stl_set.h

Go to the documentation of this file.
00001 // Set implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001, 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 /*
00031  *
00032  * Copyright (c) 1994
00033  * Hewlett-Packard Company
00034  *
00035  * Permission to use, copy, modify, distribute and sell this software
00036  * and its documentation for any purpose is hereby granted without fee,
00037  * provided that the above copyright notice appear in all copies and
00038  * that both that copyright notice and this permission notice appear
00039  * in supporting documentation.  Hewlett-Packard Company makes no
00040  * representations about the suitability of this software for any
00041  * purpose.  It is provided "as is" without express or implied warranty.
00042  *
00043  *
00044  * Copyright (c) 1996,1997
00045  * Silicon Graphics Computer Systems, Inc.
00046  *
00047  * Permission to use, copy, modify, distribute and sell this software
00048  * and its documentation for any purpose is hereby granted without fee,
00049  * provided that the above copyright notice appear in all copies and
00050  * that both that copyright notice and this permission notice appear
00051  * in supporting documentation.  Silicon Graphics makes no
00052  * representations about the suitability of this software for any
00053  * purpose.  It is provided "as is" without express or implied warranty.
00054  */
00055 
00056 /** @file stl_set.h
00057  *  This is an internal header file, included by other library headers.
00058  *  You should not attempt to use it directly.
00059  */
00060 
00061 #ifndef _SET_H
00062 #define _SET_H 1
00063 
00064 #include <bits/concept_check.h>
00065 
00066 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
00067 
00068   /**
00069    *  @brief A standard container made up of unique keys, which can be
00070    *  retrieved in logarithmic time.
00071    *
00072    *  @ingroup Containers
00073    *  @ingroup Assoc_containers
00074    *
00075    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00076    *  <a href="tables.html#66">reversible container</a>, and an
00077    *  <a href="tables.html#69">associative container</a> (using unique keys).
00078    *
00079    *  Sets support bidirectional iterators.
00080    *
00081    *  @param  Key  Type of key objects.
00082    *  @param  Compare  Comparison function object type, defaults to less<Key>.
00083    *  @param  Alloc  Allocator type, defaults to allocator<Key>.
00084    *
00085    *  @if maint
00086    *  The private tree data is declared exactly the same way for set and
00087    *  multiset; the distinction is made entirely in how the tree functions are
00088    *  called (*_unique versus *_equal, same as the standard).
00089    *  @endif
00090   */
00091   template<class _Key, class _Compare = std::less<_Key>,
00092        class _Alloc = std::allocator<_Key> >
00093     class set
00094     {
00095       // concept requirements
00096       typedef typename _Alloc::value_type                   _Alloc_value_type;
00097       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
00098       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
00099                 _BinaryFunctionConcept)
00100       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)  
00101 
00102     public:
00103       // typedefs:
00104       //@{
00105       /// Public typedefs.
00106       typedef _Key     key_type;
00107       typedef _Key     value_type;
00108       typedef _Compare key_compare;
00109       typedef _Compare value_compare;
00110       typedef _Alloc   allocator_type;
00111       //@}
00112 
00113     private:
00114       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
00115 
00116       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
00117                key_compare, _Key_alloc_type> _Rep_type;
00118       _Rep_type _M_t;  // red-black tree representing set
00119 
00120     public:
00121       //@{
00122       ///  Iterator-related typedefs.
00123       typedef typename _Key_alloc_type::pointer             pointer;
00124       typedef typename _Key_alloc_type::const_pointer       const_pointer;
00125       typedef typename _Key_alloc_type::reference           reference;
00126       typedef typename _Key_alloc_type::const_reference     const_reference;
00127       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00128       // DR 103. set::iterator is required to be modifiable,
00129       // but this allows modification of keys.
00130       typedef typename _Rep_type::const_iterator            iterator;
00131       typedef typename _Rep_type::const_iterator            const_iterator;
00132       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
00133       typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;
00134       typedef typename _Rep_type::size_type                 size_type;
00135       typedef typename _Rep_type::difference_type           difference_type;
00136       //@}
00137 
00138       // allocation/deallocation
00139       ///  Default constructor creates no elements.
