温故知新

#include <cstdio>#include <iostream>using namespace std;/* *循环双向链表 *insert,splice 都不会造成原有的list迭代器失效.  **/template <class T>struct _list_node {    typedef void * void_pointer;    void_pointer prev;    void_pointer next;    T data;};template <typename T, typename Ref, typename Ptr>struct _list_iterator {    typedef _list_iterator<T, T&, T*>   iterator;    typedef _list_iterator<T, Ref, Ptr> self;    typedef bidirectional_iterator_tag  iterator_category;//双向指针尾    typedef T value_type;    typedef Ptr pointer;    typedef Ref reference;    typedef _list_node<T> * link_type;    typedef size_t size_type;    typedef ptrdiff_t difference_type;        link_type node;//迭代器内部当然要有一个普通指针,指向list的节点        //constructor    _list_iterator(link_type x) : node(x) {}    _list_iterator() {}    _list_iterator(const iterator & x) :node(x.node){}        bool operator == (const self & x) const { return node == x.node;}    bool operator != (const self & x) const { return node != x.node;}        reference operator*()const {return (*node).data;}    pointer operator->() const {return &(operator *());}        self & operator++() {        node = (link_type)((*node).next);        return *this;    }    self operator++(int) {        self tmp = *this;        ++*this;        return tmp;    }        self & operator--() {        node = (link_type)((*node).prev);        return *this;    }    self operator--(int) {        self tmp = *this;        --*this;        return tmp;    }    };int main(){    while (1) ;    return 0;}

细看,细读.慢慢品味,发现其中无穷乐趣啊.