text: //////////////////////////////////////////////////////////////////////////////
  //
  // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
  // Software License, Version 1.0. (See accompanying file
  // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  //
  // See http://www.boost.org/libs/container for documentation.
  //
  //////////////////////////////////////////////////////////////////////////////
  
  #ifndef BOOST_CONTAINER_FLAT_SET_HPP
  #define BOOST_CONTAINER_FLAT_SET_HPP
  
  #if (defined _MSC_VER) && (_MSC_VER >= 1200)
  #  pragma once
  #endif
  
  #include <boost/container/detail/config_begin.hpp>
  #include <boost/container/detail/workaround.hpp>
  
  #include <boost/container/container_fwd.hpp>
  #include <utility>
  #include <functional>
  #include <memory>
  #include <boost/container/detail/flat_tree.hpp>
  #include <boost/container/detail/mpl.hpp>
  #include <boost/container/allocator_traits.hpp>
  #include <boost/move/utility.hpp>
  #include <boost/move/detail/move_helpers.hpp>
  
  namespace boost {
  namespace container {
  
  /// @cond
  // Forward declarations of operators < and ==, needed for friend declaration.
  
  #ifdef BOOST_CONTAINER_DOXYGEN_INVOKED
  template <class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key> >
  #else
  template <class Key, class Compare, class Allocator>
  #endif
  class flat_set;
  
  template <class Key, class Compare, class Allocator>
  inline bool operator==(const flat_set<Key,Compare,Allocator>& x,
                         const flat_set<Key,Compare,Allocator>& y);
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<(const flat_set<Key,Compare,Allocator>& x,
                        const flat_set<Key,Compare,Allocator>& y);
  /// @endcond
  
  //! flat_set is a Sorted Associative Container that stores objects of type Key.
  //! flat_set is a Simple Associative Container, meaning that its value type,
  //! as well as its key type, is Key. It is also a Unique Associative Container,
  //! meaning that no two elements are the same.
  //!
  //! flat_set is similar to std::set but it's implemented like an ordered vector.
  //! This means that inserting a new element into a flat_set invalidates
  //! previous iterators and references
  //!
  //! Erasing an element of a flat_set invalidates iterators and references
  //! pointing to elements that come after (their keys are bigger) the erased element.
  #ifdef BOOST_CONTAINER_DOXYGEN_INVOKED
  template <class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key> >
  #else
  template <class Key, class Compare, class Allocator>
  #endif
  class flat_set
  {
     /// @cond
     private:
     BOOST_COPYABLE_AND_MOVABLE(flat_set)
     typedef container_detail::flat_tree<Key, Key, container_detail::identity<Key>, Compare, Allocator> tree_t;
     tree_t m_flat_tree;  // flat tree representing flat_set
     /// @endcond
  
     public:
     //////////////////////////////////////////////
     //
     //                    types
     //
     //////////////////////////////////////////////
     typedef Key                                                                         key_type;
     typedef Key                                                                         value_type;
     typedef Compare                                                                     key_compare;
     typedef Compare                                                                     value_compare;
     typedef typename ::boost::container::allocator_traits<Allocator>::pointer           pointer;
     typedef typename ::boost::container::allocator_traits<Allocator>::const_pointer     const_pointer;
     typedef typename ::boost::container::allocator_traits<Allocator>::reference         reference;
     typedef typename ::boost::container::allocator_traits<Allocator>::const_reference   const_reference;
     typedef typename ::boost::container::allocator_traits<Allocator>::size_type         size_type;
     typedef typename ::boost::container::allocator_traits<Allocator>::difference_type   difference_type;
     typedef Allocator                                                                   allocator_type;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::stored_allocator_type)              stored_allocator_type;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::iterator)                           iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::const_iterator)                     const_iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::reverse_iterator)                   reverse_iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::const_reverse_iterator)             const_reverse_iterator;
  
     public:
     //////////////////////////////////////////////
     //
     //          construct/copy/destroy
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Default constructs an empty flat_set.
     //!
     //! <b>Complexity</b>: Constant.
     explicit flat_set()
        : m_flat_tree()
     {}
  
     //! <b>Effects</b>: Constructs an empty flat_set using the specified
     //! comparison object and allocator.
     //!
     //! <b>Complexity</b>: Constant.
     explicit flat_set(const Compare& comp,
                       const allocator_type& a = allocator_type())
        : m_flat_tree(comp, a)
     {}
  
     //! <b>Effects</b>: Constructs an empty set using the specified comparison object and
     //! allocator, and inserts elements from the range [first ,last ).
     //!
     //! <b>Complexity</b>: Linear in N if the range [first ,last ) is already sorted using
     //! comp and otherwise N logN, where N is last - first.
     template <class InputIterator>
     flat_set(InputIterator first, InputIterator last,
              const Compare& comp = Compare(),
              const allocator_type& a = allocator_type())
        : m_flat_tree(true, first, last, comp, a)
     {}
  
     //! <b>Effects</b>: Constructs an empty flat_set using the specified comparison object and
     //! allocator, and inserts elements from the ordered unique range [first ,last). This function
     //! is more efficient than the normal range creation for ordered ranges.
     //!
     //! <b>Requires</b>: [first ,last) must be ordered according to the predicate and must be
     //! unique values.
     //!
     //! <b>Complexity</b>: Linear in N.
     //!
     //! <b>Note</b>: Non-standard extension.
     template <class InputIterator>
     flat_set(ordered_unique_range_t, InputIterator first, InputIterator last,
              const Compare& comp = Compare(),
              const allocator_type& a = allocator_type())
        : m_flat_tree(ordered_range, first, last, comp, a)
     {}
  