00140       set()
00141       : _M_t(_Compare(), allocator_type()) {}
00142 
00143       /**
00144        *  @brief  Default constructor creates no elements.
00145        *
00146        *  @param  comp  Comparator to use.
00147        *  @param  a  Allocator to use.
00148        */
00149       explicit
00150       set(const _Compare& __comp,
00151       const allocator_type& __a = allocator_type())
00152       : _M_t(__comp, __a) {}
00153 
00154       /**
00155        *  @brief  Builds a %set from a range.
00156        *  @param  first  An input iterator.
00157        *  @param  last  An input iterator.
00158        *
00159        *  Create a %set consisting of copies of the elements from [first,last).
00160        *  This is linear in N if the range is already sorted, and NlogN
00161        *  otherwise (where N is distance(first,last)).
00162        */
00163       template<class _InputIterator>
00164         set(_InputIterator __first, _InputIterator __last)
00165         : _M_t(_Compare(), allocator_type())
00166         { _M_t._M_insert_unique(__first, __last); }
00167 
00168       /**
00169        *  @brief  Builds a %set from a range.
00170        *  @param  first  An input iterator.
00171        *  @param  last  An input iterator.
00172        *  @param  comp  A comparison functor.
00173        *  @param  a  An allocator object.
00174        *
00175        *  Create a %set consisting of copies of the elements from [first,last).
00176        *  This is linear in N if the range is already sorted, and NlogN
00177        *  otherwise (where N is distance(first,last)).
00178        */
00179       template<class _InputIterator>
00180         set(_InputIterator __first, _InputIterator __last,
00181         const _Compare& __comp,
00182         const allocator_type& __a = allocator_type())
00183     : _M_t(__comp, __a)
00184         { _M_t._M_insert_unique(__first, __last); }
00185 
00186       /**
00187        *  @brief  Set copy constructor.
00188        *  @param  x  A %set of identical element and allocator types.
00189        *
00190        *  The newly-created %set uses a copy of the allocation object used
00191        *  by @a x.
00192        */
00193       set(const set<_Key,_Compare,_Alloc>& __x)
00194       : _M_t(__x._M_t) { }
00195 
00196       /**
00197        *  @brief  Set assignment operator.
00198        *  @param  x  A %set of identical element and allocator types.
00199        *
00200        *  All the elements of @a x are copied, but unlike the copy constructor,
00201        *  the allocator object is not copied.
00202        */
00203       set<_Key,_Compare,_Alloc>&
00204       operator=(const set<_Key, _Compare, _Alloc>& __x)
00205       {
00206     _M_t = __x._M_t;
00207     return *this;
00208       }
00209 
00210       // accessors:
00211 
00212       ///  Returns the comparison object with which the %set was constructed.
00213       key_compare
00214       key_comp() const
00215       { return _M_t.key_comp(); }
00216       ///  Returns the comparison object with which the %set was constructed.
00217       value_compare
00218       value_comp() const
00219       { return _M_t.key_comp(); }
00220       ///  Returns the allocator object with which the %set was constructed.
00221       allocator_type
00222       get_allocator() const
00223       { return _M_t.get_allocator(); }
00224 
00225       /**
00226        *  Returns a read/write iterator that points to the first element in the
00227        *  %set.  Iteration is done in ascending order according to the keys.
00228        */
00229       iterator
00230       begin() const
00231       { return _M_t.begin(); }
00232 
00233       /**
00234        *  Returns a read/write iterator that points one past the last element in
00235        *  the %set.  Iteration is done in ascending order according to the keys.
00236        */
00237       iterator
00238       end() const
00239       { return _M_t.end(); }
00240 
00241       /**
00242        *  Returns a read/write reverse iterator that points to the last element
00243        *  in the %set.  Iteration is done in descending order according to the
00244        *  keys.
00245        */
00246       reverse_iterator
00247       rbegin() const
00248       { return _M_t.rbegin(); }
00249 
00250       /**
00251        *  Returns a read-only (constant) reverse iterator that points to the
00252        *  last pair in the %map.  Iteration is done in descending order
00253        *  according to the keys.
