### 前言
在STL标准中提供了双向链表list，本文介绍的是SGI STL中<stl_slist.h>定义的单向链表slist。单向链表的迭代器是属于正向迭代器，所以在单链表进行插入元素时，在指定节点之后插入时时间是常数O(1)，在指定节点之前插入时需要线性时间O(n)。单向链表的排序算法sort和list容器的排序算法sort一样的思想，可以再《[STL源码剖析——list容器的排序算法sort()](http://blog.csdn.net/chenhanzhun/article/details/39337331)》了解。
### 单向链表slist
### slist节点结构
slist的节点结构只有存储节点数据和指向下一个节点的指针。
~~~
//单向链表的节点基本结构
struct _Slist_node_base
{
_Slist_node_base* _M_next;
};
//单向链表节点结构
template <class _Tp>
struct _Slist_node : public _Slist_node_base
{
_Tp _M_data;
};
~~~
### slist迭代器
由于slist是单向链表，所以只提供正向迭代器，若要查找指定节点的前一个节点时，operator--不能使用，只能从头遍历，但是可以operator++和operator*操作；
~~~
//单向链表的迭代器的基本结构
struct _Slist_iterator_base
{
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef forward_iterator_tag iterator_category;//正向迭代器
_Slist_node_base* _M_node;//链表节点指针
_Slist_iterator_base(_Slist_node_base* __x) : _M_node(__x) {}
void _M_incr() { _M_node = _M_node->_M_next; }//前移一个节点
bool operator==(const _Slist_iterator_base& __x) const {
return _M_node == __x._M_node;//节点指针指向相同位置
}
bool operator!=(const _Slist_iterator_base& __x) const {
return _M_node != __x._M_node;//节点指针指向不同位置
}
};
//单向链表迭代器结构
template <class _Tp, class _Ref, class _Ptr>
struct _Slist_iterator : public _Slist_iterator_base
{
typedef _Slist_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Slist_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
typedef _Slist_iterator<_Tp, _Ref, _Ptr> _Self;
typedef _Tp value_type;
typedef _Ptr pointer;
typedef _Ref reference;
typedef _Slist_node<_Tp> _Node;
_Slist_iterator(_Node* __x) : _Slist_iterator_base(__x) {}
_Slist_iterator() : _Slist_iterator_base(0) {}
_Slist_iterator(const iterator& __x) : _Slist_iterator_base(__x._M_node) {}
//解除引用，返回节点数据
reference operator*() const { return ((_Node*) _M_node)->_M_data; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */
//前缀operator++
_Self& operator++()
{
_M_incr();
return *this;
}
//后缀operator++
_Self operator++(int)
{
_Self __tmp = *this;
_M_incr();
return __tmp;
}
//单向链表不能operator--操作
};
~~~
### slist的数据结构
slist单向链表只需要给出该链表的头部head，便可以通过head->next遍历该链表；
~~~
typedef simple_alloc<_Slist_node<_Tp>, _Alloc> _Alloc_type;
_Slist_node<_Tp>* _M_get_node() { return _Alloc_type::allocate(1); }
void _M_put_node(_Slist_node<_Tp>* __p) { _Alloc_type::deallocate(__p, 1); }
_Slist_node_base* _M_erase_after(_Slist_node_base* __pos)
{
_Slist_node<_Tp>* __next = (_Slist_node<_Tp>*) (__pos->_M_next);
_Slist_node_base* __next_next = __next->_M_next;
__pos->_M_next = __next_next;
destroy(&__next->_M_data);
_M_put_node(__next);
return __next_next;
}
_Slist_node_base* _M_erase_after(_Slist_node_base*, _Slist_node_base*);
protected:
_Slist_node_base _M_head;
};
//单向链表slist定义
template <class _Tp, class _Alloc = __STL_DEFAULT_ALLOCATOR(_Tp) >
class slist : private _Slist_base<_Tp,_Alloc>
{
// requirements:
__STL_CLASS_REQUIRES(_Tp, _Assignable);
private:
typedef _Slist_base<_Tp,_Alloc> _Base;
public:
typedef _Tp value_type;
typedef value_type* pointer;
typedef const value_type* const_pointer;
typedef value_type& reference;
typedef const value_type& const_reference;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Slist_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Slist_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
private:
typedef _Slist_node<_Tp> _Node;
typedef _Slist_node_base _Node_base;
typedef _Slist_iterator_base _Iterator_base;
...
};
~~~
### slist单向链表的源码完成剖析
~~~
#ifndef __SGI_STL_INTERNAL_SLIST_H
#define __SGI_STL_INTERNAL_SLIST_H
#include <concept_checks.h>
__STL_BEGIN_NAMESPACE
#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma set woff 1174
#pragma set woff 1375
#endif
//单向链表的节点基本结构
struct _Slist_node_base
{
_Slist_node_base* _M_next;
};
//单向链表节点结构
template <class _Tp>
struct _Slist_node : public _Slist_node_base
{
_Tp _M_data;
};
//在节点prev之后插入节点new
inline _Slist_node_base*
__slist_make_link(_Slist_node_base* __prev_node,
_Slist_node_base* __new_node)
{
//更新节点指针
//即新节点new下一节点为当前节点prev的下一个节点
__new_node->_M_next = __prev_node->_M_next;
//当前节点的prev的下一个节点为new
__prev_node->_M_next = __new_node;
return __new_node;//返回新插入节点的地址
}
//查找指定节点node的前一个节点
//由于是单向链表，需从表头head开始查找
inline _Slist_node_base*
__slist_previous(_Slist_node_base* __head,
const _Slist_node_base* __node)
{
while (__head && __head->_M_next != __node)
__head = __head->_M_next;//遍历节点，直到遇到所找节点或不存在该节点
return __head;
}
inline const _Slist_node_base*
__slist_previous(const _Slist_node_base* __head,
const _Slist_node_base* __node)
{
while (__head && __head->_M_next != __node)
__head = __head->_M_next;
return __head;
}
//将节点(before_first,before_last]插入到指定节点pos之后
inline void __slist_splice_after(_Slist_node_base* __pos,
_Slist_node_base* __before_first,
_Slist_node_base* __before_last)
{
if (__pos != __before_first && __pos != __before_last) {
_Slist_node_base* __first = __before_first->_M_next;
_Slist_node_base* __after = __pos->_M_next;
//将节点链表(before_first,before_last]从链表中移除
__before_first->_M_next = __before_last->_M_next;
//将(before_first,before_last]插入到指定位置pos之后
__pos->_M_next = __first;
__before_last->_M_next = __after;
}
}
inline void
__slist_splice_after(_Slist_node_base* __pos, _Slist_node_base* __head)
{
_Slist_node_base* __before_last = __slist_previous(__head, 0);//找出链表的最后一个节点
if (__before_last != __head) {//链表非空
_Slist_node_base* __after = __pos->_M_next;
__pos->_M_next = __head->_M_next;
__head->_M_next = 0;
__before_last->_M_next = __after;
}
}
//单向链表反转
//这里参数node必须为第一个结点即为head->next，不然链表会造成内存泄露
inline _Slist_node_base* __slist_reverse(_Slist_node_base* __node)
{
_Slist_node_base* __result = __node;
__node = __node->_M_next;
__result->_M_next = 0;//链表尾部
while(__node) {//链表非空
_Slist_node_base* __next = __node->_M_next;
__node->_M_next = __result;
__result = __node;
__node = __next;
}
return __result;
}
//返回链表大小
//节点参数node必须为第一个节点即为head->next;
inline size_t __slist_size(_Slist_node_base* __node)
{
size_t __result = 0;
for ( ; __node != 0; __node = __node->_M_next)//遍历链表节点
++__result;
return __result;
}
//单向链表的迭代器的基本结构
struct _Slist_iterator_base
{
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef forward_iterator_tag iterator_category;//正向迭代器
_Slist_node_base* _M_node;//链表节点指针
_Slist_iterator_base(_Slist_node_base* __x) : _M_node(__x) {}
void _M_incr() { _M_node = _M_node->_M_next; }//前移一个节点
bool operator==(const _Slist_iterator_base& __x) const {
return _M_node == __x._M_node;//节点指针指向相同位置
}
bool operator!=(const _Slist_iterator_base& __x) const {
return _M_node != __x._M_node;//节点指针指向不同位置
}
};
//单向链表迭代器结构
template <class _Tp, class _Ref, class _Ptr>
struct _Slist_iterator : public _Slist_iterator_base
{
typedef _Slist_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Slist_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
typedef _Slist_iterator<_Tp, _Ref, _Ptr> _Self;
typedef _Tp value_type;
typedef _Ptr pointer;
typedef _Ref reference;
typedef _Slist_node<_Tp> _Node;
_Slist_iterator(_Node* __x) : _Slist_iterator_base(__x) {}
_Slist_iterator() : _Slist_iterator_base(0) {}
_Slist_iterator(const iterator& __x) : _Slist_iterator_base(__x._M_node) {}
//解除引用，返回节点数据
reference operator*() const { return ((_Node*) _M_node)->_M_data; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */
//前缀operator++
_Self& operator++()
{
_M_incr();
return *this;
}
//后缀operator++
_Self operator++(int)
{
_Self __tmp = *this;
_M_incr();
return __tmp;
}
//单向链表不能operator--操作
};
#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION
inline ptrdiff_t* distance_type(const _Slist_iterator_base&) {
return 0;
}
inline forward_iterator_tag iterator_category(const _Slist_iterator_base&) {
return forward_iterator_tag();
}
template <class _Tp, class _Ref, class _Ptr>
inline _Tp* value_type(const _Slist_iterator<_Tp, _Ref, _Ptr>&) {
return 0;
}
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
// Base class that encapsulates details of allocators. Three cases:
// an ordinary standard-conforming allocator, a standard-conforming
// allocator with no non-static data, and an SGI-style allocator.
// This complexity is necessary only because we're worrying about backward
// compatibility and because we want to avoid wasting storage on an
// allocator instance if it isn't necessary.