     //! <b>Effects</b>: Copy constructs a set.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_set(const flat_set& x)
        : m_flat_tree(x.m_flat_tree)
     {}
  
     //! <b>Effects</b>: Move constructs a set. Constructs *this using x's resources.
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Postcondition</b>: x is emptied.
     flat_set(BOOST_RV_REF(flat_set) mx)
        : m_flat_tree(boost::move(mx.m_flat_tree))
     {}
  
     //! <b>Effects</b>: Copy constructs a set using the specified allocator.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_set(const flat_set& x, const allocator_type &a)
        : m_flat_tree(x.m_flat_tree, a)
     {}
  
     //! <b>Effects</b>: Move constructs a set using the specified allocator.
     //!                 Constructs *this using x's resources.
     //!
     //! <b>Complexity</b>: Constant if a == mx.get_allocator(), linear otherwise
     flat_set(BOOST_RV_REF(flat_set) mx, const allocator_type &a)
        : m_flat_tree(boost::move(mx.m_flat_tree), a)
     {}
  
     //! <b>Effects</b>: Makes *this a copy of x.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_set& operator=(BOOST_COPY_ASSIGN_REF(flat_set) x)
        {  m_flat_tree = x.m_flat_tree;   return *this;  }
  
     //! <b>Effects</b>: Makes *this a copy of the previous value of xx.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_set& operator=(BOOST_RV_REF(flat_set) mx)
     {  m_flat_tree = boost::move(mx.m_flat_tree);   return *this;  }
  
     //! <b>Effects</b>: Returns a copy of the Allocator that
     //!   was passed to the object's constructor.
     //!
     //! <b>Complexity</b>: Constant.
     allocator_type get_allocator() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.get_allocator(); }
  
     //! <b>Effects</b>: Returns a reference to the internal allocator.
     //!
     //! <b>Throws</b>: Nothing
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Note</b>: Non-standard extension.
     stored_allocator_type &get_stored_allocator() BOOST_CONTAINER_NOEXCEPT
     {  return m_flat_tree.get_stored_allocator(); }
  
     //! <b>Effects</b>: Returns a reference to the internal allocator.
     //!
     //! <b>Throws</b>: Nothing
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Note</b>: Non-standard extension.
     const stored_allocator_type &get_stored_allocator() const BOOST_CONTAINER_NOEXCEPT
     {  return m_flat_tree.get_stored_allocator(); }
  
     //////////////////////////////////////////////
     //
     //                iterators
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Returns an iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     iterator begin() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.begin(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator begin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.begin(); }
  
     //! <b>Effects</b>: Returns an iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     iterator end() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.end(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator end() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.end(); }
  
     //! <b>Effects</b>: Returns a reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     reverse_iterator rbegin() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rbegin(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator rbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rbegin(); }
  
     //! <b>Effects</b>: Returns a reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     reverse_iterator rend() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rend(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator rend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rend(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator cbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.cbegin(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator cend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.cend(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator crbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.crbegin(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator crend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.crend(); }
  
  
     //////////////////////////////////////////////
     //
     //                capacity
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Returns true if the container contains no elements.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     bool empty() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.empty(); }
  
     //! <b>Effects</b>: Returns the number of the elements contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type size() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.size(); }
  
     //! <b>Effects</b>: Returns the largest possible size of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type max_size() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.max_size(); }
  
     //! <b>Effects</b>: Number of elements for which memory has been allocated.
     //!   capacity() is always greater than or equal to size().
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type capacity() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.capacity(); }
  
     //! <b>Effects</b>: If n is less than or equal to capacity(), this call has no
     //!   effect. Otherwise, it is a request for allocation of additional memory.
     //!   If the request is successful, then capacity() is greater than or equal to
     //!   n; otherwise, capacity() is unchanged. In either case, size() is unchanged.
     //!
     //! <b>Throws</b>: If memory allocation allocation throws or Key's copy constructor throws.
     //!
     //! <b>Note</b>: If capacity() is less than "cnt", iterators and references to
     //!   to values might be invalidated.
     void reserve(size_type cnt)      
        { m_flat_tree.reserve(cnt);   }
  
     //! <b>Effects</b>: Tries to deallocate the excess of memory created
     //    with previous allocations. The size of the vector is unchanged
     //!
     //! <b>Throws</b>: If memory allocation throws, or Key's copy constructor throws.
     //!
     //! <b>Complexity</b>: Linear to size().
     void shrink_to_fit()
        { m_flat_tree.shrink_to_fit(); }
  
     //////////////////////////////////////////////
     //
     //                modifiers
     //
     //////////////////////////////////////////////
  
     #if defined(BOOST_CONTAINER_PERFECT_FORWARDING) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
  
     //! <b>Effects</b>: Inserts an object x of type Key constructed with
     //!   std::forward<Args>(args)... if and only if there is no element in the container
     //!   with key equivalent to the key of x.
     //!
     //! <b>Returns</b>: The bool component of the returned pair is true if and only
     //!   if the insertion takes place, and the iterator component of the pair
     //!   points to the element with key equivalent to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class... Args>
     std::pair<iterator,bool> emplace(Args&&... args)
     {  return m_flat_tree.emplace_unique(boost::forward<Args>(args)...); }
  
