unordered_map.h

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/**********************************************************\
 
  This file is part of the
  https://github.com/morzhovets/momo
  project, distributed under the MIT License. See
  https://github.com/morzhovets/momo/blob/branch_cpp11/LICENSE
  for details.
 
  momo/stdish/unordered_map.h
 
  namespace momo::stdish:
    class unordered_map
    class unordered_map_open
 
\**********************************************************/
 
#ifndef MOMO_INCLUDE_GUARD_STDISH_UNORDERED_MAP
#define MOMO_INCLUDE_GUARD_STDISH_UNORDERED_MAP
 
#include "../HashMap.h"
#include "set_map_utility.h"
 
namespace momo
{
 
namespace stdish
{
 
template<typename TKey, typename TMapped,
    typename THashFunc = HashCoder<TKey>,
    typename TEqualFunc = std::equal_to<TKey>,
    typename TAllocator = std::allocator<std::pair<const TKey, TMapped>>,
    typename THashMap = HashMap<TKey, TMapped, HashTraitsStd<TKey, THashFunc, TEqualFunc>,
        MemManagerStd<TAllocator>>>
class unordered_map
{
private:
    typedef THashMap HashMap;
    typedef typename HashMap::HashTraits HashTraits;
    typedef typename HashMap::MemManager MemManager;
 
    typedef typename HashMap::Iterator HashMapIterator;
 
public:
    typedef TKey key_type;
    typedef TMapped mapped_type;
    typedef THashFunc hasher;
    typedef TEqualFunc key_equal;
    typedef TAllocator allocator_type;
 
    typedef HashMap nested_container_type;
 
    typedef size_t size_type;
    typedef ptrdiff_t difference_type;
 
    typedef std::pair<const key_type, mapped_type> value_type;
 
    typedef momo::internal::HashDerivedIterator<HashMapIterator,
        momo::internal::MapReferenceStd> iterator;
    typedef typename iterator::ConstIterator const_iterator;
 
    typedef typename iterator::Reference reference;
    typedef typename const_iterator::Reference const_reference;
 
    typedef typename iterator::Pointer pointer;
    typedef typename const_iterator::Pointer const_pointer;
    //typedef typename std::allocator_traits<allocator_type>::pointer pointer;
    //typedef typename std::allocator_traits<allocator_type>::const_pointer const_pointer;
 
    typedef internal::map_node_handle<typename HashMap::ExtractedPair> node_type;
    typedef internal::insert_return_type<iterator, node_type> insert_return_type;
 
    typedef momo::internal::HashDerivedIterator<typename HashMap::BucketBounds::Iterator,
        momo::internal::MapReferenceStd> local_iterator;
    typedef typename local_iterator::ConstIterator const_local_iterator;
 
private:
    template<typename KeyArg>
    struct IsValidKeyArg : public HashTraits::template IsValidKeyArg<KeyArg>
    {
    };
 
    struct ConstIteratorProxy : public const_iterator
    {
        typedef const_iterator ConstIterator;
        MOMO_DECLARE_PROXY_CONSTRUCTOR(ConstIterator)
        MOMO_DECLARE_PROXY_FUNCTION(ConstIterator, GetBaseIterator,
            typename ConstIterator::BaseIterator)
    };
 
    struct IteratorProxy : public iterator
    {
        typedef iterator Iterator;
        MOMO_DECLARE_PROXY_CONSTRUCTOR(Iterator)
        MOMO_DECLARE_PROXY_FUNCTION(Iterator, GetBaseIterator, HashMapIterator)
    };
 
    struct ConstLocalIteratorProxy : public const_local_iterator
    {
        typedef const_local_iterator ConstLocalIterator;
        MOMO_DECLARE_PROXY_CONSTRUCTOR(ConstLocalIterator)
    };
 
    struct LocalIteratorProxy : public local_iterator
    {
        typedef local_iterator LocalIterator;
        MOMO_DECLARE_PROXY_CONSTRUCTOR(LocalIterator)
    };
 
    struct NodeTypeProxy : private node_type
    {
        typedef node_type NodeType;
        MOMO_DECLARE_PROXY_FUNCTION(NodeType, GetExtractedPair,
            typename NodeType::MapExtractedPair&)
    };
 
public:
    unordered_map()
    {
    }
 
    explicit unordered_map(const allocator_type& alloc)
        : mHashMap(HashTraits(), MemManager(alloc))
    {
    }
 
    explicit unordered_map(size_type bucketCount, const allocator_type& alloc = allocator_type())
        : mHashMap(HashTraits(bucketCount), MemManager(alloc))
    {
    }
 
    unordered_map(size_type bucketCount, const hasher& hashFunc,
        const allocator_type& alloc = allocator_type())
        : mHashMap(HashTraits(bucketCount, hashFunc), MemManager(alloc))
    {
    }
 
    unordered_map(size_type bucketCount, const hasher& hashFunc, const key_equal& equalFunc,
        const allocator_type& alloc = allocator_type())
        : mHashMap(HashTraits(bucketCount, hashFunc, equalFunc), MemManager(alloc))
    {
    }
 
