libstdc++
stl_set.h
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00001 // Set implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2013 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /*
00026  *
00027  * Copyright (c) 1994
00028  * Hewlett-Packard Company
00029  *
00030  * Permission to use, copy, modify, distribute and sell this software
00031  * and its documentation for any purpose is hereby granted without fee,
00032  * provided that the above copyright notice appear in all copies and
00033  * that both that copyright notice and this permission notice appear
00034  * in supporting documentation.  Hewlett-Packard Company makes no
00035  * representations about the suitability of this software for any
00036  * purpose.  It is provided "as is" without express or implied warranty.
00037  *
00038  *
00039  * Copyright (c) 1996,1997
00040  * Silicon Graphics Computer Systems, Inc.
00041  *
00042  * Permission to use, copy, modify, distribute and sell this software
00043  * and its documentation for any purpose is hereby granted without fee,
00044  * provided that the above copyright notice appear in all copies and
00045  * that both that copyright notice and this permission notice appear
00046  * in supporting documentation.  Silicon Graphics makes no
00047  * representations about the suitability of this software for any
00048  * purpose.  It is provided "as is" without express or implied warranty.
00049  */
00050 
00051 /** @file bits/stl_set.h
00052  *  This is an internal header file, included by other library headers.
00053  *  Do not attempt to use it directly. @headername{set}
00054  */
00055 
00056 #ifndef _STL_SET_H
00057 #define _STL_SET_H 1
00058 
00059 #include <bits/concept_check.h>
00060 #if __cplusplus >= 201103L
00061 #include <initializer_list>
00062 #endif
00063 
00064 namespace std _GLIBCXX_VISIBILITY(default)
00065 {
00066 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
00067 
00068   /**
00069    *  @brief A standard container made up of unique keys, which can be
00070    *  retrieved in logarithmic time.
00071    *
00072    *  @ingroup associative_containers
00073    *
00074    *  @tparam _Key  Type of key objects.
00075    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
00076    *  @tparam _Alloc  Allocator type, defaults to allocator<_Key>.
00077    *
00078    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00079    *  <a href="tables.html#66">reversible container</a>, and an
00080    *  <a href="tables.html#69">associative container</a> (using unique keys).
00081    *
00082    *  Sets support bidirectional iterators.
00083    *
00084    *  The private tree data is declared exactly the same way for set and
00085    *  multiset; the distinction is made entirely in how the tree functions are
00086    *  called (*_unique versus *_equal, same as the standard).
00087   */
00088   template<typename _Key, typename _Compare = std::less<_Key>,
00089        typename _Alloc = std::allocator<_Key> >
00090     class set
00091     {
00092       // concept requirements
00093       typedef typename _Alloc::value_type                   _Alloc_value_type;
00094       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
00095       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
00096                 _BinaryFunctionConcept)
00097       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
00098 
00099     public:
00100       // typedefs:
00101       //@{
00102       /// Public typedefs.
00103       typedef _Key     key_type;
00104       typedef _Key     value_type;
00105       typedef _Compare key_compare;
00106       typedef _Compare value_compare;
00107       typedef _Alloc   allocator_type;
00108       //@}
00109 
00110     private:
00111       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
00112 
00113       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
00114                key_compare, _Key_alloc_type> _Rep_type;
00115       _Rep_type _M_t;  // Red-black tree representing set.
00116 
00117     public:
00118       //@{
00119       ///  Iterator-related typedefs.
00120       typedef typename _Key_alloc_type::pointer             pointer;
00121       typedef typename _Key_alloc_type::const_pointer       const_pointer;
00122       typedef typename _Key_alloc_type::reference           reference;
00123       typedef typename _Key_alloc_type::const_reference     const_reference;
00124       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00125       // DR 103. set::iterator is required to be modifiable,
00126       // but this allows modification of keys.
00127       typedef typename _Rep_type::const_iterator            iterator;
00128       typedef typename _Rep_type::const_iterator            const_iterator;
00129       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
00130       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
00131       typedef typename _Rep_type::size_type                 size_type;
00132       typedef typename _Rep_type::difference_type           difference_type;
00133       //@}
00134 
00135       // allocation/deallocation
00136       /**
00137        *  @brief  Default constructor creates no elements.
