libstdc++-v3/include/bits/stl_set.h

   1 // Set implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /*
  32  *
  33  * Copyright (c) 1994
  34  * Hewlett-Packard Company
  35  *
  36  * Permission to use, copy, modify, distribute and sell this software
  37  * and its documentation for any purpose is hereby granted without fee,
  38  * provided that the above copyright notice appear in all copies and
  39  * that both that copyright notice and this permission notice appear
  40  * in supporting documentation.  Hewlett-Packard Company makes no
  41  * representations about the suitability of this software for any
  42  * purpose.  It is provided "as is" without express or implied warranty.
  43  *
  44  *
  45  * Copyright (c) 1996,1997
  46  * Silicon Graphics Computer Systems, Inc.
  47  *
  48  * Permission to use, copy, modify, distribute and sell this software
  49  * and its documentation for any purpose is hereby granted without fee,
  50  * provided that the above copyright notice appear in all copies and
  51  * that both that copyright notice and this permission notice appear
  52  * in supporting documentation.  Silicon Graphics makes no
  53  * representations about the suitability of this software for any
  54  * purpose.  It is provided "as is" without express or implied warranty.
  55  */
  56
  57 /** @file stl_set.h
  58  *  This is an internal header file, included by other library headers.
  59  *  You should not attempt to use it directly.
  60  */
  61
  62 #ifndef _STL_SET_H
  63 #define _STL_SET_H 1
  64
  65 #include <bits/concept_check.h>
  66
  67 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
  68
  69   /**
  70    *  @brief A standard container made up of unique keys, which can be
  71    *  retrieved in logarithmic time.
  72    *
  73    *  @ingroup Containers
  74    *  @ingroup Assoc_containers
  75    *
  76    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  77    *  <a href="tables.html#66">reversible container</a>, and an
  78    *  <a href="tables.html#69">associative container</a> (using unique keys).
  79    *
  80    *  Sets support bidirectional iterators.
  81    *
  82    *  @param  Key  Type of key objects.
  83    *  @param  Compare  Comparison function object type, defaults to less<Key>.
  84    *  @param  Alloc  Allocator type, defaults to allocator<Key>.
  85    *
  86    *  @if maint
  87    *  The private tree data is declared exactly the same way for set and
  88    *  multiset; the distinction is made entirely in how the tree functions are
  89    *  called (*_unique versus *_equal, same as the standard).
  90    *  @endif
  91   */
  92   template<class _Key, class _Compare = std::less<_Key>,
  93            class _Alloc = std::allocator<_Key> >
  94     class set
  95     {
  96       // concept requirements
  97       typedef typename _Alloc::value_type                   _Alloc_value_type;
  98       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
  99       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
 100                                 _BinaryFunctionConcept)
 101       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
 102
 103     public:
 104       // typedefs:
 105       //@{
 106       /// Public typedefs.
 107       typedef _Key     key_type;
 108       typedef _Key     value_type;
 109       typedef _Compare key_compare;
 110       typedef _Compare value_compare;
 111       typedef _Alloc   allocator_type;
 112       //@}
 113
 114     private:
 115       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
 116
 117       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
 118                        key_compare, _Key_alloc_type> _Rep_type;
 119       _Rep_type _M_t;  // red-black tree representing set
 120
 121     public:
 122       //@{
 123       ///  Iterator-related typedefs.
 124       typedef typename _Key_alloc_type::pointer             pointer;
 125       typedef typename _Key_alloc_type::const_pointer       const_pointer;
 126       typedef typename _Key_alloc_type::reference           reference;
 127       typedef typename _Key_alloc_type::const_reference     const_reference;
 128       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 129       // DR 103. set::iterator is required to be modifiable,
 130       // but this allows modification of keys.
 131       typedef typename _Rep_type::const_iterator            iterator;
 132       typedef typename _Rep_type::const_iterator            const_iterator;
 133       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
 134       typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;
 135       typedef typename _Rep_type::size_type                 size_type;
 136       typedef typename _Rep_type::difference_type           difference_type;
 137       //@}
 138
 139       // allocation/deallocation
 140       ///  Default constructor creates no elements.
 141       set()
 142       : _M_t(_Compare(), allocator_type()) {}
 143
 144       /**
 145        *  @brief  Default constructor creates no elements.
 146        *
 147        *  @param  comp  Comparator to use.
 148        *  @param  a  Allocator to use.
 149        */
 150       explicit
 151       set(const _Compare& __comp,
 152           const allocator_type& __a = allocator_type())
 153       : _M_t(__comp, __a) {}
 154
 155       /**
 156        *  @brief  Builds a %set from a range.
 157        *  @param  first  An input iterator.
 158        *  @param  last  An input iterator.
 159        *
 160        *  Create a %set consisting of copies of the elements from [first,last).
 161        *  This is linear in N if the range is already sorted, and NlogN
 162        *  otherwise (where N is distance(first,last)).
 163        */
 164       template<class _InputIterator>
 165         set(_InputIterator __first, _InputIterator __last)
 166         : _M_t(_Compare(), allocator_type())
 167         { _M_t._M_insert_unique(__first, __last); }
 168
 169       /**
 170        *  @brief  Builds a %set from a range.
 171        *  @param  first  An input iterator.
 172        *  @param  last  An input iterator.
 173        *  @param  comp  A comparison functor.
 174        *  @param  a  An allocator object.
 175        *
 176        *  Create a %set consisting of copies of the elements from [first,last).
 177        *  This is linear in N if the range is already sorted, and NlogN
 178        *  otherwise (where N is distance(first,last)).
 179        */
 180       template<class _InputIterator>
 181         set(_InputIterator __first, _InputIterator __last,
 182             const _Compare& __comp,
 183             const allocator_type& __a = allocator_type())
 184         : _M_t(__comp, __a)
 185         { _M_t._M_insert_unique(__first, __last); }
 186
 187       /**
 188        *  @brief  Set copy constructor.
 189        *  @param  x  A %set of identical element and allocator types.
 190        *
 191        *  The newly-created %set uses a copy of the allocation object used
 192        *  by @a x.
 193        */
 194       set(const set<_Key,_Compare,_Alloc>& __x)
 195       : _M_t(__x._M_t) { }
 196
 197       /**
 198        *  @brief  Set assignment operator.
 199        *  @param  x  A %set of identical element and allocator types.
 200        *
 201        *  All the elements of @a x are copied, but unlike the copy constructor,
 202        *  the allocator object is not copied.
 203        */
 204       set<_Key,_Compare,_Alloc>&
 205       operator=(const set<_Key, _Compare, _Alloc>& __x)
 206       {
 207         _M_t = __x._M_t;
 208         return *this;
 209       }
 210
 211       // accessors:
 212
 213       ///  Returns the comparison object with which the %set was constructed.
 214       key_compare
 215       key_comp() const
 216       { return _M_t.key_comp(); }
 217       ///  Returns the comparison object with which the %set was constructed.
 218       value_compare
 219       value_comp() const
 220       { return _M_t.key_comp(); }
 221       ///  Returns the allocator object with which the %set was constructed.
 222       allocator_type
 223       get_allocator() const
 224       { return _M_t.get_allocator(); }
 225
 226       /**
 227        *  Returns a read/write iterator that points to the first element in the
 228        *  %set.  Iteration is done in ascending order according to the keys.
 229        */
 230       iterator
 231       begin() const
 232       { return _M_t.begin(); }
 233
 234       /**
 235        *  Returns a read/write iterator that points one past the last element in
 236        *  the %set.  Iteration is done in ascending order according to the keys.
 237        */
 238       iterator
 239       end() const
 240       { return _M_t.end(); }
 241
 242       /**
 243        *  Returns a read/write reverse iterator that points to the last element
 244        *  in the %set.  Iteration is done in descending order according to the
 245        *  keys.
 246        */
 247       reverse_iterator
 248       rbegin() const
 249       { return _M_t.rbegin(); }
 250
 251       /**
 252        *  Returns a read-only (constant) reverse iterator that points to the
 253        *  last pair in the %map.  Iteration is done in descending order
 254        *  according to the keys.