    template<typename Iterator>
    unordered_map(Iterator first, Iterator last)
    {
        insert(first, last);
    }
 
    template<typename Iterator>
    unordered_map(Iterator first, Iterator last, size_type bucketCount,
        const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, alloc)
    {
        insert(first, last);
    }
 
    template<typename Iterator>
    unordered_map(Iterator first, Iterator last, size_type bucketCount, const hasher& hashFunc,
        const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, hashFunc, alloc)
    {
        insert(first, last);
    }
 
    template<typename Iterator>
    unordered_map(Iterator first, Iterator last, size_type bucketCount, const hasher& hashFunc,
        const key_equal& equalFunc, const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, hashFunc, equalFunc, alloc)
    {
        insert(first, last);
    }
 
    unordered_map(std::initializer_list<momo::internal::Identity<value_type>> values)
        : unordered_map(values.begin(), values.end())
    {
    }
 
    unordered_map(std::initializer_list<momo::internal::Identity<value_type>> values,
        size_type bucketCount, const allocator_type& alloc = allocator_type())
        : unordered_map(values.begin(), values.end(), bucketCount, alloc)
    {
    }
 
    unordered_map(std::initializer_list<momo::internal::Identity<value_type>> values,
        size_type bucketCount, const hasher& hashFunc, const allocator_type& alloc = allocator_type())
        : unordered_map(values.begin(), values.end(), bucketCount, hashFunc, alloc)
    {
    }
 
    unordered_map(std::initializer_list<momo::internal::Identity<value_type>> values,
        size_type bucketCount, const hasher& hashFunc, const key_equal& equalFunc,
        const allocator_type& alloc = allocator_type())
        : unordered_map(values.begin(), values.end(), bucketCount, hashFunc, equalFunc, alloc)
    {
    }
 
#ifdef MOMO_HAS_CONTAINERS_RANGES
    template<std::ranges::input_range Range>
    requires std::convertible_to<std::ranges::range_reference_t<Range>, value_type>
    unordered_map(std::from_range_t, Range&& values)
    {
        insert_range(std::forward<Range>(values));
    }
 
    template<std::ranges::input_range Range>
    requires std::convertible_to<std::ranges::range_reference_t<Range>, value_type>
    unordered_map(std::from_range_t, Range&& values, size_type bucketCount,
        const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, alloc)
    {
        insert_range(std::forward<Range>(values));
    }
 
    template<std::ranges::input_range Range>
    requires std::convertible_to<std::ranges::range_reference_t<Range>, value_type>
    unordered_map(std::from_range_t, Range&& values, size_type bucketCount, const hasher& hashFunc,
        const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, hashFunc, alloc)
    {
        insert_range(std::forward<Range>(values));
    }
 
    template<std::ranges::input_range Range>
    requires std::convertible_to<std::ranges::range_reference_t<Range>, value_type>
    unordered_map(std::from_range_t, Range&& values, size_type bucketCount, const hasher& hashFunc,
        const key_equal& equalFunc, const allocator_type& alloc = allocator_type())
        : unordered_map(bucketCount, hashFunc, equalFunc, alloc)
    {
        insert_range(std::forward<Range>(values));
    }
#endif // MOMO_HAS_CONTAINERS_RANGES
 
    unordered_map(unordered_map&& right) noexcept
        : mHashMap(std::move(right.mHashMap))
    {
    }
 
    unordered_map(unordered_map&& right, const momo::internal::Identity<allocator_type>& alloc)
        noexcept(std::is_empty<allocator_type>::value)
        : mHashMap(pvCreateMap(std::move(right), alloc))
    {
    }
 
    unordered_map(const unordered_map& right)
        : mHashMap(right.mHashMap)
    {
    }
 
    unordered_map(const unordered_map& right, const momo::internal::Identity<allocator_type>& alloc)
        : mHashMap(right.mHashMap, MemManager(alloc))
    {
    }
 
    ~unordered_map() = default;
 
    unordered_map& operator=(unordered_map&& right)
        noexcept(std::is_empty<allocator_type>::value ||
            std::allocator_traits<allocator_type>::propagate_on_container_move_assignment::value)
    {
        if (this != &right)
        {
            bool propagate = std::is_empty<allocator_type>::value ||
                std::allocator_traits<allocator_type>::propagate_on_container_move_assignment::value;
            allocator_type alloc = (propagate ? &right : this)->get_allocator();
            mHashMap = pvCreateMap(std::move(right), alloc);
        }
        return *this;
    }
 
    unordered_map& operator=(const unordered_map& right)
    {
        if (this != &right)
        {
            bool propagate = std::is_empty<allocator_type>::value ||
                std::allocator_traits<allocator_type>::propagate_on_container_copy_assignment::value;
            allocator_type alloc = (propagate ? &right : this)->get_allocator();
            mHashMap = HashMap(right.mHashMap, MemManager(alloc));
        }
        return *this;
    }
 