00254        */
00255       reverse_iterator
00256       rend() const
00257       { return _M_t.rend(); }
00258 
00259       ///  Returns true if the %set is empty.
00260       bool
00261       empty() const
00262       { return _M_t.empty(); }
00263 
00264       ///  Returns the size of the %set.
00265       size_type
00266       size() const
00267       { return _M_t.size(); }
00268 
00269       ///  Returns the maximum size of the %set.
00270       size_type
00271       max_size() const
00272       { return _M_t.max_size(); }
00273 
00274       /**
00275        *  @brief  Swaps data with another %set.
00276        *  @param  x  A %set of the same element and allocator types.
00277        *
00278        *  This exchanges the elements between two sets in constant time.
00279        *  (It is only swapping a pointer, an integer, and an instance of
00280        *  the @c Compare type (which itself is often stateless and empty), so it
00281        *  should be quite fast.)
00282        *  Note that the global std::swap() function is specialized such that
00283        *  std::swap(s1,s2) will feed to this function.
00284        */
00285       void
00286       swap(set<_Key,_Compare,_Alloc>& __x)
00287       { _M_t.swap(__x._M_t); }
00288 
00289       // insert/erase
00290       /**
00291        *  @brief Attempts to insert an element into the %set.
00292        *  @param  x  Element to be inserted.
00293        *  @return  A pair, of which the first element is an iterator that points
00294        *           to the possibly inserted element, and the second is a bool
00295        *           that is true if the element was actually inserted.
00296        *
00297        *  This function attempts to insert an element into the %set.  A %set
00298        *  relies on unique keys and thus an element is only inserted if it is
00299        *  not already present in the %set.
00300        *
00301        *  Insertion requires logarithmic time.
00302        */
00303       std::pair<iterator,bool>
00304       insert(const value_type& __x)
00305       {
00306     std::pair<typename _Rep_type::iterator, bool> __p =
00307       _M_t._M_insert_unique(__x);
00308     return std::pair<iterator, bool>(__p.first, __p.second);
00309       }
00310 
00311       /**
00312        *  @brief Attempts to insert an element into the %set.
00313        *  @param  position  An iterator that serves as a hint as to where the
00314        *                    element should be inserted.
00315        *  @param  x  Element to be inserted.
00316        *  @return  An iterator that points to the element with key of @a x (may
00317        *           or may not be the element passed in).
00318        *
00319        *  This function is not concerned about whether the insertion took place,
00320        *  and thus does not return a boolean like the single-argument insert()
00321        *  does.  Note that the first parameter is only a hint and can
00322        *  potentially improve the performance of the insertion process.  A bad
00323        *  hint would cause no gains in efficiency.
00324        *
00325        *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4
00326        *  for more on "hinting".
00327        *
00328        *  Insertion requires logarithmic time (if the hint is not taken).
00329        */
00330       iterator
00331       insert(iterator __position, const value_type& __x)
00332       { return _M_t._M_insert_unique(__position, __x); }
00333 
00334       /**
00335        *  @brief A template function that attemps to insert a range of elements.
00336        *  @param  first  Iterator pointing to the start of the range to be
00337        *                 inserted.
00338        *  @param  last  Iterator pointing to the end of the range.
00339        *
00340        *  Complexity similar to that of the range constructor.
00341        */
00342       template<class _InputIterator>
00343         void
00344         insert(_InputIterator __first, _InputIterator __last)
00345         { _M_t._M_insert_unique(__first, __last); }
00346 
00347       /**
00348        *  @brief Erases an element from a %set.
00349        *  @param  position  An iterator pointing to the element to be erased.
00350        *
00351        *  This function erases an element, pointed to by the given iterator,
00352        *  from a %set.  Note that this function only erases the element, and
00353        *  that if the element is itself a pointer, the pointed-to memory is not
00354        *  touched in any way.  Managing the pointer is the user's responsibilty.
00355        */
00356       void
00357       erase(iterator __position)
00358       { _M_t.erase(__position); }
00359 
00360       /**
00361        *  @brief Erases elements according to the provided key.
