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  1. // Set implementation -*- C++ -*-
  2.  
  3. // Copyright (C) 2001-2015 Free Software Foundation, Inc.
  4. //
  5. // This file is part of the GNU ISO C++ Library.  This library is free
  6. // software; you can redistribute it and/or modify it under the
  7. // terms of the GNU General Public License as published by the
  8. // Free Software Foundation; either version 3, or (at your option)
  9. // any later version.
  10.  
  11. // This library is distributed in the hope that it will be useful,
  12. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14. // GNU General Public License for more details.
  15.  
  16. // Under Section 7 of GPL version 3, you are granted additional
  17. // permissions described in the GCC Runtime Library Exception, version
  18. // 3.1, as published by the Free Software Foundation.
  19.  
  20. // You should have received a copy of the GNU General Public License and
  21. // a copy of the GCC Runtime Library Exception along with this program;
  22. // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23. // <http://www.gnu.org/licenses/>.
  24.  
  25. /*
  26.  *
  27.  * Copyright (c) 1994
  28.  * Hewlett-Packard Company
  29.  *
  30.  * Permission to use, copy, modify, distribute and sell this software
  31.  * and its documentation for any purpose is hereby granted without fee,
  32.  * provided that the above copyright notice appear in all copies and
  33.  * that both that copyright notice and this permission notice appear
  34.  * in supporting documentation.  Hewlett-Packard Company makes no
  35.  * representations about the suitability of this software for any
  36.  * purpose.  It is provided "as is" without express or implied warranty.
  37.  *
  38.  *
  39.  * Copyright (c) 1996,1997
  40.  * Silicon Graphics Computer Systems, Inc.
  41.  *
  42.  * Permission to use, copy, modify, distribute and sell this software
  43.  * and its documentation for any purpose is hereby granted without fee,
  44.  * provided that the above copyright notice appear in all copies and
  45.  * that both that copyright notice and this permission notice appear
  46.  * in supporting documentation.  Silicon Graphics makes no
  47.  * representations about the suitability of this software for any
  48.  * purpose.  It is provided "as is" without express or implied warranty.
  49.  */
  50.  
  51. /** @file bits/stl_set.h
  52.  *  This is an internal header file, included by other library headers.
  53.  *  Do not attempt to use it directly. @headername{set}
  54.  */
  55.  
  56. #ifndef _STL_SET_H
  57. #define _STL_SET_H 1
  58.  
  59. #include <bits/concept_check.h>
  60. #if __cplusplus >= 201103L
  61. #include <initializer_list>
  62. #endif
  63.  
  64. namespace std _GLIBCXX_VISIBILITY(default)
  65. {
  66. _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
  67.  
  68.   /**
  69.    *  @brief A standard container made up of unique keys, which can be
  70.    *  retrieved in logarithmic time.
  71.    *
  72.    *  @ingroup associative_containers
  73.    *
  74.    *  @tparam _Key  Type of key objects.
  75.    *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
  76.    *  @tparam _Alloc  Allocator type, defaults to allocator<_Key>.
  77.    *
  78.    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  79.    *  <a href="tables.html#66">reversible container</a>, and an
  80.    *  <a href="tables.html#69">associative container</a> (using unique keys).
  81.    *
  82.    *  Sets support bidirectional iterators.
  83.    *
  84.    *  The private tree data is declared exactly the same way for set and
  85.    *  multiset; the distinction is made entirely in how the tree functions are
  86.    *  called (*_unique versus *_equal, same as the standard).
  87.   */
  88.   template<typename _Key, typename _Compare = std::less<_Key>,
  89.            typename _Alloc = std::allocator<_Key> >
  90.     class set
  91.     {
  92.       // concept requirements
  93.       typedef typename _Alloc::value_type                   _Alloc_value_type;
  94.       __glibcxx_class_requires(_Key, _SGIAssignableConcept)
  95.       __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
  96.                                 _BinaryFunctionConcept)
  97.       __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)
  98.  
  99.     public:
  100.       // typedefs:
  101.       //@{
  102.       /// Public typedefs.
  103.       typedef _Key     key_type;
  104.       typedef _Key     value_type;
  105.       typedef _Compare key_compare;
  106.       typedef _Compare value_compare;
  107.       typedef _Alloc   allocator_type;
  108.       //@}
  109.  
  110.     private:
  111.       typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
  112.         rebind<_Key>::other _Key_alloc_type;
  113.  
  114.       typedef _Rb_tree<key_type, value_type, _Identity<value_type>,
  115.                        key_compare, _Key_alloc_type> _Rep_type;
  116.       _Rep_type _M_t;  // Red-black tree representing set.