    unordered_map& operator=(std::initializer_list<value_type> values)
    {
        HashMap hashMap(mHashMap.GetHashTraits(), MemManager(get_allocator()));
        hashMap.Insert(values.begin(), values.end());
        mHashMap = std::move(hashMap);
        return *this;
    }
 
    void swap(unordered_map& right) noexcept
    {
        MOMO_ASSERT(std::allocator_traits<allocator_type>::propagate_on_container_swap::value
            || get_allocator() == right.get_allocator());
        mHashMap.Swap(right.mHashMap);
    }
 
    friend void swap(unordered_map& left, unordered_map& right) noexcept
    {
        left.swap(right);
    }
 
    const nested_container_type& get_nested_container() const noexcept
    {
        return mHashMap;
    }
 
    nested_container_type& get_nested_container() noexcept
    {
        return mHashMap;
    }
 
    const_iterator begin() const noexcept
    {
        return ConstIteratorProxy(mHashMap.GetBegin());
    }
 
    iterator begin() noexcept
    {
        return IteratorProxy(mHashMap.GetBegin());
    }
 
    const_iterator end() const noexcept
    {
        return ConstIteratorProxy(mHashMap.GetEnd());
    }
 
    iterator end() noexcept
    {
        return IteratorProxy(mHashMap.GetEnd());
    }
 
    const_iterator cbegin() const noexcept
    {
        return begin();
    }
 
    const_iterator cend() const noexcept
    {
        return end();
    }
 
    float max_load_factor() const noexcept
    {
        return mHashMap.GetHashTraits().GetMaxLoadFactor(HashMap::bucketMaxItemCount);
    }
 
    void max_load_factor(float maxLoadFactor)
    {
        if (maxLoadFactor == max_load_factor())
            return;
        if (maxLoadFactor <= 0.0 || maxLoadFactor > static_cast<float>(HashMap::bucketMaxItemCount))
            throw std::out_of_range("invalid load factor");
        HashTraits hashTraits(mHashMap.GetHashTraits(), maxLoadFactor);
        HashMap hashMap(hashTraits, MemManager(get_allocator()));
        hashMap.Reserve(size());
        hashMap.Insert(begin(), end());
        mHashMap = std::move(hashMap);
    }
 
    hasher hash_function() const
    {
        return mHashMap.GetHashTraits().GetHashFunc();
    }
 
    key_equal key_eq() const
    {
        return mHashMap.GetHashTraits().GetEqualFunc();
    }
 
    allocator_type get_allocator() const noexcept
    {
        return allocator_type(mHashMap.GetMemManager().GetByteAllocator());
    }
 
    size_type max_size() const noexcept
    {
        return std::allocator_traits<allocator_type>::max_size(get_allocator());
    }
 
    size_type size() const noexcept
    {
        return mHashMap.GetCount();
    }
 
    MOMO_NODISCARD bool empty() const noexcept
    {
        return mHashMap.IsEmpty();
    }
 
    void clear() noexcept
    {
        mHashMap.Clear();
    }
 
    void rehash(size_type bucketCount)
    {
        bucketCount = std::minmax(bucketCount, size_t{2}).second;
        size_t logBucketCount = momo::internal::UIntMath<>::Log2(bucketCount - 1) + 1;
        bucketCount = size_t{1} << logBucketCount;
        reserve(mHashMap.GetHashTraits().CalcCapacity(bucketCount, HashMap::bucketMaxItemCount));
    }
 
    void reserve(size_type count)
    {
        mHashMap.Reserve(count);
    }
 
    MOMO_FORCEINLINE const_iterator find(const key_type& key) const
    {
        return ConstIteratorProxy(mHashMap.Find(key));
    }
 
    MOMO_FORCEINLINE iterator find(const key_type& key)
    {
        return IteratorProxy(mHashMap.Find(key));
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    const_iterator> find(const KeyArg& key) const
    {
        return ConstIteratorProxy(mHashMap.Find(key));
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    iterator> find(const KeyArg& key)
    {
        return IteratorProxy(mHashMap.Find(key));
    }
 
    MOMO_FORCEINLINE size_type count(const key_type& key) const
    {
        return contains(key) ? 1 : 0;
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    size_type> count(const KeyArg& key) const
    {
        return contains(key) ? 1 : 0;
    }
 
    MOMO_FORCEINLINE bool contains(const key_type& key) const
    {
        return mHashMap.ContainsKey(key);
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    bool> contains(const KeyArg& key) const
    {
        return mHashMap.ContainsKey(key);
    }
 
    MOMO_FORCEINLINE std::pair<const_iterator, const_iterator> equal_range(const key_type& key) const
    {
        return { find(key), end() };
    }
 