 255        */
 256       reverse_iterator
 257       rend() const
 258       { return _M_t.rend(); }
 259
 260       ///  Returns true if the %set is empty.
 261       bool
 262       empty() const
 263       { return _M_t.empty(); }
 264
 265       ///  Returns the size of the %set.
 266       size_type
 267       size() const
 268       { return _M_t.size(); }
 269
 270       ///  Returns the maximum size of the %set.
 271       size_type
 272       max_size() const
 273       { return _M_t.max_size(); }
 274
 275       /**
 276        *  @brief  Swaps data with another %set.
 277        *  @param  x  A %set of the same element and allocator types.
 278        *
 279        *  This exchanges the elements between two sets in constant time.
 280        *  (It is only swapping a pointer, an integer, and an instance of
 281        *  the @c Compare type (which itself is often stateless and empty), so it
 282        *  should be quite fast.)
 283        *  Note that the global std::swap() function is specialized such that
 284        *  std::swap(s1,s2) will feed to this function.
 285        */
 286       void
 287       swap(set<_Key,_Compare,_Alloc>& __x)
 288       { _M_t.swap(__x._M_t); }
 289
 290       // insert/erase
 291       /**
 292        *  @brief Attempts to insert an element into the %set.
 293        *  @param  x  Element to be inserted.
 294        *  @return  A pair, of which the first element is an iterator that points
 295        *           to the possibly inserted element, and the second is a bool
 296        *           that is true if the element was actually inserted.
 297        *
 298        *  This function attempts to insert an element into the %set.  A %set
 299        *  relies on unique keys and thus an element is only inserted if it is
 300        *  not already present in the %set.
 301        *
 302        *  Insertion requires logarithmic time.
 303        */
 304       std::pair<iterator,bool>
 305       insert(const value_type& __x)
 306       {
 307         std::pair<typename _Rep_type::iterator, bool> __p =
 308           _M_t._M_insert_unique(__x);
 309         return std::pair<iterator, bool>(__p.first, __p.second);
 310       }
 311
 312       /**
 313        *  @brief Attempts to insert an element into the %set.
 314        *  @param  position  An iterator that serves as a hint as to where the
 315        *                    element should be inserted.
 316        *  @param  x  Element to be inserted.
 317        *  @return  An iterator that points to the element with key of @a x (may
 318        *           or may not be the element passed in).
 319        *
 320        *  This function is not concerned about whether the insertion took place,
 321        *  and thus does not return a boolean like the single-argument insert()
 322        *  does.  Note that the first parameter is only a hint and can
 323        *  potentially improve the performance of the insertion process.  A bad
 324        *  hint would cause no gains in efficiency.
 325        *
 326        *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
 327        *  for more on "hinting".
 328        *
 329        *  Insertion requires logarithmic time (if the hint is not taken).
 330        */
 331       iterator
 332       insert(iterator __position, const value_type& __x)
 333       { return _M_t._M_insert_unique_(__position, __x); }
 334
 335       /**
 336        *  @brief A template function that attemps to insert a range of elements.
 337        *  @param  first  Iterator pointing to the start of the range to be
 338        *                 inserted.
 339        *  @param  last  Iterator pointing to the end of the range.
 340        *
 341        *  Complexity similar to that of the range constructor.
 342        */
 343       template<class _InputIterator>
 344         void
 345         insert(_InputIterator __first, _InputIterator __last)
 346         { _M_t._M_insert_unique(__first, __last); }
 347
 348       /**
 349        *  @brief Erases an element from a %set.
 350        *  @param  position  An iterator pointing to the element to be erased.
 351        *
 352        *  This function erases an element, pointed to by the given iterator,
 353        *  from a %set.  Note that this function only erases the element, and
 354        *  that if the element is itself a pointer, the pointed-to memory is not
 355        *  touched in any way.  Managing the pointer is the user's responsibilty.
 356        */
 357       void
 358       erase(iterator __position)
 359       { _M_t.erase(__position); }
 360
 361       /**
 362        *  @brief Erases elements according to the provided key.