00138        */
00139       set()
00140       : _M_t() { }
00141 
00142       /**
00143        *  @brief  Creates a %set with no elements.
00144        *  @param  __comp  Comparator to use.
00145        *  @param  __a  An allocator object.
00146        */
00147       explicit
00148       set(const _Compare& __comp,
00149       const allocator_type& __a = allocator_type())
00150       : _M_t(__comp, _Key_alloc_type(__a)) { }
00151 
00152       /**
00153        *  @brief  Builds a %set from a range.
00154        *  @param  __first  An input iterator.
00155        *  @param  __last  An input iterator.
00156        *
00157        *  Create a %set consisting of copies of the elements from
00158        *  [__first,__last).  This is linear in N if the range is
00159        *  already sorted, and NlogN otherwise (where N is
00160        *  distance(__first,__last)).
00161        */
00162       template<typename _InputIterator>
00163     set(_InputIterator __first, _InputIterator __last)
00164     : _M_t()
00165     { _M_t._M_insert_unique(__first, __last); }
00166 
00167       /**
00168        *  @brief  Builds a %set from a range.
00169        *  @param  __first  An input iterator.
00170        *  @param  __last  An input iterator.
00171        *  @param  __comp  A comparison functor.
00172        *  @param  __a  An allocator object.
00173        *
00174        *  Create a %set consisting of copies of the elements from
00175        *  [__first,__last).  This is linear in N if the range is
00176        *  already sorted, and NlogN otherwise (where N is
00177        *  distance(__first,__last)).
00178        */
00179       template<typename _InputIterator>
00180     set(_InputIterator __first, _InputIterator __last,
00181         const _Compare& __comp,
00182         const allocator_type& __a = allocator_type())
00183     : _M_t(__comp, _Key_alloc_type(__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& __x)
00194       : _M_t(__x._M_t) { }
00195 
00196 #if __cplusplus >= 201103L
00197      /**
00198        *  @brief %Set move constructor
00199        *  @param __x  A %set of identical element and allocator types.
00200        *
00201        *  The newly-created %set contains the exact contents of @a x.
00202        *  The contents of @a x are a valid, but unspecified %set.
00203        */
00204       set(set&& __x)
00205       noexcept(is_nothrow_copy_constructible<_Compare>::value)
00206       : _M_t(std::move(__x._M_t)) { }
00207 
00208       /**
00209        *  @brief  Builds a %set from an initializer_list.
00210        *  @param  __l  An initializer_list.
00211        *  @param  __comp  A comparison functor.
00212        *  @param  __a  An allocator object.
00213        *
00214        *  Create a %set consisting of copies of the elements in the list.
00215        *  This is linear in N if the list is already sorted, and NlogN
00216        *  otherwise (where N is @a __l.size()).
00217        */
00218       set(initializer_list<value_type> __l,
00219       const _Compare& __comp = _Compare(),
00220       const allocator_type& __a = allocator_type())
00221       : _M_t(__comp, _Key_alloc_type(__a))
00222       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
00223 #endif
00224 
00225       /**
00226        *  @brief  %Set assignment operator.
00227        *  @param  __x  A %set of identical element and allocator types.
00228        *
00229        *  All the elements of @a __x are copied, but unlike the copy
00230        *  constructor, the allocator object is not copied.
00231        */
00232       set&
00233       operator=(const set& __x)
00234       {
00235     _M_t = __x._M_t;
00236     return *this;
00237       }
00238 
00239 #if __cplusplus >= 201103L
00240       /**
00241        *  @brief %Set move assignment operator.
00242        *  @param __x  A %set of identical element and allocator types.
00243        *
00244        *  The contents of @a __x are moved into this %set (without copying).
00245        *  @a __x is a valid, but unspecified %set.
00246        */
00247       set&
00248       operator=(set&& __x)
00249       {
00250     // NB: DR 1204.
00251     // NB: DR 675.
00252     this->clear();
00253     this->swap(__x);
00254         return *this;
00255       }
00256 
00257       /**
00258        *  @brief  %Set list assignment operator.