#ifdef __STL_USE_STD_ALLOCATORS
// Base for general standard-conforming allocators.
template <class _Tp, class _Allocator, bool _IsStatic>
class _Slist_alloc_base {
public:
typedef typename _Alloc_traits<_Tp,_Allocator>::allocator_type
allocator_type;
allocator_type get_allocator() const { return _M_node_allocator; }
_Slist_alloc_base(const allocator_type& __a) : _M_node_allocator(__a) {}
protected:
//分配一个节点空间
_Slist_node<_Tp>* _M_get_node()
{ return _M_node_allocator.allocate(1); }
//释放指定的节点空间
void _M_put_node(_Slist_node<_Tp>* __p)
{ _M_node_allocator.deallocate(__p, 1); }
protected:
typename _Alloc_traits<_Slist_node<_Tp>,_Allocator>::allocator_type
_M_node_allocator;
_Slist_node_base _M_head;
};
// Specialization for instanceless allocators.
template <class _Tp, class _Allocator>
class _Slist_alloc_base<_Tp,_Allocator, true> {
public:
typedef typename _Alloc_traits<_Tp,_Allocator>::allocator_type
allocator_type;
allocator_type get_allocator() const { return allocator_type(); }
_Slist_alloc_base(const allocator_type&) {}
protected:
typedef typename _Alloc_traits<_Slist_node<_Tp>, _Allocator>::_Alloc_type
_Alloc_type;
_Slist_node<_Tp>* _M_get_node() { return _Alloc_type::allocate(1); }
void _M_put_node(_Slist_node<_Tp>* __p) { _Alloc_type::deallocate(__p, 1); }
protected:
_Slist_node_base _M_head;//链表头
};
template <class _Tp, class _Alloc>
struct _Slist_base
: public _Slist_alloc_base<_Tp, _Alloc,
_Alloc_traits<_Tp, _Alloc>::_S_instanceless>
{
typedef _Slist_alloc_base<_Tp, _Alloc,
_Alloc_traits<_Tp, _Alloc>::_S_instanceless>
_Base;
typedef typename _Base::allocator_type allocator_type;
_Slist_base(const allocator_type& __a)
: _Base(__a) { this->_M_head._M_next = 0; }
~_Slist_base() { _M_erase_after(&this->_M_head, 0); }
protected:
//擦除指定节点的后一个节点
_Slist_node_base* _M_erase_after(_Slist_node_base* __pos)
{
_Slist_node<_Tp>* __next = (_Slist_node<_Tp>*) (__pos->_M_next);
_Slist_node_base* __next_next = __next->_M_next;
__pos->_M_next = __next_next;
destroy(&__next->_M_data);
_M_put_node(__next);
return __next_next;
}
_Slist_node_base* _M_erase_after(_Slist_node_base*, _Slist_node_base*);
};
#else /* __STL_USE_STD_ALLOCATORS */
template <class _Tp, class _Alloc>
struct _Slist_base {
typedef _Alloc allocator_type;
allocator_type get_allocator() const { return allocator_type(); }
_Slist_base(const allocator_type&) { _M_head._M_next = 0; }
~_Slist_base() { _M_erase_after(&_M_head, 0); }
protected:
typedef simple_alloc<_Slist_node<_Tp>, _Alloc> _Alloc_type;
_Slist_node<_Tp>* _M_get_node() { return _Alloc_type::allocate(1); }
void _M_put_node(_Slist_node<_Tp>* __p) { _Alloc_type::deallocate(__p, 1); }
_Slist_node_base* _M_erase_after(_Slist_node_base* __pos)
{
_Slist_node<_Tp>* __next = (_Slist_node<_Tp>*) (__pos->_M_next);
_Slist_node_base* __next_next = __next->_M_next;
__pos->_M_next = __next_next;
destroy(&__next->_M_data);
_M_put_node(__next);
return __next_next;
}
_Slist_node_base* _M_erase_after(_Slist_node_base*, _Slist_node_base*);
protected:
_Slist_node_base _M_head;
};
#endif /* __STL_USE_STD_ALLOCATORS */
//擦除(first,last)之间的节点
template <class _Tp, class _Alloc>
_Slist_node_base*
_Slist_base<_Tp,_Alloc>::_M_erase_after(_Slist_node_base* __before_first,
_Slist_node_base* __last_node) {
_Slist_node<_Tp>* __cur = (_Slist_node<_Tp>*) (__before_first->_M_next);
while (__cur != __last_node) {
_Slist_node<_Tp>* __tmp = __cur;
__cur = (_Slist_node<_Tp>*) __cur->_M_next;
destroy(&__tmp->_M_data);
_M_put_node(__tmp);
}
__before_first->_M_next = __last_node;
return __last_node;
}
//单向链表slist定义
template <class _Tp, class _Alloc = __STL_DEFAULT_ALLOCATOR(_Tp) >
class slist : private _Slist_base<_Tp,_Alloc>
{
// requirements:
__STL_CLASS_REQUIRES(_Tp, _Assignable);
private:
typedef _Slist_base<_Tp,_Alloc> _Base;
public:
typedef _Tp value_type;
