libstdc++-v3/include/ext/pb_ds/tag_and_trait.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  19 // MA 02111-1307, USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
  36 // and this permission notice appear in supporting documentation. None
  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
  39 // purpose. It is provided "as is" without express or implied
  40 // warranty.
  41
  42 /**
  43  * @file tag_and_trait.hpp
  44  * Contains tags and traits, e.g., ones describing underlying
  45  *    data structures.
  46  */
  47
  48 #ifndef PB_DS_TAG_AND_TRAIT_HPP
  49 #define PB_DS_TAG_AND_TRAIT_HPP
  50
  51 #include <ext/pb_ds/detail/type_utils.hpp>
  52
  53 /**
  54  * @namespace __gnu_pbds
  55  * @brief GNU extension policy-based data structures for public use.
  56  */
  57
  58 namespace __gnu_pbds
  59 {
  60   // A trivial iterator tag. Signifies that the iterators has none of
  61   // the STL's movement abilities.
  62   struct trivial_iterator_tag
  63   { };
  64
  65   // Prohibit moving trivial iterators.
  66   typedef void trivial_iterator_difference_type;
  67
  68
  69   // Signifies a basic invalidation guarantee that any iterator,
  70   // pointer, or reference to a container object's mapped value type
  71   // is valid as long as the container is not modified.
  72   struct basic_invalidation_guarantee
  73   { };
  74
  75   // Signifies an invalidation guarantee that includes all those of
  76   // its base, and additionally, that any point-type iterator,
  77   // pointer, or reference to a container object's mapped value type
  78   // is valid as long as its corresponding entry has not be erased,
  79   // regardless of modifications to the container object.
  80   struct point_invalidation_guarantee : public basic_invalidation_guarantee
  81   { };
  82
  83   // Signifies an invalidation guarantee that includes all those of
  84   // its base, and additionally, that any range-type iterator
  85   // (including the returns of begin() and end()) is in the correct
  86   // relative positions to other range-type iterators as long as its
  87   // corresponding entry has not be erased, regardless of
  88   // modifications to the container object.
  89   struct range_invalidation_guarantee : public point_invalidation_guarantee
  90   { };
  91
  92
  93   // A mapped-policy indicating that an associative container is a set.
  94   // XXX should this be a trait of the form is_set<T> ??
  95   struct null_mapped_type { };
  96
  97
  98   // Base data structure tag.
  99   struct container_tag
 100   { };
 101
 102   // Basic associative-container.
 103   struct associative_container_tag : public container_tag { };
 104
 105   // Basic hash.
 106   struct basic_hash_tag : public associative_container_tag { };
 107
 108   // Collision-chaining hash.
 109   struct cc_hash_tag : public basic_hash_tag { };
 110
 111   // General-probing hash.
 112   struct gp_hash_tag : public basic_hash_tag { };
 113
 114   // Basic tree.
 115   struct basic_tree_tag : public associative_container_tag { };
 116
 117   // tree.
 118   struct tree_tag : public basic_tree_tag { };
 119
 120   // Red-black tree.
 121   struct rb_tree_tag : public tree_tag { };
 122
 123   // Splay tree.
 124   struct splay_tree_tag : public tree_tag { };
 125
 126   // Ordered-vector tree.
 127   struct ov_tree_tag : public tree_tag { };
 128
 129   // trie.
 130   struct trie_tag : public basic_tree_tag { };
 131
 132   // PATRICIA trie.
 133   struct pat_trie_tag : public trie_tag { };
 134
 135   // List-update.
 136   struct list_update_tag : public associative_container_tag { };
 137
 138   // Basic priority-queue.
 139   struct priority_queue_tag : public container_tag { };
 140
 141   // Pairing-heap.
 142   struct pairing_heap_tag : public priority_queue_tag { };
 143
 144   // Binomial-heap.
 145   struct binomial_heap_tag : public priority_queue_tag { };
 146
 147   // Redundant-counter binomial-heap.
 148   struct rc_binomial_heap_tag : public priority_queue_tag { };
 149
 150   // Binary-heap (array-based).
 151   struct binary_heap_tag : public priority_queue_tag { };
 152
 153   // Thin heap.