00259        *  @param  __l  An initializer_list.
00260        *
00261        *  This function fills a %set with copies of the elements in the
00262        *  initializer list @a __l.
00263        *
00264        *  Note that the assignment completely changes the %set and
00265        *  that the resulting %set's size is the same as the number
00266        *  of elements assigned.  Old data may be lost.
00267        */
00268       set&
00269       operator=(initializer_list<value_type> __l)
00270       {
00271     this->clear();
00272     this->insert(__l.begin(), __l.end());
00273     return *this;
00274       }
00275 #endif
00276 
00277       // accessors:
00278 
00279       ///  Returns the comparison object with which the %set was constructed.
00280       key_compare
00281       key_comp() const
00282       { return _M_t.key_comp(); }
00283       ///  Returns the comparison object with which the %set was constructed.
00284       value_compare
00285       value_comp() const
00286       { return _M_t.key_comp(); }
00287       ///  Returns the allocator object with which the %set was constructed.
00288       allocator_type
00289       get_allocator() const _GLIBCXX_NOEXCEPT
00290       { return allocator_type(_M_t.get_allocator()); }
00291 
00292       /**
00293        *  Returns a read-only (constant) iterator that points to the first
00294        *  element in the %set.  Iteration is done in ascending order according
00295        *  to the keys.
00296        */
00297       iterator
00298       begin() const _GLIBCXX_NOEXCEPT
00299       { return _M_t.begin(); }
00300 
00301       /**
00302        *  Returns a read-only (constant) iterator that points one past the last
00303        *  element in the %set.  Iteration is done in ascending order according
00304        *  to the keys.
00305        */
00306       iterator
00307       end() const _GLIBCXX_NOEXCEPT
00308       { return _M_t.end(); }
00309 
00310       /**
00311        *  Returns a read-only (constant) iterator that points to the last
00312        *  element in the %set.  Iteration is done in descending order according
00313        *  to the keys.
00314        */
00315       reverse_iterator
00316       rbegin() const _GLIBCXX_NOEXCEPT
00317       { return _M_t.rbegin(); }
00318 
00319       /**
00320        *  Returns a read-only (constant) reverse iterator that points to the
00321        *  last pair in the %set.  Iteration is done in descending order
00322        *  according to the keys.
00323        */
00324       reverse_iterator
00325       rend() const _GLIBCXX_NOEXCEPT
00326       { return _M_t.rend(); }
00327 
00328 #if __cplusplus >= 201103L
00329       /**
00330        *  Returns a read-only (constant) iterator that points to the first
00331        *  element in the %set.  Iteration is done in ascending order according
00332        *  to the keys.
00333        */
00334       iterator
00335       cbegin() const noexcept
00336       { return _M_t.begin(); }
00337 
00338       /**
00339        *  Returns a read-only (constant) iterator that points one past the last
00340        *  element in the %set.  Iteration is done in ascending order according
00341        *  to the keys.
00342        */
00343       iterator
00344       cend() const noexcept
00345       { return _M_t.end(); }
00346 
00347       /**
00348        *  Returns a read-only (constant) iterator that points to the last
00349        *  element in the %set.  Iteration is done in descending order according
00350        *  to the keys.
00351        */
00352       reverse_iterator
00353       crbegin() const noexcept
00354       { return _M_t.rbegin(); }
00355 
00356       /**
00357        *  Returns a read-only (constant) reverse iterator that points to the
00358        *  last pair in the %set.  Iteration is done in descending order
00359        *  according to the keys.
00360        */
00361       reverse_iterator
00362       crend() const noexcept
00363       { return _M_t.rend(); }
00364 #endif
00365 
00366       ///  Returns true if the %set is empty.
00367       bool
00368       empty() const _GLIBCXX_NOEXCEPT
00369       { return _M_t.empty(); }
00370 
00371       ///  Returns the size of the %set.
00372       size_type
00373       size() const _GLIBCXX_NOEXCEPT
00374       { return _M_t.size(); }
00375 
00376       ///  Returns the maximum size of the %set.
00377       size_type
00378       max_size() const _GLIBCXX_NOEXCEPT
00379       { return _M_t.max_size(); }
00380 
00381       /**
00382        *  @brief  Swaps data with another %set.