    MOMO_FORCEINLINE std::pair<iterator, iterator> equal_range(const key_type& key)
    {
        return { find(key), end() };
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    std::pair<const_iterator, const_iterator>> equal_range(const KeyArg& key) const
    {
        return { find(key), end() };
    }
 
    template<typename KeyArg>
    MOMO_FORCEINLINE momo::internal::EnableIf<IsValidKeyArg<KeyArg>::value,
    std::pair<iterator, iterator>> equal_range(const KeyArg& key)
    {
        return { find(key), end() };
    }
 
    template<typename ValueArg = std::pair<key_type, mapped_type>>
    momo::internal::EnableIf<std::is_constructible<value_type, ValueArg&&>::value,
    std::pair<iterator, bool>> insert(ValueArg&& valueArg)
    {
        return emplace(std::forward<ValueArg>(valueArg));
    }
 
    template<typename ValueArg = std::pair<key_type, mapped_type>>
    momo::internal::EnableIf<std::is_constructible<value_type, ValueArg&&>::value,
    iterator> insert(const_iterator hint, ValueArg&& valueArg)
    {
        return emplace_hint(hint, std::forward<ValueArg>(valueArg));
    }
 
    insert_return_type insert(node_type&& node)
    {
        if (node.empty())
            return { end(), false, node_type() };
        typename HashMap::InsertResult res = mHashMap.Insert(
            std::move(NodeTypeProxy::GetExtractedPair(node)));
        return { IteratorProxy(res.position), res.inserted,
            res.inserted ? node_type() : std::move(node) };
    }
 
    iterator insert(const_iterator hint, node_type&& node)
    {
#ifdef MOMO_USE_UNORDERED_HINT_ITERATORS
        if (node.empty())
            return end();
        return IteratorProxy(mHashMap.Add(ConstIteratorProxy::GetBaseIterator(hint),
            std::move(NodeTypeProxy::GetExtractedPair(node))));
#else
        (void)hint;
        return insert(std::move(node)).position;
#endif
    }
 
    template<typename Iterator>
    void insert(Iterator first, Iterator last)
    {
        pvInsertRange(first, last);
    }
 
    void insert(std::initializer_list<value_type> values)
    {
        mHashMap.Insert(values.begin(), values.end());
    }
 
#ifdef MOMO_HAS_CONTAINERS_RANGES
    template<std::ranges::input_range Range>
    requires std::convertible_to<std::ranges::range_reference_t<Range>, value_type>
    void insert_range(Range&& values)
    {
        pvInsertRange(std::ranges::begin(values), std::ranges::end(values));
    }
#endif // MOMO_HAS_CONTAINERS_RANGES
 
    std::pair<iterator, bool> emplace()
    {
        return pvEmplace(nullptr, std::tuple<>(), std::tuple<>());
    }
 
    iterator emplace_hint(const_iterator hint)
    {
        return pvEmplace(hint, std::tuple<>(), std::tuple<>()).first;
    }
 
    template<typename ValueArg>
    std::pair<iterator, bool> emplace(ValueArg&& valueArg)
    {
        return pvEmplace(nullptr,
            std::forward_as_tuple(std::get<0>(std::forward<ValueArg>(valueArg))),
            std::forward_as_tuple(std::get<1>(std::forward<ValueArg>(valueArg))));
    }
 
    template<typename ValueArg>
    iterator emplace_hint(const_iterator hint, ValueArg&& valueArg)
    {
        return pvEmplace(hint,
            std::forward_as_tuple(std::get<0>(std::forward<ValueArg>(valueArg))),
            std::forward_as_tuple(std::get<1>(std::forward<ValueArg>(valueArg)))).first;
    }
 
    template<typename KeyArg, typename MappedArg>
    std::pair<iterator, bool> emplace(KeyArg&& keyArg, MappedArg&& mappedArg)
    {
        return pvEmplace(nullptr, std::forward_as_tuple(std::forward<KeyArg>(keyArg)),
            std::forward_as_tuple(std::forward<MappedArg>(mappedArg)));
    }
 
    template<typename KeyArg, typename MappedArg>
    iterator emplace_hint(const_iterator hint, KeyArg&& keyArg, MappedArg&& mappedArg)
    {
        return pvEmplace(hint, std::forward_as_tuple(std::forward<KeyArg>(keyArg)),
            std::forward_as_tuple(std::forward<MappedArg>(mappedArg))).first;
    }
 
    template<typename... KeyArgs, typename... MappedArgs>
    std::pair<iterator, bool> emplace(std::piecewise_construct_t,
        std::tuple<KeyArgs...> keyArgs, std::tuple<MappedArgs...> mappedArgs)
    {
        return pvEmplace(nullptr, std::move(keyArgs), std::move(mappedArgs));
    }
 
    template<typename... KeyArgs, typename... MappedArgs>
    iterator emplace_hint(const_iterator hint, std::piecewise_construct_t,
        std::tuple<KeyArgs...> keyArgs, std::tuple<MappedArgs...> mappedArgs)
    {
        return pvEmplace(hint, std::move(keyArgs), std::move(mappedArgs)).first;
    }
 
    iterator erase(const_iterator where)
    {
        return IteratorProxy(mHashMap.Remove(ConstIteratorProxy::GetBaseIterator(where)));
    }
 
    iterator erase(iterator where)
    {
        return erase(static_cast<const_iterator>(where));
    }
 
    iterator erase(const_iterator first, const_iterator last)
    {
        if (first == begin() && last == end())
        {
            clear();
            return end();
        }
        if (first == last)
        {
            return IteratorProxy(mHashMap.MakeMutableIterator(
                ConstIteratorProxy::GetBaseIterator(first)));
        }
        if (first != end() && std::next(first) == last)
            return erase(first);
        throw std::invalid_argument("invalid unordered_map erase arguments");
    }
 
    size_type erase(const key_type& key)
    {
        return mHashMap.Remove(key) ? 1 : 0;
    }
 
    template<typename ValueFilter>
    friend size_type erase_if(unordered_map& cont, const ValueFilter& valueFilter)
    {
        auto pairFilter = [&valueFilter] (const key_type& key, const mapped_type& mapped)
            { return valueFilter(const_reference(key, mapped)); };
        return cont.mHashMap.Remove(pairFilter);
    }
 
    MOMO_FORCEINLINE typename HashMap::ValueReferenceRKey operator[](key_type&& key)
    {
        return mHashMap[std::move(key)];
    }
 
    MOMO_FORCEINLINE typename HashMap::ValueReferenceCKey operator[](const key_type& key)
    {
        return mHashMap[key];
    }
 
    MOMO_FORCEINLINE const mapped_type& at(const key_type& key) const
    {
        const_iterator iter = find(key);
        if (iter == end())
            throw std::out_of_range("invalid unordered_map key");
        return iter->second;
    }
 
    MOMO_FORCEINLINE mapped_type& at(const key_type& key)
    {
        iterator iter = find(key);
        if (iter == end())
            throw std::out_of_range("invalid unordered_map key");
        return iter->second;
    }
 
    template<typename... MappedArgs>
    std::pair<iterator, bool> try_emplace(key_type&& key, MappedArgs&&... mappedArgs)
    {
        return pvEmplace(nullptr, std::forward_as_tuple(std::move(key)),
            std::forward_as_tuple(std::forward<MappedArgs>(mappedArgs)...));
    }
 
    template<typename... MappedArgs>
    iterator try_emplace(const_iterator hint, key_type&& key, MappedArgs&&... mappedArgs)
    {
        return pvEmplace(hint, std::forward_as_tuple(std::move(key)),
            std::forward_as_tuple(std::forward<MappedArgs>(mappedArgs)...)).first;
    }
 
    template<typename... MappedArgs>
    std::pair<iterator, bool> try_emplace(const key_type& key, MappedArgs&&... mappedArgs)
    {
        return pvEmplace(nullptr, std::forward_as_tuple(key),
            std::forward_as_tuple(std::forward<MappedArgs>(mappedArgs)...));
    }
 
    template<typename... MappedArgs>
    iterator try_emplace(const_iterator hint, const key_type& key, MappedArgs&&... mappedArgs)
    {
        return pvEmplace(hint, std::forward_as_tuple(key),
            std::forward_as_tuple(std::forward<MappedArgs>(mappedArgs)...)).first;
    }
 
    template<typename MappedArg>
    std::pair<iterator, bool> insert_or_assign(key_type&& key, MappedArg&& mappedArg)
    {
        return pvInsertOrAssign(nullptr, std::move(key), std::forward<MappedArg>(mappedArg));
    }
 
    template<typename MappedArg>
    iterator insert_or_assign(const_iterator hint, key_type&& key, MappedArg&& mappedArg)
    {
        return pvInsertOrAssign(hint, std::move(key), std::forward<MappedArg>(mappedArg)).first;
    }
 
    template<typename MappedArg>
    std::pair<iterator, bool> insert_or_assign(const key_type& key, MappedArg&& mappedArg)
    {
        return pvInsertOrAssign(nullptr, key, std::forward<MappedArg>(mappedArg));
    }
 
    template<typename MappedArg>
    iterator insert_or_assign(const_iterator hint, const key_type& key, MappedArg&& mappedArg)
    {
        return pvInsertOrAssign(hint, key, std::forward<MappedArg>(mappedArg)).first;
    }
 
    node_type extract(const_iterator where)
    {
        return node_type(*this, where); // need RVO for exception safety
    }
 
    node_type extract(const key_type& key)
    {
        const_iterator iter = find(key);
        return (iter != end()) ? extract(iter) : node_type();
    }
 
    template<typename Map>
    void merge(Map&& map)
    {
        mHashMap.MergeFrom(map.get_nested_container());
    }
 
    size_type max_bucket_count() const noexcept
    {
        return momo::internal::UIntConst::maxSize;
        //return momo::internal::HashSetBuckets<Bucket>::maxBucketCount;
    }
 
    size_type bucket_count() const noexcept
    {
        return mHashMap.GetBucketCount();
    }
 