typedef value_type* pointer;
typedef const value_type* const_pointer;
typedef value_type& reference;
typedef const value_type& const_reference;
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Slist_iterator<_Tp, _Tp&, _Tp*> iterator;
typedef _Slist_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
typedef typename _Base::allocator_type allocator_type;
allocator_type get_allocator() const { return _Base::get_allocator(); }
private:
typedef _Slist_node<_Tp> _Node;
typedef _Slist_node_base _Node_base;
typedef _Slist_iterator_base _Iterator_base;
//创建初始值为x的节点
_Node* _M_create_node(const value_type& __x) {
_Node* __node = this->_M_get_node();
__STL_TRY {
construct(&__node->_M_data, __x);
__node->_M_next = 0;
}
__STL_UNWIND(this->_M_put_node(__node));
return __node;
}
_Node* _M_create_node() {
_Node* __node = this->_M_get_node();
__STL_TRY {
construct(&__node->_M_data);
__node->_M_next = 0;
}
__STL_UNWIND(this->_M_put_node(__node));
return __node;
}
public:
explicit slist(const allocator_type& __a = allocator_type()) : _Base(__a) {}
slist(size_type __n, const value_type& __x,
const allocator_type& __a = allocator_type()) : _Base(__a)
{ _M_insert_after_fill(&this->_M_head, __n, __x); }
explicit slist(size_type __n) : _Base(allocator_type())
{ _M_insert_after_fill(&this->_M_head, __n, value_type()); }
#ifdef __STL_MEMBER_TEMPLATES
// We don't need any dispatching tricks here, because _M_insert_after_range
// already does them.
template <class _InputIterator>
slist(_InputIterator __first, _InputIterator __last,
const allocator_type& __a = allocator_type()) : _Base(__a)
{ _M_insert_after_range(&this->_M_head, __first, __last); }
#else /* __STL_MEMBER_TEMPLATES */
slist(const_iterator __first, const_iterator __last,
const allocator_type& __a = allocator_type()) : _Base(__a)
{ _M_insert_after_range(&this->_M_head, __first, __last); }
slist(const value_type* __first, const value_type* __last,
const allocator_type& __a = allocator_type()) : _Base(__a)
{ _M_insert_after_range(&this->_M_head, __first, __last); }
#endif /* __STL_MEMBER_TEMPLATES */
slist(const slist& __x) : _Base(__x.get_allocator())
{ _M_insert_after_range(&this->_M_head, __x.begin(), __x.end()); }
slist& operator= (const slist& __x);
~slist() {}
public:
// assign(), a generalized assignment member function. Two
// versions: one that takes a count, and one that takes a range.
// The range version is a member template, so we dispatch on whether
// or not the type is an integer.
void assign(size_type __n, const _Tp& __val)
{ _M_fill_assign(__n, __val); }
void _M_fill_assign(size_type __n, const _Tp& __val);
#ifdef __STL_MEMBER_TEMPLATES
template <class _InputIterator>
void assign(_InputIterator __first, _InputIterator __last) {
typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
_M_assign_dispatch(__first, __last, _Integral());
}
template <class _Integer>
void _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
{ _M_fill_assign((size_type) __n, (_Tp) __val); }
template <class _InputIterator>
void _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
__false_type);
#endif /* __STL_MEMBER_TEMPLATES */
public:
//返回第一个节点迭代器
iterator begin() { return iterator((_Node*)this->_M_head._M_next); }
const_iterator begin() const
{ return const_iterator((_Node*)this->_M_head._M_next);}
//返回链表尾部
iterator end() { return iterator(0); }
const_iterator end() const { return const_iterator(0); }
// Experimental new feature: before_begin() returns a
// non-dereferenceable iterator that, when incremented, yields
// begin(). This iterator may be used as the argument to
// insert_after, erase_after, etc. Note that even for an empty
// slist, before_begin() is not the same iterator as end(). It
// is always necessary to increment before_begin() at least once to
// obtain end().
