// bslstl_multimap_cpp03.h                                            -*-C++-*-

// Automatically generated file.  **DO NOT EDIT**

#ifndef INCLUDED_BSLSTL_MULTIMAP_CPP03
#define INCLUDED_BSLSTL_MULTIMAP_CPP03

//@PURPOSE: Provide C++03 implementation for bslstl_multimap.h
//
//@CLASSES: See bslstl_multimap.h for list of classes
//
//@SEE_ALSO: bslstl_multimap
//
//@DESCRIPTION:  This component is the C++03 translation of a C++11 component,
// generated by the 'sim_cpp11_features.pl' program.  If the original header
// contains any specially delimited regions of C++11 code, then this generated
// file contains the C++03 equivalent, i.e., with variadic templates expanded
// and rvalue-references replaced by 'bslmf::MovableRef' objects.  The header
// code in this file is designed to be '#include'd into the original header
// when compiling with a C++03 compiler.  If there are no specially delimited
// regions of C++11 code, then this header contains no code and is not
// '#include'd in the original header.
//
// Generated on Mon Mar  6 11:50:16 2023
// Command line: sim_cpp11_features.pl bslstl_multimap.h

#ifdef COMPILING_BSLSTL_MULTIMAP_H

namespace bsl {

                             // ==============
                             // class multimap
                             // ==============

template <class KEY,
          class VALUE,
          class COMPARATOR = std::less<KEY>,
          class ALLOCATOR  = allocator<pair<const KEY, VALUE> > >
class multimap {
    // This class template implements a value-semantic container type holding
    // an ordered sequence of key-value pairs having possibly duplicate keys
    // that provide a mapping from keys (of the template parameter type, 'KEY')
    // to their associated values (of another template parameter type,
    // 'VALUE').
    //
    // This class:
    //: o supports a complete set of *value-semantic* operations
    //:   o except for BDEX serialization
    //: o is *exception-neutral*
    //: o is *alias-safe*
    //: o is 'const' *thread-safe*
    // For terminology see {'bsldoc_glossary'}.

    // PRIVATE TYPES
    typedef pair<const KEY, VALUE>                             ValueType;
        // This typedef is an alias for the type of key-value pair objects
        // maintained by this multimap.

    typedef BloombergLP::bslstl::MapComparator<KEY, VALUE, COMPARATOR>
                                                               Comparator;
        // This typedef is an alias for the comparator used internally by this
        // multimap.

    typedef BloombergLP::bslstl::TreeNode<ValueType>           Node;
        // This typedef is an alias for the type of nodes held by the tree (of
        // nodes) used to implement this multimap.

    typedef BloombergLP::bslstl::TreeNodePool<ValueType, ALLOCATOR>
                                                               NodeFactory;
        // This typedef is an alias for the factory type used to create and
        // destroy 'Node' objects.

    typedef typename bsl::allocator_traits<ALLOCATOR>          AllocatorTraits;
        // This typedef is an alias for the allocator traits type associated
        // with this container.

    typedef BloombergLP::bslmf::MovableRefUtil                 MoveUtil;
        // This typedef is a convenient alias for the utility associated with
        // movable references.

    class DataWrapper : public Comparator {
        // This class is a wrapper around the comparator and allocator data
        // members.  It takes advantage of the empty-base optimization (EBO) so
        // that if the comparator is stateless, it takes up no space.
        //
        // TBD: This class should eventually be replaced by the use of a
        // general EBO-enabled component that provides a 'pair'-like interface
        // or a 'tuple'.

        // DATA
        NodeFactory d_pool;  // pool of 'Node' objects

      private:
        // NOT IMPLEMENTED
        DataWrapper(const DataWrapper&);
        DataWrapper& operator=(const DataWrapper&);

      public:
        // CREATORS
        DataWrapper(const COMPARATOR& comparator,
                    const ALLOCATOR&  basicAllocator);
            // Create a data wrapper using a copy of the specified 'comparator'
            // to order key-value pairs and a copy of the specified
            // 'basicAllocator' to supply memory.

        DataWrapper(
              BloombergLP::bslmf::MovableRef<DataWrapper> original);// IMPLICIT
            // Create a data wrapper initialized to the contents of the 'pool'
            // associated with the specified 'original' data wrapper.  The
            // comparator and allocator associated with 'original' are
            // propagated to the new data wrapper.  'original' is left in a
            // valid but unspecified state.

        // MANIPULATORS
        NodeFactory& nodeFactory();
            // Return a reference providing modifiable access to the node
            // factory associated with this data wrapper.

        // ACCESSORS
        const NodeFactory& nodeFactory() const;
            // Return a reference providing non-modifiable access to the node
            // factory associated with this data wrapper.
    };

    // DATA
    DataWrapper                       d_compAndAlloc;
                                               // comparator and pool of 'Node'
                                               // objects

    BloombergLP::bslalg::RbTreeAnchor d_tree;  // balanced tree of 'Node'
                                               // objects

  public:
    // PUBLIC TYPES
    typedef KEY                                        key_type;
    typedef VALUE                                      mapped_type;
    typedef pair<const KEY, VALUE>                     value_type;
    typedef COMPARATOR                                 key_compare;
    typedef ALLOCATOR                                  allocator_type;
    typedef value_type&                                reference;
    typedef const value_type&                          const_reference;

    typedef typename AllocatorTraits::size_type        size_type;
    typedef typename AllocatorTraits::difference_type  difference_type;
    typedef typename AllocatorTraits::pointer          pointer;
    typedef typename AllocatorTraits::const_pointer    const_pointer;

    typedef BloombergLP::bslstl::TreeIterator<value_type,
                                              Node,
                                              difference_type> iterator;

    typedef BloombergLP::bslstl::TreeIterator<const value_type,
                                              Node,
                                              difference_type> const_iterator;

    typedef bsl::reverse_iterator<iterator>            reverse_iterator;
    typedef bsl::reverse_iterator<const_iterator>      const_reverse_iterator;

    class value_compare {
        // This nested class defines a mechanism for comparing two objects of
        // 'value_type' by adapting an object of (template parameter) type
        // 'COMPARATOR', which compares two objects of (template parameter)
        // type 'KEY' .  Note that this class exactly matches its definition in
        // the C++11 standard [23.4.4.1]; otherwise, we would have implemented
        // it as a separate component-local class.

        // FRIENDS
        friend class multimap;

      protected:
        // PROTECTED DATA
        COMPARATOR comp;  // we would not have elected to make this data
                          // member 'protected'

        // PROTECTED CREATORS
        value_compare(COMPARATOR comparator);                       // IMPLICIT
            // Create a 'value_compare' object that uses the specified
            // 'comparator'.

      public:
        // PUBLIC TYPES
        typedef bool result_type;
            // This 'typedef' is an alias for the result type of a call to the
            // overload of 'operator()' (the comparison function) provided by a
            // 'multimap::value_compare' object.

        typedef value_type first_argument_type;
            // This 'typedef' is an alias for the type of the first parameter
            // of the overload of 'operator()' (the comparison function)
            // provided by a 'multimap::value_compare' object.

        typedef value_type second_argument_type;
            // This 'typedef' is an alias for the type of the second parameter
            // of the overload of 'operator()' (the comparison function)
            // provided by a 'multimap::value_compare' object.

        // CREATORS
        //! value_compare(const value_compare& original) = default;
            // Create a 'value_compare' object having the same value as the
            // specified 'original' object.

        //! ~value_compare() = default;
            // Destroy this object.

        // MANIPULATORS
        //! value_compare& operator=(const value_compare& rhs) = default;
            // Assign to this object the value of the specified 'rhs' object,
            // and return a reference providing modifiable access to this
            // object.

        // ACCESSORS
        bool operator()(const value_type& x, const value_type& y) const;
            // Return 'true' if the specified 'x' object is ordered before the
            // specified 'y' object, as determined by the comparator supplied
            // at construction, and 'false' otherwise.
    };

  private:
    // PRIVATE CLASS METHODS
    static Node *toNode(BloombergLP::bslalg::RbTreeNode *node);
        // Return an address providing modifiable access to the specified
        // 'node'.  The behavior is undefined unless 'node' is the address of a
        // 'Node' object.

    static const Node *toNode(const BloombergLP::bslalg::RbTreeNode *node);
        // Return an address providing non-modifiable access to the specified
        // 'node'.  The behavior is undefined unless 'node' is the address of a
        // 'Node' object.

    // PRIVATE MANIPULATORS
    Comparator& comparator();
        // Return a reference providing modifiable access to the comparator for
        // this multimap.

    NodeFactory& nodeFactory();
        // Return a reference providing modifiable access to the node allocator
        // for this multimap.

    void quickSwapExchangeAllocators(multimap& other);
        // Efficiently exchange the value, comparator, and allocator of this
        // object with the value, comparator, and allocator of the specified
        // 'other' object.  This method provides the no-throw exception-safety
        // guarantee, *unless* swapping the (user-supplied) comparator or
        // allocator objects can throw.

    void quickSwapRetainAllocators(multimap& other);
        // Efficiently exchange the value and comparator of this object with
        // the value and comparator of the specified 'other' object.  This
        // method provides the no-throw exception-safety guarantee, *unless*
        // swapping the (user-supplied) comparator objects can throw.  The
        // behavior is undefined unless this object was created with the same
        // allocator as 'other'.