    size_type bucket_size(size_type bucketIndex) const
    {
        return mHashMap.GetBucketBounds(bucketIndex).GetCount();
    }
 
    local_iterator begin(size_type bucketIndex)
    {
        return LocalIteratorProxy(mHashMap.GetBucketBounds(bucketIndex).GetBegin());
    }
 
    const_local_iterator begin(size_type bucketIndex) const
    {
        return ConstLocalIteratorProxy(mHashMap.GetBucketBounds(bucketIndex).GetBegin());
    }
 
    local_iterator end(size_type bucketIndex)
    {
        return LocalIteratorProxy(mHashMap.GetBucketBounds(bucketIndex).GetEnd());
    }
 
    const_local_iterator end(size_type bucketIndex) const
    {
        return ConstLocalIteratorProxy(mHashMap.GetBucketBounds(bucketIndex).GetEnd());
    }
 
    const_local_iterator cbegin(size_type bucketIndex) const
    {
        return begin(bucketIndex);
    }
 
    const_local_iterator cend(size_type bucketIndex) const
    {
        return end(bucketIndex);
    }
 
    size_type bucket(const key_type& key) const
    {
        return mHashMap.GetBucketIndex(key);
    }
 
    float load_factor() const noexcept
    {
        size_t count = size();
        size_t bucketCount = bucket_count();
        if (count == 0 && bucketCount == 0)
            return 0.0;
        return static_cast<float>(count) / static_cast<float>(bucketCount);
    }
 
    friend bool operator==(const unordered_map& left, const unordered_map& right)
    {
        if (left.size() != right.size())
            return false;
        for (const_reference ref : left)
        {
            const_iterator iter = right.find(ref.first);
            if (iter == right.end())
                return false;
            if (!(iter->second == ref.second))
                return false;
        }
        return true;
    }
 
    friend bool operator!=(const unordered_map& left, const unordered_map& right)
    {
        return !(left == right);
    }
 
private:
    static HashMap pvCreateMap(unordered_map&& right, const allocator_type& alloc)
    {
        if (right.get_allocator() == alloc)
            return std::move(right.mHashMap);
        HashMap hashMap(right.mHashMap.GetHashTraits(), MemManager(alloc));
        hashMap.MergeFrom(right.mHashMap);
        return hashMap;
    }
 
    template<typename Hint, typename... KeyArgs, typename... MappedArgs>
    std::pair<iterator, bool> pvEmplace(Hint hint, std::tuple<KeyArgs...>&& keyArgs,
        std::tuple<MappedArgs...>&& mappedArgs)
    {
        typedef typename HashMap::KeyValueTraits
            ::template ValueCreator<MappedArgs...> MappedCreator;
        return pvInsert(hint, std::move(keyArgs),
            MappedCreator(mHashMap.GetMemManager(), std::move(mappedArgs)));
    }
 
    template<typename Hint, typename... KeyArgs, typename MappedCreator>
    std::pair<iterator, bool> pvInsert(Hint /*hint*/, std::tuple<KeyArgs...>&& keyArgs,
        MappedCreator&& mappedCreator)
    {
        MemManager& memManager = mHashMap.GetMemManager();
        typedef momo::internal::ObjectBuffer<key_type, HashMap::KeyValueTraits::keyAlignment> KeyBuffer;
        typedef momo::internal::ObjectManager<key_type, MemManager> KeyManager;
        typedef typename KeyManager::template Creator<KeyArgs...> KeyCreator;
        KeyBuffer keyBuffer;
        KeyCreator(memManager, std::move(keyArgs))(keyBuffer.GetPtr());
        key_type* keyPtr = keyBuffer.template GetPtr<true>();
        try
        {
            typename HashMap::Position pos = mHashMap.Find(*keyPtr);
            if (!!pos)
            {
                KeyManager::Destroy(memManager, *keyPtr);
                keyPtr = nullptr;
                return { IteratorProxy(pos), false };
            }
            auto valueCreator = [&memManager, &keyPtr, &mappedCreator]
                (key_type* newKey, mapped_type* newMapped)
            {
                KeyManager::Relocate(memManager, *keyPtr, newKey);
                keyPtr = nullptr;
                try
                {
                    std::forward<MappedCreator>(mappedCreator)(newMapped);
                }
                catch (...)
                {
                    KeyManager::Destroy(memManager, *newKey);
                    throw;
                }
            };
            typename HashMap::Position resPos = mHashMap.AddCrt(pos, valueCreator);
            return { IteratorProxy(resPos), true };
        }
        catch (...)
        {
            if (keyPtr != nullptr)
                KeyManager::Destroy(memManager, *keyPtr);
            throw;
        }
    }
 
    template<typename Hint, typename RKey, typename MappedCreator,
        typename Key = typename std::decay<RKey>::type>
    momo::internal::EnableIf<std::is_same<key_type, Key>::value,
    std::pair<iterator, bool>> pvInsert(Hint /*hint*/, std::tuple<RKey>&& key,
        MappedCreator&& mappedCreator)
    {
        typename HashMap::InsertResult res = mHashMap.InsertCrt(
            std::forward<RKey>(std::get<0>(key)), std::forward<MappedCreator>(mappedCreator));
        return { IteratorProxy(res.position), res.inserted };
    }
 
