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      1 // Set implementation -*- C++ -*-
      2 
      3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
      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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
     18 // permissions described in the GCC Runtime Library Exception, version
     19 // 3.1, as published by the Free Software Foundation.
     20 
     21 // You should have received a copy of the GNU General Public License and
     22 // a copy of the GCC Runtime Library Exception along with this program;
     23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     24 // <http://www.gnu.org/licenses/>.
     25 
     26 /*
     27  *
     28  * Copyright (c) 1994
     29  * Hewlett-Packard Company
     30  *
     31  * Permission to use, copy, modify, distribute and sell this software
     32  * and its documentation for any purpose is hereby granted without fee,
     33  * provided that the above copyright notice appear in all copies and
     34  * that both that copyright notice and this permission notice appear
     35  * in supporting documentation.  Hewlett-Packard Company makes no
     36  * representations about the suitability of this software for any
     37  * purpose.  It is provided "as is" without express or implied warranty.
     38  *
     39  *
     40  * Copyright (c) 1996,1997
     41  * Silicon Graphics Computer Systems, Inc.
     42  *
     43  * Permission to use, copy, modify, distribute and sell this software
     44  * and its documentation for any purpose is hereby granted without fee,
     45  * provided that the above copyright notice appear in all copies and
     46  * that both that copyright notice and this permission notice appear
     47  * in supporting documentation.  Silicon Graphics makes no
     48  * representations about the suitability of this software for any
     49  * purpose.  It is provided "as is" without express or implied warranty.
     50  */
     51 
     52 /** @file stl_set.h
     53  *  This is an internal header file, included by other library headers.
     54  *  You should not attempt to use it directly.
     55  */
     56 
     57 #ifndef _STL_SET_H
     58 #define _STL_SET_H 1
     59 
     60 #include <bits/concept_check.h>
     61 #include <initializer_list>
     62 
     63 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
     64 
     65   /**
     66    *  @brief A standard container made up of unique keys, which can be
     67    *  retrieved in logarithmic time.
     68    *
     69    *  @ingroup associative_containers
     70    *
     71    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
     72    *  <a href="tables.html#66">reversible container</a>, and an
     73    *  <a href="tables.html#69">associative container</a> (using unique keys).
     74    *
     75    *  Sets support bidirectional iterators.
     76    *
     77    *  @param  Key  Type of key objects.
     78    *  @param  Compare  Comparison function object type, defaults to less<Key>.
     79    *  @param  Alloc  Allocator type, defaults to allocator<Key>.
     80    *
     81    *  The private tree data is declared exactly the same way for set and
     82    *  multiset; the distinction is made entirely in how the tree functions are
     83    *  called (*_unique versus *_equal, same as the standard).
     84   */
     85   template<typename _Key, typename _Compare = std::less<_Key>,
     86 	   typename _Alloc = std::allocator<_Key> >
     87     class set
     88     {
     89       // concept requirements
     90       typedef typename _Alloc::value_type                   _Alloc_value_type;
     91       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
     92       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
     93 				_BinaryFunctionConcept)
     94       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
     95 
     96     public:
     97       // typedefs:
     98       //@{
     99       /// Public typedefs.
    100       typedef _Key     key_type;
    101       typedef _Key     value_type;
    102       typedef _Compare key_compare;
    103       typedef _Compare value_compare;
    104       typedef _Alloc   allocator_type;
    105       //@}
    106 
    107     private:
    108       typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;
    109 
    110       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
    111 		       key_compare, _Key_alloc_type> _Rep_type;
    112       _Rep_type _M_t;  // Red-black tree representing set.
    113 
    114     public:
    115       //@{
    116       ///  Iterator-related typedefs.
    117       typedef typename _Key_alloc_type::pointer             pointer;
    118       typedef typename _Key_alloc_type::const_pointer       const_pointer;
    119       typedef typename _Key_alloc_type::reference           reference;
    120       typedef typename _Key_alloc_type::const_reference     const_reference;
    121       // _GLIBCXX_RESOLVE_LIB_DEFECTS
    122       // DR 103. set::iterator is required to be modifiable,
    123       // but this allows modification of keys.
    124       typedef typename _Rep_type::const_iterator            iterator;
    125       typedef typename _Rep_type::const_iterator            const_iterator;
    126       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
    127       typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;
    128       typedef typename _Rep_type::size_type                 size_type;
    129       typedef typename _Rep_type::difference_type           difference_type;
    130       //@}
    131 
    132       // allocation/deallocation
    133       /**
    134        *  @brief  Default constructor creates no elements.
    135        */
    136       set()
    137       : _M_t() { }
    138 
    139       /**
    140        *  @brief  Creates a %set with no elements.
    141        *  @param  comp  Comparator to use.
    142        *  @param  a  An allocator object.
    143        */
    144       explicit
    145       set(const _Compare& __comp,
    146 	  const allocator_type& __a = allocator_type())
    147       : _M_t(__comp, __a) { }
    148 
    149       /**
    150        *  @brief  Builds a %set from a range.
    151        *  @param  first  An input iterator.
    152        *  @param  last  An input iterator.
    153        *
    154        *  Create a %set consisting of copies of the elements from [first,last).
    155        *  This is linear in N if the range is already sorted, and NlogN
    156        *  otherwise (where N is distance(first,last)).
    157        */
    158       template<typename _InputIterator>
    159         set(_InputIterator __first, _InputIterator __last)
    160 	: _M_t()
    161         { _M_t._M_insert_unique(__first, __last); }
    162 
    163       /**
    164        *  @brief  Builds a %set from a range.
    165        *  @param  first  An input iterator.
    166        *  @param  last  An input iterator.
    167        *  @param  comp  A comparison functor.
    168        *  @param  a  An allocator object.
    169        *
    170        *  Create a %set consisting of copies of the elements from [first,last).
    171        *  This is linear in N if the range is already sorted, and NlogN
    172        *  otherwise (where N is distance(first,last)).
    173        */
    174       template<typename _InputIterator>
    175         set(_InputIterator __first, _InputIterator __last,
    176 	    const _Compare& __comp,
    177 	    const allocator_type& __a = allocator_type())
    178 	: _M_t(__comp, __a)
    179         { _M_t._M_insert_unique(__first, __last); }
    180 
    181       /**
    182        *  @brief  %Set copy constructor.
    183        *  @param  x  A %set of identical element and allocator types.
    184        *
    185        *  The newly-created %set uses a copy of the allocation object used
    186        *  by @a x.
    187        */
    188       set(const set& __x)
    189       : _M_t(__x._M_t) { }
    190 
    191 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    192      /**
    193        *  @brief %Set move constructor
    194        *  @param x  A %set of identical element and allocator types.
    195        *
    196        *  The newly-created %set contains the exact contents of @a x.
    197        *  The contents of @a x are a valid, but unspecified %set.
    198        */
    199       set(set&& __x)
    200       : _M_t(std::forward<_Rep_type>(__x._M_t)) { }
    201 
    202       /**
    203        *  @brief  Builds a %set from an initializer_list.
    204        *  @param  l  An initializer_list.
    205        *  @param  comp  A comparison functor.
    206        *  @param  a  An allocator object.
    207        *
    208        *  Create a %set consisting of copies of the elements in the list.
    209        *  This is linear in N if the list is already sorted, and NlogN
    210        *  otherwise (where N is @a l.size()).
    211        */
    212       set(initializer_list<value_type> __l,
    213 	  const _Compare& __comp = _Compare(),
    214 	  const allocator_type& __a = allocator_type())
    215       : _M_t(__comp, __a)
    216       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
    217 #endif
    218 
    219       /**
    220        *  @brief  %Set assignment operator.
    221        *  @param  x  A %set of identical element and allocator types.
    222        *
    223        *  All the elements of @a x are copied, but unlike the copy constructor,
    224        *  the allocator object is not copied.
    225        */
    226       set&
    227       operator=(const set& __x)
    228       {
    229 	_M_t = __x._M_t;
    230 	return *this;
    231       }
    232 
    233 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    234       /**
    235        *  @brief %Set move assignment operator.
    236        *  @param x  A %set of identical element and allocator types.
    237        *
    238        *  The contents of @a x are moved into this %set (without copying).
    239        *  @a x is a valid, but unspecified %set.
    240        */
    241       set&
    242       operator=(set&& __x)
    243       {
    244 	// NB: DR 675.
    245 	this->clear();
    246 	this->swap(__x);
    247 	return *this;
    248       }
    249 
    250       /**
    251        *  @brief  %Set list assignment operator.
    252        *  @param  l  An initializer_list.
    253        *
    254        *  This function fills a %set with copies of the elements in the
    255        *  initializer list @a l.
    256        *
    257        *  Note that the assignment completely changes the %set and
    258        *  that the resulting %set's size is the same as the number
    259        *  of elements assigned.  Old data may be lost.
    260        */
    261       set&
    262       operator=(initializer_list<value_type> __l)
    263       {
    264 	this->clear();
    265 	this->insert(__l.begin(), __l.end());
    266 	return *this;
    267       }
    268 #endif
    269 
    270       // accessors:
    271 
    272       ///  Returns the comparison object with which the %set was constructed.
    273       key_compare
    274       key_comp() const
    275       { return _M_t.key_comp(); }
    276       ///  Returns the comparison object with which the %set was constructed.
    277       value_compare
    278       value_comp() const
    279       { return _M_t.key_comp(); }
    280       ///  Returns the allocator object with which the %set was constructed.
    281       allocator_type
    282       get_allocator() const
    283       { return _M_t.get_allocator(); }
    284 
    285       /**
    286        *  Returns a read-only (constant) iterator that points to the first
    287        *  element in the %set.  Iteration is done in ascending order according
    288        *  to the keys.
    289        */
    290       iterator
    291       begin() const
    292       { return _M_t.begin(); }
    293 
    294       /**
    295        *  Returns a read-only (constant) iterator that points one past the last
    296        *  element in the %set.  Iteration is done in ascending order according
    297        *  to the keys.
    298        */
    299       iterator
    300       end() const
    301       { return _M_t.end(); }
    302 
    303       /**
    304        *  Returns a read-only (constant) iterator that points to the last
    305        *  element in the %set.  Iteration is done in descending order according
    306        *  to the keys.
    307        */
    308       reverse_iterator
    309       rbegin() const
    310       { return _M_t.rbegin(); }
    311 
    312       /**
    313        *  Returns a read-only (constant) reverse iterator that points to the
    314        *  last pair in the %set.  Iteration is done in descending order
    315        *  according to the keys.
    316        */
    317       reverse_iterator
    318       rend() const
    319       { return _M_t.rend(); }
    320 
    321 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    322       /**
    323        *  Returns a read-only (constant) iterator that points to the first
    324        *  element in the %set.  Iteration is done in ascending order according
    325        *  to the keys.
    326        */
    327       iterator
    328       cbegin() const
    329       { return _M_t.begin(); }
    330 
    331       /**
    332        *  Returns a read-only (constant) iterator that points one past the last
    333        *  element in the %set.  Iteration is done in ascending order according
    334        *  to the keys.
    335        */
    336       iterator
    337       cend() const
    338       { return _M_t.end(); }
    339 
    340       /**
    341        *  Returns a read-only (constant) iterator that points to the last
    342        *  element in the %set.  Iteration is done in descending order according
    343        *  to the keys.
    344        */
    345       reverse_iterator
    346       crbegin() const
    347       { return _M_t.rbegin(); }
    348 
    349       /**
    350        *  Returns a read-only (constant) reverse iterator that points to the
    351        *  last pair in the %set.  Iteration is done in descending order
    352        *  according to the keys.
    353        */
    354       reverse_iterator
    355       crend() const
    356       { return _M_t.rend(); }
    357 #endif
    358 
    359       ///  Returns true if the %set is empty.
    360       bool
    361       empty() const
    362       { return _M_t.empty(); }
    363 
    364       ///  Returns the size of the %set.
    365       size_type
    366       size() const
    367       { return _M_t.size(); }
    368 
    369       ///  Returns the maximum size of the %set.
    370       size_type
    371       max_size() const
    372       { return _M_t.max_size(); }
    373 
    374       /**
    375        *  @brief  Swaps data with another %set.
    376        *  @param  x  A %set of the same element and allocator types.
    377        *
    378        *  This exchanges the elements between two sets in constant time.
    379        *  (It is only swapping a pointer, an integer, and an instance of
    380        *  the @c Compare type (which itself is often stateless and empty), so it
    381        *  should be quite fast.)
    382        *  Note that the global std::swap() function is specialized such that
    383        *  std::swap(s1,s2) will feed to this function.
    384        */
    385       void
    386 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    387       swap(set&& __x)
    388 #else
    389       swap(set& __x)
    390 #endif
    391       { _M_t.swap(__x._M_t); }
    392 
    393       // insert/erase
    394       /**
    395        *  @brief Attempts to insert an element into the %set.
    396        *  @param  x  Element to be inserted.
    397        *  @return  A pair, of which the first element is an iterator that points
    398        *           to the possibly inserted element, and the second is a bool
    399        *           that is true if the element was actually inserted.
    400        *
    401        *  This function attempts to insert an element into the %set.  A %set
    402        *  relies on unique keys and thus an element is only inserted if it is
    403        *  not already present in the %set.
    404        *
    405        *  Insertion requires logarithmic time.
    406        */
    407       std::pair<iterator, bool>
    408       insert(const value_type& __x)
    409       {
    410 	std::pair<typename _Rep_type::iterator, bool> __p =
    411 	  _M_t._M_insert_unique(__x);
    412 	return std::pair<iterator, bool>(__p.first, __p.second);
    413       }
    414 
    415       /**
    416        *  @brief Attempts to insert an element into the %set.
    417        *  @param  position  An iterator that serves as a hint as to where the
    418        *                    element should be inserted.
    419        *  @param  x  Element to be inserted.
    420        *  @return  An iterator that points to the element with key of @a x (may
    421        *           or may not be the element passed in).
    422        *
    423        *  This function is not concerned about whether the insertion took place,
    424        *  and thus does not return a boolean like the single-argument insert()
    425        *  does.  Note that the first parameter is only a hint and can
    426        *  potentially improve the performance of the insertion process.  A bad
    427        *  hint would cause no gains in efficiency.
    428        *
    429        *  For more on "hinting", see:
    430        *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html
    431        *
    432        *  Insertion requires logarithmic time (if the hint is not taken).
    433        */
    434       iterator
    435       insert(iterator __position, const value_type& __x)
    436       { return _M_t._M_insert_unique_(__position, __x); }
    437 
    438       /**
    439        *  @brief A template function that attempts to insert a range
    440        *  of elements.
    441        *  @param  first  Iterator pointing to the start of the range to be
    442        *                 inserted.
    443        *  @param  last  Iterator pointing to the end of the range.
    444        *
    445        *  Complexity similar to that of the range constructor.
    446        */
    447       template<typename _InputIterator>
    448         void
    449         insert(_InputIterator __first, _InputIterator __last)
    450         { _M_t._M_insert_unique(__first, __last); }
    451 
    452 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    453       /**
    454        *  @brief Attempts to insert a list of elements into the %set.
    455        *  @param  list  A std::initializer_list<value_type> of elements
    456        *                to be inserted.
    457        *
    458        *  Complexity similar to that of the range constructor.
    459        */
    460       void
    461       insert(initializer_list<value_type> __l)
    462       { this->insert(__l.begin(), __l.end()); }
    463 #endif
    464 
    465       /**
    466        *  @brief Erases an element from a %set.
    467        *  @param  position  An iterator pointing to the element to be erased.
    468        *
    469        *  This function erases an element, pointed to by the given iterator,
    470        *  from a %set.  Note that this function only erases the element, and
    471        *  that if the element is itself a pointer, the pointed-to memory is not
    472        *  touched in any way.  Managing the pointer is the user's responsibility.
    473        */
    474       void
    475       erase(iterator __position)
    476       { _M_t.erase(__position); }
    477 
    478       /**
    479        *  @brief Erases elements according to the provided key.
    480        *  @param  x  Key of element to be erased.
    481        *  @return  The number of elements erased.
    482        *
    483        *  This function erases all the elements located by the given key from
    484        *  a %set.
    485        *  Note that this function only erases the element, and that if
    486        *  the element is itself a pointer, the pointed-to memory is not touched
    487        *  in any way.  Managing the pointer is the user's responsibility.
    488        */
    489       size_type
    490       erase(const key_type& __x)
    491       { return _M_t.erase(__x); }
    492 
    493       /**
    494        *  @brief Erases a [first,last) range of elements from a %set.
    495        *  @param  first  Iterator pointing to the start of the range to be
    496        *                 erased.
    497        *  @param  last  Iterator pointing to the end of the range to be erased.
    498        *
    499        *  This function erases a sequence of elements from a %set.
    500        *  Note that this function only erases the element, and that if
    501        *  the element is itself a pointer, the pointed-to memory is not touched
    502        *  in any way.  Managing the pointer is the user's responsibility.
    503        */
    504       void
    505       erase(iterator __first, iterator __last)
    506       { _M_t.erase(__first, __last); }
    507 
    508       /**
    509        *  Erases all elements in a %set.  Note that this function only erases
    510        *  the elements, and that if the elements themselves are pointers, the
    511        *  pointed-to memory is not touched in any way.  Managing the pointer is
    512        *  the user's responsibility.
    513        */
    514       void
    515       clear()
    516       { _M_t.clear(); }
    517 
    518       // set operations:
    519 
    520       /**
    521        *  @brief  Finds the number of elements.
    522        *  @param  x  Element to located.
    523        *  @return  Number of elements with specified key.
    524        *
    525        *  This function only makes sense for multisets; for set the result will
    526        *  either be 0 (not present) or 1 (present).
    527        */
    528       size_type
    529       count(const key_type& __x) const
    530       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
    531 
    532       // _GLIBCXX_RESOLVE_LIB_DEFECTS
    533       // 214.  set::find() missing const overload
    534       //@{
    535       /**
    536        *  @brief Tries to locate an element in a %set.
    537        *  @param  x  Element to be located.
    538        *  @return  Iterator pointing to sought-after element, or end() if not
    539        *           found.
    540        *
    541        *  This function takes a key and tries to locate the element with which
    542        *  the key matches.  If successful the function returns an iterator
    543        *  pointing to the sought after element.  If unsuccessful it returns the
    544        *  past-the-end ( @c end() ) iterator.
    545        */
    546       iterator
    547       find(const key_type& __x)
    548       { return _M_t.find(__x); }
    549 
    550       const_iterator
    551       find(const key_type& __x) const
    552       { return _M_t.find(__x); }
    553       //@}
    554 
    555       //@{
    556       /**
    557        *  @brief Finds the beginning of a subsequence matching given key.
    558        *  @param  x  Key to be located.
    559        *  @return  Iterator pointing to first element equal to or greater
    560        *           than key, or end().
    561        *
    562        *  This function returns the first element of a subsequence of elements
    563        *  that matches the given key.  If unsuccessful it returns an iterator
    564        *  pointing to the first element that has a greater value than given key
    565        *  or end() if no such element exists.
    566        */
    567       iterator
    568       lower_bound(const key_type& __x)
    569       { return _M_t.lower_bound(__x); }
    570 
    571       const_iterator
    572       lower_bound(const key_type& __x) const
    573       { return _M_t.lower_bound(__x); }
    574       //@}
    575 
    576       //@{
    577       /**
    578        *  @brief Finds the end of a subsequence matching given key.
    579        *  @param  x  Key to be located.
    580        *  @return Iterator pointing to the first element
    581        *          greater than key, or end().
    582        */
    583       iterator
    584       upper_bound(const key_type& __x)
    585       { return _M_t.upper_bound(__x); }
    586 
    587       const_iterator
    588       upper_bound(const key_type& __x) const
    589       { return _M_t.upper_bound(__x); }
    590       //@}
    591 
    592       //@{
    593       /**
    594        *  @brief Finds a subsequence matching given key.
    595        *  @param  x  Key to be located.
    596        *  @return  Pair of iterators that possibly points to the subsequence
    597        *           matching given key.
    598        *
    599        *  This function is equivalent to
    600        *  @code
    601        *    std::make_pair(c.lower_bound(val),
    602        *                   c.upper_bound(val))
    603        *  @endcode
    604        *  (but is faster than making the calls separately).
    605        *
    606        *  This function probably only makes sense for multisets.
    607        */
    608       std::pair<iterator, iterator>
    609       equal_range(const key_type& __x)
    610       { return _M_t.equal_range(__x); }
    611 
    612       std::pair<const_iterator, const_iterator>
    613       equal_range(const key_type& __x) const
    614       { return _M_t.equal_range(__x); }
    615       //@}
    616 
    617       template<typename _K1, typename _C1, typename _A1>
    618         friend bool
    619         operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
    620 
    621       template<typename _K1, typename _C1, typename _A1>
    622         friend bool
    623         operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
    624     };
    625 
    626 
    627   /**
    628    *  @brief  Set equality comparison.
    629    *  @param  x  A %set.
    630    *  @param  y  A %set of the same type as @a x.
    631    *  @return  True iff the size and elements of the sets are equal.
    632    *
    633    *  This is an equivalence relation.  It is linear in the size of the sets.
    634    *  Sets are considered equivalent if their sizes are equal, and if
    635    *  corresponding elements compare equal.
    636   */
    637   template<typename _Key, typename _Compare, typename _Alloc>
    638     inline bool
    639     operator==(const set<_Key, _Compare, _Alloc>& __x,
    640 	       const set<_Key, _Compare, _Alloc>& __y)
    641     { return __x._M_t == __y._M_t; }
    642 
    643   /**
    644    *  @brief  Set ordering relation.
    645    *  @param  x  A %set.
    646    *  @param  y  A %set of the same type as @a x.
    647    *  @return  True iff @a x is lexicographically less than @a y.
    648    *
    649    *  This is a total ordering relation.  It is linear in the size of the
    650    *  maps.  The elements must be comparable with @c <.
    651    *
    652    *  See std::lexicographical_compare() for how the determination is made.
    653   */
    654   template<typename _Key, typename _Compare, typename _Alloc>
    655     inline bool
    656     operator<(const set<_Key, _Compare, _Alloc>& __x,
    657 	      const set<_Key, _Compare, _Alloc>& __y)
    658     { return __x._M_t < __y._M_t; }
    659 
    660   ///  Returns !(x == y).
    661   template<typename _Key, typename _Compare, typename _Alloc>
    662     inline bool
    663     operator!=(const set<_Key, _Compare, _Alloc>& __x,
    664 	       const set<_Key, _Compare, _Alloc>& __y)
    665     { return !(__x == __y); }
    666 
    667   ///  Returns y < x.
    668   template<typename _Key, typename _Compare, typename _Alloc>
    669     inline bool
    670     operator>(const set<_Key, _Compare, _Alloc>& __x,
    671 	      const set<_Key, _Compare, _Alloc>& __y)
    672     { return __y < __x; }
    673 
    674   ///  Returns !(y < x)
    675   template<typename _Key, typename _Compare, typename _Alloc>
    676     inline bool
    677     operator<=(const set<_Key, _Compare, _Alloc>& __x,
    678 	       const set<_Key, _Compare, _Alloc>& __y)
    679     { return !(__y < __x); }
    680 
    681   ///  Returns !(x < y)
    682   template<typename _Key, typename _Compare, typename _Alloc>
    683     inline bool
    684     operator>=(const set<_Key, _Compare, _Alloc>& __x,
    685 	       const set<_Key, _Compare, _Alloc>& __y)
    686     { return !(__x < __y); }
    687 
    688   /// See std::set::swap().
    689   template<typename _Key, typename _Compare, typename _Alloc>
    690     inline void
    691     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
    692     { __x.swap(__y); }
    693 
    694 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    695   template<typename _Key, typename _Compare, typename _Alloc>
    696     inline void
    697     swap(set<_Key, _Compare, _Alloc>&& __x, set<_Key, _Compare, _Alloc>& __y)
    698     { __x.swap(__y); }
    699 
    700   template<typename _Key, typename _Compare, typename _Alloc>
    701     inline void
    702     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>&& __y)
    703     { __x.swap(__y); }
    704 #endif
    705 
    706 _GLIBCXX_END_NESTED_NAMESPACE
    707 
    708 #endif /* _STL_SET_H */
    709