00383        *  @param  __x  A %set of the same element and allocator types.
00384        *
00385        *  This exchanges the elements between two sets in constant
00386        *  time.  (It is only swapping a pointer, an integer, and an
00387        *  instance of the @c Compare type (which itself is often
00388        *  stateless and empty), so it should be quite fast.)  Note
00389        *  that the global std::swap() function is specialized such
00390        *  that std::swap(s1,s2) will feed to this function.
00391        */
00392       void
00393       swap(set& __x)
00394       { _M_t.swap(__x._M_t); }
00395 
00396       // insert/erase
00397 #if __cplusplus >= 201103L
00398       /**
00399        *  @brief Attempts to build and insert an element into the %set.
00400        *  @param __args  Arguments used to generate an element.
00401        *  @return  A pair, of which the first element is an iterator that points
00402        *           to the possibly inserted element, and the second is a bool
00403        *           that is true if the element was actually inserted.
00404        *
00405        *  This function attempts to build and insert an element into the %set.
00406        *  A %set relies on unique keys and thus an element is only inserted if
00407        *  it is not already present in the %set.
00408        *
00409        *  Insertion requires logarithmic time.
00410        */
00411       template<typename... _Args>
00412     std::pair<iterator, bool>
00413     emplace(_Args&&... __args)
00414     { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
00415 
00416       /**
00417        *  @brief Attempts to insert an element into the %set.
00418        *  @param  __pos  An iterator that serves as a hint as to where the
00419        *                element should be inserted.
00420        *  @param  __args  Arguments used to generate the element to be
00421        *                 inserted.
00422        *  @return An iterator that points to the element with key equivalent to
00423        *          the one generated from @a __args (may or may not be the
00424        *          element itself).
00425        *
00426        *  This function is not concerned about whether the insertion took place,
00427        *  and thus does not return a boolean like the single-argument emplace()
00428        *  does.  Note that the first parameter is only a hint and can
00429        *  potentially improve the performance of the insertion process.  A bad
00430        *  hint would cause no gains in efficiency.
00431        *
00432        *  For more on @a hinting, see:
00433        *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
00434        *
00435        *  Insertion requires logarithmic time (if the hint is not taken).
00436        */
00437       template<typename... _Args>
00438     iterator
00439     emplace_hint(const_iterator __pos, _Args&&... __args)
00440     {
00441       return _M_t._M_emplace_hint_unique(__pos,
00442                          std::forward<_Args>(__args)...);
00443     }
00444 #endif
00445 
00446       /**
00447        *  @brief Attempts to insert an element into the %set.
00448        *  @param  __x  Element to be inserted.
00449        *  @return  A pair, of which the first element is an iterator that points
00450        *           to the possibly inserted element, and the second is a bool
00451        *           that is true if the element was actually inserted.
00452        *
00453        *  This function attempts to insert an element into the %set.  A %set
00454        *  relies on unique keys and thus an element is only inserted if it is
00455        *  not already present in the %set.
00456        *
00457        *  Insertion requires logarithmic time.
00458        */
00459       std::pair<iterator, bool>
00460       insert(const value_type& __x)
00461       {
00462     std::pair<typename _Rep_type::iterator, bool> __p =
00463       _M_t._M_insert_unique(__x);
00464     return std::pair<iterator, bool>(__p.first, __p.second);
00465       }
00466 
00467 #if __cplusplus >= 201103L
00468       std::pair<iterator, bool>
00469       insert(value_type&& __x)
00470       {
00471     std::pair<typename _Rep_type::iterator, bool> __p =
00472       _M_t._M_insert_unique(std::move(__x));
00473     return std::pair<iterator, bool>(__p.first, __p.second);
00474       }
00475 #endif
00476 
00477       /**
00478        *  @brief Attempts to insert an element into the %set.
00479        *  @param  __position  An iterator that serves as a hint as to where the
00480        *                    element should be inserted.
00481        *  @param  __x  Element to be inserted.
00482        *  @return An iterator that points to the element with key of
00483        *           @a __x (may or may not be the element passed in).