    // PRIVATE ACCESSORS
    const Comparator& comparator() const;
        // Return a reference providing non-modifiable access to the comparator
        // for this multimap.

    const NodeFactory& nodeFactory() const;
        // Return a reference providing non-modifiable access to the node
        // allocator for this multimap.

  public:
    // CREATORS
    multimap();
    explicit multimap(const COMPARATOR& comparator,
                      const ALLOCATOR&  basicAllocator = ALLOCATOR())
        // Create an empty multimap.  Optionally specify a 'comparator' used to
        // order key-value pairs contained in this object.  If 'comparator' is
        // not supplied, a default-constructed object of the (template
        // parameter) type 'COMPARATOR' is used.  Optionally specify a
        // 'basicAllocator' used to supply memory.  If 'basicAllocator' is not
        // supplied, a default-constructed object of the (template parameter)
        // type 'ALLOCATOR' is used.  If the type 'ALLOCATOR' is
        // 'bsl::allocator' (the default), then 'basicAllocator', if supplied,
        // shall be convertible to 'bslma::Allocator *'.  If the type
        // 'ALLOCATOR' is 'bsl::allocator' and 'basicAllocator' is not
        // supplied, the currently installed default allocator is used.
    : d_compAndAlloc(comparator, basicAllocator)
    , d_tree()
    {
        // The implementation is placed here in the class definition to work
        // around an AIX compiler bug, where the constructor can fail to
        // compile because it is unable to find the definition of the default
        // argument.  This occurs when a parameterized class wraps around the
        // container and the comparator is defined after the new class.
    }

    explicit multimap(const ALLOCATOR& basicAllocator);
        // Create an empty multimap that uses the specified 'basicAllocator' to
        // supply memory.  Use a default-constructed object of the (template
        // parameter) type 'COMPARATOR' to order the key-value pairs contained
        // in this multimap.  Note that a 'bslma::Allocator *' can be supplied
        // for 'basicAllocator' if the (template parameter) 'ALLOCATOR' is
        // 'bsl::allocator' (the default).

    multimap(const multimap& original);
        // Create a multimap having the same value as the specified 'original'
        // object.  Use a copy of 'original.key_comp()' to order the key-value
        // pairs contained in this multimap.  Use the allocator returned by
        // 'bsl::allocator_traits<ALLOCATOR>::
        // select_on_container_copy_construction(original.get_allocator())' to
        // allocate memory.  This method requires that the (template parameter)
        // types 'KEY' and 'VALUE' both be 'copy-insertable' into this multimap
        // (see {Requirements on 'KEY' and 'VALUE'}).

    multimap(BloombergLP::bslmf::MovableRef<multimap> original);    // IMPLICIT
        // Create a multimap having the same value as the specified 'original'
        // object by moving (in constant time) the contents of 'original' to
        // the new multimap.  Use a copy of 'original.key_comp()' to order the
        // key-value pairs contained in this multimap.  The allocator
        // associated with 'original' is propagated for use in the
        // newly-created multimap.  'original' is left in a valid but
        // unspecified state.

    multimap(const multimap&                                original,
             const typename type_identity<ALLOCATOR>::type& basicAllocator);
        // Create a multimap having the same value as the specified 'original'
        // object that uses the specified 'basicAllocator' to supply memory.
        // Use a copy of 'original.key_comp()' to order the key-value pairs
        // contained in this multimap.  This method requires that the (template
        // parameter) types 'KEY' and 'VALUE' both be 'copy-insertable' into
        // this multimap (see {Requirements on 'KEY' and 'VALUE'}).  Note that
        // a 'bslma::Allocator *' can be supplied for 'basicAllocator' if the
        // (template parameter) 'ALLOCATOR' is 'bsl::allocator' (the default).

    multimap(BloombergLP::bslmf::MovableRef<multimap>       original,
             const typename type_identity<ALLOCATOR>::type& basicAllocator);
        // Create a multimap having the same value as the specified 'original'
        // object that uses the specified 'basicAllocator' to supply memory.
        // The contents of 'original' are moved (in constant time) to the new
        // multimap if 'basicAllocator == original.get_allocator()', and are
        // move-inserted (in linear time) using 'basicAllocator' otherwise.
        // 'original' is left in a valid but unspecified state.  Use a copy of
        // 'original.key_comp()' to order the key-value pairs contained in this
        // multimap.  This method requires that the (template parameter) types
        // 'KEY' and 'VALUE' both be 'move-insertable' into this multimap (see
        // {Requirements on 'KEY' and 'VALUE'}).  Note that a 'bslma::Allocator
        // *' can be supplied for 'basicAllocator' if the (template parameter)
        // 'ALLOCATOR' is 'bsl::allocator' (the default).

    template <class INPUT_ITERATOR>
    multimap(INPUT_ITERATOR    first,
             INPUT_ITERATOR    last,
             const COMPARATOR& comparator     = COMPARATOR(),
             const ALLOCATOR&  basicAllocator = ALLOCATOR());
    template <class INPUT_ITERATOR>
    multimap(INPUT_ITERATOR    first,
             INPUT_ITERATOR    last,
             const ALLOCATOR&  basicAllocator);
        // Create a multimap, and insert each 'value_type' object in the
        // sequence starting at the specified 'first' element, and ending
        // immediately before the specified 'last' element.  Optionally specify
        // a 'comparator' used to order key-value pairs contained in this
        // object.  If 'comparator' is not supplied, a default-constructed
        // object of the (template parameter) type 'COMPARATOR' is used.
        // Optionally specify a 'basicAllocator' used to supply memory.  If
        // 'basicAllocator' is not supplied, a default-constructed object of
        // the (template parameter) type 'ALLOCATOR' is used.  If the type
        // 'ALLOCATOR' is 'bsl::allocator' (the default), then
        // 'basicAllocator', if supplied, shall be convertible to
        // 'bslma::Allocator *'.  If the type 'ALLOCATOR' is 'bsl::allocator'
        // and 'basicAllocator' is not supplied, the currently installed
        // default allocator is used.  If the sequence 'first' to 'last' is
        // ordered according to 'comparator', then this operation has 'O[N]'
        // complexity, where 'N' is the number of elements between 'first' and
        // 'last'; otherwise, this operation has 'O[N * log(N)]' complexity.
        // The (template parameter) type 'INPUT_ITERATOR' shall meet the
        // requirements of an input iterator defined in the C++11 standard
        // [24.2.3] providing access to values of a type convertible to
        // 'value_type', and 'value_type' must be 'emplace-constructible' from
        // '*i' into this multimap, where 'i' is a dereferenceable iterator in
        // the range '[first .. last)' (see {Requirements on 'KEY' and
        // 'VALUE'}).  The behavior is undefined unless 'first' and 'last'
        // refer to a sequence of valid values where 'first' is at a position
        // at or before 'last'.

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
    multimap(std::initializer_list<value_type> values,
             const COMPARATOR&                 comparator     = COMPARATOR(),
             const ALLOCATOR&                  basicAllocator = ALLOCATOR());
    multimap(std::initializer_list<value_type> values,
             const ALLOCATOR&                  basicAllocator);
        // Create a multimap and insert each 'value_type' object in the
        // specified 'values' initializer list.  Optionally specify a
        // 'comparator' used to order keys contained in this object.  If
        // 'comparator' is not supplied, a default-constructed object of the
        // (template parameter) type 'COMPARATOR' is used.  Optionally specify
        // a 'basicAllocator' used to supply memory.  If 'basicAllocator' is
        // not supplied, a default-constructed object of the (template
        // parameter) type 'ALLOCATOR' is used.  If the type 'ALLOCATOR' is
        // 'bsl::allocator' (the default), then 'basicAllocator', if supplied,
        // shall be convertible to 'bslma::Allocator *'.  If the type
        // 'ALLOCATOR' is 'bsl::allocator' and 'basicAllocator' is not
        // supplied, the currently installed default allocator is used.  If
        // 'values' is ordered according to 'comparator', then this operation
        // has 'O[N]' complexity, where 'N' is the number of elements in
        // 'values'; otherwise, this operation has 'O[N * log(N)]' complexity.
        // This method requires that the (template parameter) types 'KEY' and
        // 'VALUE' both be 'copy-insertable' into this multimap (see
        // {Requirements on 'KEY' and 'VALUE'}).
#endif

    ~multimap();
        // Destroy this object.

    // MANIPULATORS
    multimap& operator=(const multimap& rhs);
        // Assign to this object the value and comparator of the specified
        // 'rhs' object, propagate to this object the allocator of 'rhs' if the
        // 'ALLOCATOR' type has trait 'propagate_on_container_copy_assignment',
        // and return a reference providing modifiable access to this object.
        // If an exception is thrown, '*this' is left in a valid but
        // unspecified state.  This method requires that the (template
        // parameter) types 'KEY' and 'VALUE' both be 'copy-assignable' and
        // 'copy-insertable' into this multimap (see {Requirements on 'KEY' and
        // 'VALUE'}).

    multimap& operator=(BloombergLP::bslmf::MovableRef<multimap> rhs)
        BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(
                           AllocatorTraits::is_always_equal::value &&
                           std::is_nothrow_move_assignable<COMPARATOR>::value);
        // Assign to this object the value and comparator of the specified
        // 'rhs' object, propagate to this object the allocator of 'rhs' if the
        // 'ALLOCATOR' type has trait 'propagate_on_container_move_assignment',
        // and return a reference providing modifiable access to this object.
        // The contents of 'rhs' are moved (in constant time) to this multimap
        // if 'get_allocator() == rhs.get_allocator()' (after accounting for
        // the aforementioned trait); otherwise, all elements in this multimap
        // are either destroyed or move-assigned to and each additional element
        // in 'rhs' is move-inserted into this multimap.  'rhs' is left in a
        // valid but unspecified state, and if an exception is thrown, '*this'
        // is left in a valid but unspecified state.  This method requires that
        // the (template parameter) types 'KEY' and 'VALUE' both be
        // 'move-assignable' and 'move-insertable' into this multimap (see
        // {Requirements on 'KEY' and 'VALUE'}).

