linked stack.h

链式栈

#include <iostream>
#include "node.h"

typedef char Stack_entry; 

enum Error_code {success,overflow,underflow};

class Linkedstack 
{
public:
	/*these are standard stack methods*/
	Linkedstack();
	bool empty()const;
	Error_code push(const Stack_entry & item);
	Error_code pop();
	Error_code top(Stack_entry & item)const;
	/*these are safety features for linked structures*/
	~Linkedstack();
	Linkedstack(const Linkedstack & original);
	void operator=(const Linkedstack & original);
protected:
    Node *top_node;
};