 154   struct thin_heap_tag : public priority_queue_tag { };
 155
 156
 157   template<typename Tag>
 158   struct container_traits_base;
 159
 160   template<>
 161   struct container_traits_base<cc_hash_tag>
 162   {
 163     typedef cc_hash_tag container_category;
 164     typedef point_invalidation_guarantee invalidation_guarantee;
 165
 166     enum
 167       {
 168         order_preserving = false,
 169         erase_can_throw = false,
 170         split_join_can_throw = false,
 171         reverse_iteration = false
 172       };
 173   };
 174
 175   template<>
 176   struct container_traits_base<gp_hash_tag>
 177   {
 178     typedef gp_hash_tag container_category;
 179     typedef basic_invalidation_guarantee invalidation_guarantee;
 180
 181     enum
 182       {
 183         order_preserving = false,
 184         erase_can_throw = false,
 185         split_join_can_throw = false,
 186         reverse_iteration = false
 187       };
 188   };
 189
 190   template<>
 191   struct container_traits_base<rb_tree_tag>
 192   {
 193     typedef rb_tree_tag container_category;
 194     typedef range_invalidation_guarantee invalidation_guarantee;
 195
 196     enum
 197       {
 198         order_preserving = true,
 199         erase_can_throw = false,
 200         split_join_can_throw = false,
 201         reverse_iteration = true
 202       };
 203   };
 204
 205   template<>
 206   struct container_traits_base<splay_tree_tag>
 207   {
 208     typedef splay_tree_tag container_category;
 209     typedef range_invalidation_guarantee invalidation_guarantee;
 210
 211     enum
 212       {
 213         order_preserving = true,
 214         erase_can_throw = false,
 215         split_join_can_throw = false,
 216         reverse_iteration = true
 217       };
 218   };
 219
 220   template<>
 221   struct container_traits_base<ov_tree_tag>
 222   {
 223     typedef ov_tree_tag container_category;
 224     typedef basic_invalidation_guarantee invalidation_guarantee;
 225
 226     enum
 227       {
 228         order_preserving = true,
 229         erase_can_throw = true,
 230         split_join_can_throw = true,
 231         reverse_iteration = false
 232       };
 233   };
 234
 235   template<>
 236   struct container_traits_base<pat_trie_tag>
 237   {
 238     typedef pat_trie_tag container_category;
 239     typedef range_invalidation_guarantee invalidation_guarantee;
 240
 241     enum
 242       {
 243         order_preserving = true,
 244         erase_can_throw = false,
 245         split_join_can_throw = true,
 246         reverse_iteration = true
 247       };
 248   };
 249
 250   template<>
 251   struct container_traits_base<list_update_tag>
 252   {
 253     typedef list_update_tag container_category;
 254     typedef point_invalidation_guarantee invalidation_guarantee;
 255
 256     enum
 257       {
 258         order_preserving = false,
 259         erase_can_throw = false,
 260         split_join_can_throw = false,
 261         reverse_iteration = false
 262       };
 263   };
 264
 265
 266   template<>
 267   struct container_traits_base<pairing_heap_tag>
 268   {
 269     typedef pairing_heap_tag container_category;
 270     typedef point_invalidation_guarantee invalidation_guarantee;
 271
 272     enum
 273       {
 274         order_preserving = false,
 275         erase_can_throw = false,
 276         split_join_can_throw = false,
 277         reverse_iteration = false
 278       };
 279   };
 280
 281   template<>
 282   struct container_traits_base<thin_heap_tag>
 283   {
 284     typedef thin_heap_tag container_category;
 285     typedef point_invalidation_guarantee invalidation_guarantee;
 286
 287     enum
 288       {
 289         order_preserving = false,
 290         erase_can_throw = false,
 291         split_join_can_throw = false,
 292         reverse_iteration = false
 293       };
 294   };
 295
 296   template<>
 297   struct container_traits_base<binomial_heap_tag>
 298   {
 299     typedef binomial_heap_tag container_category;
 300     typedef point_invalidation_guarantee invalidation_guarantee;
 301
 302     enum
 303       {
 304         order_preserving = false,
 305         erase_can_throw = false,
 306         split_join_can_throw = false,
 307         reverse_iteration = false
 308       };
 309   };
 310
 311   template<>
 312   struct container_traits_base<rc_binomial_heap_tag>
 313   {
 314     typedef rc_binomial_heap_tag container_category;
 315     typedef point_invalidation_guarantee invalidation_guarantee;
 316
 317     enum
 318       {
 319         order_preserving = false,
 320         erase_can_throw = false,
 321         split_join_can_throw = false,
 322         reverse_iteration = false
 323       };
 324   };
 325
 326   template<>
 327   struct container_traits_base<binary_heap_tag>
 328   {
 329     typedef binary_heap_tag container_category;
 330     typedef basic_invalidation_guarantee invalidation_guarantee;
 331
 332     enum
 333       {
 334         order_preserving = false,
 335         erase_can_throw = false,
 336         split_join_can_throw = true,
 337         reverse_iteration = false
 338       };
 339   };
 340
 341
 342   // See Matt Austern for the name, S. Meyers MEFC++ #2, others.
 343   template<typename Cntnr>
 344   struct container_traits
 345   : public container_traits_base<typename Cntnr::container_category>
 346   {
 347     typedef Cntnr container_type;
 348     typedef typename Cntnr::container_category container_category;
 349     typedef container_traits_base<container_category> base_type;
 350     typedef typename base_type::invalidation_guarantee invalidation_guarantee;
 351
 352     enum
 353       {
 354         order_preserving = base_type::order_preserving,
 355         erase_can_throw = base_type::erase_can_throw,
 356         split_join_can_throw = base_type::split_join_can_throw,
 357         reverse_iteration = base_type::reverse_iteration
 358       };
 359   };
 360 } // namespace __gnu_pbds
 361
 362 #endif