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
    multimap& operator=(std::initializer_list<value_type> values);
        // Assign to this object the value resulting from first clearing this
        // multimap and then inserting each 'value_type' object in the
        // specified 'values' initializer list, and return a reference
        // providing modifiable access to this object.  This method requires
        // that the (template parameter) types 'KEY' and 'VALUE' both be
        // 'copy-insertable' into this multimap (see {Requirements on 'KEY' and
        // 'VALUE'}).
#endif

    iterator begin() BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing modifiable access to the first
        // 'value_type' object in the ordered sequence of 'value_type' objects
        // maintained by this multimap, or the 'end' iterator if this multimap
        // is empty.

    iterator end() BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing modifiable access to the past-the-end
        // element in the ordered sequence of 'value_type' objects maintained
        // by this multimap.

    reverse_iterator rbegin() BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing modifiable access to the last
        // 'value_type' object in the ordered sequence of 'value_type' objects
        // maintained by this multimap, or 'rend' if this multimap is empty.

    reverse_iterator rend() BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing modifiable access to the
        // prior-to-the-beginning element in the ordered sequence of
        // 'value_type' objects maintained by this multimap.

    iterator insert(const value_type& value);
        // Insert the specified 'value' into this multimap.  If a range
        // containing elements equivalent to 'value' already exists, insert the
        // 'value' at the end of that range.  Return an iterator referring to
        // the newly inserted 'value_type' object.  This method requires that
        // the (template parameter) types 'KEY' and 'VALUE' both be
        // 'copy-insertable' into this multimap (see {Requirements on 'KEY' and
        // 'VALUE'}).

#if defined(BSLS_PLATFORM_CMP_SUN) && BSLS_PLATFORM_CMP_VERSION < 0x5130
    template <class ALT_VALUE_TYPE>
    iterator
#elif !defined(BSLS_COMPILERFEATURES_SUPPORT_TRAITS_HEADER)
    template <class ALT_VALUE_TYPE>
    typename enable_if<is_convertible<ALT_VALUE_TYPE, value_type>::value,
                       iterator>::type
#else
    template <class ALT_VALUE_TYPE>
    typename enable_if<std::is_constructible<value_type,
                                             ALT_VALUE_TYPE&&>::value,
                       iterator>::type
#endif
    insert(BSLS_COMPILERFEATURES_FORWARD_REF(ALT_VALUE_TYPE) value)
        // Insert into this multimap a 'value_type' object created from the
        // specified 'value'.  If a range containing elements equivalent to
        // 'value_type' object already exists, insert the 'value_type' object
        // at the end of that range.  Return an iterator referring to the newly
        // inserted 'value_type' object.  This method requires that the
        // (template parameter) types 'KEY' and 'VALUE' both be
        // 'move-insertable' into this multimap (see {Requirements on 'KEY' and
        // 'VALUE'}), and the 'value_type' be constructible from the (template
        // parameter) 'ALT_VALUE_TYPE'.
    {
        // Note that some compilers fail when this method is defined
        // out-of-line.

        return emplace(BSLS_COMPILERFEATURES_FORWARD(ALT_VALUE_TYPE, value));
    }

    iterator insert(const_iterator hint, const value_type& value);
        // Insert the specified 'value' into this multimap (in amortized
        // constant time if the specified 'hint' is a valid immediate successor
        // to the key of 'value').  Return an iterator referring to the newly
        // inserted 'value_type' object.  If 'hint' is not a valid immediate
        // successor to the key of 'value', this operation has 'O[log(N)]'
        // complexity, where 'N' is the size of this multimap.  This method
        // requires that the (template parameter) types 'KEY' and 'VALUE' both
        // be 'copy-insertable' into this multimap (see {Requirements on 'KEY'
        // and 'VALUE'}).  The behavior is undefined unless 'hint' is an
        // iterator in the range '[begin() .. end()]' (both endpoints
        // included).

#if defined(BSLS_PLATFORM_CMP_SUN) && BSLS_PLATFORM_CMP_VERSION < 0x5130
    template <class ALT_VALUE_TYPE>
    iterator
#elif !defined(BSLS_COMPILERFEATURES_SUPPORT_TRAITS_HEADER)
    template <class ALT_VALUE_TYPE>
    typename enable_if<is_convertible<ALT_VALUE_TYPE, value_type>::value,
                       iterator>::type
#else
    template <class ALT_VALUE_TYPE>
    typename enable_if<std::is_constructible<value_type,
                                             ALT_VALUE_TYPE&&>::value,
                       iterator>::type
#endif
    insert(const_iterator                                    hint,
           BSLS_COMPILERFEATURES_FORWARD_REF(ALT_VALUE_TYPE) value)
        // Insert into this multimap a 'value_type' object created from the
        // specified 'value' (in amortized constant time if the specified
        // 'hint' is a valid immediate successor to the object created from
        // 'value').  Return an iterator referring to the newly inserted
        // 'value_type' object in this multimap.  If 'hint' is not a valid
        // immediate successor to the object created from 'value', this
        // operation has 'O[log(N)]' complexity, where 'N' is the size of this
        // multimap.  This method requires that the (template parameter) types
        // 'KEY' and 'VALUE' both be 'move-insertable' into this multimap (see
        // {Requirements on 'KEY' and 'VALUE'}), and the 'value_type' be
        // constructible from the (template parameter) 'ALT_VALUE_TYPE'.  The
        // behavior is undefined unless 'hint' is an iterator in the range
        // '[begin() .. end()]' (both endpoints included).
    {
        // Note that some compilers fail when this method is defined
        // out-of-line.

        return emplace_hint(hint,
                        BSLS_COMPILERFEATURES_FORWARD(ALT_VALUE_TYPE, value));
    }

    template <class INPUT_ITERATOR>
    void insert(INPUT_ITERATOR first, INPUT_ITERATOR last);
        // Insert into this multimap the value of each 'value_type' object in
        // the range starting at the specified 'first' iterator and ending
        // immediately before the specified 'last' iterator.  The (template
        // parameter) type 'INPUT_ITERATOR' shall meet the requirements of an
        // input iterator defined in the C++11 standard [24.2.3] providing
        // access to values of a type convertible to 'value_type', and
        // 'value_type' must be 'emplace-constructible' from '*i' into this
        // multimap, where 'i' is a dereferenceable iterator in the range
        // '[first .. last)' (see {Requirements on 'KEY' and 'VALUE'}).  The
        // behavior is undefined unless 'first' and 'last' refer to a sequence
        // of valid values where 'first' is at a position at or before 'last'.

#if defined(BSLS_PLATFORM_CMP_SUN) && BSLS_PLATFORM_CMP_VERSION < 0x5130
    void insert(const_iterator first, const_iterator last);
        // This method is provided only on Sun to work around a bug in the Sun
        // Studio 12.3 compiler, which prevents us from disabling (at compile
        // time) the overload of 'insert' taking a 'const_iterator' and a
        // forwarding reference if the second argument is not convertible to
        // the value type associated with the map.  Without such a check, in
        // certain cases, the same compiler complains of ambiguity between
        // the 'insert' method taking two input iterators and the 'insert'
        // method taking a 'const_iterator' and a forwarding reference; such
        // an ambiguity is resolved by providing this method, which is
        // equivalent to the 'insert' method (above) taking two input iterators
        // of template parameter type.
#endif

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
    void insert(std::initializer_list<value_type> values);
        // Insert into this multimap the value of each 'value_type' object in
        // the specified 'values' initializer list.  This method requires that
        // the (template parameter) types 'KEY' and 'VALUE' both be
        // 'copy-insertable' into this multimap (see {Requirements on 'KEY' and
        // 'VALUE'}).
#endif

#if BSLS_COMPILERFEATURES_SIMULATE_VARIADIC_TEMPLATES
// {{{ BEGIN GENERATED CODE
// Command line: sim_cpp11_features.pl bslstl_multimap.h
#ifndef BSLSTL_MULTIMAP_VARIADIC_LIMIT
#define BSLSTL_MULTIMAP_VARIADIC_LIMIT 2
#endif
#ifndef BSLSTL_MULTIMAP_VARIADIC_LIMIT_A
#define BSLSTL_MULTIMAP_VARIADIC_LIMIT_A BSLSTL_MULTIMAP_VARIADIC_LIMIT
#endif
#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 0
    iterator emplace();
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 0

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 1
    template <class Args_1>
    iterator emplace(BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1);
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 1

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 2
    template <class Args_1,
              class Args_2>
    iterator emplace(BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1,
                     BSLS_COMPILERFEATURES_FORWARD_REF(Args_2) args_2);
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 2


#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 0
    iterator emplace_hint(const_iterator hint);
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 0

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 1
    template <class Args_1>
    iterator emplace_hint(const_iterator hint,
                             BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1);
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 1

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 2
    template <class Args_1,
              class Args_2>
    iterator emplace_hint(const_iterator hint,
                             BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1,
                             BSLS_COMPILERFEATURES_FORWARD_REF(Args_2) args_2);
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_A >= 2

#else
// The generated code below is a workaround for the absence of perfect
// forwarding in some compilers.
    template <class... Args>
    iterator emplace(BSLS_COMPILERFEATURES_FORWARD_REF(Args)... args);

    template <class... Args>
    iterator emplace_hint(const_iterator hint,
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args)... args);
// }}} END GENERATED CODE
#endif

    iterator erase(const_iterator position);
    iterator erase(iterator position);
        // Remove from this multimap the 'value_type' object at the specified
        // 'position', and return an iterator referring to the element
        // immediately following the removed element, or to the past-the-end
        // position if the removed element was the last element in the sequence
        // of elements maintained by this multimap.   This method invalidates
        // only iterators and references to the removed element and previously
        // saved values of the 'end()' iterator.  The behavior is undefined
        // unless 'position' refers to a 'value_type' object in this multimap.

    size_type erase(const key_type& key);
        // Remove from this multimap all 'value_type' objects whose keys are
        // equivalent to the specified 'key', if such entries exist, and return
        // the number of erased objects; otherwise, if there is no 'value_type'
        // objects having an equivalent key, return 0 with no other effect.
        // This method invalidates only iterators and references to the removed
        // element and previously saved values of the 'end()' iterator.

    iterator erase(const_iterator first, const_iterator last);
        // Remove from this multimap the 'value_type' objects starting at the
        // specified 'first' position up to, but including the specified 'last'
        // position, and return 'last'.   This method invalidates only
        // iterators and references to the removed element and previously saved
        // values of the 'end()' iterator.  The behavior is undefined unless
        // 'first' and 'last' either refer to elements in this multimap or are
        // the 'end' iterator, and the 'first' position is at or before the
        // 'last' position in the ordered sequence provided by this container.

    void swap(multimap& other) BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(
                                 AllocatorTraits::is_always_equal::value &&
                                 bsl::is_nothrow_swappable<COMPARATOR>::value);
        // Exchange the value and comparator of this object with those of the
        // specified 'other' object; also exchange the allocator of this object
        // with that of 'other' if the (template parameter) type 'ALLOCATOR'
        // has the 'propagate_on_container_swap' trait, and do not modify
        // either allocator otherwise.  This method provides the no-throw
        // exception-safety guarantee if and only if the (template parameter)
        // type 'COMPARATOR' provides a no-throw swap operation, and provides
        // the basic exception-safety guarantee otherwise; if an exception is
        // thrown, both objects are left in valid but unspecified states.  This
        // operation has 'O[1]' complexity if either this object was created
        // with the same allocator as 'other' or 'ALLOCATOR' has the
        // 'propagate_on_container_swap' trait; otherwise, it has 'O[n + m]'
        // complexity, where 'n' and 'm' are the number of elements in this
        // object and 'other', respectively.  Note that this method's support
        // for swapping objects created with different allocators when
        // 'ALLOCATOR' does not have the 'propagate_on_container_swap' trait is
        // a departure from the C++ Standard.

    void clear() BSLS_KEYWORD_NOEXCEPT;
        // Remove all entries from this multimap.  Note that the multimap is
        // empty after this call, but allocated memory may be retained for
        // future use.

    // Turn off complaints about necessarily class-defined methods.
    // BDE_VERIFY pragma: push
    // BDE_VERIFY pragma: -CD01

    iterator find(const key_type& key)
        // Return an iterator providing modifiable access to the first
        // 'value_type' object in this multimap whose key is equivalent to the
        // specified 'key', if such an entry exists, and the past-the-end
        // ('end') iterator otherwise.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::find(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        iterator>::type
    find(const LOOKUP_KEY& key)
        // Return an iterator providing modifiable access to the first
        // 'value_type' object in this multimap whose key is equivalent to the
        // specified 'key', if such an entry exists, and the past-the-end
        // ('end') iterator otherwise.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::find(
            d_tree, this->comparator(), key));
    }

    iterator lower_bound(const key_type& key)
        // Return an iterator providing modifiable access to the first (i.e.,
        // ordered least) 'value_type' object in this multimap whose key is
        // greater-than or equal-to the specified 'key', and the past-the-end
        // iterator if this multimap does not contain a 'value_type' object
        // whose key is greater-than or equal-to 'key'.  Note that this
        // function returns the *first* position before which a 'value_type'
        // object having an equivalent key could be inserted into the ordered
        // sequence maintained by this multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::lowerBound(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        iterator>::type
    lower_bound(const LOOKUP_KEY& key)
        // Return an iterator providing modifiable access to the first (i.e.,
        // ordered least) 'value_type' object in this multimap whose key is
        // greater-than or equal-to the specified 'key', and the past-the-end
        // iterator if this multimap does not contain a 'value_type' object
        // whose key is greater-than or equal-to 'key'.  Note that this
        // function returns the *first* position before which a 'value_type'
        // object having an equivalent key could be inserted into the ordered
        // sequence maintained by this multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::lowerBound(
            d_tree, this->comparator(), key));
    }

    iterator upper_bound(const key_type& key)
        // Return an iterator providing modifiable access to the first (i.e.,
        // ordered least) 'value_type' object in this multimap whose key is
        // greater than the specified 'key', and the past-the-end iterator if
        // this multimap does not contain a 'value_type' object whose key is
        // greater-than 'key'.  Note that this function returns the *last*
        // position before which a 'value_type' object having an equivalent key
        // could be inserted into the ordered sequence maintained by this
        // multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::upperBound(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        iterator>::type
    upper_bound(const LOOKUP_KEY& key)
        // Return an iterator providing modifiable access to the first (i.e.,
        // ordered least) 'value_type' object in this multimap whose key is
        // greater than the specified 'key', and the past-the-end iterator if
        // this multimap does not contain a 'value_type' object whose key is
        // greater-than 'key'.  Note that this function returns the *last*
        // position before which a 'value_type' object having an equivalent key
        // could be inserted into the ordered sequence maintained by this
        // multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::upperBound(
            d_tree, this->comparator(), key));
    }

    bsl::pair<iterator,iterator> equal_range(const key_type& key)
        // Return a pair of iterators providing modifiable access to the
        // sequence of 'value_type' objects in this multimap whose keys are
        // equivalent to the specified 'key', where the first iterator is
        // positioned at the start of the sequence and the second is positioned
        // one past the end of the sequence.  The first returned iterator will
        // be 'lower_bound(key)', the second returned iterator will be
        // 'upper_bound(key)', and, if this multimap contains no 'value_type'
        // object with an equivalent key, then the two returned iterators will
        // have the same value.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        iterator startIt = lower_bound(key);
        iterator endIt   = startIt;
        if (endIt != end() && !comparator()(key, *endIt.node())) {
            endIt = upper_bound(key);
        }
        return bsl::pair<iterator, iterator>(startIt, endIt);
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        pair<iterator, iterator> >::type
    equal_range(const LOOKUP_KEY& key)
        // Return a pair of iterators providing modifiable access to the
        // sequence of 'value_type' objects in this multimap whose keys are
        // equivalent to the specified 'key', where the first iterator is
        // positioned at the start of the sequence and the second is positioned
        // one past the end of the sequence.  The first returned iterator will
        // be 'lower_bound(key)', the second returned iterator will be
        // 'upper_bound(key)', and, if this multimap contains no 'value_type'
        // object with an equivalent key, then the two returned iterators will
        // have the same value.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        iterator startIt = lower_bound(key);
        iterator endIt   = startIt;
        if (endIt != end() && !comparator()(key, *endIt.node())) {
            endIt = upper_bound(key);
        }
        return pair<iterator, iterator>(startIt, endIt);
    }

    // BDE_VERIFY pragma: pop

    // ACCESSORS
    allocator_type get_allocator() const BSLS_KEYWORD_NOEXCEPT;
        // Return (a copy of) the allocator used for memory allocation by this
        // multimap.

    const_iterator begin() const BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing non-modifiable access to the first
        // 'value_type' object in the ordered sequence of 'value_type' objects
        // maintained by this multimap, or the 'end' iterator if this multimap
        // is empty.

    const_iterator end() const BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing non-modifiable access to the
        // past-the-end element in the ordered sequence of 'value_type' objects
        // maintained by this multimap.

    const_reverse_iterator rbegin() const BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing non-modifiable access to the
        // last 'value_type' object in the ordered sequence of 'value_type'
        // objects maintained by this multimap, or 'rend' if this multimap is
        // empty.

    const_reverse_iterator rend() const BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing non-modifiable access to the
        // prior-to-the-beginning element in the ordered sequence of
        // 'value_type' objects maintained by this multimap.

    const_iterator cbegin() const BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing non-modifiable access to the first
        // 'value_type' object in the ordered sequence of 'value_type' objects
        // maintained by this multimap, or the 'cend' iterator if this multimap
        // is empty.

    const_iterator cend() const BSLS_KEYWORD_NOEXCEPT;
        // Return an iterator providing non-modifiable access to the
        // past-the-end element in the ordered sequence of 'value_type' objects
        // maintained by this multimap.

    const_reverse_iterator crbegin() const BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing non-modifiable access to the
        // last 'value_type' object in the ordered sequence of 'value_type'
        // objects maintained by this multimap, or 'rend' if this multimap is
        // empty.

    const_reverse_iterator crend() const BSLS_KEYWORD_NOEXCEPT;
        // Return a reverse iterator providing non-modifiable access to the
        // prior-to-the-beginning element in the ordered sequence of
        // 'value_type' objects maintained by this multimap.

    bool contains(const key_type &key) const;
        // Return 'true' if this multimap contains an element whose key is
        // equivalent to the specified 'key'.

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        bool>::type
    contains(const LOOKUP_KEY& key) const
        // Return 'true' if this multimap contains an element whose key is
        // equivalent to the specified 'key'.
        //
        // Note: implemented inline due to Sun CC compilation error
    {
        return find(key) != end();
    }

    bool empty() const BSLS_KEYWORD_NOEXCEPT;
        // Return 'true' if this multimap contains no elements, and 'false'
        // otherwise.

    size_type size() const BSLS_KEYWORD_NOEXCEPT;
        // Return the number of elements in this multimap.

    size_type max_size() const BSLS_KEYWORD_NOEXCEPT;
        // Return a theoretical upper bound on the largest number of elements
        // that this multimap could possibly hold.  Note that there is no
        // guarantee that the multimap can successfully grow to the returned
        // size, or even close to that size without running out of resources.

    key_compare key_comp() const;
        // Return the key-comparison functor (or function pointer) used by this
        // multimap; if a comparator was supplied at construction, return its
        // value, otherwise return a default constructed 'key_compare' object.
        // Note that this comparator compares objects of type 'KEY', which is
        // the key part of the 'value_type' objects contained in this multimap.

    value_compare value_comp() const;
        // Return a functor for comparing two 'value_type' objects by comparing
        // their respective keys using 'key_comp()'.   Note that this
        // comparator compares objects of type 'value_type' (i.e., 'pair<const
        // KEY, VALUE>').

    // Turn off complaints about necessarily class-defined methods.
    // BDE_VERIFY pragma: push
    // BDE_VERIFY pragma: -CD01

    const_iterator find(const key_type& key) const
        // Return an iterator providing non-modifiable access to the first
        // 'value_type' object having the specified 'key' in the ordered
        // sequence maintained by this multimap, if such an object exists, and
        // the past-the-end ('end') iterator otherwise.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return const_iterator(BloombergLP::bslalg::RbTreeUtil::find(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        const_iterator>::type
    find(const LOOKUP_KEY& key) const
        // Return an iterator providing non-modifiable access to the first
        // 'value_type' object having the specified 'key' in the ordered
        // sequence maintained by this multimap, if such an object exists, and
        // the past-the-end ('end') iterator otherwise.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return const_iterator(BloombergLP::bslalg::RbTreeUtil::find(
            d_tree, this->comparator(), key));
    }

    size_type count(const key_type& key) const
        // Return the number of 'value_type' objects within this multimap whose
        // keys are equivalent to the specified 'key'.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        int            count = 0;
        const_iterator it    = lower_bound(key);

        while (it != end() && !comparator()(key, *it.node())) {
            ++it;
            ++count;
        }
        return count;
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        size_type>::type
    count(const LOOKUP_KEY& key) const
        // Return the number of 'value_type' objects within this multimap whose
        // keys are equivalent to the specified 'key'.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        int            count = 0;
        const_iterator it    = lower_bound(key);

        while (it != end() && !comparator()(key, *it.node())) {
            ++it;
            ++count;
        }
        return count;
    }

    const_iterator lower_bound(const key_type& key) const
        // Return an iterator providing non-modifiable access to the first
        // (i.e., ordered least) 'value_type' object in this multimap whose key
        // is greater-than or equal-to the specified 'key', and the
        // past-the-end iterator if this multimap does not contain a
        // 'value_type' object whose key is greater-than or equal-to 'key'.
        // Note that this function returns the *first* position before which a
        // 'value_type' object having an equivalent key could be inserted into
        // the ordered sequence maintained by this multimap, while preserving
        // its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return iterator(BloombergLP::bslalg::RbTreeUtil::lowerBound(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        const_iterator>::type
    lower_bound(const LOOKUP_KEY& key) const
        // Return an iterator providing non-modifiable access to the first
        // (i.e., ordered least) 'value_type' object in this multimap whose key
        // is greater-than or equal-to the specified 'key', and the
        // past-the-end iterator if this multimap does not contain a
        // 'value_type' object whose key is greater-than or equal-to 'key'.
        // Note that this function returns the *first* position before which a
        // 'value_type' object having an equivalent key could be inserted into
        // the ordered sequence maintained by this multimap, while preserving
        // its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return const_iterator(BloombergLP::bslalg::RbTreeUtil::lowerBound(
            d_tree, this->comparator(), key));
    }

    const_iterator upper_bound(const key_type& key) const
        // Return an iterator providing non-modifiable access to the first
        // (i.e., ordered least) 'value_type' object in this multimap whose key
        // is greater than the specified 'key', and the past-the-end iterator
        // if this multimap does not contain a 'value_type' object whose key is
        // greater-than 'key'.  Note that this function returns the *last*
        // position before which a 'value_type' object having an equivalent key
        // could be inserted into the ordered sequence maintained by this
        // multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return const_iterator(BloombergLP::bslalg::RbTreeUtil::upperBound(
            d_tree, this->comparator(), key));
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        const_iterator>::type
    upper_bound(const LOOKUP_KEY& key) const
        // Return an iterator providing non-modifiable access to the first
        // (i.e., ordered least) 'value_type' object in this multimap whose key
        // is greater than the specified 'key', and the past-the-end iterator
        // if this multimap does not contain a 'value_type' object whose key is
        // greater-than 'key'.  Note that this function returns the *last*
        // position before which a 'value_type' object having an equivalent key
        // could be inserted into the ordered sequence maintained by this
        // multimap, while preserving its ordering.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        return const_iterator(BloombergLP::bslalg::RbTreeUtil::upperBound(
            d_tree, this->comparator(), key));
    }

    pair<const_iterator, const_iterator> equal_range(const key_type& key) const
        // Return a pair of iterators providing non-modifiable access to the
        // sequence of 'value_type' objects in this multimap whose keys are
        // equivalent to the specified 'key', where the first iterator is
        // positioned at the start of the sequence and the second iterator is
        // positioned one past the end of the sequence.  The first returned
        // iterator will be 'lower_bound(key)', the second returned iterator
        // will be 'upper_bound(key)', and, if this multimap contains no
        // 'value_type' objects having keys equivalent to 'key', then the two
        // returned iterators will have the same value.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        const_iterator startIt = lower_bound(key);
        const_iterator endIt   = startIt;
        if (endIt != end() && !comparator()(key, *endIt.node())) {
            endIt = upper_bound(key);
        }
        return bsl::pair<const_iterator, const_iterator>(startIt, endIt);
    }

    template <class LOOKUP_KEY>
    typename bsl::enable_if<
        BloombergLP::bslmf::IsTransparentPredicate<COMPARATOR,
                                                   LOOKUP_KEY>::value,
        pair<const_iterator, const_iterator> >::type
    equal_range(const LOOKUP_KEY& key) const
        // Return a pair of iterators providing non-modifiable access to the
        // sequence of 'value_type' objects in this multimap whose keys are
        // equivalent to the specified 'key', where the first iterator is
        // positioned at the start of the sequence and the second iterator is
        // positioned one past the end of the sequence.  The first returned
        // iterator will be 'lower_bound(key)', the second returned iterator
        // will be 'upper_bound(key)', and, if this multimap contains no
        // 'value_type' objects having keys equivalent to 'key', then the two
        // returned iterators will have the same value.
        //
        // Note: implemented inline due to Sun CC compilation error.
    {
        const_iterator startIt = lower_bound(key);
        const_iterator endIt   = startIt;
        if (endIt != end() && !comparator()(key, *endIt.node())) {
            endIt = upper_bound(key);
        }
        return pair<const_iterator, const_iterator>(startIt, endIt);
    }

    // BDE_VERIFY pragma: pop
};

#ifdef BSLS_COMPILERFEATURES_SUPPORT_CTAD
// CLASS TEMPLATE DEDUCTION GUIDES

template <
    class INPUT_ITERATOR,
    class KEY = BloombergLP::bslstl::IteratorUtil::IterKey_t<INPUT_ITERATOR>,
    class VALUE =
               BloombergLP::bslstl::IteratorUtil::IterMapped_t<INPUT_ITERATOR>,
    class COMPARATOR = std::less<KEY>,
    class ALLOCATOR = bsl::allocator<
             BloombergLP::bslstl::IteratorUtil::IterToAlloc_t<INPUT_ITERATOR>>,
    class = bsl::enable_if_t<!bsl::IsStdAllocator_v<COMPARATOR>>,
    class = bsl::enable_if_t<bsl::IsStdAllocator_v<ALLOCATOR>>
    >
multimap(INPUT_ITERATOR,
    INPUT_ITERATOR,
    COMPARATOR = COMPARATOR(),
    ALLOCATOR = ALLOCATOR())
-> multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the iterators supplied to the constructor of 'multimap'.  Deduce the
    // template parameters 'COMPARATOR' and 'ALLOCATOR' from the other
    // parameters passed to the constructor.  This deduction guide does not
    // participate unless the supplied allocator meets the requirements of a
    // standard allocator.

template <
    class INPUT_ITERATOR,
    class COMPARATOR,
    class ALLOC,
    class KEY = BloombergLP::bslstl::IteratorUtil::IterKey_t<INPUT_ITERATOR>,
    class VALUE =
               BloombergLP::bslstl::IteratorUtil::IterMapped_t<INPUT_ITERATOR>,
    class DEFAULT_ALLOCATOR = bsl::allocator<pair<const KEY, VALUE>>,
    class = bsl::enable_if_t<bsl::is_convertible_v<ALLOC *, DEFAULT_ALLOCATOR>>
    >
multimap(INPUT_ITERATOR, INPUT_ITERATOR, COMPARATOR, ALLOC *)
-> multimap<KEY, VALUE, COMPARATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the iterators supplied to the constructor of 'multimap'.  Deduce the
    // template parameter 'COMPARATOR' from the other parameter passed to the
    // constructor.  This deduction guide does not participate unless the
    // supplied allocator is convertible to
    // 'bsl::allocator<bsl::pair<const KEY, VALUE>>'.

template <
    class INPUT_ITERATOR,
    class ALLOCATOR,
    class KEY = BloombergLP::bslstl::IteratorUtil::IterKey_t<INPUT_ITERATOR>,
    class VALUE =
               BloombergLP::bslstl::IteratorUtil::IterMapped_t<INPUT_ITERATOR>,
    class = bsl::enable_if_t<bsl::IsStdAllocator_v<ALLOCATOR>>
    >
multimap(INPUT_ITERATOR, INPUT_ITERATOR, ALLOCATOR)
-> multimap<KEY, VALUE, std::less<KEY>, ALLOCATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the iterators supplied to the constructor of 'multimap'.  This
    // deduction guide does not participate unless the supplied allocator meets
    // the requirements of a standard allocator.

template <
    class INPUT_ITERATOR,
    class ALLOC,
    class KEY = BloombergLP::bslstl::IteratorUtil::IterKey_t<INPUT_ITERATOR>,
    class VALUE =
               BloombergLP::bslstl::IteratorUtil::IterMapped_t<INPUT_ITERATOR>,
    class DEFAULT_ALLOCATOR = bsl::allocator<pair<const KEY, VALUE>>,
    class = bsl::enable_if_t<bsl::is_convertible_v<ALLOC *, DEFAULT_ALLOCATOR>>
    >
multimap(INPUT_ITERATOR, INPUT_ITERATOR, ALLOC *)
-> multimap<KEY, VALUE>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the iterators supplied to the constructor of 'multimap'.  This
    // deduction guide does not participate unless the supplied allocator is
    // convertible to 'bsl::allocator<bsl::pair<const KEY, VALUE>>'.

template <
    class KEY,
    class VALUE,
    class COMPARATOR = std::less<KEY>,
    class ALLOCATOR = bsl::allocator<bsl::pair<const KEY, VALUE>>,
    class = bsl::enable_if_t<!bsl::IsStdAllocator_v<COMPARATOR>>,
    class = bsl::enable_if_t<bsl::IsStdAllocator_v<ALLOCATOR>>
    >
multimap(std::initializer_list<pair<const KEY, VALUE>>,
         COMPARATOR = COMPARATOR(),
         ALLOCATOR = ALLOCATOR())
-> multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the initializer_list supplied to the constructor of 'multimap'.
    // Deduce the template parameters 'COMPARATOR' and 'ALLOCATOR' from the
    // other parameters passed to the constructor.  This deduction guide does
    // not participate unless the supplied allocator meets the requirements of
    // a standard allocator.