00362        *  @param  x  Key of element to be erased.
00363        *  @return  The number of elements erased.
00364        *
00365        *  This function erases all the elements located by the given key from
00366        *  a %set.
00367        *  Note that this function only erases the element, and that if
00368        *  the element is itself a pointer, the pointed-to memory is not touched
00369        *  in any way.  Managing the pointer is the user's responsibilty.
00370        */
00371       size_type
00372       erase(const key_type& __x)
00373       { return _M_t.erase(__x); }
00374 
00375       /**
00376        *  @brief Erases a [first,last) range of elements from a %set.
00377        *  @param  first  Iterator pointing to the start of the range to be
00378        *                 erased.
00379        *  @param  last  Iterator pointing to the end of the range to be erased.
00380        *
00381        *  This function erases a sequence of elements from a %set.
00382        *  Note that this function only erases the element, and that if
00383        *  the element is itself a pointer, the pointed-to memory is not touched
00384        *  in any way.  Managing the pointer is the user's responsibilty.
00385        */
00386       void
00387       erase(iterator __first, iterator __last)
00388       { _M_t.erase(__first, __last); }
00389 
00390       /**
00391        *  Erases all elements in a %set.  Note that this function only erases
00392        *  the elements, and that if the elements themselves are pointers, the
00393        *  pointed-to memory is not touched in any way.  Managing the pointer is
00394        *  the user's responsibilty.
00395        */
00396       void
00397       clear()
00398       { _M_t.clear(); }
00399 
00400       // set operations:
00401 
00402       /**
00403        *  @brief  Finds the number of elements.
00404        *  @param  x  Element to located.
00405        *  @return  Number of elements with specified key.
00406        *
00407        *  This function only makes sense for multisets; for set the result will
00408        *  either be 0 (not present) or 1 (present).
00409        */
00410       size_type
00411       count(const key_type& __x) const
00412       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
00413 
00414       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00415       // 214.  set::find() missing const overload
00416       //@{
00417       /**
00418        *  @brief Tries to locate an element in a %set.
00419        *  @param  x  Element to be located.
00420        *  @return  Iterator pointing to sought-after element, or end() if not
00421        *           found.
00422        *
00423        *  This function takes a key and tries to locate the element with which
00424        *  the key matches.  If successful the function returns an iterator
00425        *  pointing to the sought after element.  If unsuccessful it returns the
00426        *  past-the-end ( @c end() ) iterator.
00427        */
00428       iterator
00429       find(const key_type& __x)
00430       { return _M_t.find(__x); }
00431 
00432       const_iterator
00433       find(const key_type& __x) const
00434       { return _M_t.find(__x); }
00435       //@}
00436 
00437       //@{
00438       /**
00439        *  @brief Finds the beginning of a subsequence matching given key.
00440        *  @param  x  Key to be located.
00441        *  @return  Iterator pointing to first element equal to or greater
00442        *           than key, or end().
00443        *
00444        *  This function returns the first element of a subsequence of elements
00445        *  that matches the given key.  If unsuccessful it returns an iterator
00446        *  pointing to the first element that has a greater value than given key
00447        *  or end() if no such element exists.
00448        */
00449       iterator
00450       lower_bound(const key_type& __x)
00451       { return _M_t.lower_bound(__x); }
00452 
00453       const_iterator
00454       lower_bound(const key_type& __x) const
00455       { return _M_t.lower_bound(__x); }
00456       //@}
00457 
00458       //@{
00459       /**
00460        *  @brief Finds the end of a subsequence matching given key.
00461        *  @param  x  Key to be located.
00462        *  @return Iterator pointing to the first element
00463        *          greater than key, or end().
00464        */
00465       iterator
00466       upper_bound(const key_type& __x)
00467       { return _M_t.upper_bound(__x); }
00468 
00469       const_iterator
00470       upper_bound(const key_type& __x) const
00471       { return _M_t.upper_bound(__x); }
00472       //@}
00473 
00474       //@{
00475       /**
00476        *  @brief Finds a subsequence matching given key.
