c++用双向链表实现模板栈

可直接编译运行，其中方法status为形象的显示出栈的结构：

 // visual stack , need define "cout<<" 

 #include <iostream>
 using std::cout;

 template<typename T>
 struct item
 {
     item():value(),last(NULL),next(NULL){}
     item *last,*next;
     T value;
 };
 template<typename T>
 class Stack
 {
     public:
         Stack():m_size(),m_bottom(NULL),m_top(NULL){}
         int size();
         bool push(const T&);
         T pop();
         T top();
         bool empty();
         void status();
     private:
         item<T> *m_bottom,*m_top;
         int m_size;
 };

 ///////////////////
 int main()
 {
     Stack<int> st;
     for(int i=;i<;i++)
     {
         st.push(i);
         st.status();
     }
     cout<<"size="<<st.size()<<"\n";

     for(    i=;i<;i++)
     {
         st.pop();
         st.status();
     }
     if(st.empty())cout<<"empty\n";
     cout<<st.top()<<"\n";
     return ;
 }

 ////////////////////////////
 template<typename T>
 inline int Stack<T>::size(){return m_size;}

 template<typename T>
 inline bool Stack<T>::empty(){return m_size==?false:true;}

 template<typename T>
 inline T Stack<T>::top(){return m_size!=?m_top->value:T();}

 template<typename T>
 bool Stack<T>::push(const T& t)
 {
     if(m_size==)
     {
         m_bottom=new item<T>;
         m_bottom->value=t;
         m_top=m_bottom;
     }
     else
     {
         m_top->next=new item<T>;
         m_top->next->value=t;
         m_top->next->last=m_top;
         m_top=m_top->next;
     }
     m_size++;
     return true;
 }

 template<typename T>
 T Stack<T>::pop()
 {
     if(m_size==)
     {
         T t=m_top->value;
         delete m_top;
         m_bottom=m_top=NULL;
         m_size=;
         return t;
     }
     else if(m_size==)
     {
         return T();
     }
     else
     {
         T t=m_top->value;
         m_top=m_top->last;
         delete m_top->next;
         m_top->next=NULL;
         m_size--;
         return t;
     }
     return T();
 }

 template<typename T>
 void Stack<T>::status()
 {
     item<T> *p;
     cout<<"栈顶  |\n";
     if( m_size== )return ;
     else if(m_size<)
     {
         for(p=m_top;p!=NULL;p=p->last)
         {
             if(p->last==NULL)cout<<"栈底  |"<<p->value<<"|\n";
             else cout<<"      |"<<p->value<<"|\n";
         }
     }
     else
     {
         int i;
         for(p=m_top,i=;i<;p=p->last,i++)cout<<"      |"<<p->value<<"|\n";
         for(p=m_bottom,i=;i<;p=p->next,i++);
         cout<<"      略...\n";
         for(;i>=;i--,p=p->last)
         {
             if(i==)cout<<"栈底  |"<<p->value<<"|\n";
             else cout<<"      |"<<p->value<<"|\n";
         }
     }
 }