00484        *
00485        *  This function is not concerned about whether the insertion took place,
00486        *  and thus does not return a boolean like the single-argument insert()
00487        *  does.  Note that the first parameter is only a hint and can
00488        *  potentially improve the performance of the insertion process.  A bad
00489        *  hint would cause no gains in efficiency.
00490        *
00491        *  For more on @a hinting, see:
00492        *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
00493        *
00494        *  Insertion requires logarithmic time (if the hint is not taken).
00495        */
00496       iterator
00497       insert(const_iterator __position, const value_type& __x)
00498       { return _M_t._M_insert_unique_(__position, __x); }
00499 
00500 #if __cplusplus >= 201103L
00501       iterator
00502       insert(const_iterator __position, value_type&& __x)
00503       { return _M_t._M_insert_unique_(__position, std::move(__x)); }
00504 #endif
00505 
00506       /**
00507        *  @brief A template function that attempts to insert a range
00508        *  of elements.
00509        *  @param  __first  Iterator pointing to the start of the range to be
00510        *                   inserted.
00511        *  @param  __last  Iterator pointing to the end of the range.
00512        *
00513        *  Complexity similar to that of the range constructor.
00514        */
00515       template<typename _InputIterator>
00516     void
00517     insert(_InputIterator __first, _InputIterator __last)
00518     { _M_t._M_insert_unique(__first, __last); }
00519 
00520 #if __cplusplus >= 201103L
00521       /**
00522        *  @brief Attempts to insert a list of elements into the %set.
00523        *  @param  __l  A std::initializer_list<value_type> of elements
00524        *               to be inserted.
00525        *
00526        *  Complexity similar to that of the range constructor.
00527        */
00528       void
00529       insert(initializer_list<value_type> __l)
00530       { this->insert(__l.begin(), __l.end()); }
00531 #endif
00532 
00533 #if __cplusplus >= 201103L
00534       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00535       // DR 130. Associative erase should return an iterator.
00536       /**
00537        *  @brief Erases an element from a %set.
00538        *  @param  __position  An iterator pointing to the element to be erased.
00539        *  @return An iterator pointing to the element immediately following
00540        *          @a __position prior to the element being erased. If no such
00541        *          element exists, end() is returned.
00542        *
00543        *  This function erases an element, pointed to by the given iterator,
00544        *  from a %set.  Note that this function only erases the element, and
00545        *  that if the element is itself a pointer, the pointed-to memory is not
00546        *  touched in any way.  Managing the pointer is the user's
00547        *  responsibility.
00548        */
00549       _GLIBCXX_ABI_TAG_CXX11
00550       iterator
00551       erase(const_iterator __position)
00552       { return _M_t.erase(__position); }
00553 #else
00554       /**
00555        *  @brief Erases an element from a %set.
00556        *  @param  position  An iterator pointing to the element to be erased.
00557        *
00558        *  This function erases an element, pointed to by the given iterator,
00559        *  from a %set.  Note that this function only erases the element, and
00560        *  that if the element is itself a pointer, the pointed-to memory is not
00561        *  touched in any way.  Managing the pointer is the user's
00562        *  responsibility.
00563        */
00564       void
00565       erase(iterator __position)
00566       { _M_t.erase(__position); }
00567 #endif
00568 
00569       /**
00570        *  @brief Erases elements according to the provided key.
00571        *  @param  __x  Key of element to be erased.
00572        *  @return  The number of elements erased.
00573        *
00574        *  This function erases all the elements located by the given key from
00575        *  a %set.
00576        *  Note that this function only erases the element, and that if
00577        *  the element is itself a pointer, the pointed-to memory is not touched
00578        *  in any way.  Managing the pointer is the user's responsibility.
00579        */
00580       size_type
00581       erase(const key_type& __x)
00582       { return _M_t.erase(__x); }
00583 
00584 #if __cplusplus >= 201103L
00585       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00586       // DR 130. Associative erase should return an iterator.
00587       /**
00588        *  @brief Erases a [__first,__last) range of elements from a %set.
00589        *  @param  __first  Iterator pointing to the start of the range to be
00590        *                 erased.