00477        *  @param  x  Key to be located.
00478        *  @return  Pair of iterators that possibly points to the subsequence
00479        *           matching given key.
00480        *
00481        *  This function is equivalent to
00482        *  @code
00483        *    std::make_pair(c.lower_bound(val),
00484        *                   c.upper_bound(val))
00485        *  @endcode
00486        *  (but is faster than making the calls separately).
00487        *
00488        *  This function probably only makes sense for multisets.
00489        */
00490       std::pair<iterator, iterator>
00491       equal_range(const key_type& __x)
00492       { return _M_t.equal_range(__x); }
00493 
00494       std::pair<const_iterator, const_iterator>
00495       equal_range(const key_type& __x) const
00496       { return _M_t.equal_range(__x); }
00497       //@}
00498 
00499       template<class _K1, class _C1, class _A1>
00500         friend bool
00501         operator== (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
00502 
00503       template<class _K1, class _C1, class _A1>
00504         friend bool
00505         operator< (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
00506     };
00507 
00508 
00509   /**
00510    *  @brief  Set equality comparison.
00511    *  @param  x  A %set.
00512    *  @param  y  A %set of the same type as @a x.
00513    *  @return  True iff the size and elements of the sets are equal.
00514    *
00515    *  This is an equivalence relation.  It is linear in the size of the sets.
00516    *  Sets are considered equivalent if their sizes are equal, and if
00517    *  corresponding elements compare equal.
00518   */
00519   template<class _Key, class _Compare, class _Alloc>
00520     inline bool
00521     operator==(const set<_Key, _Compare, _Alloc>& __x,
00522            const set<_Key, _Compare, _Alloc>& __y)
00523     { return __x._M_t == __y._M_t; }
00524 
00525   /**
00526    *  @brief  Set ordering relation.
00527    *  @param  x  A %set.
00528    *  @param  y  A %set of the same type as @a x.
00529    *  @return  True iff @a x is lexicographically less than @a y.
00530    *
00531    *  This is a total ordering relation.  It is linear in the size of the
00532    *  maps.  The elements must be comparable with @c <.
00533    *
00534    *  See std::lexicographical_compare() for how the determination is made.
00535   */
00536   template<class _Key, class _Compare, class _Alloc>
00537     inline bool
00538     operator<(const set<_Key, _Compare, _Alloc>& __x,
00539           const set<_Key, _Compare, _Alloc>& __y)
00540     { return __x._M_t < __y._M_t; }
00541 
00542   ///  Returns !(x == y).
00543   template<class _Key, class _Compare, class _Alloc>
00544     inline bool
00545     operator!=(const set<_Key, _Compare, _Alloc>& __x,
00546            const set<_Key, _Compare, _Alloc>& __y)
00547     { return !(__x == __y); }
00548 
00549   ///  Returns y < x.
00550   template<class _Key, class _Compare, class _Alloc>
00551     inline bool
00552     operator>(const set<_Key, _Compare, _Alloc>& __x,
00553           const set<_Key, _Compare, _Alloc>& __y)
00554     { return __y < __x; }
00555 
00556   ///  Returns !(y < x)
00557   template<class _Key, class _Compare, class _Alloc>
00558     inline bool
00559     operator<=(const set<_Key, _Compare, _Alloc>& __x,
00560            const set<_Key, _Compare, _Alloc>& __y)
00561     { return !(__y < __x); }
00562 
00563   ///  Returns !(x < y)
00564   template<class _Key, class _Compare, class _Alloc>
00565     inline bool
00566     operator>=(const set<_Key, _Compare, _Alloc>& __x,
00567            const set<_Key, _Compare, _Alloc>& __y)
00568     { return !(__x < __y); }
00569 
00570   /// See std::set::swap().
00571   template<class _Key, class _Compare, class _Alloc>
00572     inline void
00573     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
00574     { __x.swap(__y); }
00575 
00576 _GLIBCXX_END_NESTED_NAMESPACE
00577 
00578 #endif /* _SET_H */

Generated on Thu Nov 1 13:12:34 2007 for libstdc++ by  doxygen 1.5.1