 363        *  @param  x  Key of element to be erased.
 364        *  @return  The number of elements erased.
 365        *
 366        *  This function erases all the elements located by the given key from
 367        *  a %set.
 368        *  Note that this function only erases the element, and that if
 369        *  the element is itself a pointer, the pointed-to memory is not touched
 370        *  in any way.  Managing the pointer is the user's responsibilty.
 371        */
 372       size_type
 373       erase(const key_type& __x)
 374       { return _M_t.erase(__x); }
 375
 376       /**
 377        *  @brief Erases a [first,last) range of elements from a %set.
 378        *  @param  first  Iterator pointing to the start of the range to be
 379        *                 erased.
 380        *  @param  last  Iterator pointing to the end of the range to be erased.
 381        *
 382        *  This function erases a sequence of elements from a %set.
 383        *  Note that this function only erases the element, and that if
 384        *  the element is itself a pointer, the pointed-to memory is not touched
 385        *  in any way.  Managing the pointer is the user's responsibilty.
 386        */
 387       void
 388       erase(iterator __first, iterator __last)
 389       { _M_t.erase(__first, __last); }
 390
 391       /**
 392        *  Erases all elements in a %set.  Note that this function only erases
 393        *  the elements, and that if the elements themselves are pointers, the
 394        *  pointed-to memory is not touched in any way.  Managing the pointer is
 395        *  the user's responsibilty.
 396        */
 397       void
 398       clear()
 399       { _M_t.clear(); }
 400
 401       // set operations:
 402
 403       /**
 404        *  @brief  Finds the number of elements.
 405        *  @param  x  Element to located.
 406        *  @return  Number of elements with specified key.
 407        *
 408        *  This function only makes sense for multisets; for set the result will
 409        *  either be 0 (not present) or 1 (present).
 410        */
 411       size_type
 412       count(const key_type& __x) const
 413       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
 414
 415       // _GLIBCXX_RESOLVE_LIB_DEFECTS
 416       // 214.  set::find() missing const overload
 417       //@{
 418       /**
 419        *  @brief Tries to locate an element in a %set.
 420        *  @param  x  Element to be located.
 421        *  @return  Iterator pointing to sought-after element, or end() if not
 422        *           found.
 423        *
 424        *  This function takes a key and tries to locate the element with which
 425        *  the key matches.  If successful the function returns an iterator
 426        *  pointing to the sought after element.  If unsuccessful it returns the
 427        *  past-the-end ( @c end() ) iterator.
 428        */
 429       iterator
 430       find(const key_type& __x)
 431       { return _M_t.find(__x); }
 432
 433       const_iterator
 434       find(const key_type& __x) const
 435       { return _M_t.find(__x); }
 436       //@}
 437
 438       //@{
 439       /**
 440        *  @brief Finds the beginning of a subsequence matching given key.
 441        *  @param  x  Key to be located.
 442        *  @return  Iterator pointing to first element equal to or greater
 443        *           than key, or end().
 444        *
 445        *  This function returns the first element of a subsequence of elements
 446        *  that matches the given key.  If unsuccessful it returns an iterator
 447        *  pointing to the first element that has a greater value than given key
 448        *  or end() if no such element exists.
 449        */
 450       iterator
 451       lower_bound(const key_type& __x)
 452       { return _M_t.lower_bound(__x); }
 453
 454       const_iterator
 455       lower_bound(const key_type& __x) const
 456       { return _M_t.lower_bound(__x); }
 457       //@}
 458
 459       //@{
 460       /**
 461        *  @brief Finds the end of a subsequence matching given key.
 462        *  @param  x  Key to be located.
 463        *  @return Iterator pointing to the first element
 464        *          greater than key, or end().
 465        */
 466       iterator
 467       upper_bound(const key_type& __x)
 468       { return _M_t.upper_bound(__x); }
 469
 470       const_iterator
 471       upper_bound(const key_type& __x) const
 472       { return _M_t.upper_bound(__x); }
 473       //@}
 474
 475       //@{
 476       /**
 477        *  @brief Finds a subsequence matching given key.