     //! <b>Effects</b>: Inserts an object of type Key constructed with
     //!   std::forward<Args>(args)... in the container if and only if there is
     //!   no element in the container with key equivalent to the key of x.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent
     //!   to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class... Args>
     iterator emplace_hint(const_iterator hint, Args&&... args)
     {  return m_flat_tree.emplace_hint_unique(hint, boost::forward<Args>(args)...); }
  
     #else //#ifdef BOOST_CONTAINER_PERFECT_FORWARDING
  
     #define BOOST_PP_LOCAL_MACRO(n)                                                                 \
     BOOST_PP_EXPR_IF(n, template<) BOOST_PP_ENUM_PARAMS(n, class P) BOOST_PP_EXPR_IF(n, >)          \
     std::pair<iterator,bool> emplace(BOOST_PP_ENUM(n, BOOST_CONTAINER_PP_PARAM_LIST, _))            \
     {  return m_flat_tree.emplace_unique(BOOST_PP_ENUM(n, BOOST_CONTAINER_PP_PARAM_FORWARD, _)); }  \
                                                                                                     \
     BOOST_PP_EXPR_IF(n, template<) BOOST_PP_ENUM_PARAMS(n, class P) BOOST_PP_EXPR_IF(n, >)          \
     iterator emplace_hint(const_iterator hint                                                       \
                           BOOST_PP_ENUM_TRAILING(n, BOOST_CONTAINER_PP_PARAM_LIST, _))              \
     {  return m_flat_tree.emplace_hint_unique                                                       \
              (hint BOOST_PP_ENUM_TRAILING(n, BOOST_CONTAINER_PP_PARAM_FORWARD, _)); }               \
     //!
     #define BOOST_PP_LOCAL_LIMITS (0, BOOST_CONTAINER_MAX_CONSTRUCTOR_PARAMETERS)
     #include BOOST_PP_LOCAL_ITERATE()
  
     #endif   //#ifdef BOOST_CONTAINER_PERFECT_FORWARDING
  
     #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
     //! <b>Effects</b>: Inserts x if and only if there is no element in the container
     //!   with key equivalent to the key of x.
     //!
     //! <b>Returns</b>: The bool component of the returned pair is true if and only
     //!   if the insertion takes place, and the iterator component of the pair
     //!   points to the element with key equivalent to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     std::pair<iterator, bool> insert(const value_type &x);
  
     //! <b>Effects</b>: Inserts a new value_type move constructed from the pair if and
     //! only if there is no element in the container with key equivalent to the key of x.
     //!
     //! <b>Returns</b>: The bool component of the returned pair is true if and only
     //!   if the insertion takes place, and the iterator component of the pair
     //!   points to the element with key equivalent to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     std::pair<iterator, bool> insert(value_type &&x);
     #else
     private:
     typedef std::pair<iterator, bool> insert_return_pair;
     public:
     BOOST_MOVE_CONVERSION_AWARE_CATCH(insert, value_type, insert_return_pair, this->priv_insert)
     #endif
  
     #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
     //! <b>Effects</b>: Inserts a copy of x in the container if and only if there is
     //!   no element in the container with key equivalent to the key of x.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent
     //!   to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(const_iterator p, const value_type &x);
  
     //! <b>Effects</b>: Inserts an element move constructed from x in the container.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(const_iterator position, value_type &&x);
     #else
     BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(insert, value_type, iterator, this->priv_insert, const_iterator)
     #endif
  
     //! <b>Requires</b>: first, last are not iterators into *this.
     //!
     //! <b>Effects</b>: inserts each element from the range [first,last) if and only
     //!   if there is no element with key equivalent to the key of that element.
     //!
     //! <b>Complexity</b>: At most N log(size()+N) (N is the distance from first to last)
     //!   search time plus N*size() insertion time.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class InputIterator>
     void insert(InputIterator first, InputIterator last)
        {  m_flat_tree.insert_unique(first, last);  }
  
     //! <b>Requires</b>: first, last are not iterators into *this and
     //! must be ordered according to the predicate and must be
     //! unique values.
     //!
     //! <b>Effects</b>: inserts each element from the range [first,last) .This function
     //! is more efficient than the normal range creation for ordered ranges.
     //!
     //! <b>Complexity</b>: At most N log(size()+N) (N is the distance from first to last)
     //!   search time plus N*size() insertion time.
     //!
     //! <b>Note</b>: Non-standard extension. If an element is inserted it might invalidate elements.
     template <class InputIterator>
     void insert(ordered_unique_range_t, InputIterator first, InputIterator last)
        {  m_flat_tree.insert_unique(ordered_unique_range, first, last);  }
  
     //! <b>Effects</b>: Erases the element pointed to by position.
     //!
     //! <b>Returns</b>: Returns an iterator pointing to the element immediately
     //!   following q prior to the element being erased. If no such element exists,
     //!   returns end().
     //!
     //! <b>Complexity</b>: Linear to the elements with keys bigger than position
     //!
     //! <b>Note</b>: Invalidates elements with keys
     //!   not less than the erased element.
     iterator erase(const_iterator position)
        {  return m_flat_tree.erase(position); }
  
     //! <b>Effects</b>: Erases all elements in the container with key equivalent to x.
     //!
     //! <b>Returns</b>: Returns the number of erased elements.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus erasure time
     //!   linear to the elements with bigger keys.
     size_type erase(const key_type& x)
        {  return m_flat_tree.erase(x); }
  
     //! <b>Effects</b>: Erases all the elements in the range [first, last).
     //!
     //! <b>Returns</b>: Returns last.
     //!
     //! <b>Complexity</b>: size()*N where N is the distance from first to last.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus erasure time
     //!   linear to the elements with bigger keys.
     iterator erase(const_iterator first, const_iterator last)
        {  return m_flat_tree.erase(first, last);  }
  
     //! <b>Effects</b>: Swaps the contents of *this and x.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     void swap(flat_set& x)
     { m_flat_tree.swap(x.m_flat_tree); }
  
     //! <b>Effects</b>: erase(a.begin(),a.end()).
     //!
     //! <b>Postcondition</b>: size() == 0.
     //!
     //! <b>Complexity</b>: linear in size().
     void clear() BOOST_CONTAINER_NOEXCEPT
        { m_flat_tree.clear(); }
  
     //////////////////////////////////////////////
     //
     //                observers
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Returns the comparison object out
     //!   of which a was constructed.
     //!
     //! <b>Complexity</b>: Constant.
     key_compare key_comp() const
        { return m_flat_tree.key_comp(); }
  
     //! <b>Effects</b>: Returns an object of value_compare constructed out
     //!   of the comparison object.
     //!
     //! <b>Complexity</b>: Constant.
     value_compare value_comp() const
        { return m_flat_tree.key_comp(); }
  
     //////////////////////////////////////////////
     //
     //              set operations
     //
     //////////////////////////////////////////////
  
     //! <b>Returns</b>: An iterator pointing to an element with the key
     //!   equivalent to x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic.
     iterator find(const key_type& x)
        { return m_flat_tree.find(x); }
  
     //! <b>Returns</b>: Allocator const_iterator pointing to an element with the key
     //!   equivalent to x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic.s
     const_iterator find(const key_type& x) const
        { return m_flat_tree.find(x); }
  
     //! <b>Returns</b>: The number of elements with key equivalent to x.
     //!
     //! <b>Complexity</b>: log(size())+count(k)
     size_type count(const key_type& x) const
        {  return m_flat_tree.find(x) == m_flat_tree.end() ? 0 : 1;  }
  
     //! <b>Returns</b>: An iterator pointing to the first element with key not less
     //!   than k, or a.end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     iterator lower_bound(const key_type& x)
        {  return m_flat_tree.lower_bound(x); }
  
     //! <b>Returns</b>: Allocator const iterator pointing to the first element with key not
     //!   less than k, or a.end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     const_iterator lower_bound(const key_type& x) const
        {  return m_flat_tree.lower_bound(x); }
  
     //! <b>Returns</b>: An iterator pointing to the first element with key not less
     //!   than x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     iterator upper_bound(const key_type& x)
        {  return m_flat_tree.upper_bound(x);    }
  
     //! <b>Returns</b>: Allocator const iterator pointing to the first element with key not
     //!   less than x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     const_iterator upper_bound(const key_type& x) const
        {  return m_flat_tree.upper_bound(x);    }
  
     //! <b>Effects</b>: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
     //!
     //! <b>Complexity</b>: Logarithmic
     std::pair<const_iterator, const_iterator> equal_range(const key_type& x) const
        {  return m_flat_tree.equal_range(x); }
  
     //! <b>Effects</b>: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
     //!
     //! <b>Complexity</b>: Logarithmic
     std::pair<iterator,iterator> equal_range(const key_type& x)
        {  return m_flat_tree.equal_range(x); }
  
     /// @cond
     template <class K1, class C1, class A1>
     friend bool operator== (const flat_set<K1,C1,A1>&, const flat_set<K1,C1,A1>&);
  
     template <class K1, class C1, class A1>
     friend bool operator< (const flat_set<K1,C1,A1>&, const flat_set<K1,C1,A1>&);
  
     private:
     template<class KeyType>
     std::pair<iterator, bool> priv_insert(BOOST_FWD_REF(KeyType) x)
     {  return m_flat_tree.insert_unique(::boost::forward<KeyType>(x));  }
  
     template<class KeyType>
     iterator priv_insert(const_iterator p, BOOST_FWD_REF(KeyType) x)
     {  return m_flat_tree.insert_unique(p, ::boost::forward<KeyType>(x)); }
     /// @endcond
  };
  
  template <class Key, class Compare, class Allocator>
  inline bool operator==(const flat_set<Key,Compare,Allocator>& x,
                         const flat_set<Key,Compare,Allocator>& y)
     {  return x.m_flat_tree == y.m_flat_tree;  }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<(const flat_set<Key,Compare,Allocator>& x,
                        const flat_set<Key,Compare,Allocator>& y)
     {  return x.m_flat_tree < y.m_flat_tree;   }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator!=(const flat_set<Key,Compare,Allocator>& x,
                         const flat_set<Key,Compare,Allocator>& y)
     {  return !(x == y);   }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator>(const flat_set<Key,Compare,Allocator>& x,
                        const flat_set<Key,Compare,Allocator>& y)
     {  return y < x; }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<=(const flat_set<Key,Compare,Allocator>& x,
                         const flat_set<Key,Compare,Allocator>& y)
     {  return !(y < x); }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator>=(const flat_set<Key,Compare,Allocator>& x,
                         const flat_set<Key,Compare,Allocator>& y)
     {  return !(x < y);  }
  
  template <class Key, class Compare, class Allocator>
  inline void swap(flat_set<Key,Compare,Allocator>& x, flat_set<Key,Compare,Allocator>& y)
     {  x.swap(y);  }
  
  /// @cond
  
  }  //namespace container {
  
  //!has_trivial_destructor_after_move<> == true_type
  //!specialization for optimizations
  template <class Key, class C, class Allocator>
  struct has_trivial_destructor_after_move<boost::container::flat_set<Key, C, Allocator> >
  {
     static const bool value = has_trivial_destructor_after_move<Allocator>::value &&has_trivial_destructor_after_move<C>::value;
  };
  
  namespace container {
  
  // Forward declaration of operators < and ==, needed for friend declaration.
  
