reverse_iterator的封装实现

 Reverse_Iterator.h

namespace xx
{// 所有容器的反向迭代器// 迭代器适配器template<class Iterator, class Ref, class Ptr>struct Reverse_iterator{Iterator _it;typedef Reverse_iterator<Iterator, Ref, Ptr> Self;Reverse_iterator(Iterator it):_it(it){}Ref operator*(){Iterator temp(_it);--temp;return *temp;}//Ref operator*()//{//	Iterator tmp = _it;//	return *(--tmp);//}Ptr operator->(){return &(operator*());}Self& operator++(){--_it;return *this;}Self& operator--(){++_it;return *this;}bool operator!=(const Self& s){return _it != s._it;}};
}

适配到vector和list中做反向迭代器

vector.h

#include"Reverse_Iterator.h"
namespace xx
{template<class T>class vector{public:typedef T* iterator;typedef const T* const_iterator;// 反向迭代器适配支持typedef Reverse_iterator<iterator, T&, T*> reverse_iterator;typedef Reverse_iterator<const_iterator, const T&, const T*> const_reverse_iterator;const_reverse_iterator rbegin() const{// list_node<int>*return const_reverse_iterator(end());}const_reverse_iterator rend() const{return const_reverse_iterator(begin());}reverse_iterator rbegin(){return reverse_iterator(end());}reverse_iterator rend(){return reverse_iterator(begin());}iterator begin(){return _start;}iterator end(){return _finish;}const_iterator begin() const{return _start;}const_iterator end() const{return _finish;}// ...
}

list.h

namesapce xx
{template<class T>class list{typedef list_node<T> Node;public:typedef ListIterator<T, T&, T*> iterator;typedef ListIterator<T, const T&, const T*> const_iterator;// 反向迭代器适配支持typedef Reverse_iterator<iterator, T&, T*> reverse_iterator;typedef Reverse_iterator<const_iterator, const T&, const T*> const_reverse_iterator;const_iterator begin() const{// list_node<int>*return const_iterator(_head->_next);}const_iterator end() const{return const_iterator(_head);}iterator begin(){return iterator(_head->_next);//return _head->_next;}iterator end(){return iterator(_head);}const_reverse_iterator rbegin() const{// list_node<int>*return const_reverse_iterator(end());}const_reverse_iterator rend() const{return const_reverse_iterator(begin());}reverse_iterator rbegin(){return reverse_iterator(end());}reverse_iterator rend(){return reverse_iterator(begin());}//...}}