  117.  
  118.       typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits;
  119.  
  120.     public:
  121.       //@{
  122.       ///  Iterator-related typedefs.
  123.       typedef typename _Alloc_traits::pointer               pointer;
  124.       typedef typename _Alloc_traits::const_pointer         const_pointer;
  125.       typedef typename _Alloc_traits::reference             reference;
  126.       typedef typename _Alloc_traits::const_reference       const_reference;
  127.       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  128.       // DR 103. set::iterator is required to be modifiable,
  129.       // but this allows modification of keys.
  130.       typedef typename _Rep_type::const_iterator            iterator;
  131.       typedef typename _Rep_type::const_iterator            const_iterator;
  132.       typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;
  133.       typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
  134.       typedef typename _Rep_type::size_type                 size_type;
  135.       typedef typename _Rep_type::difference_type           difference_type;
  136.       //@}
  137.  
  138.       // allocation/deallocation
  139.       /**
  140.        *  @brief  Default constructor creates no elements.
  141.        */
  142.       set()
  143. #if __cplusplus >= 201103L
  144.       noexcept(is_nothrow_default_constructible<allocator_type>::value)
  145. #endif
  146.       : _M_t() { }
  147.  
  148.       /**
  149.        *  @brief  Creates a %set with no elements.
  150.        *  @param  __comp  Comparator to use.
  151.        *  @param  __a  An allocator object.
  152.        */
  153.       explicit
  154.       set(const _Compare& __comp,
  155.           const allocator_type& __a = allocator_type())
  156.       : _M_t(__comp, _Key_alloc_type(__a)) { }
  157.  
  158.       /**
  159.        *  @brief  Builds a %set from a range.
  160.        *  @param  __first  An input iterator.
  161.        *  @param  __last  An input iterator.
  162.        *
  163.        *  Create a %set consisting of copies of the elements from
  164.        *  [__first,__last).  This is linear in N if the range is
  165.        *  already sorted, and NlogN otherwise (where N is
  166.        *  distance(__first,__last)).
  167.        */
  168.       template<typename _InputIterator>
  169.         set(_InputIterator __first, _InputIterator __last)
  170.         : _M_t()
  171.         { _M_t._M_insert_unique(__first, __last); }
  172.  
  173.       /**
  174.        *  @brief  Builds a %set from a range.
  175.        *  @param  __first  An input iterator.
  176.        *  @param  __last  An input iterator.
  177.        *  @param  __comp  A comparison functor.
  178.        *  @param  __a  An allocator object.
  179.        *
  180.        *  Create a %set consisting of copies of the elements from
  181.        *  [__first,__last).  This is linear in N if the range is
  182.        *  already sorted, and NlogN otherwise (where N is
  183.        *  distance(__first,__last)).
  184.        */
  185.       template<typename _InputIterator>
  186.         set(_InputIterator __first, _InputIterator __last,
  187.             const _Compare& __comp,
  188.             const allocator_type& __a = allocator_type())
  189.         : _M_t(__comp, _Key_alloc_type(__a))
  190.         { _M_t._M_insert_unique(__first, __last); }
  191.  
  192.       /**
  193.        *  @brief  %Set copy constructor.
  194.        *  @param  __x  A %set of identical element and allocator types.
  195.        *
  196.        *  The newly-created %set uses a copy of the allocation object used
  197.        *  by @a __x.
  198.        */
  199.       set(const set& __x)
  200.       : _M_t(__x._M_t) { }
  201.  
  202. #if __cplusplus >= 201103L
  203.      /**
  204.        *  @brief %Set move constructor
  205.        *  @param __x  A %set of identical element and allocator types.
  206.        *
  207.        *  The newly-created %set contains the exact contents of @a x.
  208.        *  The contents of @a x are a valid, but unspecified %set.
  209.        */
  210.       set(set&& __x)
  211.       noexcept(is_nothrow_copy_constructible<_Compare>::value)
  212.       : _M_t(std::move(__x._M_t)) { }
  213.  
  214.       /**
  215.        *  @brief  Builds a %set from an initializer_list.
  216.        *  @param  __l  An initializer_list.
  217.        *  @param  __comp  A comparison functor.
  218.        *  @param  __a  An allocator object.
  219.        *
  220.        *  Create a %set consisting of copies of the elements in the list.
  221.        *  This is linear in N if the list is already sorted, and NlogN
  222.        *  otherwise (where N is @a __l.size()).
  223.        */
  224.       set(initializer_list<value_type> __l,
  225.           const _Compare& __comp = _Compare(),
  226.           const allocator_type& __a = allocator_type())
  227.       : _M_t(__comp, _Key_alloc_type(__a))
  228.       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
  229.  
  230.       /// Allocator-extended default constructor.
  231.       explicit
  232.       set(const allocator_type& __a)
  233.       : _M_t(_Compare(), _Key_alloc_type(__a)) { }
  234.  
  235.       /// Allocator-extended copy constructor.
  236.       set(const set& __x, const allocator_type& __a)
  237.       : _M_t(__x._M_t, _Key_alloc_type(__a)) { }
  238.  
  239.       /// Allocator-extended move constructor.
  240.       set(set&& __x, const allocator_type& __a)
  241.       noexcept(is_nothrow_copy_constructible<_Compare>::value
  242.                && _Alloc_traits::_S_always_equal())
  243.       : _M_t(std::move(__x._M_t), _Key_alloc_type(__a)) { }
  244.  
  245.       /// Allocator-extended initialier-list constructor.
  246.       set(initializer_list<value_type> __l, const allocator_type& __a)
  247.       : _M_t(_Compare(), _Key_alloc_type(__a))
  248.       { _M_t._M_insert_unique(__l.begin(), __l.end()); }
  249.  
  250.       /// Allocator-extended range constructor.
  251.       template<typename _InputIterator>
  252.         set(_InputIterator __first, _InputIterator __last,
  253.             const allocator_type& __a)
  254.         : _M_t(_Compare(), _Key_alloc_type(__a))
  255.         { _M_t._M_insert_unique(__first, __last); }
  256. #endif
  257.  
  258.       /**
  259.        *  @brief  %Set assignment operator.
  260.        *  @param  __x  A %set of identical element and allocator types.
  261.        *
  262.        *  All the elements of @a __x are copied, but unlike the copy
  263.        *  constructor, the allocator object is not copied.
  264.        */
  265.       set&
  266.       operator=(const set& __x)
  267.       {
  268.         _M_t = __x._M_t;
  269.         return *this;
  270.       }
  271.  
  272. #if __cplusplus >= 201103L
  273.       /// Move assignment operator.
  274.       set&
  275.       operator=(set&&) = default;
  276.  
  277.       /**
  278.        *  @brief  %Set list assignment operator.
  279.        *  @param  __l  An initializer_list.
  280.        *
  281.        *  This function fills a %set with copies of the elements in the
  282.        *  initializer list @a __l.
  283.        *
  284.        *  Note that the assignment completely changes the %set and
  285.        *  that the resulting %set's size is the same as the number
  286.        *  of elements assigned.  Old data may be lost.
  287.        */
  288.       set&
  289.       operator=(initializer_list<value_type> __l)
  290.       {
  291.         _M_t._M_assign_unique(__l.begin(), __l.end());
  292.         return *this;
  293.       }
  294. #endif
  295.  
  296.       // accessors:
  297.  
  298.       ///  Returns the comparison object with which the %set was constructed.
  299.       key_compare
  300.       key_comp() const
  301.       { return _M_t.key_comp(); }
  302.       ///  Returns the comparison object with which the %set was constructed.
  303.       value_compare
  304.       value_comp() const
  305.       { return _M_t.key_comp(); }
  306.       ///  Returns the allocator object with which the %set was constructed.
  307.       allocator_type
  308.       get_allocator() const _GLIBCXX_NOEXCEPT
  309.       { return allocator_type(_M_t.get_allocator()); }
  310.  
  311.       /**
  312.        *  Returns a read-only (constant) iterator that points to the first
  313.        *  element in the %set.  Iteration is done in ascending order according
  314.        *  to the keys.
  315.        */
  316.       iterator
  317.       begin() const _GLIBCXX_NOEXCEPT
  318.       { return _M_t.begin(); }
  319.  
  320.       /**
  321.        *  Returns a read-only (constant) iterator that points one past the last
  322.        *  element in the %set.  Iteration is done in ascending order according
  323.        *  to the keys.
  324.        */
  325.       iterator
  326.       end() const _GLIBCXX_NOEXCEPT
  327.       { return _M_t.end(); }
  328.  
  329.       /**
  330.        *  Returns a read-only (constant) iterator that points to the last
  331.        *  element in the %set.  Iteration is done in descending order according
  332.        *  to the keys.
  333.        */
  334.       reverse_iterator
  335.       rbegin() const _GLIBCXX_NOEXCEPT
  336.       { return _M_t.rbegin(); }
  337.  
  338.       /**
  339.        *  Returns a read-only (constant) reverse iterator that points to the
  340.        *  last pair in the %set.  Iteration is done in descending order
  341.        *  according to the keys.
  342.        */
  343.       reverse_iterator
  344.       rend() const _GLIBCXX_NOEXCEPT
  345.       { return _M_t.rend(); }
  346.  
  347. #if __cplusplus >= 201103L
  348.       /**
  349.        *  Returns a read-only (constant) iterator that points to the first
  350.        *  element in the %set.  Iteration is done in ascending order according
  351.        *  to the keys.
  352.        */
  353.       iterator
  354.       cbegin() const noexcept
  355.       { return _M_t.begin(); }
  356.  
  357.       /**
  358.        *  Returns a read-only (constant) iterator that points one past the last
  359.        *  element in the %set.  Iteration is done in ascending order according
  360.        *  to the keys.
  361.        */
  362.       iterator
  363.       cend() const noexcept
  364.       { return _M_t.end(); }
  365.  
  366.       /**
  367.        *  Returns a read-only (constant) iterator that points to the last
  368.        *  element in the %set.  Iteration is done in descending order according
  369.        *  to the keys.
  370.        */
  371.       reverse_iterator
  372.       crbegin() const noexcept
  373.       { return _M_t.rbegin(); }
  374.  
  375.       /**
  376.        *  Returns a read-only (constant) reverse iterator that points to the
  377.        *  last pair in the %set.  Iteration is done in descending order
  378.        *  according to the keys.
  379.        */
  380.       reverse_iterator
  381.       crend() const noexcept
  382.       { return _M_t.rend(); }
  383. #endif
  384.  
  385.       ///  Returns true if the %set is empty.
  386.       bool
  387.       empty() const _GLIBCXX_NOEXCEPT
  388.       { return _M_t.empty(); }
  389.  
  390.       ///  Returns the size of the %set.
  391.       size_type
  392.       size() const _GLIBCXX_NOEXCEPT
  393.       { return _M_t.size(); }
  394.  
  395.       ///  Returns the maximum size of the %set.
  396.       size_type
  397.       max_size() const _GLIBCXX_NOEXCEPT
  398.       { return _M_t.max_size(); }
  399.  
  400.       /**
  401.        *  @brief  Swaps data with another %set.
  402.        *  @param  __x  A %set of the same element and allocator types.
  403.        *
  404.        *  This exchanges the elements between two sets in constant
  405.        *  time.  (It is only swapping a pointer, an integer, and an
  406.        *  instance of the @c Compare type (which itself is often
  407.        *  stateless and empty), so it should be quite fast.)  Note
  408.        *  that the global std::swap() function is specialized such
  409.        *  that std::swap(s1,s2) will feed to this function.
  410.        */
  411.       void
  412.       swap(set& __x)
  413. #if __cplusplus >= 201103L
  414.       noexcept(_Alloc_traits::_S_nothrow_swap())
  415. #endif
  416.       { _M_t.swap(__x._M_t); }
  417.  
  418.       // insert/erase
  419. #if __cplusplus >= 201103L
  420.       /**
  421.        *  @brief Attempts to build and insert an element into the %set.
  422.        *  @param __args  Arguments used to generate an element.
  423.        *  @return  A pair, of which the first element is an iterator that points
  424.        *           to the possibly inserted element, and the second is a bool
  425.        *           that is true if the element was actually inserted.
  426.        *
  427.        *  This function attempts to build and insert an element into the %set.
  428.        *  A %set relies on unique keys and thus an element is only inserted if
  429.        *  it is not already present in the %set.
  430.        *
  431.        *  Insertion requires logarithmic time.
  432.        */
  433.       template<typename... _Args>
  434.         std::pair<iterator, bool>
  435.         emplace(_Args&&... __args)
  436.         { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
  437.  
  438.       /**
  439.        *  @brief Attempts to insert an element into the %set.
  440.        *  @param  __pos  An iterator that serves as a hint as to where the
  441.        *                element should be inserted.
  442.        *  @param  __args  Arguments used to generate the element to be
  443.        *                 inserted.
  444.        *  @return An iterator that points to the element with key equivalent to
  445.        *          the one generated from @a __args (may or may not be the
  446.        *          element itself).
  447.        *
  448.        *  This function is not concerned about whether the insertion took place,
  449.        *  and thus does not return a boolean like the single-argument emplace()
  450.        *  does.  Note that the first parameter is only a hint and can
  451.        *  potentially improve the performance of the insertion process.  A bad
  452.        *  hint would cause no gains in efficiency.
