//--------------------------------------------------------------------
//
//  Laboratory 5                                          stacklnk.h
//
//  Class declarations for the linked list implementation of the
//  Stack ADT
//
//--------------------------------------------------------------------

#include <new>
#include <stdexcept>

using namespace std;

template < class DT >        // Forward declaration of the Stack class
class Stack;

template < class DT >
class StackNode              // Facilitator class for the Stack class
{
  private:

    // Constructor
    StackNode ( const DT &nodeData, StackNode *nextPtr );

    // Data members
    DT dataItem;        // Stack data item
    StackNode *next;    // Pointer to the next data item

  friend class Stack<DT>;
};

//--------------------------------------------------------------------

template < class DT >
class Stack
{
  public:

    // Constructor
    Stack ( int ignored = 0 ) throw ( bad_alloc );

    // Destructor
    ~Stack ();

    // Stack manipulation operations
    void push ( const DT &newDataItem )    // Push data item
        throw ( bad_alloc );
    DT pop ()                              // Pop data item
        throw ( logic_error );
    void clear ();                         // Clear stack

    // Stack status operations
    bool isEmpty () const;                 // Stack is empty
    bool isFull () const;                  // Stack is full

    // Output the stack structure -- used in testing/debugging
    void showStructure () const;

  private:

    // Data member
    StackNode<DT> *top;   // Pointer to the top data item
};