条款41: 区分继承和模板

template<class T>
class stack
{
public:
    stack();
    ~stack();

    void push(const T&object);
    T pop();
    bool empty()const;

private:
    struct stackNode
    {
        T data;
        stackNode *next;
        stackNode(const T &newData, stackNode *nextNode)
            :data(newData), next(nextNode){}
    };

    stackNode *top;

    stack(const stack &rhs);//防止拷贝和赋值
    stack &operator=(const stack &rhs);
};

template<class T>
stack<T>::stack() :top(0){}

template<class T>
void stack<T>::push(const T &object)
{
    top = new stackNode(object, top);
}

template<class T>
T stack<T>::pop()
{
    stackNode *temp = top;
    top = top->next;

    T data = temp->data;
    delete temp;

    return data;
}

template<class T>
stack<T>::stack()
{
    while (top)
    {
        stackNode *temp = top;
        top = top->next;
        delete temp;
    }
}

template<class T>
bool stack<T>::empty()const
{
    return top == 0;
}