  453.        *
  454.        *  For more on @a hinting, see:
  455.        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
  456.        *
  457.        *  Insertion requires logarithmic time (if the hint is not taken).
  458.        */
  459.       template<typename... _Args>
  460.         iterator
  461.         emplace_hint(const_iterator __pos, _Args&&... __args)
  462.         {
  463.           return _M_t._M_emplace_hint_unique(__pos,
  464.                                              std::forward<_Args>(__args)...);
  465.         }
  466. #endif
  467.  
  468.       /**
  469.        *  @brief Attempts to insert an element into the %set.
  470.        *  @param  __x  Element to be inserted.
  471.        *  @return  A pair, of which the first element is an iterator that points
  472.        *           to the possibly inserted element, and the second is a bool
  473.        *           that is true if the element was actually inserted.
  474.        *
  475.        *  This function attempts to insert an element into the %set.  A %set
  476.        *  relies on unique keys and thus an element is only inserted if it is
  477.        *  not already present in the %set.
  478.        *
  479.        *  Insertion requires logarithmic time.
  480.        */
  481.       std::pair<iterator, bool>
  482.       insert(const value_type& __x)
  483.       {
  484.         std::pair<typename _Rep_type::iterator, bool> __p =
  485.           _M_t._M_insert_unique(__x);
  486.         return std::pair<iterator, bool>(__p.first, __p.second);
  487.       }
  488.  
  489. #if __cplusplus >= 201103L
  490.       std::pair<iterator, bool>
  491.       insert(value_type&& __x)
  492.       {
  493.         std::pair<typename _Rep_type::iterator, bool> __p =
  494.           _M_t._M_insert_unique(std::move(__x));
  495.         return std::pair<iterator, bool>(__p.first, __p.second);
  496.       }
  497. #endif
  498.  
  499.       /**
  500.        *  @brief Attempts to insert an element into the %set.
  501.        *  @param  __position  An iterator that serves as a hint as to where the
  502.        *                    element should be inserted.
  503.        *  @param  __x  Element to be inserted.
  504.        *  @return An iterator that points to the element with key of
  505.        *           @a __x (may or may not be the element passed in).
  506.        *
  507.        *  This function is not concerned about whether the insertion took place,
  508.        *  and thus does not return a boolean like the single-argument insert()
  509.        *  does.  Note that the first parameter is only a hint and can
  510.        *  potentially improve the performance of the insertion process.  A bad
  511.        *  hint would cause no gains in efficiency.
  512.        *
  513.        *  For more on @a hinting, see:
  514.        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
  515.        *
  516.        *  Insertion requires logarithmic time (if the hint is not taken).
  517.        */
  518.       iterator
  519.       insert(const_iterator __position, const value_type& __x)
  520.       { return _M_t._M_insert_unique_(__position, __x); }
  521.  
  522. #if __cplusplus >= 201103L
  523.       iterator
  524.       insert(const_iterator __position, value_type&& __x)
  525.       { return _M_t._M_insert_unique_(__position, std::move(__x)); }
  526. #endif
  527.  
  528.       /**
  529.        *  @brief A template function that attempts to insert a range
  530.        *  of elements.
  531.        *  @param  __first  Iterator pointing to the start of the range to be
  532.        *                   inserted.
  533.        *  @param  __last  Iterator pointing to the end of the range.
  534.        *
  535.        *  Complexity similar to that of the range constructor.
  536.        */
  537.       template<typename _InputIterator>
  538.         void
  539.         insert(_InputIterator __first, _InputIterator __last)
  540.         { _M_t._M_insert_unique(__first, __last); }
  541.  
  542. #if __cplusplus >= 201103L
  543.       /**
  544.        *  @brief Attempts to insert a list of elements into the %set.
  545.        *  @param  __l  A std::initializer_list<value_type> of elements
  546.        *               to be inserted.
  547.        *
  548.        *  Complexity similar to that of the range constructor.
  549.        */
  550.       void
  551.       insert(initializer_list<value_type> __l)
  552.       { this->insert(__l.begin(), __l.end()); }
  553. #endif
  554.  
  555. #if __cplusplus >= 201103L
  556.       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  557.       // DR 130. Associative erase should return an iterator.
  558.       /**
  559.        *  @brief Erases an element from a %set.
  560.        *  @param  __position  An iterator pointing to the element to be erased.
  561.        *  @return An iterator pointing to the element immediately following
  562.        *          @a __position prior to the element being erased. If no such
  563.        *          element exists, end() is returned.
