STL-Map 源碼剖析

 1 G++ 2.91.57，cygnus\cygwin-b20\include\g++\stl_map.h 完整列表  2 /*
 3  *  4  * Copyright (c) 1994  5  * Hewlett-Packard Company  6  *  7  * Permission to use, copy, modify, distribute and sell this software  8  * and its documentation for any purpose is hereby granted without fee,  9  * provided that the above copyright notice appear in all copies and  10  * that both that copyright notice and this permission notice appear  11  * in supporting documentation. Hewlett-Packard Company makes no  12  * representations about the suitability of this software for any  13  * purpose. It is provided "as is" without express or implied warranty.  14  *  15  *  16  * Copyright (c) 1996,1997  17  * Silicon Graphics Computer Systems, Inc.  18  *  19  * Permission to use, copy, modify, distribute and sell this software  20  * and its documentation for any purpose is hereby granted without fee,  21  * provided that the above copyright notice appear in all copies and  22  * that both that copyright notice and this permission notice appear  23  * in supporting documentation. Silicon Graphics makes no  24  * representations about the suitability of this software for any  25  * purpose. It is provided "as is" without express or implied warranty.  26  */
 27 
 28 /* NOTE: This is an internal header file, included by other STL headers.  29  * You should not attempt to use it directly.  30  */
 31 
 32 #ifndef __SGI_STL_INTERNAL_MAP_H  33 #define __SGI_STL_INTERNAL_MAP_H
 34 
 35 __STL_BEGIN_NAMESPACE  36 
 37 #if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
 38 #pragma set woff 1174
 39 #endif
 40 
 41 #ifndef __STL_LIMITED_DEFAULT_TEMPLATES  42 // 注意，如下Key 為鍵值（key）型別，T為資料（data）型別。
 43 template <class Key, class T, class Compare = less<Key>, class Alloc = alloc>
 44 #else
 45 template <class Key, class T, class Compare, class Alloc = alloc>
 46 #endif
 47 class map {  48 public:  49 
 50 // typedefs:
 51 
 52   typedef Key key_type;    // 鍵值型別
 53   typedef T data_type;        // 資料（真值）型別
 54   typedef T mapped_type;    // 
 55   typedef pair<const Key, T> value_type;    // 元素型別（鍵值/真值）
 56   typedef Compare key_compare;    // 鍵值比較函式  57     
 58   // 如下定義一個 functor，其做用就是喚起 元素比較函式。
 59   class value_compare  60     : public binary_function<value_type, value_type, bool> {  61   friend class map<Key, T, Compare, Alloc>;  62   protected :  63  Compare comp;  64  value_compare(Compare c) : comp(c) {}  65   public:  66     bool operator()(const value_type& x, const value_type& y) const {  67       return comp(x.first, y.first);  68  }  69  };  70 
 71 private:  72   // 如下定義表述型別（representation type）。以map元素型別（一個pair）  73   // 的第一型別，作為RB-tree節點的鍵值型別。
 74   typedef rb_tree<key_type, value_type,  75                   select1st<value_type>, key_compare, Alloc> rep_type;  76   rep_type t;  // 以紅黑樹（RB-tree）表現 map
 77 public:  78  typedef typename rep_type::pointer pointer;  79  typedef typename rep_type::const_pointer const_pointer;  80  typedef typename rep_type::reference reference;  81  typedef typename rep_type::const_reference const_reference;  82  typedef typename rep_type::iterator iterator;  83   // 注意上一行，為什麼不像set一樣地將iterator 定義為 RB-tree 的 const_iterator？  84   // 按說map 的元素有必定次序安排，不允許使用者在任意處作寫入動做，所以  85   // 迭代器應該無法執行寫入動做纔是。 
 86  typedef typename rep_type::const_iterator const_iterator;  87  typedef typename rep_type::reverse_iterator reverse_iterator;  88  typedef typename rep_type::const_reverse_iterator const_reverse_iterator;  89  typedef typename rep_type::size_type size_type;  90  typedef typename rep_type::difference_type difference_type;  91 
 92   // allocation/deallocation  93   // 注意， map 必定使用 insert_unique() 而不使用 insert_equal()。  94   // multimap 才使用 insert_equal()。
 95 
 96  map() : t(Compare()) {}  97   explicit map(const Compare& comp) : t(comp) {}  98 
 99 #ifdef __STL_MEMBER_TEMPLATES 100   template <class InputIterator>
101  map(InputIterator first, InputIterator last) 102  : t(Compare()) { t.insert_unique(first, last); } 103 
104   template <class InputIterator>
105   map(InputIterator first, InputIterator last, const Compare& comp) 106  : t(comp) { t.insert_unique(first, last); } 107 #else
108   map(const value_type* first, const value_type* last) 109  : t(Compare()) { t.insert_unique(first, last); } 110   map(const value_type* first, const value_type* last, const Compare& comp) 111  : t(comp) { t.insert_unique(first, last); } 112 
