// This is the header file from Display 17-17. This is the interface for the class Stack,
// which is a template class for a stack of items of type T.
//
// It is the same file as stack.h.
//
#ifndef STACK_H
#define STACK_H

namespace StackSavitch
{
    template<class T>
    class Node
    {
    public:
        Node(T theData, Node<T>* theLink) : data(theData), link(theLink){}
        Node<T>* getLink( ) const { return link; }
        const T getData( ) const { return data; }
        void setData(const T& theData) { data = theData; }
        void setLink(Node<T>* pointer) { link = pointer; }
    private:
        T data;
        Node<T> *link;
    };

    template<class T>
    class Stack
    {
    public:
        Stack( );
        //Initializes the object to an empty stack.

        Stack(const Stack<T>& aStack);

        Stack<T>& operator =(const Stack<T>& rightSide);

        virtual ~Stack( );

        void push(T stackFrame);
        //Postcondition: stackFrame has been added to the stack.

        T pop( );
        //Precondition: The stack is not empty.
        //Returns the top stack frame and removes that top
        //stack frame from the stack.

        bool isEmpty( ) const;
        //Returns true if the stack is empty. Returns false otherwise.
    private:
        Node<T> *top;
    };

}//StackSavitch
#endif //STACK_H