gcc/libstdc++-v3/include/bits/stl_multiset.h

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

// Copyright (C) 2001, 2002, 2004 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.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// 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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/*
 *
 * 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 __gnu_norm
{

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

template <class _Key, class _Compare = less<_Key>,
          class _Alloc = 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
    __glibcxx_class_requires(_Key, _SGIAssignableConcept)
    __glibcxx_class_requires4(_Compare, bool, _Key, _Key, _BinaryFunctionConcept)

  public:
    
    // typedefs:
    
    typedef _Key     key_type;
    typedef _Key     value_type;
    typedef _Compare key_compare;
    typedef _Compare value_compare;

  private:
    /// @if maint  This turns a red-black tree into a [multi]set.  @endif
    typedef _Rb_tree<key_type, value_type, 
		     _Identity<value_type>, key_compare, _Alloc> _Rep_type;
    /// @if maint  The actual tree structure.  @endif
    _Rep_type _M_t;

  public:
    typedef typename _Alloc::pointer pointer;
    typedef typename _Alloc::const_pointer const_pointer;
    typedef typename _Alloc::reference reference;
    typedef typename _Alloc::const_reference const_reference;
    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;
    typedef typename _Rep_type::allocator_type allocator_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) {
      typedef typename _Rep_type::iterator _Rep_iterator;
      return _M_t.insert_equal((_Rep_iterator&)__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) { 
      typedef typename _Rep_type::iterator _Rep_iterator;
      _M_t.erase((_Rep_iterator&)__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) { 
      typedef typename _Rep_type::iterator _Rep_iterator;
      _M_t.erase((_Rep_iterator&)__first, (_Rep_iterator&)__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.
     */
    pair<iterator,iterator> equal_range(const key_type& __x) {
      return _M_t.equal_range(__x);
    }
    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 __gnu_norm

#endif /* _MULTISET_H */