113  map(const_iterator first, const_iterator last) 114  : t(Compare()) { t.insert_unique(first, last); } 115   map(const_iterator first, const_iterator last, const Compare& comp) 116  : t(comp) { t.insert_unique(first, last); } 117 #endif /* __STL_MEMBER_TEMPLATES */
118 
119   map(const map<Key, T, Compare, Alloc>& x) : t(x.t) {} 120   map<Key, T, Compare, Alloc>& operator=(const map<Key, T, Compare, Alloc>& x) 121  { 122     t = x.t; 123     return *this; 124  } 125 
126   // accessors: 127   // 如下全部的 map操做行為，RB-tree 都已提供，因此map只要轉呼叫便可。
128 
129   key_compare key_comp() const { return t.key_comp(); } 130   value_compare value_comp() const { return value_compare(t.key_comp()); } 131   iterator begin() { return t.begin(); } 132   const_iterator begin() const { return t.begin(); } 133   iterator end() { return t.end(); } 134   const_iterator end() const { return t.end(); } 135   reverse_iterator rbegin() { return t.rbegin(); } 136   const_reverse_iterator rbegin() const { return t.rbegin(); } 137   reverse_iterator rend() { return t.rend(); } 138   const_reverse_iterator rend() const { return t.rend(); } 139   bool empty() const { return t.empty(); } 140   size_type size() const { return t.size(); } 141   size_type max_size() const { return t.max_size(); } 142   // 注意如下 註標（subscript）運算子
143   T& operator[](const key_type& k) { 144     return (*((insert(value_type(k, T()))).first)).second; 145  } 146   void swap(map<Key, T, Compare, Alloc>& x) { t.swap(x.t); } 147 
148   // insert/erase 149 
150   // 注意如下 insert 動做傳回的型別
151   pair<iterator,bool> insert(const value_type& x) { return t.insert_unique(x); } 152   iterator insert(iterator position, const value_type& x) { 153     return t.insert_unique(position, x); 154  } 155 #ifdef __STL_MEMBER_TEMPLATES 156   template <class InputIterator>
157   void insert(InputIterator first, InputIterator last) { 158  t.insert_unique(first, last); 159  } 160 #else
161   void insert(const value_type* first, const value_type* last) { 162  t.insert_unique(first, last); 163  } 164   void insert(const_iterator first, const_iterator last) { 165  t.insert_unique(first, last); 166  } 167 #endif /* __STL_MEMBER_TEMPLATES */
168 
169   void erase(iterator position) { t.erase(position); } 170   size_type erase(const key_type& x) { return t.erase(x); } 171   void erase(iterator first, iterator last) { t.erase(first, last); } 172   void clear() { t.clear(); } 173 
174   // map operations:
175 
176   iterator find(const key_type& x) { return t.find(x); } 177   const_iterator find(const key_type& x) const { return t.find(x); } 178   size_type count(const key_type& x) const { return t.count(x); } 179   iterator lower_bound(const key_type& x) {return t.lower_bound(x); } 180   const_iterator lower_bound(const key_type& x) const { 181     return t.lower_bound(x); 182  } 183   iterator upper_bound(const key_type& x) {return t.upper_bound(x); } 184   const_iterator upper_bound(const key_type& x) const { 185     return t.upper_bound(x); 186  } 187   
188   pair<iterator,iterator> equal_range(const key_type& x) { 189     return t.equal_range(x); 190  } 191   pair<const_iterator,const_iterator> equal_range(const key_type& x) const { 192     return t.equal_range(x); 193  } 194   friend bool operator== __STL_NULL_TMPL_ARGS (const map&, const map&); 195   friend bool operator< __STL_NULL_TMPL_ARGS (const map&, const map&); 196 }; 197 
198 template <class Key, class T, class Compare, class Alloc>
199 inline bool operator==(const map<Key, T, Compare, Alloc>& x, 200                        const map<Key, T, Compare, Alloc>& y) { 201   return x.t == y.t; 202 } 203 
204 template <class Key, class T, class Compare, class Alloc>
205 inline bool operator<(const map<Key, T, Compare, Alloc>& x, 206                       const map<Key, T, Compare, Alloc>& y) { 207   return x.t < y.t; 208 } 209 
210 #ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER 211 
212 template <class Key, class T, class Compare, class Alloc>
213 inline void swap(map<Key, T, Compare, Alloc>& x, 214                  map<Key, T, Compare, Alloc>& y) { 215  x.swap(y); 216 } 217 
218 #endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */
219 
220 #if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)
221 #pragma reset woff 1174
222 #endif
223 
224 __STL_END_NAMESPACE 225 
226 #endif /* __SGI_STL_INTERNAL_MAP_H */
227 
228 // Local Variables: 229 // mode:C++ 230 // End: