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///////////////////////////////////////////////////////////////////////////////
// EASTL/map.h
//
// Copyright (c) 2005, Electronic Arts. All rights reserved.
// Written by Paul Pedriana.
//////////////////////////////////////////////////////////////////////////////



#ifndef EASTL_MAP_H
#define EASTL_MAP_H



#include <EASTL/internal/config.h>
#include <EASTL/internal/red_black_tree.h>
#include <EASTL/functional.h>
#include <EASTL/utility.h>



namespace eastl
{

    /// EASTL_MAP_DEFAULT_NAME
    ///
    /// Defines a default container name in the absence of a user-provided name.
    ///
    #ifndef EASTL_MAP_DEFAULT_NAME
        #define EASTL_MAP_DEFAULT_NAME EASTL_DEFAULT_NAME_PREFIX " map" // Unless the user overrides something, this is "EASTL map".
    #endif


    /// EASTL_MULTIMAP_DEFAULT_NAME
    ///
    /// Defines a default container name in the absence of a user-provided name.
    ///
    #ifndef EASTL_MULTIMAP_DEFAULT_NAME
        #define EASTL_MULTIMAP_DEFAULT_NAME EASTL_DEFAULT_NAME_PREFIX " multimap" // Unless the user overrides something, this is "EASTL multimap".
    #endif


    /// EASTL_MAP_DEFAULT_ALLOCATOR
    ///
    #ifndef EASTL_MAP_DEFAULT_ALLOCATOR
        #define EASTL_MAP_DEFAULT_ALLOCATOR allocator_type(EASTL_MAP_DEFAULT_NAME)
    #endif

    /// EASTL_MULTIMAP_DEFAULT_ALLOCATOR
    ///
    #ifndef EASTL_MULTIMAP_DEFAULT_ALLOCATOR
        #define EASTL_MULTIMAP_DEFAULT_ALLOCATOR allocator_type(EASTL_MULTIMAP_DEFAULT_NAME)
    #endif



    /// map
    ///
    /// Implements a canonical map. 
    ///
    /// The large majority of the implementation of this class is found in the rbtree
    /// base class. We control the behaviour of rbtree via template parameters.
    ///
    /// Pool allocation
    /// If you want to make a custom memory pool for a map container, your pool 
    /// needs to contain items of type map::node_type. So if you have a memory
    /// pool that has a constructor that takes the size of pool items and the
    /// count of pool items, you would do this (assuming that MemoryPool implements
    /// the Allocator interface):
    ///     typedef map<Widget, int, less<Widget>, MemoryPool> WidgetMap;  // Delare your WidgetMap type.
    ///     MemoryPool myPool(sizeof(WidgetMap::node_type), 100);          // Make a pool of 100 Widget nodes.
    ///     WidgetMap myMap(&myPool);                                      // Create a map that uses the pool.
    ///
    template <typename Key, typename T, typename Compare = eastl::less<Key>, typename Allocator = EASTLAllocatorType>
    class map
        : public rbtree<Key, eastl::pair<const Key, T>, Compare, Allocator, eastl::use_first<eastl::pair<const Key, T> >, true, true>
    {
    public:
        typedef rbtree<Key, eastl::pair<const Key, T>, Compare, Allocator,
                        eastl::use_first<eastl::pair<const Key, T> >, true, true>   base_type;
        typedef map<Key, T, Compare, Allocator>                                     this_type;
        typedef typename base_type::size_type                                       size_type;
        typedef typename base_type::key_type                                        key_type;
        typedef T                                                                   mapped_type;
        typedef typename base_type::value_type                                      value_type;
        typedef typename base_type::node_type                                       node_type;
        typedef typename base_type::iterator                                        iterator;
        typedef typename base_type::const_iterator                                  const_iterator;
        typedef typename base_type::allocator_type                                  allocator_type;
        typedef typename base_type::insert_return_type                              insert_return_type;
        typedef typename base_type::extract_key                                     extract_key;
        // Other types are inherited from the base class.

        using base_type::begin;
        using base_type::end;
        using base_type::find;
        using base_type::lower_bound;
        using base_type::upper_bound;
        using base_type::mCompare;

        #if !defined(__GNUC__) || (__GNUC__ >= 3) // GCC 2.x has a bug which we work around.
        using base_type::insert;
        using base_type::erase;
        #endif

    public:
        map(const allocator_type& allocator = EASTL_MAP_DEFAULT_ALLOCATOR);
        map(const Compare& compare, const allocator_type& allocator = EASTL_MAP_DEFAULT_ALLOCATOR);
        map(const this_type& x);

        template <typename Iterator>
        map(Iterator itBegin, Iterator itEnd); // allocator arg removed because VC7.1 fails on the default arg. To consider: Make a second version of this function without a default arg.

    public:
        /// This is an extension to the C++ standard. We insert a default-constructed 
        /// element with the given key. The reason for this is that we can avoid the 
        /// potentially expensive operation of creating and/or copying a mapped_type
        /// object on the stack.
        insert_return_type insert(const Key& key);

        #if defined(__GNUC__) && (__GNUC__ < 3) // If using old GCC (GCC 2.x has a bug which we work around)
            template <typename InputIterator>
            void               insert(InputIterator first, InputIterator last)     { return base_type::insert(first, last);     }
            insert_return_type insert(const value_type& value)                     { return base_type::insert(value);           }
            iterator           insert(iterator position, const value_type& value)  { return base_type::insert(position, value); }
            iterator           erase(iterator position)                            { return base_type::erase(position);         }
            iterator           erase(iterator first, iterator last)                { return base_type::erase(first, last);      }
        #endif

        size_type erase(const Key& key);
        size_type count(const Key& key) const;

        eastl::pair<iterator, iterator>             equal_range(const Key& key);
        eastl::pair<const_iterator, const_iterator> equal_range(const Key& key) const;

        T& operator[](const Key& key); // Of map, multimap, set, and multimap, only map has operator[].

    }; // map






    /// multimap
    ///
    /// Implements a canonical multimap.
    ///
    /// The large majority of the implementation of this class is found in the rbtree
    /// base class. We control the behaviour of rbtree via template parameters.
    ///
    /// Pool allocation
    /// If you want to make a custom memory pool for a multimap container, your pool 
    /// needs to contain items of type multimap::node_type. So if you have a memory
    /// pool that has a constructor that takes the size of pool items and the
    /// count of pool items, you would do this (assuming that MemoryPool implements
    /// the Allocator interface):
    ///     typedef multimap<Widget, int, less<Widget>, MemoryPool> WidgetMap;  // Delare your WidgetMap type.
    ///     MemoryPool myPool(sizeof(WidgetMap::node_type), 100);               // Make a pool of 100 Widget nodes.
    ///     WidgetMap myMap(&myPool);                                           // Create a map that uses the pool.
    ///
    template <typename Key, typename T, typename Compare = eastl::less<Key>, typename Allocator = EASTLAllocatorType>
    class multimap
        : public rbtree<Key, eastl::pair<const Key, T>, Compare, Allocator, eastl::use_first<eastl::pair<const Key, T> >, true, false>
    {
    public:
        typedef rbtree<Key, eastl::pair<const Key, T>, Compare, Allocator, 
                        eastl::use_first<eastl::pair<const Key, T> >, true, false>  base_type;
        typedef multimap<Key, T, Compare, Allocator>                                this_type;
        typedef typename base_type::size_type                                       size_type;
        typedef typename base_type::key_type                                        key_type;
        typedef T                                                                   mapped_type;
        typedef typename base_type::value_type                                      value_type;
        typedef typename base_type::node_type                                       node_type;
        typedef typename base_type::iterator                                        iterator;
        typedef typename base_type::const_iterator                                  const_iterator;
        typedef typename base_type::allocator_type                                  allocator_type;
        typedef typename base_type::insert_return_type                              insert_return_type;
        typedef typename base_type::extract_key                                     extract_key;
        // Other types are inherited from the base class.

        using base_type::begin;
        using base_type::end;
        using base_type::find;
        using base_type::lower_bound;
        using base_type::upper_bound;
        using base_type::mCompare;

        #if !defined(__GNUC__) || (__GNUC__ >= 3) // GCC 2.x has a bug which we work around.
        using base_type::insert;
        using base_type::erase;
        #endif

    public:
        multimap(const allocator_type& allocator = EASTL_MULTIMAP_DEFAULT_ALLOCATOR);
        multimap(const Compare& compare, const allocator_type& allocator = EASTL_MULTIMAP_DEFAULT_ALLOCATOR);
        multimap(const this_type& x);

        template <typename Iterator>
        multimap(Iterator itBegin, Iterator itEnd); // allocator arg removed because VC7.1 fails on the default arg. To consider: Make a second version of this function without a default arg.

    public:
        /// This is an extension to the C++ standard. We insert a default-constructed 
        /// element with the given key. The reason for this is that we can avoid the 
        /// potentially expensive operation of creating and/or copying a mapped_type
        /// object on the stack.
        insert_return_type insert(const Key& key);

        #if defined(__GNUC__) && (__GNUC__ < 3) // If using old GCC (GCC 2.x has a bug which we work around)
            template <typename InputIterator>
            void               insert(InputIterator first, InputIterator last)     { return base_type::insert(first, last);     }
            insert_return_type insert(const value_type& value)                     { return base_type::insert(value);           }
            iterator           insert(iterator position, const value_type& value)  { return base_type::insert(position, value); }
            iterator           erase(iterator position)                            { return base_type::erase(position);         }
            iterator           erase(iterator first, iterator last)                { return base_type::erase(first, last);      }
        #endif

        size_type erase(const Key& key);
        size_type count(const Key& key) const;

        eastl::pair<iterator, iterator>             equal_range(const Key& key);
        eastl::pair<const_iterator, const_iterator> equal_range(const Key& key) const;

        /// equal_range_small
        /// This is a special version of equal_range which is optimized for the 
        /// case of there being few or no duplicated keys in the tree.
        eastl::pair<iterator, iterator>             equal_range_small(const Key& key);
        eastl::pair<const_iterator, const_iterator> equal_range_small(const Key& key) const;

    }; // multimap





    ///////////////////////////////////////////////////////////////////////
    // map
    ///////////////////////////////////////////////////////////////////////

    template <typename Key, typename T, typename Compare, typename Allocator>
    inline map<Key, T, Compare, Allocator>::map(const allocator_type& allocator)
        : base_type(allocator) { }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline map<Key, T, Compare, Allocator>::map(const Compare& compare, const allocator_type& allocator)
        : base_type(compare, allocator) { }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline map<Key, T, Compare, Allocator>::map(const this_type& x)
        : base_type(x) { }


    template <typename Key, typename T, typename Compare, typename Allocator>
    template <typename Iterator>
    inline map<Key, T, Compare, Allocator>::map(Iterator itBegin, Iterator itEnd)
        : base_type(itBegin, itEnd, Compare(), EASTL_MAP_DEFAULT_ALLOCATOR) { }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename map<Key, T, Compare, Allocator>::insert_return_type
    map<Key, T, Compare, Allocator>::insert(const Key& key)
    {
        return base_type::DoInsertKey(key, true_type());
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename map<Key, T, Compare, Allocator>::size_type
    map<Key, T, Compare, Allocator>::erase(const Key& key)
    {
        const iterator it(find(key));

        if(it != end()) // If it exists...
        {
            base_type::erase(it);
            return 1;
        }
        return 0;
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename map<Key, T, Compare, Allocator>::size_type
    map<Key, T, Compare, Allocator>::count(const Key& key) const
    {
        const const_iterator it(find(key));
        return (it != end()) ? 1 : 0;
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename map<Key, T, Compare, Allocator>::iterator,
                       typename map<Key, T, Compare, Allocator>::iterator>
    map<Key, T, Compare, Allocator>::equal_range(const Key& key)
    {
        // The resulting range will either be empty or have one element,
        // so instead of doing two tree searches (one for lower_bound and 
        // one for upper_bound), we do just lower_bound and see if the 
        // result is a range of size zero or one.
        const iterator itLower(lower_bound(key));

        if((itLower == end()) || mCompare(key, itLower.mpNode->mValue.first)) // If at the end or if (key is < itLower)...
            return eastl::pair<iterator, iterator>(itLower, itLower);

        iterator itUpper(itLower);
        return eastl::pair<iterator, iterator>(itLower, ++itUpper);
    }
    

    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename map<Key, T, Compare, Allocator>::const_iterator, 
                       typename map<Key, T, Compare, Allocator>::const_iterator>
    map<Key, T, Compare, Allocator>::equal_range(const Key& key) const
    {
        // See equal_range above for comments.
        const const_iterator itLower(lower_bound(key));

        if((itLower == end()) || mCompare(key, itLower.mpNode->mValue.first)) // If at the end or if (key is < itLower)...
            return eastl::pair<const_iterator, const_iterator>(itLower, itLower);

        const_iterator itUpper(itLower);
        return eastl::pair<const_iterator, const_iterator>(itLower, ++itUpper);
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline T& map<Key, T, Compare, Allocator>::operator[](const Key& key)
    {
        iterator itLower(lower_bound(key)); // itLower->first is >= key.

        if((itLower == end()) || mCompare(key, (*itLower).first))
        {
            itLower = base_type::insert(itLower, value_type(key, T()));

            // To do: Convert this to use the more efficient:
            //    itLower = DoInsertKey(itLower, key, true_type());
            // when we gain confidence in that function.
        }

        return (*itLower).second;

        // Reference implementation of this function, which may not be as fast:
        //iterator it(base_type::insert(eastl::pair<iterator, iterator>(key, T())).first);
        //return it->second;
    }






    ///////////////////////////////////////////////////////////////////////
    // multimap
    ///////////////////////////////////////////////////////////////////////

    template <typename Key, typename T, typename Compare, typename Allocator>
    inline multimap<Key, T, Compare, Allocator>::multimap(const allocator_type& allocator)
        : base_type(allocator)
    {
        // Empty
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline multimap<Key, T, Compare, Allocator>::multimap(const Compare& compare, const allocator_type& allocator)
        : base_type(compare, allocator)
    {
        // Empty
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline multimap<Key, T, Compare, Allocator>::multimap(const this_type& x)
        : base_type(x)
    {
        // Empty
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    template <typename Iterator>
    inline multimap<Key, T, Compare, Allocator>::multimap(Iterator itBegin, Iterator itEnd)
        : base_type(itBegin, itEnd, Compare(), EASTL_MULTIMAP_DEFAULT_ALLOCATOR)
    {
        // Empty
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename multimap<Key, T, Compare, Allocator>::insert_return_type
    multimap<Key, T, Compare, Allocator>::insert(const Key& key)
    {
        return base_type::DoInsertKey(key, false_type());
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename multimap<Key, T, Compare, Allocator>::size_type
    multimap<Key, T, Compare, Allocator>::erase(const Key& key)
    {
        const eastl::pair<iterator, iterator> range(equal_range(key));
        const size_type n = (size_type)eastl::distance(range.first, range.second);
        base_type::erase(range.first, range.second);
        return n;
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline typename multimap<Key, T, Compare, Allocator>::size_type
    multimap<Key, T, Compare, Allocator>::count(const Key& key) const
    {
        const eastl::pair<const_iterator, const_iterator> range(equal_range(key));
        return (size_type)eastl::distance(range.first, range.second);
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename multimap<Key, T, Compare, Allocator>::iterator,
                       typename multimap<Key, T, Compare, Allocator>::iterator>
    multimap<Key, T, Compare, Allocator>::equal_range(const Key& key)
    {
        // There are multiple ways to implement equal_range. The implementation mentioned
        // in the C++ standard and which is used by most (all?) commercial STL implementations
        // is this:
        //    return eastl::pair<iterator, iterator>(lower_bound(key), upper_bound(key));
        //
        // This does two tree searches -- one for the lower bound and one for the 
        // upper bound. This works well for the case whereby you have a large container
        // and there are lots of duplicated values. We provide an alternative version
        // of equal_range called equal_range_small for cases where the user is confident
        // that the number of duplicated items is only a few.

        return eastl::pair<iterator, iterator>(lower_bound(key), upper_bound(key));
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename multimap<Key, T, Compare, Allocator>::const_iterator, 
                       typename multimap<Key, T, Compare, Allocator>::const_iterator>
    multimap<Key, T, Compare, Allocator>::equal_range(const Key& key) const
    {
        // See comments above in the non-const version of equal_range.
        return eastl::pair<const_iterator, const_iterator>(lower_bound(key), upper_bound(key));
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename multimap<Key, T, Compare, Allocator>::iterator,
                       typename multimap<Key, T, Compare, Allocator>::iterator>
    multimap<Key, T, Compare, Allocator>::equal_range_small(const Key& key)
    {
        // We provide alternative version of equal_range here which works faster
        // for the case where there are at most small number of potential duplicated keys.
        const iterator itLower(lower_bound(key));
        iterator       itUpper(itLower);

        while((itUpper != end()) && !mCompare(key, itUpper.mpNode->mValue.first))
            ++itUpper;

        return eastl::pair<iterator, iterator>(itLower, itUpper);
    }


    template <typename Key, typename T, typename Compare, typename Allocator>
    inline eastl::pair<typename multimap<Key, T, Compare, Allocator>::const_iterator, 
                       typename multimap<Key, T, Compare, Allocator>::const_iterator>
    multimap<Key, T, Compare, Allocator>::equal_range_small(const Key& key) const
    {
        // We provide alternative version of equal_range here which works faster
        // for the case where there are at most small number of potential duplicated keys.
        const const_iterator itLower(lower_bound(key));
        const_iterator       itUpper(itLower);

        while((itUpper != end()) && !mCompare(key, itUpper.mpNode->mValue.first))
            ++itUpper;

        return eastl::pair<const_iterator, const_iterator>(itLower, itUpper);
    }




} // namespace eastl


#endif // Header include guard