  564.        *
  565.        *  This function erases an element, pointed to by the given iterator,
  566.        *  from a %set.  Note that this function only erases the element, and
  567.        *  that if the element is itself a pointer, the pointed-to memory is not
  568.        *  touched in any way.  Managing the pointer is the user's
  569.        *  responsibility.
  570.        */
  571.       _GLIBCXX_ABI_TAG_CXX11
  572.       iterator
  573.       erase(const_iterator __position)
  574.       { return _M_t.erase(__position); }
  575. #else
  576.       /**
  577.        *  @brief Erases an element from a %set.
  578.        *  @param  position  An iterator pointing to the element to be erased.
  579.        *
  580.        *  This function erases an element, pointed to by the given iterator,
  581.        *  from a %set.  Note that this function only erases the element, and
  582.        *  that if the element is itself a pointer, the pointed-to memory is not
  583.        *  touched in any way.  Managing the pointer is the user's
  584.        *  responsibility.
  585.        */
  586.       void
  587.       erase(iterator __position)
  588.       { _M_t.erase(__position); }
  589. #endif
  590.  
  591.       /**
  592.        *  @brief Erases elements according to the provided key.
  593.        *  @param  __x  Key of element to be erased.
  594.        *  @return  The number of elements erased.
  595.        *
  596.        *  This function erases all the elements located by the given key from
  597.        *  a %set.
  598.        *  Note that this function only erases the element, and that if
  599.        *  the element is itself a pointer, the pointed-to memory is not touched
  600.        *  in any way.  Managing the pointer is the user's responsibility.
  601.        */
  602.       size_type
  603.       erase(const key_type& __x)
  604.       { return _M_t.erase(__x); }
  605.  
  606. #if __cplusplus >= 201103L
  607.       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  608.       // DR 130. Associative erase should return an iterator.
  609.       /**
  610.        *  @brief Erases a [__first,__last) range of elements from a %set.
  611.        *  @param  __first  Iterator pointing to the start of the range to be
  612.        *                 erased.
  613.  
  614.        *  @param __last Iterator pointing to the end of the range to
  615.        *  be erased.
  616.        *  @return The iterator @a __last.
  617.        *
  618.        *  This function erases a sequence of elements from a %set.
  619.        *  Note that this function only erases the element, and that if
  620.        *  the element is itself a pointer, the pointed-to memory is not touched
  621.        *  in any way.  Managing the pointer is the user's responsibility.
  622.        */
  623.       _GLIBCXX_ABI_TAG_CXX11
  624.       iterator
  625.       erase(const_iterator __first, const_iterator __last)
  626.       { return _M_t.erase(__first, __last); }
  627. #else
  628.       /**
  629.        *  @brief Erases a [first,last) range of elements from a %set.
  630.        *  @param  __first  Iterator pointing to the start of the range to be
  631.        *                 erased.
  632.        *  @param __last Iterator pointing to the end of the range to
  633.        *  be erased.
  634.        *
  635.        *  This function erases a sequence of elements from a %set.
  636.        *  Note that this function only erases the element, and that if
  637.        *  the element is itself a pointer, the pointed-to memory is not touched
  638.        *  in any way.  Managing the pointer is the user's responsibility.
  639.        */
  640.       void
  641.       erase(iterator __first, iterator __last)
  642.       { _M_t.erase(__first, __last); }
  643. #endif
  644.  
  645.       /**
  646.        *  Erases all elements in a %set.  Note that this function only erases
  647.        *  the elements, and that if the elements themselves are pointers, the
  648.        *  pointed-to memory is not touched in any way.  Managing the pointer is
  649.        *  the user's responsibility.
  650.        */
  651.       void
  652.       clear() _GLIBCXX_NOEXCEPT
  653.       { _M_t.clear(); }
  654.  
  655.       // set operations:
  656.  
  657.       //@{
  658.       /**
  659.        *  @brief  Finds the number of elements.
  660.        *  @param  __x  Element to located.
  661.        *  @return  Number of elements with specified key.
  662.        *
  663.        *  This function only makes sense for multisets; for set the result will
  664.        *  either be 0 (not present) or 1 (present).
  665.        */
  666.       size_type
  667.       count(const key_type& __x) const
  668.       { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
  669.  
  670. #if __cplusplus > 201103L
  671.       template<typename _Kt>
  672.         auto
  673.         count(const _Kt& __x) const
  674.         -> decltype(_M_t._M_count_tr(__x))
  675.         { return _M_t._M_find_tr(__x) == _M_t.end() ? 0 : 1; }
  676. #endif
  677.       //@}
  678.  