00591 
00592        *  @param __last Iterator pointing to the end of the range to
00593        *  be erased.
00594        *  @return The iterator @a __last.
00595        *
00596        *  This function erases a sequence of elements from a %set.
00597        *  Note that this function only erases the element, and that if
00598        *  the element is itself a pointer, the pointed-to memory is not touched
00599        *  in any way.  Managing the pointer is the user's responsibility.
00600        */
00601       _GLIBCXX_ABI_TAG_CXX11
00602       iterator
00603       erase(const_iterator __first, const_iterator __last)
00604       { return _M_t.erase(__first, __last); }
00605 #else
00606       /**
00607        *  @brief Erases a [first,last) range of elements from a %set.
00608        *  @param  __first  Iterator pointing to the start of the range to be
00609        *                 erased.
00610        *  @param __last Iterator pointing to the end of the range to
00611        *  be erased.
00612        *
00613        *  This function erases a sequence of elements from a %set.
00614        *  Note that this function only erases the element, and that if
00615        *  the element is itself a pointer, the pointed-to memory is not touched
00616        *  in any way.  Managing the pointer is the user's responsibility.
00617        */
00618       void
00619       erase(iterator __first, iterator __last)
00620       { _M_t.erase(__first, __last); }
00621 #endif
00622 
00623       /**
00624        *  Erases all elements in a %set.  Note that this function only erases
00625        *  the elements, and that if the elements themselves are pointers, the
00626        *  pointed-to memory is not touched in any way.  Managing the pointer is
00627        *  the user's responsibility.
00628        */
00629       void
00630       clear() _GLIBCXX_NOEXCEPT
00631       { _M_t.clear(); }
00632 
00633       // set operations:
00634 
00635       /**
00636        *  @brief  Finds the number of elements.
00637        *  @param  __x  Element to located.
00638        *  @return  Number of elements with specified key.
00639        *
00640        *  This function only makes sense for multisets; for set the result will
00641        *  either be 0 (not present) or 1 (present).
00642        */
00643       size_type
00644       count(const key_type& __x) const
00645       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
00646 
00647       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00648       // 214.  set::find() missing const overload
00649       //@{
00650       /**
00651        *  @brief Tries to locate an element in a %set.
00652        *  @param  __x  Element to be located.
00653        *  @return  Iterator pointing to sought-after element, or end() if not
00654        *           found.
00655        *
00656        *  This function takes a key and tries to locate the element with which
00657        *  the key matches.  If successful the function returns an iterator
00658        *  pointing to the sought after element.  If unsuccessful it returns the
00659        *  past-the-end ( @c end() ) iterator.
00660        */
00661       iterator
00662       find(const key_type& __x)
00663       { return _M_t.find(__x); }
00664 
00665       const_iterator
00666       find(const key_type& __x) const
00667       { return _M_t.find(__x); }
00668       //@}
00669 
00670       //@{
00671       /**
00672        *  @brief Finds the beginning of a subsequence matching given key.
00673        *  @param  __x  Key to be located.
00674        *  @return  Iterator pointing to first element equal to or greater
00675        *           than key, or end().
00676        *
00677        *  This function returns the first element of a subsequence of elements
00678        *  that matches the given key.  If unsuccessful it returns an iterator
00679        *  pointing to the first element that has a greater value than given key
00680        *  or end() if no such element exists.
00681        */
00682       iterator
00683       lower_bound(const key_type& __x)
00684       { return _M_t.lower_bound(__x); }
00685 
00686       const_iterator
00687       lower_bound(const key_type& __x) const
00688       { return _M_t.lower_bound(__x); }
00689       //@}
00690 
00691       //@{
00692       /**
00693        *  @brief Finds the end of a subsequence matching given key.
00694        *  @param  __x  Key to be located.
00695        *  @return Iterator pointing to the first element
00696        *          greater than key, or end().
00697        */
00698       iterator
00699       upper_bound(const key_type& __x)
00700       { return _M_t.upper_bound(__x); }
00701 
00702       const_iterator
00703       upper_bound(const key_type& __x) const
00704       { return _M_t.upper_bound(__x); }
00705       //@}
00706 
00707       //@{
00708       /**
00709        *  @brief Finds a subsequence matching given key.
