#ifndef Stack__SEEN
#define Stack__SEEN
///////    Stack.h    ///////
//  stack derived from list<T>
#include "List.h"

template <class T>
class Stack : private List<T>    // keyword private is optional
{  public:
     Stack() { }                 // default constructor
     Stack(T& z) { put_on(z); }  // constructor
     int push(T& z)              // push reference z
        { return put_on(z); }
     int pop(T& z);              // returns -1 if failed
     List<T>::is_empty;          // make is_empty visible
};
#endif