//链表头
iterator before_begin() { return iterator((_Node*) &this->_M_head); }
const_iterator before_begin() const
{ return const_iterator((_Node*) &this->_M_head); }
//返回链表大小
size_type size() const { return __slist_size(this->_M_head._M_next); }
size_type max_size() const { return size_type(-1); }
//判断是否为空链表
bool empty() const { return this->_M_head._M_next == 0; }
//交换链表内容
//实质上只交换指向链表的指针
void swap(slist& __x)
{ __STD::swap(this->_M_head._M_next, __x._M_head._M_next); }
public:
//返回第一个节点数据
reference front() { return ((_Node*) this->_M_head._M_next)->_M_data; }
const_reference front() const
{ return ((_Node*) this->_M_head._M_next)->_M_data; }
//在链表头部新增节点
void push_front(const value_type& __x) {
__slist_make_link(&this->_M_head, _M_create_node(__x));
}
void push_front() { __slist_make_link(&this->_M_head, _M_create_node()); }
//删除节点
void pop_front() {
_Node* __node = (_Node*) this->_M_head._M_next;
this->_M_head._M_next = __node->_M_next;
destroy(&__node->_M_data);
this->_M_put_node(__node);
}
//返回指定节点的前一个节点
iterator previous(const_iterator __pos) {
return iterator((_Node*) __slist_previous(&this->_M_head, __pos._M_node));
}
const_iterator previous(const_iterator __pos) const {
return const_iterator((_Node*) __slist_previous(&this->_M_head,
__pos._M_node));
}
private:
//在指定节点后面插入值为x的节点
_Node* _M_insert_after(_Node_base* __pos, const value_type& __x) {
return (_Node*) (__slist_make_link(__pos, _M_create_node(__x)));
}
_Node* _M_insert_after(_Node_base* __pos) {
return (_Node*) (__slist_make_link(__pos, _M_create_node()));
}
//在指定节点后面连续插入n个值为x的节点
void _M_insert_after_fill(_Node_base* __pos,
size_type __n, const value_type& __x) {
for (size_type __i = 0; __i < __n; ++__i)
__pos = __slist_make_link(__pos, _M_create_node(__x));
}
#ifdef __STL_MEMBER_TEMPLATES
// Check whether it's an integral type. If so, it's not an iterator.
//在指定节点之后插入[first,last)数据节点
//首先判断输入数据类型是否为整数
template <class _InIter>
void _M_insert_after_range(_Node_base* __pos,
_InIter __first, _InIter __last) {
typedef typename _Is_integer<_InIter>::_Integral _Integral;
_M_insert_after_range(__pos, __first, __last, _Integral());
}
//若是整数，则在指定节点之后连续插入n个相同节点
template <class _Integer>
void _M_insert_after_range(_Node_base* __pos, _Integer __n, _Integer __x,
__true_type) {
_M_insert_after_fill(__pos, __n, __x);
}
//若不是整数，则一个一个节点一次插入
template <class _InIter>
void _M_insert_after_range(_Node_base* __pos,
_InIter __first, _InIter __last,
__false_type) {
while (__first != __last) {
__pos = __slist_make_link(__pos, _M_create_node(*__first));
++__first;
}
}
#else /* __STL_MEMBER_TEMPLATES */
void _M_insert_after_range(_Node_base* __pos,
const_iterator __first, const_iterator __last) {
while (__first != __last) {
__pos = __slist_make_link(__pos, _M_create_node(*__first));
++__first;
}
}
void _M_insert_after_range(_Node_base* __pos,
const value_type* __first,
const value_type* __last) {
while (__first != __last) {
__pos = __slist_make_link(__pos, _M_create_node(*__first));
++__first;
}
}
#endif /* __STL_MEMBER_TEMPLATES */
public:
//对外接口
iterator insert_after(iterator __pos, const value_type& __x) {
return iterator(_M_insert_after(__pos._M_node, __x));
}
iterator insert_after(iterator __pos) {
return insert_after(__pos, value_type());
}
void insert_after(iterator __pos, size_type __n, const value_type& __x) {
_M_insert_after_fill(__pos._M_node, __n, __x);
}
#ifdef __STL_MEMBER_TEMPLATES
// We don't need any dispatching tricks here, because _M_insert_after_range
// already does them.
template <class _InIter>
void insert_after(iterator __pos, _InIter __first, _InIter __last) {
_M_insert_after_range(__pos._M_node, __first, __last);
}
#else /* __STL_MEMBER_TEMPLATES */
void insert_after(iterator __pos,
const_iterator __first, const_iterator __last) {
_M_insert_after_range(__pos._M_node, __first, __last);
}
void insert_after(iterator __pos,
const value_type* __first, const value_type* __last) {
_M_insert_after_range(__pos._M_node, __first, __last);
}
#endif /* __STL_MEMBER_TEMPLATES */
//在指定节点之前插入
iterator insert(iterator __pos, const value_type& __x) {
//这里首先找出指定节点的前一个节点，然后再把新节点插入到前一节点的后面
return iterator(_M_insert_after(__slist_previous(&this->_M_head,
__pos._M_node),
__x));
}
iterator insert(iterator __pos) {
return iterator(_M_insert_after(__slist_previous(&this->_M_head,
__pos._M_node),
value_type()));
}
void insert(iterator __pos, size_type __n, const value_type& __x) {
_M_insert_after_fill(__slist_previous(&this->_M_head, __pos._M_node),
__n, __x);
}
#ifdef __STL_MEMBER_TEMPLATES
// We don't need any dispatching tricks here, because _M_insert_after_range
// already does them.
template <class _InIter>
void insert(iterator __pos, _InIter __first, _InIter __last) {
_M_insert_after_range(__slist_previous(&this->_M_head, __pos._M_node),
__first, __last);
}
#else /* __STL_MEMBER_TEMPLATES */
void insert(iterator __pos, const_iterator __first, const_iterator __last) {
_M_insert_after_range(__slist_previous(&this->_M_head, __pos._M_node),
__first, __last);
}
void insert(iterator __pos, const value_type* __first,
const value_type* __last) {
_M_insert_after_range(__slist_previous(&this->_M_head, __pos._M_node),
__first, __last);
}
#endif /* __STL_MEMBER_TEMPLATES */
public:
//在指定节点之后擦除节点
iterator erase_after(iterator __pos) {
return iterator((_Node*) this->_M_erase_after(__pos._M_node));
}
iterator erase_after(iterator __before_first, iterator __last) {
return iterator((_Node*) this->_M_erase_after(__before_first._M_node,
__last._M_node));
}
iterator erase(iterator __pos) {
return (_Node*) this->_M_erase_after(__slist_previous(&this->_M_head,
__pos._M_node));
}
iterator erase(iterator __first, iterator __last) {
return (_Node*) this->_M_erase_after(
__slist_previous(&this->_M_head, __first._M_node), __last._M_node);
}
//从新分配单向链表大小
void resize(size_type new_size, const _Tp& __x);
void resize(size_type new_size) { resize(new_size, _Tp()); }
//清除链表
void clear() { this->_M_erase_after(&this->_M_head, 0); }
public:
// Moves the range [__before_first + 1, __before_last + 1) to *this,
// inserting it immediately after __pos. This is constant time.
void splice_after(iterator __pos,
iterator __before_first, iterator __before_last)
{
if (__before_first != __before_last)
__slist_splice_after(__pos._M_node, __before_first._M_node,
__before_last._M_node);
}
// Moves the element that follows __prev to *this, inserting it immediately
// after __pos. This is constant time.
void splice_after(iterator __pos, iterator __prev)
{
__slist_splice_after(__pos._M_node,
__prev._M_node, __prev._M_node->_M_next);
}
// Removes all of the elements from the list __x to *this, inserting
// them immediately after __pos. __x must not be *this. Complexity:
// linear in __x.size().
void splice_after(iterator __pos, slist& __x)
{
__slist_splice_after(__pos._M_node, &__x._M_head);
}
// Linear in distance(begin(), __pos), and linear in __x.size().
void splice(iterator __pos, slist& __x) {
if (__x._M_head._M_next)
__slist_splice_after(__slist_previous(&this->_M_head, __pos._M_node),
&__x._M_head, __slist_previous(&__x._M_head, 0));
}
// Linear in distance(begin(), __pos), and in distance(__x.begin(), __i).
void splice(iterator __pos, slist& __x, iterator __i) {
__slist_splice_after(__slist_previous(&this->_M_head, __pos._M_node),
__slist_previous(&__x._M_head, __i._M_node),
__i._M_node);
}
// Linear in distance(begin(), __pos), in distance(__x.begin(), __first),
// and in distance(__first, __last).
void splice(iterator __pos, slist& __x, iterator __first, iterator __last)
{
if (__first != __last)
__slist_splice_after(__slist_previous(&this->_M_head, __pos._M_node),
__slist_previous(&__x._M_head, __first._M_node),
__slist_previous(__first._M_node, __last._M_node));
}
public:
void reverse() {
if (this->_M_head._M_next)
this->_M_head._M_next = __slist_reverse(this->_M_head._M_next);
}
void remove(const _Tp& __val);
void unique();
void merge(slist& __x);
void sort();
#ifdef __STL_MEMBER_TEMPLATES
template <class _Predicate>
void remove_if(_Predicate __pred);
template <class _BinaryPredicate>
void unique(_BinaryPredicate __pred);
template <class _StrictWeakOrdering>
void merge(slist&, _StrictWeakOrdering);
template <class _StrictWeakOrdering>
void sort(_StrictWeakOrdering __comp);
#endif /* __STL_MEMBER_TEMPLATES */
};
//实现整个单向链表的赋值
template <class _Tp, class _Alloc>
slist<_Tp,_Alloc>& slist<_Tp,_Alloc>::operator=(const slist<_Tp,_Alloc>& __x)
{
if (&__x != this) {
_Node_base* __p1 = &this->_M_head;
_Node* __n1 = (_Node*) this->_M_head._M_next;
const _Node* __n2 = (const _Node*) __x._M_head._M_next;
while (__n1 && __n2) {
__n1->_M_data = __n2->_M_data;
__p1 = __n1;
__n1 = (_Node*) __n1->_M_next;
__n2 = (const _Node*) __n2->_M_next;
}
if (__n2 == 0)//擦除多余的节点
this->_M_erase_after(__p1, 0);
else//插入剩下的节点
_M_insert_after_range(__p1, const_iterator((_Node*)__n2),
const_iterator(0));
}
return *this;
}
template <class _Tp, class _Alloc>
void slist<_Tp, _Alloc>::_M_fill_assign(size_type __n, const _Tp& __val) {
_Node_base* __prev = &this->_M_head;
_Node* __node = (_Node*) this->_M_head._M_next;
for ( ; __node != 0 && __n > 0 ; --__n) {
__node->_M_data = __val;
__prev = __node;
__node = (_Node*) __node->_M_next;
}
if (__n > 0)
_M_insert_after_fill(__prev, __n, __val);
else
this->_M_erase_after(__prev, 0);
}
#ifdef __STL_MEMBER_TEMPLATES
template <class _Tp, class _Alloc> template <class _InputIter>
void
slist<_Tp, _Alloc>::_M_assign_dispatch(_InputIter __first, _InputIter __last,
__false_type)
{
_Node_base* __prev = &this->_M_head;
_Node* __node = (_Node*) this->_M_head._M_next;
while (__node != 0 && __first != __last) {
__node->_M_data = *__first;
__prev = __node;
__node = (_Node*) __node->_M_next;
++__first;
}
if (__first != __last)
_M_insert_after_range(__prev, __first, __last);
else
this->_M_erase_after(__prev, 0);
}
#endif /* __STL_MEMBER_TEMPLATES */
template <class _Tp, class _Alloc>
inline bool
operator==(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2)
{
typedef typename slist<_Tp,_Alloc>::const_iterator const_iterator;
const_iterator __end1 = _SL1.end();
const_iterator __end2 = _SL2.end();
const_iterator __i1 = _SL1.begin();
const_iterator __i2 = _SL2.begin();
while (__i1 != __end1 && __i2 != __end2 && *__i1 == *__i2) {
++__i1;
++__i2;
}
return __i1 == __end1 && __i2 == __end2;
}
template <class _Tp, class _Alloc>
inline bool
operator<(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2)
{
return lexicographical_compare(_SL1.begin(), _SL1.end(),
_SL2.begin(), _SL2.end());
}
#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER
template <class _Tp, class _Alloc>
inline bool
operator!=(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2) {
return !(_SL1 == _SL2);
}
template <class _Tp, class _Alloc>
inline bool
operator>(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2) {
return _SL2 < _SL1;
}
template <class _Tp, class _Alloc>
inline bool
operator<=(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2) {
return !(_SL2 < _SL1);
}
template <class _Tp, class _Alloc>
inline bool
operator>=(const slist<_Tp,_Alloc>& _SL1, const slist<_Tp,_Alloc>& _SL2) {
return !(_SL1 < _SL2);
}
template <class _Tp, class _Alloc>
inline void swap(slist<_Tp,_Alloc>& __x, slist<_Tp,_Alloc>& __y) {
__x.swap(__y);
}
#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */
template <class _Tp, class _Alloc>
void slist<_Tp,_Alloc>::resize(size_type __len, const _Tp& __x)
{
_Node_base* __cur = &this->_M_head;
while (__cur->_M_next != 0 && __len > 0) {
--__len;
__cur = __cur->_M_next;
}
if (__cur->_M_next) //若新的大小比原来的小
this->_M_erase_after(__cur, 0);
else//若新的大小比原来的大
_M_insert_after_fill(__cur, __len, __x);
}
//删除所有值为val的节点
template <class _Tp, class _Alloc>
void slist<_Tp,_Alloc>::remove(const _Tp& __val)
{
_Node_base* __cur = &this->_M_head;
while (__cur && __cur->_M_next) {
if (((_Node*) __cur->_M_next)->_M_data == __val)
this->_M_erase_after(__cur);
else
__cur = __cur->_M_next;
}
}
//删除连续相同值的节点，使其唯一
template <class _Tp, class _Alloc>
void slist<_Tp,_Alloc>::unique()
{
_Node_base* __cur = this->_M_head._M_next;
if (__cur) {
while (__cur->_M_next) {
if (((_Node*)__cur)->_M_data ==
((_Node*)(__cur->_M_next))->_M_data)
this->_M_erase_after(__cur);
else
__cur = __cur->_M_next;
}
}
}
//合并两个有序单链表
template <class _Tp, class _Alloc>
void slist<_Tp,_Alloc>::merge(slist<_Tp,_Alloc>& __x)
{
_Node_base* __n1 = &this->_M_head;
while (__n1->_M_next && __x._M_head._M_next) {
if (((_Node*) __x._M_head._M_next)->_M_data <
((_Node*) __n1->_M_next)->_M_data)
__slist_splice_after(__n1, &__x._M_head, __x._M_head._M_next);
__n1 = __n1->_M_next;
}
if (__x._M_head._M_next) {
__n1->_M_next = __x._M_head._M_next;
__x._M_head._M_next = 0;
}
}
//这里的排序算法跟list的相似
template <class _Tp, class _Alloc>
void slist<_Tp,_Alloc>::sort()
{
if (this->_M_head._M_next && this->_M_head._M_next->_M_next) {
slist __carry;
slist __counter[64];
int __fill = 0;
while (!empty()) {
__slist_splice_after(&__carry._M_head,
&this->_M_head, this->_M_head._M_next);
int __i = 0;
while (__i < __fill && !__counter[__i].empty()) {