  679.       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  680.       // 214.  set::find() missing const overload
  681.       //@{
  682.       /**
  683.        *  @brief Tries to locate an element in a %set.
  684.        *  @param  __x  Element to be located.
  685.        *  @return  Iterator pointing to sought-after element, or end() if not
  686.        *           found.
  687.        *
  688.        *  This function takes a key and tries to locate the element with which
  689.        *  the key matches.  If successful the function returns an iterator
  690.        *  pointing to the sought after element.  If unsuccessful it returns the
  691.        *  past-the-end ( @c end() ) iterator.
  692.        */
  693.       iterator
  694.       find(const key_type& __x)
  695.       { return _M_t.find(__x); }
  696.  
  697.       const_iterator
  698.       find(const key_type& __x) const
  699.       { return _M_t.find(__x); }
  700.  
  701. #if __cplusplus > 201103L
  702.       template<typename _Kt>
  703.         auto
  704.         find(const _Kt& __x)
  705.         -> decltype(iterator{_M_t._M_find_tr(__x)})
  706.         { return iterator{_M_t._M_find_tr(__x)}; }
  707.  
  708.       template<typename _Kt>
  709.         auto
  710.         find(const _Kt& __x) const
  711.         -> decltype(const_iterator{_M_t._M_find_tr(__x)})
  712.         { return const_iterator{_M_t._M_find_tr(__x)}; }
  713. #endif
  714.       //@}
  715.  
  716.       //@{
  717.       /**
  718.        *  @brief Finds the beginning of a subsequence matching given key.
  719.        *  @param  __x  Key to be located.
  720.        *  @return  Iterator pointing to first element equal to or greater
  721.        *           than key, or end().
  722.        *
  723.        *  This function returns the first element of a subsequence of elements
  724.        *  that matches the given key.  If unsuccessful it returns an iterator
  725.        *  pointing to the first element that has a greater value than given key
  726.        *  or end() if no such element exists.
  727.        */
  728.       iterator
  729.       lower_bound(const key_type& __x)
  730.       { return _M_t.lower_bound(__x); }
  731.  
  732.       const_iterator
  733.       lower_bound(const key_type& __x) const
  734.       { return _M_t.lower_bound(__x); }
  735.  
  736. #if __cplusplus > 201103L
  737.       template<typename _Kt>
  738.         auto
  739.         lower_bound(const _Kt& __x)
  740.         -> decltype(_M_t._M_lower_bound_tr(__x))
  741.         { return _M_t._M_lower_bound_tr(__x); }
  742.  
  743.       template<typename _Kt>
  744.         auto
  745.         lower_bound(const _Kt& __x) const
  746.         -> decltype(_M_t._M_lower_bound_tr(__x))
  747.         { return _M_t._M_lower_bound_tr(__x); }
  748. #endif
  749.       //@}
  750.  
  751.       //@{
  752.       /**
  753.        *  @brief Finds the end of a subsequence matching given key.
  754.        *  @param  __x  Key to be located.
  755.        *  @return Iterator pointing to the first element
  756.        *          greater than key, or end().
  757.        */
  758.       iterator
  759.       upper_bound(const key_type& __x)
  760.       { return _M_t.upper_bound(__x); }
  761.  
  762.       const_iterator
  763.       upper_bound(const key_type& __x) const
  764.       { return _M_t.upper_bound(__x); }
  765.  
  766. #if __cplusplus > 201103L
  767.       template<typename _Kt>
  768.         auto
  769.         upper_bound(const _Kt& __x)
  770.         -> decltype(_M_t._M_upper_bound_tr(__x))
  771.         { return _M_t._M_upper_bound_tr(__x); }
  772.  
  773.       template<typename _Kt>
  774.         auto
  775.         upper_bound(const _Kt& __x) const
  776.         -> decltype(_M_t._M_upper_bound_tr(__x))
  777.         { return _M_t._M_upper_bound_tr(__x); }
  778. #endif
  779.       //@}
  780.  
  781.       //@{
  782.       /**
  783.        *  @brief Finds a subsequence matching given key.
  784.        *  @param  __x  Key to be located.
  785.        *  @return  Pair of iterators that possibly points to the subsequence
  786.        *           matching given key.
  787.        *
  788.        *  This function is equivalent to
  789.        *  @code
  790.        *    std::make_pair(c.lower_bound(val),
  791.        *                   c.upper_bound(val))
  792.        *  @endcode
  793.        *  (but is faster than making the calls separately).
  794.        *
  795.        *  This function probably only makes sense for multisets.
  796.        */
  797.       std::pair<iterator, iterator>
  798.       equal_range(const key_type& __x)
  799.       { return _M_t.equal_range(__x); }
  800.  
  801.       std::pair<const_iterator, const_iterator>
  802.       equal_range(const key_type& __x) const
  803.       { return _M_t.equal_range(__x); }
  804.  
  805. #if __cplusplus > 201103L
  806.       template<typename _Kt>
  807.         auto
  808.         equal_range(const _Kt& __x)
  809.         -> decltype(_M_t._M_equal_range_tr(__x))
  810.         { return _M_t._M_equal_range_tr(__x); }
  811.  
  812.       template<typename _Kt>
  813.         auto
  814.         equal_range(const _Kt& __x) const
  815.         -> decltype(_M_t._M_equal_range_tr(__x))
  816.         { return _M_t._M_equal_range_tr(__x); }
  817. #endif
  818.       //@}
  819.  
  820.       template<typename _K1, typename _C1, typename _A1>
  821.         friend bool
  822.         operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
  823.  
  824.       template<typename _K1, typename _C1, typename _A1>
  825.         friend bool
  826.         operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&);
  827.     };
  828.  
  829.  
  830.   /**
  831.    *  @brief  Set equality comparison.
  832.    *  @param  __x  A %set.
  833.    *  @param  __y  A %set of the same type as @a x.
  834.    *  @return  True iff the size and elements of the sets are equal.
  835.    *
  836.    *  This is an equivalence relation.  It is linear in the size of the sets.
  837.    *  Sets are considered equivalent if their sizes are equal, and if
  838.    *  corresponding elements compare equal.
  839.   */
  840.   template<typename _Key, typename _Compare, typename _Alloc>
  841.     inline bool
  842.     operator==(const set<_Key, _Compare, _Alloc>& __x,
  843.                const set<_Key, _Compare, _Alloc>& __y)
  844.     { return __x._M_t == __y._M_t; }
  845.  
  846.   /**
  847.    *  @brief  Set ordering relation.
  848.    *  @param  __x  A %set.
  849.    *  @param  __y  A %set of the same type as @a x.
  850.    *  @return  True iff @a __x is lexicographically less than @a __y.
  851.    *
  852.    *  This is a total ordering relation.  It is linear in the size of the
  853.    *  sets.  The elements must be comparable with @c <.
  854.    *
  855.    *  See std::lexicographical_compare() for how the determination is made.
  856.   */
  857.   template<typename _Key, typename _Compare, typename _Alloc>
  858.     inline bool
  859.     operator<(const set<_Key, _Compare, _Alloc>& __x,
  860.               const set<_Key, _Compare, _Alloc>& __y)
  861.     { return __x._M_t < __y._M_t; }
  862.  
  863.   ///  Returns !(x == y).
  864.   template<typename _Key, typename _Compare, typename _Alloc>
  865.     inline bool
  866.     operator!=(const set<_Key, _Compare, _Alloc>& __x,
  867.                const set<_Key, _Compare, _Alloc>& __y)
  868.     { return !(__x == __y); }
  869.  
  870.   ///  Returns y < x.
  871.   template<typename _Key, typename _Compare, typename _Alloc>
  872.     inline bool
  873.     operator>(const set<_Key, _Compare, _Alloc>& __x,
  874.               const set<_Key, _Compare, _Alloc>& __y)
  875.     { return __y < __x; }
  876.  
  877.   ///  Returns !(y < x)
  878.   template<typename _Key, typename _Compare, typename _Alloc>
  879.     inline bool
  880.     operator<=(const set<_Key, _Compare, _Alloc>& __x,
  881.                const set<_Key, _Compare, _Alloc>& __y)
  882.     { return !(__y < __x); }
  883.  
  884.   ///  Returns !(x < y)
  885.   template<typename _Key, typename _Compare, typename _Alloc>
  886.     inline bool
  887.     operator>=(const set<_Key, _Compare, _Alloc>& __x,
  888.                const set<_Key, _Compare, _Alloc>& __y)
  889.     { return !(__x < __y); }
  890.  
  891.   /// See std::set::swap().
  892.   template<typename _Key, typename _Compare, typename _Alloc>
  893.     inline void
  894.     swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y)
  895.     { __x.swap(__y); }
  896.  
  897. _GLIBCXX_END_NAMESPACE_CONTAINER
  898. } //namespace std
  899. #endif /* _STL_SET_H */
  900.