// Map implementation -*- C++ -*-
// Copyright (C) 2001-2016 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 3, 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// .
/*
 *
 * 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) 1996,1997
 * 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 bits/stl_map.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{map}
 */
#ifndef _STL_MAP_H
#define _STL_MAP_H 1
#include 
#include 
#if __cplusplus >= 201103L
#include 
#include 
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
  template 
    class multimap;
  /**
   *  @brief A standard container made up of (key,value) pairs, which can be
   *  retrieved based on a key, in logarithmic time.
   *
   *  @ingroup associative_containers
   *
   *  @tparam _Key  Type of key objects.
   *  @tparam  _Tp  Type of mapped objects.
   *  @tparam _Compare  Comparison function object type, defaults to less<_Key>.
   *  @tparam _Alloc  Allocator type, defaults to 
   *                  allocator.
   *
   *  Meets the requirements of a container, a
   *  reversible container, and an
   *  associative container (using unique keys).
   *  For a @c map the key_type is Key, the mapped_type is T, and the
   *  value_type is std::pair.
   *
   *  Maps support bidirectional iterators.
   *
   *  The private tree data is declared exactly the same way for map and
   *  multimap; the distinction is made entirely in how the tree functions are
   *  called (*_unique versus *_equal, same as the standard).
  */
  template ,
            typename _Alloc = std::allocator > >
    class map
    {
    public:
      typedef _Key                                          key_type;
      typedef _Tp                                           mapped_type;
      typedef std::pair                    value_type;
      typedef _Compare                                      key_compare;
      typedef _Alloc                                        allocator_type;
    private:
      // concept requirements
      typedef typename _Alloc::value_type                   _Alloc_value_type;
      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
      __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
				_BinaryFunctionConcept)
      __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
    public:
      class value_compare
      : public std::binary_function
      {
	friend class map<_Key, _Tp, _Compare, _Alloc>;
      protected:
	_Compare comp;
	value_compare(_Compare __c)
	: comp(__c) { }
      public:
	bool operator()(const value_type& __x, const value_type& __y) const
	{ return comp(__x.first, __y.first); }
      };
    private:
      /// This turns a red-black tree into a [multi]map. 
      typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
	rebind::other _Pair_alloc_type;
      typedef _Rb_tree,
		       key_compare, _Pair_alloc_type> _Rep_type;
      /// The actual tree structure.
      _Rep_type _M_t;
      typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
    public:
      // many of these are specified differently in ISO, but the following are
      // "functionally equivalent"
      typedef typename _Alloc_traits::pointer            pointer;
      typedef typename _Alloc_traits::const_pointer      const_pointer;
      typedef typename _Alloc_traits::reference          reference;
      typedef typename _Alloc_traits::const_reference    const_reference;
      typedef typename _Rep_type::iterator               iterator;
      typedef typename _Rep_type::const_iterator         const_iterator;
      typedef typename _Rep_type::size_type              size_type;
      typedef typename _Rep_type::difference_type        difference_type;
      typedef typename _Rep_type::reverse_iterator       reverse_iterator;
      typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
#if __cplusplus > 201402L
      using node_type = typename _Rep_type::node_type;
      using insert_return_type = typename _Rep_type::insert_return_type;
#endif
      // [23.3.1.1] construct/copy/destroy
      // (get_allocator() is also listed in this section)
      /**
       *  @brief  Default constructor creates no elements.
       */
      map()
      _GLIBCXX_NOEXCEPT_IF(
	  is_nothrow_default_constructible::value
	  && is_nothrow_default_constructible::value)
      : _M_t() { }
      /**
       *  @brief  Creates a %map with no elements.
       *  @param  __comp  A comparison object.
       *  @param  __a  An allocator object.
       */
      explicit
      map(const _Compare& __comp,
	  const allocator_type& __a = allocator_type())
      : _M_t(__comp, _Pair_alloc_type(__a)) { }
      /**
       *  @brief  %Map copy constructor.
       *  @param  __x  A %map of identical element and allocator types.
       *
       *  The newly-created %map uses a copy of the allocator object used
       *  by @a __x (unless the allocator traits dictate a different object).
       */
      map(const map& __x)
      : _M_t(__x._M_t) { }
#if __cplusplus >= 201103L
      /**
       *  @brief  %Map move constructor.
       *  @param  __x  A %map of identical element and allocator types.
       *
       *  The newly-created %map contains the exact contents of @a __x.
       *  The contents of @a __x are a valid, but unspecified %map.
       */
      map(map&& __x)
      noexcept(is_nothrow_copy_constructible<_Compare>::value)
      : _M_t(std::move(__x._M_t)) { }
      /**
       *  @brief  Builds a %map from an initializer_list.
       *  @param  __l  An initializer_list.
       *  @param  __comp  A comparison object.
       *  @param  __a  An allocator object.
       *
       *  Create a %map consisting of copies of the elements in the
       *  initializer_list @a __l.
       *  This is linear in N if the range is already sorted, and NlogN
       *  otherwise (where N is @a __l.size()).
       */
      map(initializer_list __l,
	  const _Compare& __comp = _Compare(),
	  const allocator_type& __a = allocator_type())
      : _M_t(__comp, _Pair_alloc_type(__a))
      { _M_t._M_insert_unique(__l.begin(), __l.end()); }
      /// Allocator-extended default constructor.
      explicit
      map(const allocator_type& __a)
      : _M_t(_Compare(), _Pair_alloc_type(__a)) { }
      /// Allocator-extended copy constructor.
      map(const map& __m, const allocator_type& __a)
      : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
      /// Allocator-extended move constructor.
      map(map&& __m, const allocator_type& __a)
      noexcept(is_nothrow_copy_constructible<_Compare>::value
	       && _Alloc_traits::_S_always_equal())
      : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
      /// Allocator-extended initialier-list constructor.
      map(initializer_list __l, const allocator_type& __a)
      : _M_t(_Compare(), _Pair_alloc_type(__a))
      { _M_t._M_insert_unique(__l.begin(), __l.end()); }
      /// Allocator-extended range constructor.
      template
        map(_InputIterator __first, _InputIterator __last,
	    const allocator_type& __a)
	: _M_t(_Compare(), _Pair_alloc_type(__a))
        { _M_t._M_insert_unique(__first, __last); }
#endif
      /**
       *  @brief  Builds a %map from a range.
       *  @param  __first  An input iterator.
       *  @param  __last  An input iterator.
       *
       *  Create a %map 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
        map(_InputIterator __first, _InputIterator __last)
	: _M_t()
        { _M_t._M_insert_unique(__first, __last); }
      /**
       *  @brief  Builds a %map 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 %map 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
        map(_InputIterator __first, _InputIterator __last,
	    const _Compare& __comp,
	    const allocator_type& __a = allocator_type())
	: _M_t(__comp, _Pair_alloc_type(__a))
        { _M_t._M_insert_unique(__first, __last); }
      // FIXME There is no dtor declared, but we should have something
      // generated by Doxygen.  I don't know what tags to add to this
      // paragraph to make that happen:
      /**
       *  The dtor only erases the elements, and note that if the elements
       *  themselves are pointers, the pointed-to memory is not touched in any
       *  way.  Managing the pointer is the user's responsibility.
       */
      /**
       *  @brief  %Map assignment operator.
       *  @param  __x  A %map of identical element and allocator types.
       *
       *  All the elements of @a __x are copied.
       *
       *  Whether the allocator is copied depends on the allocator traits.
       */
      map&
      operator=(const map& __x)
      {
	_M_t = __x._M_t;
	return *this;
      }
#if __cplusplus >= 201103L
      /// Move assignment operator.
      map&
      operator=(map&&) = default;
      /**
       *  @brief  %Map list assignment operator.
       *  @param  __l  An initializer_list.
       *
       *  This function fills a %map with copies of the elements in the
       *  initializer list @a __l.
       *
       *  Note that the assignment completely changes the %map and
       *  that the resulting %map's size is the same as the number
       *  of elements assigned.
       */
      map&
      operator=(initializer_list __l)
      {
	_M_t._M_assign_unique(__l.begin(), __l.end());
	return *this;
      }
#endif
      /// Get a copy of the memory allocation object.
      allocator_type
      get_allocator() const _GLIBCXX_NOEXCEPT
      { return allocator_type(_M_t.get_allocator()); }
      // iterators
      /**
       *  Returns a read/write iterator that points to the first pair in the
       *  %map.
       *  Iteration is done in ascending order according to the keys.
       */
      iterator
      begin() _GLIBCXX_NOEXCEPT
      { return _M_t.begin(); }
      /**
       *  Returns a read-only (constant) iterator that points to the first pair
       *  in the %map.  Iteration is done in ascending order according to the
       *  keys.
       */
      const_iterator
      begin() const _GLIBCXX_NOEXCEPT
      { return _M_t.begin(); }
      /**
       *  Returns a read/write iterator that points one past the last
       *  pair in the %map.  Iteration is done in ascending order
       *  according to the keys.
       */
      iterator
      end() _GLIBCXX_NOEXCEPT
      { return _M_t.end(); }
      /**
       *  Returns a read-only (constant) iterator that points one past the last
       *  pair in the %map.  Iteration is done in ascending order according to
       *  the keys.
       */
      const_iterator
      end() const _GLIBCXX_NOEXCEPT
      { return _M_t.end(); }
      /**
       *  Returns a read/write reverse iterator that points to the last pair in
       *  the %map.  Iteration is done in descending order according to the
       *  keys.
       */
      reverse_iterator
      rbegin() _GLIBCXX_NOEXCEPT
      { return _M_t.rbegin(); }
      /**
       *  Returns a read-only (constant) reverse iterator that points to the
       *  last pair in the %map.  Iteration is done in descending order
       *  according to the keys.
       */
      const_reverse_iterator
      rbegin() const _GLIBCXX_NOEXCEPT
      { return _M_t.rbegin(); }
      /**
       *  Returns a read/write reverse iterator that points to one before the
       *  first pair in the %map.  Iteration is done in descending order
       *  according to the keys.
       */
      reverse_iterator
      rend() _GLIBCXX_NOEXCEPT
      { return _M_t.rend(); }
      /**
       *  Returns a read-only (constant) reverse iterator that points to one
       *  before the first pair in the %map.  Iteration is done in descending
       *  order according to the keys.
       */
      const_reverse_iterator
      rend() const _GLIBCXX_NOEXCEPT
      { return _M_t.rend(); }
#if __cplusplus >= 201103L
      /**
       *  Returns a read-only (constant) iterator that points to the first pair
       *  in the %map.  Iteration is done in ascending order according to the
       *  keys.
       */
      const_iterator
      cbegin() const noexcept
      { return _M_t.begin(); }
      /**
       *  Returns a read-only (constant) iterator that points one past the last
       *  pair in the %map.  Iteration is done in ascending order according to
       *  the keys.
       */
      const_iterator
      cend() const noexcept
      { return _M_t.end(); }
      /**
       *  Returns a read-only (constant) reverse iterator that points to the
       *  last pair in the %map.  Iteration is done in descending order
       *  according to the keys.
       */
      const_reverse_iterator
      crbegin() const noexcept
      { return _M_t.rbegin(); }
      /**
       *  Returns a read-only (constant) reverse iterator that points to one
       *  before the first pair in the %map.  Iteration is done in descending
       *  order according to the keys.
       */
      const_reverse_iterator
      crend() const noexcept
      { return _M_t.rend(); }
#endif
      // capacity
      /** Returns true if the %map is empty.  (Thus begin() would equal
       *  end().)
      */
      bool
      empty() const _GLIBCXX_NOEXCEPT
      { return _M_t.empty(); }
      /** Returns the size of the %map.  */
      size_type
      size() const _GLIBCXX_NOEXCEPT
      { return _M_t.size(); }
      /** Returns the maximum size of the %map.  */
      size_type
      max_size() const _GLIBCXX_NOEXCEPT
      { return _M_t.max_size(); }
      // [23.3.1.2] element access
      /**
       *  @brief  Subscript ( @c [] ) access to %map data.
       *  @param  __k  The key for which data should be retrieved.
       *  @return  A reference to the data of the (key,data) %pair.
       *
       *  Allows for easy lookup with the subscript ( @c [] )
       *  operator.  Returns data associated with the key specified in
       *  subscript.  If the key does not exist, a pair with that key
       *  is created using default values, which is then returned.
       *
       *  Lookup requires logarithmic time.
       */
      mapped_type&
      operator[](const key_type& __k)
      {
	// concept requirements
	__glibcxx_function_requires(_DefaultConstructibleConcept)
	iterator __i = lower_bound(__k);
	// __i->first is greater than or equivalent to __k.
	if (__i == end() || key_comp()(__k, (*__i).first))
#if __cplusplus >= 201103L
	  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
					    std::tuple(__k),
					    std::tuple<>());
#else
          __i = insert(__i, value_type(__k, mapped_type()));
#endif
	return (*__i).second;
      }
#if __cplusplus >= 201103L
      mapped_type&
      operator[](key_type&& __k)
      {
	// concept requirements
	__glibcxx_function_requires(_DefaultConstructibleConcept)
	iterator __i = lower_bound(__k);
	// __i->first is greater than or equivalent to __k.
	if (__i == end() || key_comp()(__k, (*__i).first))
	  __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
					std::forward_as_tuple(std::move(__k)),
					std::tuple<>());
	return (*__i).second;
      }
#endif
      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // DR 464. Suggestion for new member functions in standard containers.
      /**
       *  @brief  Access to %map data.
       *  @param  __k  The key for which data should be retrieved.
       *  @return  A reference to the data whose key is equivalent to @a __k, if
       *           such a data is present in the %map.
       *  @throw  std::out_of_range  If no such data is present.
       */
      mapped_type&
      at(const key_type& __k)
      {
	iterator __i = lower_bound(__k);
	if (__i == end() || key_comp()(__k, (*__i).first))
	  __throw_out_of_range(__N("map::at"));
	return (*__i).second;
      }
      const mapped_type&
      at(const key_type& __k) const
      {
	const_iterator __i = lower_bound(__k);
	if (__i == end() || key_comp()(__k, (*__i).first))
	  __throw_out_of_range(__N("map::at"));
	return (*__i).second;
      }
      // modifiers
#if __cplusplus >= 201103L
      /**
       *  @brief Attempts to build and insert a std::pair into the %map.
       *
       *  @param __args  Arguments used to generate a new pair instance (see
       *	        std::piecewise_contruct for passing arguments to each
       *	        part of the pair constructor).
       *
       *  @return  A pair, of which the first element is an iterator that points
       *           to the possibly inserted pair, and the second is a bool that
       *           is true if the pair was actually inserted.
       *
       *  This function attempts to build and insert a (key, value) %pair into
       *  the %map.
       *  A %map relies on unique keys and thus a %pair is only inserted if its
       *  first element (the key) is not already present in the %map.
       *
       *  Insertion requires logarithmic time.
       */
      template
	std::pair
	emplace(_Args&&... __args)
	{ return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
      /**
       *  @brief Attempts to build and insert a std::pair into the %map.
       *
       *  @param  __pos  An iterator that serves as a hint as to where the pair
       *                should be inserted.
       *  @param  __args  Arguments used to generate a new pair instance (see
       *	         std::piecewise_contruct for passing arguments to each
       *	         part of the pair constructor).
       *  @return An iterator that points to the element with key of the
       *          std::pair built from @a __args (may or may not be that
       *          std::pair).
       *
       *  This function is not concerned about whether the insertion took place,
       *  and thus does not return a boolean like the single-argument emplace()
       *  does.
       *  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
       *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
       *  for more on @a hinting.
       *
       *  Insertion requires logarithmic time (if the hint is not taken).
       */
      template
	iterator
	emplace_hint(const_iterator __pos, _Args&&... __args)
	{
	  return _M_t._M_emplace_hint_unique(__pos,
					     std::forward<_Args>(__args)...);
	}
#endif
#if __cplusplus > 201402L
      /// Extract a node.
      node_type
      extract(const_iterator __pos)
      {
	__glibcxx_assert(__pos != end());
	return _M_t.extract(__pos);
      }
      /// Extract a node.
      node_type
      extract(const key_type& __x)
      { return _M_t.extract(__x); }
      /// Re-insert an extracted node.
      insert_return_type
      insert(node_type&& __nh)
      { return _M_t._M_reinsert_node_unique(std::move(__nh)); }
      /// Re-insert an extracted node.
      iterator
      insert(const_iterator __hint, node_type&& __nh)
      { return _M_t._M_reinsert_node_hint_unique(__hint, std::move(__nh)); }
      template
	friend class _Rb_tree_merge_helper;
      template
	void
	merge(map<_Key, _Tp, _C2, _Alloc>& __source)
	{
	  using _Merge_helper = _Rb_tree_merge_helper