template <
    class KEY,
    class VALUE,
    class COMPARATOR,
    class ALLOC,
    class DEFAULT_ALLOCATOR = bsl::allocator<bsl::pair<const KEY, VALUE>>,
    class = bsl::enable_if_t<bsl::is_convertible_v<ALLOC *, DEFAULT_ALLOCATOR>>
    >
multimap(std::initializer_list<pair<const KEY, VALUE>>, COMPARATOR, ALLOC *)
-> multimap<KEY, VALUE, COMPARATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the initializer_list supplied to the constructor of 'multimap'.
    // Deduce the template parameter 'COMPARATOR' from the other parameters
    // passed to the constructor.  This deduction guide does not participate
    // unless the supplied allocator is convertible to
    // 'bsl::allocator<bsl::pair<const KEY, VALUE>>'.

template <
    class KEY,
    class VALUE,
    class ALLOCATOR,
    class = bsl::enable_if_t<bsl::IsStdAllocator_v<ALLOCATOR>>
    >
multimap(std::initializer_list<pair<const KEY, VALUE>>, ALLOCATOR)
-> multimap<KEY, VALUE, std::less<KEY>, ALLOCATOR>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the initializer_list supplied to the constructor of 'multimap'.
    // Deduce the template parameter 'ALLOCATOR' from the other parameter
    // passed to the constructor.  This deduction guide does not participate
    // unless the supplied allocator meets the requirements of a standard
    // allocator.

template <
    class KEY,
    class VALUE,
    class ALLOC,
    class DEFAULT_ALLOCATOR = bsl::allocator<bsl::pair<const KEY, VALUE>>,
    class = bsl::enable_if_t<bsl::is_convertible_v<ALLOC *, DEFAULT_ALLOCATOR>>
    >
multimap(std::initializer_list<pair<const KEY, VALUE>>, ALLOC *)
-> multimap<KEY, VALUE>;
    // Deduce the template parameters 'KEY' and 'VALUE' from the 'value_type'
    // of the initializer_list supplied to the constructor of 'multimap'.  This
    // deduction guide does not participate unless the supplied allocator is
    // convertible to 'bsl::allocator<bsl::pair<const KEY, VALUE>>'.
#endif

// FREE OPERATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator==(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the specified 'lhs' and 'rhs' objects have the same
    // value, and 'false' otherwise.  Two 'multimap' objects 'lhs' and 'rhs'
    // have the same value if they have the same number of key-value pairs, and
    // each element in the ordered sequence of key-value pairs of 'lhs' has the
    // same value as the corresponding element in the ordered sequence of
    // key-value pairs of 'rhs'.  This method requires that the (template
    // parameter) types 'KEY' and 'VALUE' both be 'equality-comparable' (see
    // {Requirements on 'KEY' and 'VALUE'}).

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator!=(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the specified 'lhs' and 'rhs' objects do not have the
    // same value, and 'false' otherwise.  Two 'multimap' objects 'lhs' and
    // 'rhs' do not have the same value if they do not have the same number of
    // key-value pairs, or some element in the ordered sequence of key-value
    // pairs of 'lhs' does not have the same value as the corresponding element
    // in the ordered sequence of key-value pairs of 'rhs'.  This method
    // requires that the (template parameter) types 'KEY' and 'VALUE' both be
    // 'equality-comparable' (see {Requirements on 'KEY' and 'VALUE'}).

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator<(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
               const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the value of the specified 'lhs' multimap is
    // lexicographically less than that of the specified 'rhs' multimap, and
    // 'false' otherwise.  Given iterators 'i' and 'j' over the respective
    // sequences '[lhs.begin() .. lhs.end())' and '[rhs.begin() .. rhs.end())',
    // the value of multimap 'lhs' is lexicographically less than that of
    // multimap 'rhs' if 'true == *i < *j' for the first pair of corresponding
    // iterator positions where '*i < *j' and '*j < *i' are not both 'false'.
    // If no such corresponding iterator position exists, the value of 'lhs' is
    // lexicographically less than that of 'rhs' if 'lhs.size() < rhs.size()'.
    // This method requires that 'operator<', inducing a total order, be
    // defined for 'value_type'.

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator>(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
               const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the value of the specified 'lhs' multimap is
    // lexicographically greater than that of the specified 'rhs' multimap, and
    // 'false' otherwise.  The value of multimap 'lhs' is lexicographically
    // greater than that of multimap 'rhs' if 'rhs' is lexicographically less
    // than 'lhs' (see 'operator<').  This method requires that 'operator<',
    // inducing a total order, be defined for 'value_type'.  Note that this
    // operator returns 'rhs < lhs'.

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator<=(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the value of the specified 'lhs' multimap is
    // lexicographically less than or equal to that of the specified 'rhs'
    // multimap, and 'false' otherwise.  The value of multimap 'lhs' is
    // lexicographically less than or equal to that of multimap 'rhs' if 'rhs'
    // is not lexicographically less than 'lhs' (see 'operator<').  This method
    // requires that 'operator<', inducing a total order, be defined for
    // 'value_type'.  Note that this operator returns '!(rhs < lhs)'.

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
bool operator>=(const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                const multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs);
    // Return 'true' if the value of the specified 'lhs' multimap is
    // lexicographically greater than or equal to that of the specified 'rhs'
    // multimap, and 'false' otherwise.  The value of multimap 'lhs' is
    // lexicographically greater than or equal to that of multimap 'rhs' if
    // 'lhs' is not lexicographically less than 'rhs' (see 'operator<').  This
    // method requires that 'operator<', inducing a total order, be defined for
    // 'value_type'.  Note that this operator returns '!(lhs < rhs)'.

// FREE FUNCTIONS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
void swap(multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& a,
          multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& b)
             BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(false);
    // Exchange the value and comparator of the specified 'a' object with those
    // of the specified 'b' object; also exchange the allocator of 'a' with
    // that of 'b' if the (template parameter) type 'ALLOCATOR' has the
    // 'propagate_on_container_swap' trait, and do not modify either allocator
    // otherwise.  This function provides the no-throw exception-safety
    // guarantee if and only if the (template parameter) type 'COMPARATOR'
    // provides a no-throw swap operation, and provides the basic
    // exception-safety guarantee otherwise; if an exception is thrown, both
    // objects are left in valid but unspecified states.  This operation has
    // 'O[1]' complexity if either 'a' was created with the same allocator as
    // 'b' or 'ALLOCATOR' has the 'propagate_on_container_swap' trait;
    // otherwise, it has 'O[n + m]' complexity, where 'n' and 'm' are the
    // number of elements in 'a' and 'b', respectively.  Note that this
    // function's support for swapping objects created with different
    // allocators when 'ALLOCATOR' does not have the
    // 'propagate_on_container_swap' trait is a departure from the C++
    // Standard.

// ============================================================================
//                      INLINE FUNCTION DEFINITIONS
// ============================================================================

                             // -----------------
                             // class DataWrapper
                             // -----------------

// CREATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::DataWrapper::DataWrapper(
                                              const COMPARATOR& comparator,
                                              const ALLOCATOR&  basicAllocator)
: ::bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::Comparator(comparator)
, d_pool(basicAllocator)
{
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::DataWrapper::DataWrapper(
                          BloombergLP::bslmf::MovableRef<DataWrapper> original)
: ::bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::Comparator(
                                    MoveUtil::access(original).keyComparator())
, d_pool(MoveUtil::move(MoveUtil::access(original).d_pool))
{
}

// MANIPULATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::NodeFactory&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::DataWrapper::nodeFactory()
{
    return d_pool;
}

// ACCESSORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
const typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::NodeFactory&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::DataWrapper::nodeFactory() const
{
    return d_pool;
}

                             // -----------------------------
                             // class multimap::value_compare
                             // -----------------------------

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::value_compare::value_compare(
                                                         COMPARATOR comparator)
: comp(comparator)
{
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::value_compare::operator()(
                                                     const value_type& x,
                                                     const value_type& y) const
{
    return comp(x.first, y.first);
}

                             // --------------
                             // class multimap
                             // --------------

// PRIVATE MANIPULATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::Comparator&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::comparator()
{
    return d_compAndAlloc;
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::NodeFactory&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::nodeFactory()
{
    return d_compAndAlloc.nodeFactory();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::quickSwapExchangeAllocators(
                                                               multimap& other)
{
    BloombergLP::bslalg::RbTreeUtil::swap(&d_tree, &other.d_tree);
    nodeFactory().swapExchangeAllocators(other.nodeFactory());

    // 'DataWrapper' contains a 'NodeFactory' object and inherits from
    // 'Comparator'.  If the empty-base-class optimization has been applied to
    // 'Comparator', then we must not call 'swap' on it because
    // 'sizeof(Comparator) > 0' and, therefore, we will incorrectly swap bytes
    // of the 'NodeFactory' members!

    if (sizeof(NodeFactory) != sizeof(DataWrapper)) {
        comparator().swap(other.comparator());
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::quickSwapRetainAllocators(
                                                               multimap& other)
{
    BloombergLP::bslalg::RbTreeUtil::swap(&d_tree, &other.d_tree);
    nodeFactory().swapRetainAllocators(other.nodeFactory());

    // See 'quickSwapExchangeAllocators' (above).

    if (sizeof(NodeFactory) != sizeof(DataWrapper)) {
        comparator().swap(other.comparator());
    }
}

// PRIVATE ACCESSORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
const typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::Comparator&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::comparator() const
{
    return d_compAndAlloc;
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
const typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::NodeFactory&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::nodeFactory() const
{
    return d_compAndAlloc.nodeFactory();
}

// CREATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap()
: d_compAndAlloc(COMPARATOR(), ALLOCATOR())
, d_tree()
{
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                                               const ALLOCATOR& basicAllocator)
: d_compAndAlloc(COMPARATOR(), basicAllocator)
, d_tree()
{
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(const multimap& original)
: d_compAndAlloc(original.comparator().keyComparator(),
                 AllocatorTraits::select_on_container_copy_construction(
                                           original.nodeFactory().allocator()))
, d_tree()
{
    if (0 < original.size()) {
        nodeFactory().reserveNodes(original.size());
        BloombergLP::bslalg::RbTreeUtil::copyTree(&d_tree,
                                                  original.d_tree,
                                                  &nodeFactory());
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                             BloombergLP::bslmf::MovableRef<multimap> original)
: d_compAndAlloc(MoveUtil::move(MoveUtil::access(original).d_compAndAlloc))
, d_tree()
{
    multimap& lvalue = original;
    BloombergLP::bslalg::RbTreeUtil::swap(&d_tree, &lvalue.d_tree);
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                 const multimap&                                original,
                 const typename type_identity<ALLOCATOR>::type& basicAllocator)
: d_compAndAlloc(original.comparator().keyComparator(), basicAllocator)
, d_tree()
{
    if (0 < original.size()) {
        nodeFactory().reserveNodes(original.size());
        BloombergLP::bslalg::RbTreeUtil::copyTree(&d_tree,
                                                  original.d_tree,
                                                  &nodeFactory());
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                 BloombergLP::bslmf::MovableRef<multimap> original,
                 const typename type_identity<ALLOCATOR>::type& basicAllocator)
: d_compAndAlloc(MoveUtil::access(original).comparator().keyComparator(),
                 basicAllocator)
, d_tree()
{
    multimap& lvalue = original;

    if (BSLS_PERFORMANCEHINT_PREDICT_LIKELY(
              nodeFactory().allocator() == lvalue.nodeFactory().allocator())) {
        d_compAndAlloc.nodeFactory().adopt(
                          MoveUtil::move(lvalue.d_compAndAlloc.nodeFactory()));
        BloombergLP::bslalg::RbTreeUtil::swap(&d_tree, &lvalue.d_tree);
    }
    else {
        if (0 < lvalue.size()) {
            nodeFactory().reserveNodes(lvalue.size());
            BloombergLP::bslalg::RbTreeUtil::moveTree(&d_tree,
                                                      &lvalue.d_tree,
                                                      &nodeFactory(),
                                                      &lvalue.nodeFactory());
        }
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class INPUT_ITERATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                                              INPUT_ITERATOR    first,
                                              INPUT_ITERATOR    last,
                                              const COMPARATOR& comparator,
                                              const ALLOCATOR&  basicAllocator)
: d_compAndAlloc(comparator, basicAllocator)
, d_tree()
{
    if (first != last) {

        size_type numElements =
                BloombergLP::bslstl::IteratorUtil::insertDistance(first, last);

        if (0 < numElements) {
            nodeFactory().reserveNodes(numElements);
        }

        BloombergLP::bslalg::RbTreeUtilTreeProctor<NodeFactory> proctor(
                                                               &d_tree,
                                                               &nodeFactory());

        // The following loop guarantees amortized linear time to insert an
        // ordered sequence of values (as required by the standard).   If the
        // values are in sorted order, we are guaranteed the next node can be
        // inserted as the right child of the previous node, and can call
        // 'insertAt'.

        insert(*first);
        BloombergLP::bslalg::RbTreeNode *prevNode = d_tree.rootNode();
        while (++first != last) {
            // The values are not in order, so insert them normally.

            const value_type& value = *first;
            if (this->comparator()(value.first, *prevNode)) {
                insert(value);
                insert(++first, last);
                break;
            }
            BloombergLP::bslalg::RbTreeNode *node =
                nodeFactory().emplaceIntoNewNode(value);
            BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                                      prevNode,
                                                      false,
                                                      node);
            prevNode = node;
        }
        proctor.release();
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class INPUT_ITERATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                                              INPUT_ITERATOR    first,
                                              INPUT_ITERATOR    last,
                                              const ALLOCATOR&  basicAllocator)
: d_compAndAlloc(COMPARATOR(), basicAllocator)
, d_tree()
{
    if (first != last) {

        size_type numElements =
                BloombergLP::bslstl::IteratorUtil::insertDistance(first, last);

        if (0 < numElements) {
            nodeFactory().reserveNodes(numElements);
        }

        BloombergLP::bslalg::RbTreeUtilTreeProctor<NodeFactory> proctor(
                                                               &d_tree,
                                                               &nodeFactory());

        // The following loop guarantees amortized linear time to insert an
        // ordered sequence of values (as required by the standard).   If the
        // values are in sorted order, we are guaranteed the next node can be
        // inserted as the right child of the previous node, and can call
        // 'insertAt'.

        insert(*first);
        BloombergLP::bslalg::RbTreeNode *prevNode = d_tree.rootNode();
        while (++first != last) {
            // The values are not in order, so insert them normally.

            const value_type& value = *first;
            if (this->comparator()(value.first, *prevNode)) {
                insert(value);
                insert(++first, last);
                break;
            }
            BloombergLP::bslalg::RbTreeNode *node =
                nodeFactory().emplaceIntoNewNode(value);
            BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                                      prevNode,
                                                      false,
                                                      node);
            prevNode = node;
        }
        proctor.release();
    }
}

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                              std::initializer_list<value_type> values,
                              const COMPARATOR&                 comparator,
                              const ALLOCATOR&                  basicAllocator)
: multimap(values.begin(), values.end(), comparator, basicAllocator)
{
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::multimap(
                              std::initializer_list<value_type> values,
                              const ALLOCATOR&                  basicAllocator)
: multimap(values.begin(), values.end(), COMPARATOR(), basicAllocator)
{
}
#endif

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::~multimap()
{
    clear();
}

// MANIPULATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::operator=(const multimap& rhs)
{
    if (BSLS_PERFORMANCEHINT_PREDICT_LIKELY(this != &rhs)) {
        if (AllocatorTraits::propagate_on_container_copy_assignment::value) {
            multimap other(rhs, rhs.nodeFactory().allocator());
            quickSwapExchangeAllocators(other);
        }
        else {
            multimap other(rhs, nodeFactory().allocator());
            quickSwapRetainAllocators(other);
        }
    }
    return *this;
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::operator=(
                                  BloombergLP::bslmf::MovableRef<multimap> rhs)
    BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(
                            AllocatorTraits::is_always_equal::value &&
                            std::is_nothrow_move_assignable<COMPARATOR>::value)
{
    multimap& lvalue = rhs;

    if (BSLS_PERFORMANCEHINT_PREDICT_LIKELY(this != &lvalue)) {
        if (nodeFactory().allocator() == lvalue.nodeFactory().allocator()) {
            multimap other(MoveUtil::move(lvalue));
            quickSwapRetainAllocators(other);
        }
        else if (
              AllocatorTraits::propagate_on_container_move_assignment::value) {
            multimap other(MoveUtil::move(lvalue));
            quickSwapExchangeAllocators(other);
        }
        else {
            multimap other(MoveUtil::move(lvalue), nodeFactory().allocator());
            quickSwapRetainAllocators(other);
        }
    }
    return *this;
}

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>&
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::operator=(
                                      std::initializer_list<value_type> values)
{
    clear();
    insert(values.begin(), values.end());
    return *this;
}
#endif

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::begin() BSLS_KEYWORD_NOEXCEPT
{
    return iterator(d_tree.firstNode());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::end() BSLS_KEYWORD_NOEXCEPT
{
    return iterator(d_tree.sentinel());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::rbegin() BSLS_KEYWORD_NOEXCEPT
{
    return reverse_iterator(end());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::rend() BSLS_KEYWORD_NOEXCEPT
{
    return reverse_iterator(begin());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::insert(const value_type& value)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(&leftChild,
                                                            &d_tree,
                                                            this->comparator(),
                                                            value.first);

    BloombergLP::bslalg::RbTreeNode *node =
        nodeFactory().emplaceIntoNewNode(value);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class INPUT_ITERATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::insert(INPUT_ITERATOR first,
                                                         INPUT_ITERATOR last)
{
    ///Implementation Notes
    ///--------------------
    // First, consume currently held free nodes.  Tf those nodes are
    // insufficient *and* one can calculate the remaining number of elements,
    // then reserve exactly that many free nodes.  There is no more than one
    // call to 'reserveNodes' per invocation of this method, hence the use of
    // 'BSLS_PERFORMANCEHINT_PREDICT_UNLIKELY'.

    const bool canCalculateInsertDistance =
             is_convertible<typename
                            iterator_traits<INPUT_ITERATOR>::iterator_category,
                            forward_iterator_tag>::value;

    while (first != last) {
        if (canCalculateInsertDistance
        && BSLS_PERFORMANCEHINT_PREDICT_UNLIKELY(
                                              !nodeFactory().hasFreeNodes())) {
            const size_type numElements =
                BloombergLP::bslstl::IteratorUtil::insertDistance(first, last);

            nodeFactory().reserveNodes(numElements);
        }
        insert(*first);
        ++first;
    }
}

#if defined(BSLS_PLATFORM_CMP_SUN) && BSLS_PLATFORM_CMP_VERSION < 0x5130
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::insert(const_iterator first,
                                                         const_iterator last)
{
    while (first != last) {
        insert(*first);
        ++first;
    }
}
#endif

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::insert(const_iterator    hint,
                                                    const value_type& value)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *hintNode =
                const_cast<BloombergLP::bslalg::RbTreeNode *>(hint.node());

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(&leftChild,
                                                            &d_tree,
                                                            this->comparator(),
                                                            value.first,
                                                            hintNode);

    BloombergLP::bslalg::RbTreeNode *node =
        nodeFactory().emplaceIntoNewNode(value);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}

#if defined(BSLS_COMPILERFEATURES_SUPPORT_GENERALIZED_INITIALIZERS)
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::insert(
                                      std::initializer_list<value_type> values)
{
    insert(values.begin(), values.end());
}
#endif

#if BSLS_COMPILERFEATURES_SIMULATE_VARIADIC_TEMPLATES
// {{{ BEGIN GENERATED CODE
// Command line: sim_cpp11_features.pl bslstl_multimap.h
#ifndef BSLSTL_MULTIMAP_VARIADIC_LIMIT
#define BSLSTL_MULTIMAP_VARIADIC_LIMIT 2
#endif
#ifndef BSLSTL_MULTIMAP_VARIADIC_LIMIT_B
#define BSLSTL_MULTIMAP_VARIADIC_LIMIT_B BSLSTL_MULTIMAP_VARIADIC_LIMIT
#endif
#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 0
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace(
                               )
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        );

