stl_multiset.h

// Filename:    stl_multiset.h

// Comment By:  凝霜

// E-mail:      mdl2009@vip.qq.com

// Blog:        http://blog.csdn.net/mdl13412

/*

 *

 * Copyright (c) 1994

 * Hewlett-Packard Company

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Hewlett-Packard Company makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 *

 *

 * Copyright (c) 1996

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

/* NOTE: This is an internal header file, included by other STL headers.

 *   You should not attempt to use it directly.

 */

#ifndef __SGI_STL_INTERNAL_MULTISET_H

#define __SGI_STL_INTERNAL_MULTISET_H

__STL_BEGIN_NAMESPACE

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)

#pragma set woff 1174

#endif

// 如果编译器不能根据前面模板参数推导出后面使用的默认参数类型,

// 那么就需要手工指定, 本实作multiset内部元素默认使用less进行比较

// 内部维护的数据结构是红黑树, 具有非常优秀的最坏情况的时间复杂度

// 注意: 与set不同, multiset允许有重复的元素

#ifndef __STL_LIMITED_DEFAULT_TEMPLATES

template <class Key, class Compare = less<Key>, class Alloc = alloc>

#else

template <class Key, class Compare, class Alloc = alloc>

#endif

class multiset

{

public:

  // 这里和set定义相同, 见<stl_set.h>

  typedef Key key_type;

  typedef Key value_type;

  typedef Compare key_compare;

  typedef Compare value_compare;

private:

  // 内部采用红黑树为数据结构, 其实现在<stl_tree.h>

  typedef rb_tree<key_type, value_type,

                  identity<value_type>, key_compare, Alloc> rep_type;

  rep_type t;  // red-black tree representing multiset

public:

  // 标记为'STL标准强制要求'的typedefs用于提供iterator_traits<I>支持

  // 注意: 迭代器, 引用类型都设计为const, 这是由multiset的性质决定的,

  //      如果用户自行更改其数值, 可能会导致内部的红黑树出现问题

  typedef typename rep_type::const_pointer pointer;            // STL标准强制要求

  typedef typename rep_type::const_pointer const_pointer;

  typedef typename rep_type::const_reference reference;        // STL标准强制要求

  typedef typename rep_type::const_reference const_reference;

  typedef typename rep_type::const_iterator iterator;          // STL标准强制要求

  typedef typename rep_type::const_iterator const_iterator;

  typedef typename rep_type::const_reverse_iterator reverse_iterator;

  typedef typename rep_type::const_reverse_iterator const_reverse_iterator;

  typedef typename rep_type::size_type size_type;

  typedef typename rep_type::difference_type difference_type;  // STL标准强制要求

  multiset() : t(Compare()) {}

  explicit multiset(const Compare& comp) : t(comp) {}

#ifdef __STL_MEMBER_TEMPLATES

  template <class InputIterator>

  multiset(InputIterator first, InputIterator last)

    : t(Compare()) { t.insert_equal(first, last); }

  template <class InputIterator>

  multiset(InputIterator first, InputIterator last, const Compare& comp)

    : t(comp) { t.insert_equal(first, last); }

#else

  multiset(const value_type* first, const value_type* last)

    : t(Compare()) { t.insert_equal(first, last); }

  multiset(const value_type* first, const value_type* last,

           const Compare& comp)

    : t(comp) { t.insert_equal(first, last); }

  multiset(const_iterator first, const_iterator last)

    : t(Compare()) { t.insert_equal(first, last); }

  multiset(const_iterator first, const_iterator last, const Compare& comp)

    : t(comp) { t.insert_equal(first, last); }

#endif /* __STL_MEMBER_TEMPLATES */

  multiset(const multiset<Key, Compare, Alloc>& x) : t(x.t) {}

  multiset<Key, Compare, Alloc>&

  operator=(const multiset<Key, Compare, Alloc>& x)

  {

    t = x.t;

    return *this;

  }

  // 返回用于key比较的函数

  key_compare key_comp() const { return t.key_comp(); }

  // 由于multiset的性质, value比较和key使用同一个比较函数

  value_compare value_comp() const { return t.key_comp(); }

  iterator begin() const { return t.begin(); }

  iterator end() const { return t.end(); }

  reverse_iterator rbegin() const { return t.rbegin(); }

  reverse_iterator rend() const { return t.rend(); }

  bool empty() const { return t.empty(); }

  size_type size() const { return t.size(); }

  size_type max_size() const { return t.max_size(); }

  // 这里调用的是专用的swap, 不是全局的swap, 定于于<stl_tree.h>

  void swap(multiset<Key, Compare, Alloc>& x) { t.swap(x.t); }

  // 插入元素, 注意, 插入的元素key允许重复

  iterator insert(const value_type& x)

  {

    return t.insert_equal(x);

  }

  // 在position处插入元素, 但是position仅仅是个提示, 如果给出的位置不能进行插入,

  // STL会进行查找, 这会导致很差的效率

  iterator insert(iterator position, const value_type& x)

  {

    typedef typename rep_type::iterator rep_iterator;

    return t.insert_equal((rep_iterator&)position, x);

  }

#ifdef __STL_MEMBER_TEMPLATES

  template <class InputIterator>

  void insert(InputIterator first, InputIterator last)

  {

    t.insert_equal(first, last);

  }

#else

  void insert(const value_type* first, const value_type* last) {

    t.insert_equal(first, last);

  }

  void insert(const_iterator first, const_iterator last) {

    t.insert_equal(first, last);

  }

#endif /* __STL_MEMBER_TEMPLATES */

  // 擦除指定位置的元素, 会导致内部的红黑树重新排列

  void erase(iterator position)

  {

    typedef typename rep_type::iterator rep_iterator;

    t.erase((rep_iterator&)position);

  }

  // 会返回擦除元素的个数

  size_type erase(const key_type& x)

  {

    return t.erase(x);

  }

  // 擦除指定区间的元素, 会导致红黑树有较大变化

  void erase(iterator first, iterator last)

  {

    typedef typename rep_type::iterator rep_iterator;

    t.erase((rep_iterator&)first, (rep_iterator&)last);

  }

  // 好吧, clear all, 再见吧红黑树

  void clear() { t.clear(); }

  // 查找指定的元素

  iterator find(const key_type& x) const { return t.find(x); }

  // 返回指定元素的个数

  size_type count(const key_type& x) const { return t.count(x); }

  // 返回小于当前元素的第一个可插入的位置

  iterator lower_bound(const key_type& x) const

  {

    return t.lower_bound(x);

  }

  // 返回大于当前元素的第一个可插入的位置

  iterator upper_bound(const key_type& x) const

  {

    return t.upper_bound(x);

  }

  pair<iterator,iterator> equal_range(const key_type& x) const

  {

    return t.equal_range(x);

  }

  friend bool operator== __STL_NULL_TMPL_ARGS (const multiset&,

                                               const multiset&);

  friend bool operator< __STL_NULL_TMPL_ARGS (const multiset&,

                                              const multiset&);

};

// 比较两个multiset比较的是其内部的红黑树, 会触发红黑树的operator

template <class Key, class Compare, class Alloc>

inline bool operator==(const multiset<Key, Compare, Alloc>& x,

                       const multiset<Key, Compare, Alloc>& y)

{

  return x.t == y.t;

}

template <class Key, class Compare, class Alloc>

inline bool operator<(const multiset<Key, Compare, Alloc>& x,

                      const multiset<Key, Compare, Alloc>& y)

{

  return x.t < y.t;

}

// 如果编译器支持模板函数特化优先级

// 那么将全局的swap实现为使用multiset私有的swap以提高效率

#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER

template <class Key, class Compare, class Alloc>

inline void swap(multiset<Key, Compare, Alloc>& x,

                 multiset<Key, Compare, Alloc>& y)

{

  x.swap(y);

}

#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */

#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)

#pragma reset woff 1174

#endif

__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_MULTISET_H */

// Local Variables:

// mode:C++

// End: