set_ptr(int *p)  { ptr->ip=p;  }
             /////此处有异议，ptr->ip原来的值由谁来释放？？？         
//             void set_ptr(int *p) { free(ptr->ip); ptr->ip=p; }
             void set_int(int i) { val=i; }   
            
             int get_ptr_val() const { return *ptr->ip; }
             void set_ptr_val(int i) { *ptr->ip =ip; }
      private:
              U_Ptr *ptr;
              int val;      
};

int main()
{
    getchar();
    return 0;
}