STL 双端队列

template<class T, class A = allocator<T> >class deque {public:    //类型定义    typedef A allocator_type;    typedef A::size_type size_type;    typedef A::difference_type difference_type;    typedef A::reference reference;    typedef A::const_reference const_reference;    typedef A::value_type value_type;    typedef T0 iterator;    typedef T1 const_iterator;    typedef reverse_iterator<iterator, value_type,        reference, A::pointer, difference_type>        reverse_iterator;    typedef reverse_iterator<const_iterator, value_type,        const_reference, A::const_pointer, difference_type>        const_reverse_iterator;    //构造函数    explicit deque(const A& al = A());    explicit deque(size_type n, const T& v = T(), const A& al = A());    deque(const deque& x);    deque(const_iterator first, const_iterator last,        const A& al = A());    //返回第一个开始元素迭代    iterator begin();    const_iterator begin() const;    //返回结束尾后元素迭代器    iterator end();    iterator end() const;    //返回反向开始元素迭代    reverse_iterator rbegin();    const_reverse_iterator rbegin() const;    //返回反向尾后迭代    reverse_iterator rend();    const_reverse_iterator rend() const;    //中心分配大小    void resize(size_type n, T x = T());    //返回元素个数    size_type size() const;    //返回元素最大容量    size_type max_size() const;    //如果队列为空返回false    bool empty() const;    A get_allocator() const;    //获取指定位置元素    reference at(size_type pos);    const_reference at(size_type pos) const;    //重载[]运算符    reference operator[](size_type pos);    const_reference operator[](size_type pos);    //返回首元素引用    reference front();    const_reference front() const;    //返回尾元素引用    reference back();    const_reference back() const;    //队头压入元素    void push_front(const T& x);    //队头弹出元素    void pop_front();    //队尾压入元素    void push_back(const T& x);    //队尾弹出元素    void pop_back();    //清空原队列，根据指定容器进行    void assign(const_iterator first, const_iterator last);    void assign(size_type n, const T& x = T());    //插入元素    iterator insert(iterator it, const T& x = T());    void insert(iterator it, size_type n, const T& x);    void insert(iterator it,        const_iterator first, const_iterator last);    //删除元素    iterator erase(iterator it);    iterator erase(iterator first, iterator last);    //清空    void clear();    //交换    void swap(deque x);protected:    A allocator;};