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                               &leftChild,
                               &d_tree,
                               this->comparator(),
                               static_cast<const Node *>(node)->value().first);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 0

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 1
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class Args_1>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace(
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args_1, args_1));

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                               &leftChild,
                               &d_tree,
                               this->comparator(),
                               static_cast<const Node *>(node)->value().first);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 1

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 2
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class Args_1,
          class Args_2>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace(
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1,
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_2) args_2)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args_1, args_1),
        BSLS_COMPILERFEATURES_FORWARD(Args_2, args_2));

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                               &leftChild,
                               &d_tree,
                               this->comparator(),
                               static_cast<const Node *>(node)->value().first);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 2


#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 0
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace_hint(const_iterator hint)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        );

    BloombergLP::bslalg::RbTreeNode *hintNode =
                    const_cast<BloombergLP::bslalg::RbTreeNode *>(hint.node());

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                                &leftChild,
                                &d_tree,
                                this->comparator(),
                                static_cast<const Node *>(node)->value().first,
                                hintNode);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 0

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 1
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class Args_1>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace_hint(const_iterator hint,
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args_1, args_1));

    BloombergLP::bslalg::RbTreeNode *hintNode =
                    const_cast<BloombergLP::bslalg::RbTreeNode *>(hint.node());

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                                &leftChild,
                                &d_tree,
                                this->comparator(),
                                static_cast<const Node *>(node)->value().first,
                                hintNode);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 1

#if BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 2
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class Args_1,
          class Args_2>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace_hint(const_iterator hint,
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_1) args_1,
                              BSLS_COMPILERFEATURES_FORWARD_REF(Args_2) args_2)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args_1, args_1),
        BSLS_COMPILERFEATURES_FORWARD(Args_2, args_2));

    BloombergLP::bslalg::RbTreeNode *hintNode =
                    const_cast<BloombergLP::bslalg::RbTreeNode *>(hint.node());

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                                &leftChild,
                                &d_tree,
                                this->comparator(),
                                static_cast<const Node *>(node)->value().first,
                                hintNode);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}
#endif  // BSLSTL_MULTIMAP_VARIADIC_LIMIT_B >= 2

#else
// The generated code below is a workaround for the absence of perfect
// forwarding in some compilers.
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class... Args>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace(
                               BSLS_COMPILERFEATURES_FORWARD_REF(Args)... args)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args, args)...);

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                               &leftChild,
                               &d_tree,
                               this->comparator(),
                               static_cast<const Node *>(node)->value().first);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
template <class... Args>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::emplace_hint(const_iterator hint,
                               BSLS_COMPILERFEATURES_FORWARD_REF(Args)... args)
{
    bool leftChild;

    BloombergLP::bslalg::RbTreeNode *node = nodeFactory().emplaceIntoNewNode(
        BSLS_COMPILERFEATURES_FORWARD(Args, args)...);

    BloombergLP::bslalg::RbTreeNode *hintNode =
                    const_cast<BloombergLP::bslalg::RbTreeNode *>(hint.node());

    BloombergLP::bslalg::RbTreeNode *insertLocation =
        BloombergLP::bslalg::RbTreeUtil::findInsertLocation(
                                &leftChild,
                                &d_tree,
                                this->comparator(),
                                static_cast<const Node *>(node)->value().first,
                                hintNode);

    BloombergLP::bslalg::RbTreeUtil::insertAt(&d_tree,
                                              insertLocation,
                                              leftChild,
                                              node);
    return iterator(node);
}

// }}} END GENERATED CODE
#endif

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::erase(const_iterator position)
{
    BSLS_ASSERT_SAFE(position != end());

    BloombergLP::bslalg::RbTreeNode *node =
                const_cast<BloombergLP::bslalg::RbTreeNode *>(position.node());
    BloombergLP::bslalg::RbTreeNode *result =
                                   BloombergLP::bslalg::RbTreeUtil::next(node);
    BloombergLP::bslalg::RbTreeUtil::remove(&d_tree, node);
    nodeFactory().deleteNode(node);
    return iterator(result);
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::erase(iterator position)
{
    return erase(const_iterator(position));
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::size_type
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::erase(const key_type& key)
{
    size_type      count = 0;
    const_iterator first = find(key);

    if (first != end()) {
        const_iterator last = upper_bound(key);
        while (first != last) {
            first = erase(first);
            ++count;
        }
    }
    return count;
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::erase(const_iterator first,
                                                   const_iterator last)
{
    while (first != last) {
        first = erase(first);
    }
    return iterator(last.node());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::swap(multimap& other)
    BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(
                                  AllocatorTraits::is_always_equal::value &&
                                  bsl::is_nothrow_swappable<COMPARATOR>::value)
{
    if (AllocatorTraits::propagate_on_container_swap::value) {
        quickSwapExchangeAllocators(other);
    }
    else {
        // C++11 behavior for member 'swap': undefined for unequal allocators.
        // BSLS_ASSERT(allocator() == other.allocator());

        if (BSLS_PERFORMANCEHINT_PREDICT_LIKELY(
               nodeFactory().allocator() == other.nodeFactory().allocator())) {
            quickSwapRetainAllocators(other);
        }
        else {
            BSLS_PERFORMANCEHINT_UNLIKELY_HINT;

            multimap toOtherCopy(MoveUtil::move(*this),
                                 other.nodeFactory().allocator());
            multimap toThisCopy( MoveUtil::move(other),
                                 nodeFactory().allocator());

            this->quickSwapRetainAllocators(toThisCopy);
            other.quickSwapRetainAllocators(toOtherCopy);
        }
    }
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::clear() BSLS_KEYWORD_NOEXCEPT
{
    BSLS_ASSERT_SAFE(d_tree.firstNode());

    if (d_tree.rootNode()) {
        BSLS_ASSERT_SAFE(0 < d_tree.numNodes());
        BSLS_ASSERT_SAFE(d_tree.firstNode() != d_tree.sentinel());

        BloombergLP::bslalg::RbTreeUtil::deleteTree(&d_tree, &nodeFactory());
    }
#if defined(BSLS_ASSERT_SAFE_IS_USED)
    else {
        BSLS_ASSERT_SAFE(0 == d_tree.numNodes());
        BSLS_ASSERT_SAFE(d_tree.firstNode() == d_tree.sentinel());
    }
#endif
}

// ACCESSORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::allocator_type
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::get_allocator() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return nodeFactory().allocator();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::begin() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return cbegin();
}


template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::end() const BSLS_KEYWORD_NOEXCEPT
{
    return cend();
}


template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::rbegin() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return crbegin();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::rend() const BSLS_KEYWORD_NOEXCEPT
{
    return crend();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::cbegin() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return const_iterator(d_tree.firstNode());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::cend() const BSLS_KEYWORD_NOEXCEPT
{
    return const_iterator(d_tree.sentinel());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::crbegin() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return const_reverse_iterator(end());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::const_reverse_iterator
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::crend() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return const_reverse_iterator(begin());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::contains(
                                                     const key_type& key) const
{
    return find(key) != end();
}

// capacity:
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::empty() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return 0 == d_tree.numNodes();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::size_type
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::size() const BSLS_KEYWORD_NOEXCEPT
{
    return d_tree.numNodes();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::size_type
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::max_size() const
                                                          BSLS_KEYWORD_NOEXCEPT
{
    return AllocatorTraits::max_size(get_allocator());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::key_compare
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::key_comp() const
{
    return comparator().keyComparator();
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
typename multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::value_compare
multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>::value_comp() const
{
    return value_compare(key_comp());
}

}  // close namespace bsl

// FREE OPERATORS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator==(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return BloombergLP::bslalg::RangeCompare::equal(lhs.begin(),
                                                    lhs.end(),
                                                    lhs.size(),
                                                    rhs.begin(),
                                                    rhs.end(),
                                                    rhs.size());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator!=(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return !(lhs == rhs);
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator<(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return 0 > BloombergLP::bslalg::RangeCompare::lexicographical(lhs.begin(),
                                                                  lhs.end(),
                                                                  lhs.size(),
                                                                  rhs.begin(),
                                                                  rhs.end(),
                                                                  rhs.size());
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator>(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return rhs < lhs;
}

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator<=(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return !(rhs < lhs);
}


template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
bool bsl::operator>=(
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& lhs,
                   const bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& rhs)
{
    return !(lhs < rhs);
}

// FREE FUNCTIONS
template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
inline
void bsl::swap(bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& a,
               bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR>& b)
                                     BSLS_KEYWORD_NOEXCEPT_SPECIFICATION(false)
{
    a.swap(b);
}

// ============================================================================
//                                TYPE TRAITS
// ============================================================================

// Type traits for STL *ordered* containers:
//: o An ordered container defines STL iterators.
//: o An ordered container uses 'bslma' allocators if the (template parameter)
//:   type 'ALLOCATOR' is convertible from 'bslma::Allocator *'.

namespace BloombergLP {

namespace bslalg {

template <class KEY, class VALUE, class COMPARATOR, class ALLOCATOR>
struct HasStlIterators<bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR> >
    : bsl::true_type
{
};

}  // close namespace bslalg

namespace bslma {

template <class KEY,   class VALUE, class COMPARATOR, class ALLOCATOR>
struct UsesBslmaAllocator<bsl::multimap<KEY, VALUE, COMPARATOR, ALLOCATOR> >
    : bsl::is_convertible<Allocator*, ALLOCATOR>
{};

}  // close namespace bslma

}  // close enterprise namespace

#else // if ! defined(DEFINED_BSLSTL_MULTIMAP_H)
# error Not valid except when included from bslstl_multimap.h
#endif // ! defined(COMPILING_BSLSTL_MULTIMAP_H)

#endif // ! defined(INCLUDED_BSLSTL_MULTIMAP_CPP03)

// ----------------------------------------------------------------------------
// Copyright 2023 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------