__counter[__i].merge(__carry);
__carry.swap(__counter[__i]);
++__i;
}
__carry.swap(__counter[__i]);
if (__i == __fill)
++__fill;
}
for (int __i = 1; __i < __fill; ++__i)
__counter[__i].merge(__counter[__i-1]);
this->swap(__counter[__fill-1]);
}
}
#ifdef __STL_MEMBER_TEMPLATES
template <class _Tp, class _Alloc>
template <class _Predicate>
void slist<_Tp,_Alloc>::remove_if(_Predicate __pred)
{
_Node_base* __cur = &this->_M_head;
while (__cur->_M_next) {
if (__pred(((_Node*) __cur->_M_next)->_M_data))
this->_M_erase_after(__cur);
else
__cur = __cur->_M_next;
}
}
template <class _Tp, class _Alloc> template <class _BinaryPredicate>
void slist<_Tp,_Alloc>::unique(_BinaryPredicate __pred)
{
_Node* __cur = (_Node*) this->_M_head._M_next;
if (__cur) {
while (__cur->_M_next) {
if (__pred(((_Node*)__cur)->_M_data,
((_Node*)(__cur->_M_next))->_M_data))
this->_M_erase_after(__cur);
else
__cur = (_Node*) __cur->_M_next;
}
}
}
template <class _Tp, class _Alloc> template <class _StrictWeakOrdering>
void slist<_Tp,_Alloc>::merge(slist<_Tp,_Alloc>& __x,
_StrictWeakOrdering __comp)
{
_Node_base* __n1 = &this->_M_head;
while (__n1->_M_next && __x._M_head._M_next) {
if (__comp(((_Node*) __x._M_head._M_next)->_M_data,
((_Node*) __n1->_M_next)->_M_data))
__slist_splice_after(__n1, &__x._M_head, __x._M_head._M_next);
__n1 = __n1->_M_next;
}
if (__x._M_head._M_next) {
__n1->_M_next = __x._M_head._M_next;
__x._M_head._M_next = 0;
}
}
template <class _Tp, class _Alloc> template <class _StrictWeakOrdering>
void slist<_Tp,_Alloc>::sort(_StrictWeakOrdering __comp)
{
if (this->_M_head._M_next && this->_M_head._M_next->_M_next) {
slist __carry;
slist __counter[64];
int __fill = 0;
while (!empty()) {
__slist_splice_after(&__carry._M_head,
&this->_M_head, this->_M_head._M_next);
int __i = 0;
while (__i < __fill && !__counter[__i].empty()) {
__counter[__i].merge(__carry, __comp);
__carry.swap(__counter[__i]);
++__i;
}
__carry.swap(__counter[__i]);
if (__i == __fill)
++__fill;
}
for (int __i = 1; __i < __fill; ++__i)
__counter[__i].merge(__counter[__i-1], __comp);
this->swap(__counter[__fill-1]);
}
}
#endif /* __STL_MEMBER_TEMPLATES */
// Specialization of insert_iterator so that insertions will be constant
// time rather than linear time.
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
template <class _Tp, class _Alloc>
class insert_iterator<slist<_Tp, _Alloc> > {
protected:
typedef slist<_Tp, _Alloc> _Container;
_Container* container;
typename _Container::iterator iter;
public:
typedef _Container container_type;
typedef output_iterator_tag iterator_category;
typedef void value_type;
typedef void difference_type;
typedef void pointer;
typedef void reference;
insert_iterator(_Container& __x, typename _Container::iterator __i)
: container(&__x) {
if (__i == __x.begin())
iter = __x.before_begin();
else
iter = __x.previous(__i);
}
insert_iterator<_Container>&
operator=(const typename _Container::value_type& __value) {
iter = container->insert_after(iter, __value);
return *this;
}
insert_iterator<_Container>& operator*() { return *this; }
insert_iterator<_Container>& operator++() { return *this; }
insert_iterator<_Container>& operator++(int) { return *this; }
};
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
#pragma reset woff 1174
#pragma reset woff 1375
#endif
__STL_END_NAMESPACE
#endif /* __SGI_STL_INTERNAL_SLIST_H */
// Local Variables:
// mode:C++
// End:
~~~
参考资料：
《STL源码剖析》侯捷
[《STL源码剖析---stl_slist.h阅读笔记》](http://blog.csdn.net/kangroger/article/details/38561817)
[《STL源码剖析-- stl_slist.h》](http://blog.csdn.net/mdl13412/article/details/6648134)
- 前言
- 空间配置器
- Traits编程技术
- STL源码剖析——迭代器
- 全局函数construct(),destroy(),uninitialized_copy(),uninitialized_fill(),uninitialized_fill_n()
- 序列容器之vector
- list容器的排序算法sort()
- 序列容器之list
- 序列容器之deque
- 容器配接器之stack
- 容器配接器之queue
- 容器配接器之priority_queue
- 最大堆heap
- 单向链表slist
- RB-Tree(红黑树)
- 关联容器之set
- stl_pair.h学习
- 关联容器之map
- 关联容器之multiset
- 关联容器之multimap
- 散列表hashtable
- stl_hash_fun.h学习
- 关联容器之hash_set
- 关联容器之hash_multiset
- 关联容器之hash_map
- 关联容器之hash_multimap
- 数值算法stl_numeric.h
- stl_relops.h学习
- 基本算法stl_algobase.h
- STL算法之set集合算法
- STL算法stl_algo.h
- STL算法之sort排序算法
- STL算法之find查找算法
- STL算法之merge合并算法
- STL算法之remove删除算法
- STL算法之permutation排列组合
- STL函数对象