  #ifdef BOOST_CONTAINER_DOXYGEN_INVOKED
  template <class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key> >
  #else
  template <class Key, class Compare, class Allocator>
  #endif
  class flat_multiset;
  
  template <class Key, class Compare, class Allocator>
  inline bool operator==(const flat_multiset<Key,Compare,Allocator>& x,
                         const flat_multiset<Key,Compare,Allocator>& y);
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<(const flat_multiset<Key,Compare,Allocator>& x,
                        const flat_multiset<Key,Compare,Allocator>& y);
  /// @endcond
  
  //! flat_multiset is a Sorted Associative Container that stores objects of type Key.
  //! flat_multiset is a Simple Associative Container, meaning that its value type,
  //! as well as its key type, is Key.
  //! flat_Multiset can store multiple copies of the same key value.
  //!
  //! flat_multiset is similar to std::multiset but it's implemented like an ordered vector.
  //! This means that inserting a new element into a flat_multiset invalidates
  //! previous iterators and references
  //!
  //! Erasing an element of a flat_multiset invalidates iterators and references
  //! pointing to elements that come after (their keys are equal or bigger) the erased element.
  #ifdef BOOST_CONTAINER_DOXYGEN_INVOKED
  template <class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key> >
  #else
  template <class Key, class Compare, class Allocator>
  #endif
  class flat_multiset
  {
     /// @cond
     private:
     BOOST_COPYABLE_AND_MOVABLE(flat_multiset)
     typedef container_detail::flat_tree<Key, Key, container_detail::identity<Key>, Compare, Allocator> tree_t;
     tree_t m_flat_tree;  // flat tree representing flat_multiset
     /// @endcond
  
     public:
     //////////////////////////////////////////////
     //
     //                    types
     //
     //////////////////////////////////////////////
     typedef Key                                                                         key_type;
     typedef Key                                                                         value_type;
     typedef Compare                                                                     key_compare;
     typedef Compare                                                                     value_compare;
     typedef typename ::boost::container::allocator_traits<Allocator>::pointer           pointer;
     typedef typename ::boost::container::allocator_traits<Allocator>::const_pointer     const_pointer;
     typedef typename ::boost::container::allocator_traits<Allocator>::reference         reference;
     typedef typename ::boost::container::allocator_traits<Allocator>::const_reference   const_reference;
     typedef typename ::boost::container::allocator_traits<Allocator>::size_type         size_type;
     typedef typename ::boost::container::allocator_traits<Allocator>::difference_type   difference_type;
     typedef Allocator                                                                   allocator_type;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::stored_allocator_type)              stored_allocator_type;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::iterator)                           iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::const_iterator)                     const_iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::reverse_iterator)                   reverse_iterator;
     typedef typename BOOST_CONTAINER_IMPDEF(tree_t::const_reverse_iterator)             const_reverse_iterator;
  
     //! <b>Effects</b>: Default constructs an empty flat_multiset.
     //!
     //! <b>Complexity</b>: Constant.
     explicit flat_multiset()
        : m_flat_tree()
     {}
  
     explicit flat_multiset(const Compare& comp,
                            const allocator_type& a = allocator_type())
        : m_flat_tree(comp, a) {}
  
     template <class InputIterator>
     flat_multiset(InputIterator first, InputIterator last,
                   const Compare& comp        = Compare(),
                   const allocator_type& a = allocator_type())
        : m_flat_tree(false, first, last, comp, a)
     {}
  
     //! <b>Effects</b>: Constructs an empty flat_multiset using the specified comparison object and
     //! allocator, and inserts elements from the ordered range [first ,last ). This function
     //! is more efficient than the normal range creation for ordered ranges.
     //!
     //! <b>Requires</b>: [first ,last) must be ordered according to the predicate.
     //!
     //! <b>Complexity</b>: Linear in N.
     //!
     //! <b>Note</b>: Non-standard extension.
     template <class InputIterator>
     flat_multiset(ordered_range_t, InputIterator first, InputIterator last,
                   const Compare& comp        = Compare(),
                   const allocator_type& a = allocator_type())
        : m_flat_tree(ordered_range, first, last, comp, a)
     {}
  
     //! <b>Effects</b>: Copy constructs a flat_multiset.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_multiset(const flat_multiset& x)
        : m_flat_tree(x.m_flat_tree)
     {}
  
     //! <b>Effects</b>: Move constructs a flat_multiset. Constructs *this using x's resources.
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Postcondition</b>: x is emptied.
     flat_multiset(BOOST_RV_REF(flat_multiset) mx)
        : m_flat_tree(boost::move(mx.m_flat_tree))
     {}
  
     //! <b>Effects</b>: Copy constructs a flat_multiset using the specified allocator.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_multiset(const flat_multiset& x, const allocator_type &a)
        : m_flat_tree(x.m_flat_tree, a)
     {}
  
     //! <b>Effects</b>: Move constructs a flat_multiset using the specified allocator.
     //!                 Constructs *this using x's resources.
     //!
     //! <b>Complexity</b>: Constant if a == mx.get_allocator(), linear otherwise
     flat_multiset(BOOST_RV_REF(flat_multiset) mx, const allocator_type &a)
        : m_flat_tree(boost::move(mx.m_flat_tree), a)
     {}
  
     //! <b>Effects</b>: Makes *this a copy of x.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_multiset& operator=(BOOST_COPY_ASSIGN_REF(flat_multiset) x)
        {  m_flat_tree = x.m_flat_tree;   return *this;  }
  
     //! <b>Effects</b>: Makes *this a copy of x.
     //!
     //! <b>Complexity</b>: Linear in x.size().
     flat_multiset& operator=(BOOST_RV_REF(flat_multiset) mx)
     {  m_flat_tree = boost::move(mx.m_flat_tree);   return *this;  }
  
     //! <b>Effects</b>: Returns a copy of the Allocator that
     //!   was passed to the object's constructor.
     //!
     //! <b>Complexity</b>: Constant.
     allocator_type get_allocator() const BOOST_CONTAINER_NOEXCEPT
     { return m_flat_tree.get_allocator(); }
  
     //! <b>Effects</b>: Returns a reference to the internal allocator.
     //!
     //! <b>Throws</b>: Nothing
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Note</b>: Non-standard extension.
     stored_allocator_type &get_stored_allocator() BOOST_CONTAINER_NOEXCEPT
     { return m_flat_tree.get_stored_allocator(); }
  
     //! <b>Effects</b>: Returns a reference to the internal allocator.
     //!
     //! <b>Throws</b>: Nothing
     //!
     //! <b>Complexity</b>: Constant.
     //!
     //! <b>Note</b>: Non-standard extension.
     const stored_allocator_type &get_stored_allocator() const BOOST_CONTAINER_NOEXCEPT
     { return m_flat_tree.get_stored_allocator(); }
  
     //! <b>Effects</b>: Returns an iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     iterator begin() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.begin(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator begin() const
        { return m_flat_tree.begin(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the first element contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator cbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.cbegin(); }
  
     //! <b>Effects</b>: Returns an iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     iterator end() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.end(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator end() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.end(); }
  
     //! <b>Effects</b>: Returns a const_iterator to the end of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_iterator cend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.cend(); }
  
     //! <b>Effects</b>: Returns a reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     reverse_iterator rbegin() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rbegin(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator rbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rbegin(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator crbegin() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.crbegin(); }
  
     //! <b>Effects</b>: Returns a reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     reverse_iterator rend() BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rend(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator rend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.rend(); }
  
     //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the end
     //! of the reversed container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     const_reverse_iterator crend() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.crend(); }
  
     //////////////////////////////////////////////
     //
     //                capacity
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Returns true if the container contains no elements.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     bool empty() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.empty(); }
  
     //! <b>Effects</b>: Returns the number of the elements contained in the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type size() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.size(); }
  
     //! <b>Effects</b>: Returns the largest possible size of the container.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type max_size() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.max_size(); }
  
     //! <b>Effects</b>: Number of elements for which memory has been allocated.
     //!   capacity() is always greater than or equal to size().
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     size_type capacity() const BOOST_CONTAINER_NOEXCEPT
        { return m_flat_tree.capacity(); }
  
     //! <b>Effects</b>: If n is less than or equal to capacity(), this call has no
     //!   effect. Otherwise, it is a request for allocation of additional memory.
     //!   If the request is successful, then capacity() is greater than or equal to
     //!   n; otherwise, capacity() is unchanged. In either case, size() is unchanged.
     //!
     //! <b>Throws</b>: If memory allocation allocation throws or Key's copy constructor throws.
     //!
     //! <b>Note</b>: If capacity() is less than "cnt", iterators and references to
     //!   to values might be invalidated.
     void reserve(size_type cnt)      
        { m_flat_tree.reserve(cnt);   }
  
     //! <b>Effects</b>: Tries to deallocate the excess of memory created
     //    with previous allocations. The size of the vector is unchanged
     //!
     //! <b>Throws</b>: If memory allocation throws, or Key's copy constructor throws.
     //!
     //! <b>Complexity</b>: Linear to size().
     void shrink_to_fit()
        { m_flat_tree.shrink_to_fit(); }
  
     //////////////////////////////////////////////
     //
     //                modifiers
     //
     //////////////////////////////////////////////
  
     #if defined(BOOST_CONTAINER_PERFECT_FORWARDING) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
  
     //! <b>Effects</b>: Inserts an object of type Key constructed with
     //!   std::forward<Args>(args)... and returns the iterator pointing to the
     //!   newly inserted element.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class... Args>
     iterator emplace(Args&&... args)
     {  return m_flat_tree.emplace_equal(boost::forward<Args>(args)...); }
  
     //! <b>Effects</b>: Inserts an object of type Key constructed with
     //!   std::forward<Args>(args)... in the container.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent
     //!   to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class... Args>
     iterator emplace_hint(const_iterator hint, Args&&... args)
     {  return m_flat_tree.emplace_hint_equal(hint, boost::forward<Args>(args)...); }
  
     #else //#ifdef BOOST_CONTAINER_PERFECT_FORWARDING
  
     #define BOOST_PP_LOCAL_MACRO(n)                                                                 \
     BOOST_PP_EXPR_IF(n, template<) BOOST_PP_ENUM_PARAMS(n, class P) BOOST_PP_EXPR_IF(n, >)          \
     iterator emplace(BOOST_PP_ENUM(n, BOOST_CONTAINER_PP_PARAM_LIST, _))                            \
     {  return m_flat_tree.emplace_equal(BOOST_PP_ENUM(n, BOOST_CONTAINER_PP_PARAM_FORWARD, _)); }   \
                                                                                                     \
     BOOST_PP_EXPR_IF(n, template<) BOOST_PP_ENUM_PARAMS(n, class P) BOOST_PP_EXPR_IF(n, >)          \
     iterator emplace_hint(const_iterator hint                                                       \
                           BOOST_PP_ENUM_TRAILING(n, BOOST_CONTAINER_PP_PARAM_LIST, _))              \
     {  return m_flat_tree.emplace_hint_equal                                                        \
              (hint BOOST_PP_ENUM_TRAILING(n, BOOST_CONTAINER_PP_PARAM_FORWARD, _)); }               \
     //!
     #define BOOST_PP_LOCAL_LIMITS (0, BOOST_CONTAINER_MAX_CONSTRUCTOR_PARAMETERS)
     #include BOOST_PP_LOCAL_ITERATE()
  
     #endif   //#ifdef BOOST_CONTAINER_PERFECT_FORWARDING
  
     #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
     //! <b>Effects</b>: Inserts x and returns the iterator pointing to the
     //!   newly inserted element.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(const value_type &x);
  
     //! <b>Effects</b>: Inserts a new value_type move constructed from x
     //!   and returns the iterator pointing to the newly inserted element.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus linear insertion
     //!   to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(value_type &&x);
     #else
     BOOST_MOVE_CONVERSION_AWARE_CATCH(insert, value_type, iterator, this->priv_insert)
     #endif
  
     #if defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
     //! <b>Effects</b>: Inserts a copy of x in the container.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent
     //!   to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(const_iterator p, const value_type &x);
  
     //! <b>Effects</b>: Inserts a new value move constructed  from x in the container.
     //!   p is a hint pointing to where the insert should start to search.
     //!
     //! <b>Returns</b>: An iterator pointing to the element with key equivalent
     //!   to the key of x.
     //!
     //! <b>Complexity</b>: Logarithmic search time (constant if x is inserted
     //!   right before p) plus insertion linear to the elements with bigger keys than x.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     iterator insert(const_iterator position, value_type &&x);
     #else
     BOOST_MOVE_CONVERSION_AWARE_CATCH_1ARG(insert, value_type, iterator, this->priv_insert, const_iterator)
     #endif
  
     //! <b>Requires</b>: first, last are not iterators into *this.
     //!
     //! <b>Effects</b>: inserts each element from the range [first,last) .
     //!
     //! <b>Complexity</b>: At most N log(size()+N) (N is the distance from first to last)
     //!   search time plus N*size() insertion time.
     //!
     //! <b>Note</b>: If an element is inserted it might invalidate elements.
     template <class InputIterator>
     void insert(InputIterator first, InputIterator last)
        {  m_flat_tree.insert_equal(first, last);  }
  
     //! <b>Requires</b>: first, last are not iterators into *this and
     //! must be ordered according to the predicate.
     //!
     //! <b>Effects</b>: inserts each element from the range [first,last) .This function
     //! is more efficient than the normal range creation for ordered ranges.
     //!
     //! <b>Complexity</b>: At most N log(size()+N) (N is the distance from first to last)
     //!   search time plus N*size() insertion time.
     //!
     //! <b>Note</b>: Non-standard extension. If an element is inserted it might invalidate elements.
     template <class InputIterator>
     void insert(ordered_range_t, InputIterator first, InputIterator last)
        {  m_flat_tree.insert_equal(ordered_range, first, last);  }
  
     //! <b>Effects</b>: Erases the element pointed to by position.
     //!
     //! <b>Returns</b>: Returns an iterator pointing to the element immediately
     //!   following q prior to the element being erased. If no such element exists,
     //!   returns end().
     //!
     //! <b>Complexity</b>: Linear to the elements with keys bigger than position
     //!
     //! <b>Note</b>: Invalidates elements with keys
     //!   not less than the erased element.
     iterator erase(const_iterator position)
        {  return m_flat_tree.erase(position); }
  
     //! <b>Effects</b>: Erases all elements in the container with key equivalent to x.
     //!
     //! <b>Returns</b>: Returns the number of erased elements.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus erasure time
     //!   linear to the elements with bigger keys.
     size_type erase(const key_type& x)
        {  return m_flat_tree.erase(x); }
  
     //! <b>Effects</b>: Erases all the elements in the range [first, last).
     //!
     //! <b>Returns</b>: Returns last.
     //!
     //! <b>Complexity</b>: size()*N where N is the distance from first to last.
     //!
     //! <b>Complexity</b>: Logarithmic search time plus erasure time
     //!   linear to the elements with bigger keys.
     iterator erase(const_iterator first, const_iterator last)
        {  return m_flat_tree.erase(first, last);  }
  
     //! <b>Effects</b>: Swaps the contents of *this and x.
     //!
     //! <b>Throws</b>: Nothing.
     //!
     //! <b>Complexity</b>: Constant.
     void swap(flat_multiset& x)
     { m_flat_tree.swap(x.m_flat_tree); }
  
     //! <b>Effects</b>: erase(a.begin(),a.end()).
     //!
     //! <b>Postcondition</b>: size() == 0.
     //!
     //! <b>Complexity</b>: linear in size().
     void clear() BOOST_CONTAINER_NOEXCEPT
        { m_flat_tree.clear(); }
  
     //////////////////////////////////////////////
     //
     //                observers
     //
     //////////////////////////////////////////////
  