#ifdef MOMO_USE_UNORDERED_HINT_ITERATORS
    template<typename... KeyArgs, typename MappedCreator>
    std::pair<iterator, bool> pvInsert(const_iterator hint, std::tuple<KeyArgs...>&& keyArgs,
        MappedCreator&& mappedCreator)
    {
        MemManager& memManager = mHashMap.GetMemManager();
        typedef momo::internal::ObjectManager<key_type, MemManager> KeyManager;
        typedef typename KeyManager::template Creator<KeyArgs...> KeyCreator;
        auto valueCreator = [&memManager, &keyArgs, &mappedCreator]
            (key_type* newKey, mapped_type* newMapped)
        {
            KeyCreator(memManager, std::move(keyArgs))(newKey);
            try
            {
                std::forward<MappedCreator>(mappedCreator)(newMapped);
            }
            catch (...)
            {
                KeyManager::Destroy(memManager, *newKey);
                throw;
            }
        };
        typename HashMap::Position resPos = mHashMap.AddCrt(
            ConstIteratorProxy::GetBaseIterator(hint), valueCreator);
        return { IteratorProxy(resPos), true };
    }
 
    template<typename RKey, typename MappedCreator,
        typename Key = typename std::decay<RKey>::type>
    momo::internal::EnableIf<std::is_same<key_type, Key>::value,
    std::pair<iterator, bool>> pvInsert(const_iterator hint, std::tuple<RKey>&& key,
        MappedCreator&& mappedCreator)
    {
        typename HashMap::Position resPos = mHashMap.AddCrt(ConstIteratorProxy::GetBaseIterator(hint),
            std::forward<RKey>(std::get<0>(key)), std::forward<MappedCreator>(mappedCreator));
        return { IteratorProxy(resPos), true };
    }
#endif // MOMO_USE_UNORDERED_HINT_ITERATORS
 
    template<typename Iterator, typename Sentinel>
    momo::internal::EnableIf<momo::internal::IsMapArgIteratorStd<Iterator, key_type>::value,
    void> pvInsertRange(Iterator begin, Sentinel end)
    {
        mHashMap.Insert(std::move(begin), std::move(end));
    }
 
    template<typename Iterator, typename Sentinel>
    momo::internal::EnableIf<!momo::internal::IsMapArgIteratorStd<Iterator, key_type>::value,
    void> pvInsertRange(Iterator begin, Sentinel end)
    {
        for (Iterator iter = std::move(begin); iter != end; ++iter)
            insert(*iter);
    }
 
    template<typename Hint, typename RKey, typename MappedArg>
    std::pair<iterator, bool> pvInsertOrAssign(Hint hint, RKey&& key, MappedArg&& mappedArg)
    {
        std::pair<iterator, bool> res = pvEmplace(hint,
            std::forward_as_tuple(std::forward<RKey>(key)),
            std::forward_as_tuple(std::forward<MappedArg>(mappedArg)));
        if (!res.second)
            res.first->second = std::forward<MappedArg>(mappedArg);
        return res;
    }
 
private:
    HashMap mHashMap;
};
 
template<typename TKey, typename TMapped,
    typename THashFunc = HashCoder<TKey>,
    typename TEqualFunc = std::equal_to<TKey>,
    typename TAllocator = std::allocator<std::pair<const TKey, TMapped>>>
class unordered_map_open : public unordered_map<TKey, TMapped, THashFunc, TEqualFunc, TAllocator,
    HashMap<TKey, TMapped, HashTraitsStd<TKey, THashFunc, TEqualFunc, HashBucketOpenDefault>,
        MemManagerStd<TAllocator>>>
{
private:
    typedef unordered_map<TKey, TMapped, THashFunc, TEqualFunc, TAllocator,
        momo::HashMap<TKey, TMapped, HashTraitsStd<TKey, THashFunc, TEqualFunc, HashBucketOpenDefault>,
        MemManagerStd<TAllocator>>> UnorderedMap;
 
public:
    using typename UnorderedMap::key_type;
    using typename UnorderedMap::mapped_type;
    using typename UnorderedMap::size_type;
    using typename UnorderedMap::value_type;
    using typename UnorderedMap::const_reference;
 
public:
    using UnorderedMap::UnorderedMap;
 
    unordered_map_open() {} // clang 3.6
 
    unordered_map_open& operator=(std::initializer_list<value_type> values)
    {
        UnorderedMap::operator=(values);
        return *this;
    }
 
    friend void swap(unordered_map_open& left, unordered_map_open& right) noexcept
    {
        left.swap(right);
    }
 
    template<typename ValueFilter>
    friend size_type erase_if(unordered_map_open& cont, const ValueFilter& valueFilter)
    {
        auto pairFilter = [&valueFilter] (const key_type& key, const mapped_type& mapped)
            { return valueFilter(const_reference(key, mapped)); };
        return cont.get_nested_container().Remove(pairFilter);
    }
};
 
#ifdef MOMO_HAS_DEDUCTION_GUIDES
 
#define MOMO_DECLARE_DEDUCTION_GUIDES(unordered_map) \
template<typename Iterator, \
    typename Value = typename std::iterator_traits<Iterator>::value_type, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>> \
unordered_map(Iterator, Iterator) \
    -> unordered_map<Key, Mapped>; \
template<typename Iterator, \
    typename Value = typename std::iterator_traits<Iterator>::value_type, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashCoder<Key>>> \
unordered_map(Iterator, Iterator, size_t, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashCoder<Key>, std::equal_to<Key>, Allocator>; \
template<typename Iterator, typename HashFunc, \
    typename Value = typename std::iterator_traits<Iterator>::value_type, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc>> \
unordered_map(Iterator, Iterator, size_t, HashFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, std::equal_to<Key>, Allocator>; \
template<typename Iterator, typename HashFunc, typename EqualFunc, \
    typename Value = typename std::iterator_traits<Iterator>::value_type, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc, EqualFunc>> \
unordered_map(Iterator, Iterator, size_t, HashFunc, EqualFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, EqualFunc, Allocator>; \
template<typename CKey, typename Mapped, \
    typename Key = std::remove_const_t<CKey>> \
unordered_map(std::initializer_list<std::pair<CKey, Mapped>>) \
    -> unordered_map<Key, Mapped>; \
template<typename CKey, typename Mapped, \
    typename Key = std::remove_const_t<CKey>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashCoder<Key>>> \
unordered_map(std::initializer_list<std::pair<CKey, Mapped>>, size_t, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashCoder<Key>, std::equal_to<Key>, Allocator>; \
template<typename CKey, typename Mapped, typename HashFunc, \
    typename Key = std::remove_const_t<CKey>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc>> \
unordered_map(std::initializer_list<std::pair<CKey, Mapped>>, size_t, HashFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, std::equal_to<Key>, Allocator>; \
template<typename CKey, typename Mapped, typename HashFunc, typename EqualFunc, \
    typename Key = std::remove_const_t<CKey>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc, EqualFunc>> \
unordered_map(std::initializer_list<std::pair<CKey, Mapped>>, size_t, HashFunc, EqualFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, EqualFunc, Allocator>;
 
MOMO_DECLARE_DEDUCTION_GUIDES(unordered_map)
MOMO_DECLARE_DEDUCTION_GUIDES(unordered_map_open)
 
#undef MOMO_DECLARE_DEDUCTION_GUIDES
 
#ifdef MOMO_HAS_CONTAINERS_RANGES
 
#define MOMO_DECLARE_DEDUCTION_GUIDES_RANGES(unordered_map) \
template<std::ranges::input_range Range, \
    typename Value = std::ranges::range_value_t<Range>, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>> \
unordered_map(std::from_range_t, Range&&) \
    -> unordered_map<Key, Mapped>; \
template<std::ranges::input_range Range, \
    typename Value = std::ranges::range_value_t<Range>, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashCoder<Key>>> \
unordered_map(std::from_range_t, Range&&, size_t, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashCoder<Key>, std::equal_to<Key>, Allocator>; \
template<std::ranges::input_range Range, typename HashFunc, \
    typename Value = std::ranges::range_value_t<Range>, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc>> \
unordered_map(std::from_range_t, Range&&, size_t, HashFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, std::equal_to<Key>, Allocator>; \
template<std::ranges::input_range Range, typename HashFunc, typename EqualFunc, \
    typename Value = std::ranges::range_value_t<Range>, \
    typename Key = std::decay_t<typename Value::first_type>, \
    typename Mapped = std::decay_t<typename Value::second_type>, \
    typename Allocator = std::allocator<std::pair<const Key, Mapped>>, \
    typename = internal::unordered_checker<Key, Allocator, HashFunc, EqualFunc>> \
unordered_map(std::from_range_t, Range&&, size_t, HashFunc, EqualFunc, Allocator = Allocator()) \
    -> unordered_map<Key, Mapped, HashFunc, EqualFunc, Allocator>;
 
MOMO_DECLARE_DEDUCTION_GUIDES_RANGES(unordered_map)
MOMO_DECLARE_DEDUCTION_GUIDES_RANGES(unordered_map_open)
 
#undef MOMO_DECLARE_DEDUCTION_GUIDES_RANGES
 
#endif // MOMO_HAS_CONTAINERS_RANGES
 
#endif // MOMO_HAS_DEDUCTION_GUIDES
 
} // namespace stdish
 
} // namespace momo
 
#endif // MOMO_INCLUDE_GUARD_STDISH_UNORDERED_MAP