 478        *  @param  x  Key to be located.
 479        *  @return  Pair of iterators that possibly points to the subsequence
 480        *           matching given key.
 481        *
 482        *  This function is equivalent to
 483        *  @code
 484        *    std::make_pair(c.lower_bound(val),
 485        *                   c.upper_bound(val))
 486        *  @endcode
 487        *  (but is faster than making the calls separately).
 488        *
 489        *  This function probably only makes sense for multisets.
 490        */
 491       std::pair<iterator, iterator>
 492       equal_range(const key_type& __x)
 493       { return _M_t.equal_range(__x); }
 494
 495       std::pair<const_iterator, const_iterator>
 496       equal_range(const key_type& __x) const
 497       { return _M_t.equal_range(__x); }
 498       //@}
 499
 500       template<class _K1, class _C1, class _A1>
 501         friend bool
 502         operator== (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
 503
 504       template<class _K1, class _C1, class _A1>
 505         friend bool
 506         operator< (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
 507     };
 508
 509
 510   /**
 511    *  @brief  Set equality comparison.
 512    *  @param  x  A %set.
 513    *  @param  y  A %set of the same type as @a x.
 514    *  @return  True iff the size and elements of the sets are equal.
 515    *
 516    *  This is an equivalence relation.  It is linear in the size of the sets.
 517    *  Sets are considered equivalent if their sizes are equal, and if
 518    *  corresponding elements compare equal.
 519   */
 520   template<class _Key, class _Compare, class _Alloc>
 521     inline bool
 522     operator==(const set<_Key, _Compare, _Alloc>& __x,
 523                const set<_Key, _Compare, _Alloc>& __y)
 524     { return __x._M_t == __y._M_t; }
 525
 526   /**
 527    *  @brief  Set ordering relation.
 528    *  @param  x  A %set.
 529    *  @param  y  A %set of the same type as @a x.
 530    *  @return  True iff @a x is lexicographically less than @a y.
 531    *
 532    *  This is a total ordering relation.  It is linear in the size of the
 533    *  maps.  The elements must be comparable with @c <.
 534    *
 535    *  See std::lexicographical_compare() for how the determination is made.
 536   */
 537   template<class _Key, class _Compare, class _Alloc>
 538     inline bool
 539     operator<(const set<_Key, _Compare, _Alloc>& __x,
 540               const set<_Key, _Compare, _Alloc>& __y)
 541     { return __x._M_t < __y._M_t; }
 542
 543   ///  Returns !(x == y).
 544   template<class _Key, class _Compare, class _Alloc>
 545     inline bool
 546     operator!=(const set<_Key, _Compare, _Alloc>& __x,
 547                const set<_Key, _Compare, _Alloc>& __y)
 548     { return !(__x == __y); }
 549
 550   ///  Returns y < x.
 551   template<class _Key, class _Compare, class _Alloc>
 552     inline bool
 553     operator>(const set<_Key, _Compare, _Alloc>& __x,
 554               const set<_Key, _Compare, _Alloc>& __y)
 555     { return __y < __x; }
 556
 557   ///  Returns !(y < x)
 558   template<class _Key, class _Compare, class _Alloc>
 559     inline bool
 560     operator<=(const set<_Key, _Compare, _Alloc>& __x,
 561                const set<_Key, _Compare, _Alloc>& __y)
 562     { return !(__y < __x); }
 563
 564   ///  Returns !(x < y)
 565   template<class _Key, class _Compare, class _Alloc>
 566     inline bool
 567     operator>=(const set<_Key, _Compare, _Alloc>& __x,
 568                const set<_Key, _Compare, _Alloc>& __y)
 569     { return !(__x < __y); }
 570
 571   /// See std::set::swap().
 572   template<class _Key, class _Compare, class _Alloc>
 573     inline void
 574     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
 575     { __x.swap(__y); }
 576
 577 _GLIBCXX_END_NESTED_NAMESPACE
 578
 579 #endif /* _STL_SET_H */