     //! <b>Effects</b>: Returns the comparison object out
     //!   of which a was constructed.
     //!
     //! <b>Complexity</b>: Constant.
     key_compare key_comp() const
        { return m_flat_tree.key_comp(); }
  
     //! <b>Effects</b>: Returns an object of value_compare constructed out
     //!   of the comparison object.
     //!
     //! <b>Complexity</b>: Constant.
     value_compare value_comp() const
        { return m_flat_tree.key_comp(); }
  
     //////////////////////////////////////////////
     //
     //              set operations
     //
     //////////////////////////////////////////////
  
     //! <b>Returns</b>: An iterator pointing to an element with the key
     //!   equivalent to x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic.
     iterator find(const key_type& x)
        { return m_flat_tree.find(x); }
  
     //! <b>Returns</b>: Allocator const_iterator pointing to an element with the key
     //!   equivalent to x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic.s
     const_iterator find(const key_type& x) const
        { return m_flat_tree.find(x); }
  
     //! <b>Returns</b>: The number of elements with key equivalent to x.
     //!
     //! <b>Complexity</b>: log(size())+count(k)
     size_type count(const key_type& x) const
        { return m_flat_tree.count(x); }
  
     //! <b>Returns</b>: An iterator pointing to the first element with key not less
     //!   than k, or a.end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     iterator lower_bound(const key_type& x)
        {  return m_flat_tree.lower_bound(x); }
  
     //! <b>Returns</b>: Allocator const iterator pointing to the first element with key not
     //!   less than k, or a.end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     const_iterator lower_bound(const key_type& x) const
        {  return m_flat_tree.lower_bound(x); }
  
     //! <b>Returns</b>: An iterator pointing to the first element with key not less
     //!   than x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     iterator upper_bound(const key_type& x)
        {  return m_flat_tree.upper_bound(x);    }
  
     //! <b>Returns</b>: Allocator const iterator pointing to the first element with key not
     //!   less than x, or end() if such an element is not found.
     //!
     //! <b>Complexity</b>: Logarithmic
     const_iterator upper_bound(const key_type& x) const
        {  return m_flat_tree.upper_bound(x);    }
  
     //! <b>Effects</b>: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
     //!
     //! <b>Complexity</b>: Logarithmic
     std::pair<const_iterator, const_iterator> equal_range(const key_type& x) const
        {  return m_flat_tree.equal_range(x); }
  
     //! <b>Effects</b>: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).
     //!
     //! <b>Complexity</b>: Logarithmic
     std::pair<iterator,iterator> equal_range(const key_type& x)
        {  return m_flat_tree.equal_range(x); }
  
     /// @cond
     template <class K1, class C1, class A1>
     friend bool operator== (const flat_multiset<K1,C1,A1>&,
                             const flat_multiset<K1,C1,A1>&);
     template <class K1, class C1, class A1>
     friend bool operator< (const flat_multiset<K1,C1,A1>&,
                            const flat_multiset<K1,C1,A1>&);
     private:
     template <class KeyType>
     iterator priv_insert(BOOST_FWD_REF(KeyType) x)
     {  return m_flat_tree.insert_equal(::boost::forward<KeyType>(x));  }
  
     template <class KeyType>
     iterator priv_insert(const_iterator p, BOOST_FWD_REF(KeyType) x)
     {  return m_flat_tree.insert_equal(p, ::boost::forward<KeyType>(x)); }
     /// @endcond
  };
  
  template <class Key, class Compare, class Allocator>
  inline bool operator==(const flat_multiset<Key,Compare,Allocator>& x,
                         const flat_multiset<Key,Compare,Allocator>& y)
     {  return x.m_flat_tree == y.m_flat_tree;  }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<(const flat_multiset<Key,Compare,Allocator>& x,
                        const flat_multiset<Key,Compare,Allocator>& y)
     {  return x.m_flat_tree < y.m_flat_tree;   }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator!=(const flat_multiset<Key,Compare,Allocator>& x,
                         const flat_multiset<Key,Compare,Allocator>& y)
     {  return !(x == y);  }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator>(const flat_multiset<Key,Compare,Allocator>& x,
                        const flat_multiset<Key,Compare,Allocator>& y)
     {  return y < x;  }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator<=(const flat_multiset<Key,Compare,Allocator>& x,
                         const flat_multiset<Key,Compare,Allocator>& y)
     {  return !(y < x);  }
  
  template <class Key, class Compare, class Allocator>
  inline bool operator>=(const flat_multiset<Key,Compare,Allocator>& x,
                         const flat_multiset<Key,Compare,Allocator>& y)
  {  return !(x < y);  }
  
  template <class Key, class Compare, class Allocator>
  inline void swap(flat_multiset<Key,Compare,Allocator>& x, flat_multiset<Key,Compare,Allocator>& y)
     {  x.swap(y);  }
  
  /// @cond
  
  }  //namespace container {
  
  //!has_trivial_destructor_after_move<> == true_type
  //!specialization for optimizations
  template <class Key, class C, class Allocator>
  struct has_trivial_destructor_after_move<boost::container::flat_multiset<Key, C, Allocator> >
  {
     static const bool value = has_trivial_destructor_after_move<Allocator>::value && has_trivial_destructor_after_move<C>::value;
  };
  
  namespace container {
  
  /// @endcond
  
  }}
  
  #include <boost/container/detail/config_end.hpp>
  
  #endif /* BOOST_CONTAINER_FLAT_SET_HPP */
  