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// Multiset implementation -*- C++ -*-

// Copyright (C) 2001, 2002, 2004, 2005 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 2, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

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// USA.

// As a special exception, you may use this file as part of a free software

// library without restriction.  Specifically, if other files instantiate

// templates or use macros or inline functions from this file, or you compile

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// file does not by itself cause the resulting executable to be covered by

// the GNU General Public License.  This exception does not however

// invalidate any other reasons why the executable file might be covered by

// the GNU General Public License.

/*

 *

 * Copyright (c) 1994

 * Hewlett-Packard Company

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Hewlett-Packard Company makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 *

 *

 * Copyright (c) 1996

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

/** @file stl_multiset.h

 *  This is an internal header file, included by other library headers.

 *  You should not attempt to use it directly.

 */

#ifndef _MULTISET_H

#define _MULTISET_H 1

#include <bits/concept_check.h>

namespace _GLIBCXX_STD

{

  // Forward declaration of operators < and ==, needed for friend declaration.

  template <class _Key, class _Compare = std::less<_Key>,

            class _Alloc = std::allocator<_Key> >

    class multiset;

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator==(const multiset<_Key, _Compare, _Alloc>& __x,

               const multiset<_Key, _Compare, _Alloc>& __y);

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator<(const multiset<_Key, _Compare, _Alloc>& __x,

              const multiset<_Key, _Compare, _Alloc>& __y);

  /**

   *  @brief A standard container made up of elements, which can be retrieved

   *  in logarithmic time.

   *

   *  @ingroup Containers

   *  @ingroup Assoc_containers

   *

   *  Meets the requirements of a <a href="tables.html#65">container</a>, a

   *  <a href="tables.html#66">reversible container</a>, and an

   *  <a href="tables.html#69">associative container</a> (using equivalent

   *  keys).  For a @c multiset<Key> the key_type and value_type are Key.

   *

   *  Multisets support bidirectional iterators.

   *

   *  @if maint

   *  The private tree data is declared exactly the same way for set and

   *  multiset; the distinction is made entirely in how the tree functions are

   *  called (*_unique versus *_equal, same as the standard).

   *  @endif

  */

  template <class _Key, class _Compare, class _Alloc>

    class multiset

    {

      // concept requirements

      typedef typename _Alloc::value_type                   _Alloc_value_type;

      __glibcxx_class_requires(_Key, _SGIAssignableConcept)

      __glibcxx_class_requires4(_Compare, bool, _Key, _Key,

                                _BinaryFunctionConcept)

      __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept)

    public:

      // typedefs:

      typedef _Key     key_type;

      typedef _Key     value_type;

      typedef _Compare key_compare;

      typedef _Compare value_compare;

      typedef _Alloc   allocator_type;

    private:

      /// @if maint  This turns a red-black tree into a [multi]set.  @endif

      typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type;

      typedef _Rb_tree<key_type, value_type, _Identity<value_type>,

                       key_compare, _Key_alloc_type> _Rep_type;

      /// @if maint  The actual tree structure.  @endif

      _Rep_type _M_t;

    public:

      typedef typename _Key_alloc_type::pointer             pointer;

      typedef typename _Key_alloc_type::const_pointer       const_pointer;

      typedef typename _Key_alloc_type::reference           reference;

      typedef typename _Key_alloc_type::const_reference     const_reference;

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // DR 103. set::iterator is required to be modifiable,

      // but this allows modification of keys.

      typedef typename _Rep_type::const_iterator            iterator;

      typedef typename _Rep_type::const_iterator            const_iterator;

      typedef typename _Rep_type::const_reverse_iterator    reverse_iterator;

      typedef typename _Rep_type::const_reverse_iterator    const_reverse_iterator;

      typedef typename _Rep_type::size_type                 size_type;

      typedef typename _Rep_type::difference_type           difference_type;

      // allocation/deallocation

      /**

       *  @brief  Default constructor creates no elements.

       */

      multiset()

      : _M_t(_Compare(), allocator_type()) { }

      explicit

      multiset(const _Compare& __comp,

               const allocator_type& __a = allocator_type())

      : _M_t(__comp, __a) { }

      /**

       *  @brief  Builds a %multiset from a range.

       *  @param  first  An input iterator.

       *  @param  last  An input iterator.

       *

       *  Create a %multiset consisting of copies of the elements from

       *  [first,last).  This is linear in N if the range is already sorted,

       *  and NlogN otherwise (where N is distance(first,last)).

       */

      template <class _InputIterator>

        multiset(_InputIterator __first, _InputIterator __last)

        : _M_t(_Compare(), allocator_type())

        { _M_t.insert_equal(__first, __last); }

      /**

       *  @brief  Builds a %multiset from a range.

       *  @param  first  An input iterator.

       *  @param  last  An input iterator.

       *  @param  comp  A comparison functor.

       *  @param  a  An allocator object.

       *

       *  Create a %multiset consisting of copies of the elements from

       *  [first,last).  This is linear in N if the range is already sorted,

       *  and NlogN otherwise (where N is distance(first,last)).

       */

      template <class _InputIterator>

        multiset(_InputIterator __first, _InputIterator __last,

                 const _Compare& __comp,

                 const allocator_type& __a = allocator_type())

        : _M_t(__comp, __a)

        { _M_t.insert_equal(__first, __last); }

      /**

       *  @brief  %Multiset copy constructor.

       *  @param  x  A %multiset of identical element and allocator types.

       *

       *  The newly-created %multiset uses a copy of the allocation object used

       *  by @a x.

       */

      multiset(const multiset<_Key,_Compare,_Alloc>& __x)

      : _M_t(__x._M_t) { }

      /**

       *  @brief  %Multiset assignment operator.

       *  @param  x  A %multiset of identical element and allocator types.

       *

       *  All the elements of @a x are copied, but unlike the copy constructor,

       *  the allocator object is not copied.

       */

      multiset<_Key,_Compare,_Alloc>&

      operator=(const multiset<_Key,_Compare,_Alloc>& __x)

      {

        _M_t = __x._M_t;

        return *this;

      }

      // accessors:

      ///  Returns the comparison object.

      key_compare

      key_comp() const

      { return _M_t.key_comp(); }

      ///  Returns the comparison object.

      value_compare

      value_comp() const

      { return _M_t.key_comp(); }

      ///  Returns the memory allocation object.

      allocator_type

      get_allocator() const

      { return _M_t.get_allocator(); }

      /**

       *  Returns a read/write iterator that points to the first element in the

       *  %multiset.  Iteration is done in ascending order according to the

       *  keys.

       */

      iterator

      begin() const

      { return _M_t.begin(); }

      /**

       *  Returns a read/write iterator that points one past the last element in

       *  the %multiset.  Iteration is done in ascending order according to the

       *  keys.

       */

      iterator

      end() const

      { return _M_t.end(); }

      /**

       *  Returns a read/write reverse iterator that points to the last element

       *  in the %multiset.  Iteration is done in descending order according to

       *  the keys.

       */

      reverse_iterator

      rbegin() const

      { return _M_t.rbegin(); }

      /**

       *  Returns a read/write reverse iterator that points to the last element

       *  in the %multiset.  Iteration is done in descending order according to

       *  the keys.

       */

      reverse_iterator

      rend() const

      { return _M_t.rend(); }

      ///  Returns true if the %set is empty.

      bool

      empty() const

      { return _M_t.empty(); }

      ///  Returns the size of the %set.

      size_type

      size() const

      { return _M_t.size(); }

      ///  Returns the maximum size of the %set.

      size_type

      max_size() const

      { return _M_t.max_size(); }

      /**

       *  @brief  Swaps data with another %multiset.

       *  @param  x  A %multiset of the same element and allocator types.

       *

       *  This exchanges the elements between two multisets in constant time.

       *  (It is only swapping a pointer, an integer, and an instance of the @c

       *  Compare type (which itself is often stateless and empty), so it should

       *  be quite fast.)

       *  Note that the global std::swap() function is specialized such that

       *  std::swap(s1,s2) will feed to this function.

       */

      void

      swap(multiset<_Key, _Compare, _Alloc>& __x)

      { _M_t.swap(__x._M_t); }

      // insert/erase

      /**

       *  @brief Inserts an element into the %multiset.

       *  @param  x  Element to be inserted.

       *  @return An iterator that points to the inserted element.

       *

       *  This function inserts an element into the %multiset.  Contrary

       *  to a std::set the %multiset does not rely on unique keys and thus

       *  multiple copies of the same element can be inserted.

       *

       *  Insertion requires logarithmic time.

       */

      iterator

      insert(const value_type& __x)

      { return _M_t.insert_equal(__x); }

      /**

       *  @brief Inserts an element into the %multiset.

       *  @param  position  An iterator that serves as a hint as to where the

       *                    element should be inserted.

       *  @param  x  Element to be inserted.

       *  @return An iterator that points to the inserted element.

       *

       *  This function inserts an element into the %multiset.  Contrary

       *  to a std::set the %multiset does not rely on unique keys and thus

       *  multiple copies of the same element can be inserted.

       *

       *  Note that the first parameter is only a hint and can potentially

       *  improve the performance of the insertion process.  A bad hint would

       *  cause no gains in efficiency.

       *

       *  See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4

       *  for more on "hinting".

       *

       *  Insertion requires logarithmic time (if the hint is not taken).

       */

      iterator

      insert(iterator __position, const value_type& __x)

      { return _M_t.insert_equal(__position, __x); }

      /**

       *  @brief A template function that attemps to insert a range of elements.

       *  @param  first  Iterator pointing to the start of the range to be

       *                 inserted.

       *  @param  last  Iterator pointing to the end of the range.

       *

       *  Complexity similar to that of the range constructor.

       */

      template <class _InputIterator>

        void

        insert(_InputIterator __first, _InputIterator __last)

        { _M_t.insert_equal(__first, __last); }

      /**

       *  @brief Erases an element from a %multiset.

       *  @param  position  An iterator pointing to the element to be erased.

       *

       *  This function erases an element, pointed to by the given iterator,

       *  from a %multiset.  Note that this function only erases the element,

       *  and that if the element is itself a pointer, the pointed-to memory is

       *  not touched in any way.  Managing the pointer is the user's

       *  responsibilty.

       */

      void

      erase(iterator __position)

      { _M_t.erase(__position); }

      /**

       *  @brief Erases elements according to the provided key.

       *  @param  x  Key of element to be erased.

       *  @return  The number of elements erased.

       *

       *  This function erases all elements located by the given key from a

       *  %multiset.

       *  Note that this function only erases the element, and that if

       *  the element is itself a pointer, the pointed-to memory is not touched

       *  in any way.  Managing the pointer is the user's responsibilty.

       */

      size_type

      erase(const key_type& __x)

      { return _M_t.erase(__x); }

      /**

       *  @brief Erases a [first,last) range of elements from a %multiset.

       *  @param  first  Iterator pointing to the start of the range to be

       *                 erased.

       *  @param  last  Iterator pointing to the end of the range to be erased.

       *

       *  This function erases a sequence of elements from a %multiset.

       *  Note that this function only erases the elements, and that if

       *  the elements themselves are pointers, the pointed-to memory is not

       *  touched in any way.  Managing the pointer is the user's responsibilty.

       */

      void

      erase(iterator __first, iterator __last)

      { _M_t.erase(__first, __last); }

      /**

       *  Erases all elements in a %multiset.  Note that this function only

       *  erases the elements, and that if the elements themselves are pointers,

       *  the pointed-to memory is not touched in any way.  Managing the pointer

       *  is the user's responsibilty.

       */

      void

      clear()

      { _M_t.clear(); }

      // multiset operations:

      /**

       *  @brief Finds the number of elements with given key.

       *  @param  x  Key of elements to be located.

       *  @return Number of elements with specified key.

       */

      size_type

      count(const key_type& __x) const

      { return _M_t.count(__x); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 214.  set::find() missing const overload

      //@{

      /**

       *  @brief Tries to locate an element in a %set.

       *  @param  x  Element to be located.

       *  @return  Iterator pointing to sought-after element, or end() if not

       *           found.

       *

       *  This function takes a key and tries to locate the element with which

       *  the key matches.  If successful the function returns an iterator

       *  pointing to the sought after element.  If unsuccessful it returns the

       *  past-the-end ( @c end() ) iterator.

       */

      iterator

      find(const key_type& __x)

      { return _M_t.find(__x); }

      const_iterator

      find(const key_type& __x) const

      { return _M_t.find(__x); }

      //@}

      //@{

      /**

       *  @brief Finds the beginning of a subsequence matching given key.

       *  @param  x  Key to be located.

       *  @return  Iterator pointing to first element equal to or greater

       *           than key, or end().

       *

       *  This function returns the first element of a subsequence of elements

       *  that matches the given key.  If unsuccessful it returns an iterator

       *  pointing to the first element that has a greater value than given key

       *  or end() if no such element exists.

       */

      iterator

      lower_bound(const key_type& __x)

      { return _M_t.lower_bound(__x); }

      const_iterator

      lower_bound(const key_type& __x) const

      { return _M_t.lower_bound(__x); }

      //@}

      //@{

      /**

       *  @brief Finds the end of a subsequence matching given key.

       *  @param  x  Key to be located.

       *  @return Iterator pointing to the first element

       *          greater than key, or end().

       */

      iterator

      upper_bound(const key_type& __x)

      { return _M_t.upper_bound(__x); }

      const_iterator

      upper_bound(const key_type& __x) const

      { return _M_t.upper_bound(__x); }

      //@}

      //@{

      /**

       *  @brief Finds a subsequence matching given key.

       *  @param  x  Key to be located.

       *  @return  Pair of iterators that possibly points to the subsequence

       *           matching given key.

       *

       *  This function is equivalent to

       *  @code

       *    std::make_pair(c.lower_bound(val),

       *                   c.upper_bound(val))

       *  @endcode

       *  (but is faster than making the calls separately).

       *

       *  This function probably only makes sense for multisets.

       */

      std::pair<iterator, iterator>

      equal_range(const key_type& __x)

      { return _M_t.equal_range(__x); }

      std::pair<const_iterator, const_iterator>

      equal_range(const key_type& __x) const

      { return _M_t.equal_range(__x); }

      template <class _K1, class _C1, class _A1>

        friend bool

        operator== (const multiset<_K1, _C1, _A1>&,

                    const multiset<_K1, _C1, _A1>&);

      template <class _K1, class _C1, class _A1>

        friend bool

        operator< (const multiset<_K1, _C1, _A1>&,

                   const multiset<_K1, _C1, _A1>&);

    };

  /**

   *  @brief  Multiset equality comparison.

   *  @param  x  A %multiset.

   *  @param  y  A %multiset of the same type as @a x.

   *  @return  True iff the size and elements of the multisets are equal.

   *

   *  This is an equivalence relation.  It is linear in the size of the

   *  multisets.

   *  Multisets are considered equivalent if their sizes are equal, and if

   *  corresponding elements compare equal.

  */

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator==(const multiset<_Key, _Compare, _Alloc>& __x,

               const multiset<_Key, _Compare, _Alloc>& __y)

    { return __x._M_t == __y._M_t; }

  /**

   *  @brief  Multiset ordering relation.

   *  @param  x  A %multiset.

   *  @param  y  A %multiset of the same type as @a x.

   *  @return  True iff @a x is lexicographically less than @a y.

   *

   *  This is a total ordering relation.  It is linear in the size of the

   *  maps.  The elements must be comparable with @c <.

   *

   *  See std::lexicographical_compare() for how the determination is made.

  */

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator<(const multiset<_Key, _Compare, _Alloc>& __x,

              const multiset<_Key, _Compare, _Alloc>& __y)

    { return __x._M_t < __y._M_t; }

  ///  Returns !(x == y).

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator!=(const multiset<_Key, _Compare, _Alloc>& __x,

               const multiset<_Key, _Compare, _Alloc>& __y)

    { return !(__x == __y); }

  ///  Returns y < x.

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator>(const multiset<_Key,_Compare,_Alloc>& __x,

              const multiset<_Key,_Compare,_Alloc>& __y)

    { return __y < __x; }

  ///  Returns !(y < x)

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator<=(const multiset<_Key, _Compare, _Alloc>& __x,

               const multiset<_Key, _Compare, _Alloc>& __y)

    { return !(__y < __x); }

  ///  Returns !(x < y)

  template <class _Key, class _Compare, class _Alloc>

    inline bool

    operator>=(const multiset<_Key, _Compare, _Alloc>& __x,

               const multiset<_Key, _Compare, _Alloc>& __y)

    { return !(__x < __y); }

  /// See std::multiset::swap().

  template <class _Key, class _Compare, class _Alloc>

    inline void

    swap(multiset<_Key, _Compare, _Alloc>& __x,

         multiset<_Key, _Compare, _Alloc>& __y)

    { __x.swap(__y); }

} // namespace std

#endif /* _MULTISET_H */