00710        *  @param  __x  Key to be located.
00711        *  @return  Pair of iterators that possibly points to the subsequence
00712        *           matching given key.
00713        *
00714        *  This function is equivalent to
00715        *  @code
00716        *    std::make_pair(c.lower_bound(val),
00717        *                   c.upper_bound(val))
00718        *  @endcode
00719        *  (but is faster than making the calls separately).
00720        *
00721        *  This function probably only makes sense for multisets.
00722        */
00723       std::pair<iterator, iterator>
00724       equal_range(const key_type& __x)
00725       { return _M_t.equal_range(__x); }
00726 
00727       std::pair<const_iterator, const_iterator>
00728       equal_range(const key_type& __x) const
00729       { return _M_t.equal_range(__x); }
00730       //@}
00731 
00732       template<typename _K1, typename _C1, typename _A1>
00733     friend bool
00734     operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
00735 
00736       template<typename _K1, typename _C1, typename _A1>
00737     friend bool
00738     operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
00739     };
00740 
00741 
00742   /**
00743    *  @brief  Set equality comparison.
00744    *  @param  __x  A %set.
00745    *  @param  __y  A %set of the same type as @a x.
00746    *  @return  True iff the size and elements of the sets are equal.
00747    *
00748    *  This is an equivalence relation.  It is linear in the size of the sets.
00749    *  Sets are considered equivalent if their sizes are equal, and if
00750    *  corresponding elements compare equal.
00751   */
00752   template<typename _Key, typename _Compare, typename _Alloc>
00753     inline bool
00754     operator==(const set<_Key, _Compare, _Alloc>& __x,
00755            const set<_Key, _Compare, _Alloc>& __y)
00756     { return __x._M_t == __y._M_t; }
00757 
00758   /**
00759    *  @brief  Set ordering relation.
00760    *  @param  __x  A %set.
00761    *  @param  __y  A %set of the same type as @a x.
00762    *  @return  True iff @a __x is lexicographically less than @a __y.
00763    *
00764    *  This is a total ordering relation.  It is linear in the size of the
00765    *  maps.  The elements must be comparable with @c <.
00766    *
00767    *  See std::lexicographical_compare() for how the determination is made.
00768   */
00769   template<typename _Key, typename _Compare, typename _Alloc>
00770     inline bool
00771     operator<(const set<_Key, _Compare, _Alloc>& __x,
00772           const set<_Key, _Compare, _Alloc>& __y)
00773     { return __x._M_t < __y._M_t; }
00774 
00775   ///  Returns !(x == y).
00776   template<typename _Key, typename _Compare, typename _Alloc>
00777     inline bool
00778     operator!=(const set<_Key, _Compare, _Alloc>& __x,
00779            const set<_Key, _Compare, _Alloc>& __y)
00780     { return !(__x == __y); }
00781 
00782   ///  Returns y < x.
00783   template<typename _Key, typename _Compare, typename _Alloc>
00784     inline bool
00785     operator>(const set<_Key, _Compare, _Alloc>& __x,
00786           const set<_Key, _Compare, _Alloc>& __y)
00787     { return __y < __x; }
00788 
00789   ///  Returns !(y < x)
00790   template<typename _Key, typename _Compare, typename _Alloc>
00791     inline bool
00792     operator<=(const set<_Key, _Compare, _Alloc>& __x,
00793            const set<_Key, _Compare, _Alloc>& __y)
00794     { return !(__y < __x); }
00795 
00796   ///  Returns !(x < y)
00797   template<typename _Key, typename _Compare, typename _Alloc>
00798     inline bool
00799     operator>=(const set<_Key, _Compare, _Alloc>& __x,
00800            const set<_Key, _Compare, _Alloc>& __y)
00801     { return !(__x < __y); }
00802 
00803   /// See std::set::swap().
00804   template<typename _Key, typename _Compare, typename _Alloc>
00805     inline void
00806     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
00807     { __x.swap(__y); }
00808 
00809 _GLIBCXX_END_NAMESPACE_CONTAINER
00810 } //namespace std
00811 #endif /* _STL_SET_H */