/**
 * MIT License
 * 
 * Copyright (c) 2017 Tessil
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef TSL_ARRAY_MAP_H
#define TSL_ARRAY_MAP_H

#include <cstddef>
#include <cstdint>
#include <initializer_list>
#include <iterator>
#include <string>
#include <type_traits>
#include <utility>
#include "array_hash.h"

namespace tsl {


/**
 * Implementation of a cache-conscious string hash map.
 * 
 * The map stores the strings as `const CharT*`. If `StoreNullTerminator` is true,
 * the strings are stored with the a null-terminator (the `key()` method of the iterators
 * will return a pointer to this null-terminated string). Otherwise the null character
 * is not stored (which allow an economy of 1 byte per string).
 * 
 * The value `T` must be either nothrow move-constructible, copy-constuctible or both.
 * 
 * The size of a key string is limited to `std::numeric_limits<KeySizeT>::max() - 1`. 
 * That is 65 535 characters by default, but can be raised with the `KeySizeT` template parameter. 
 * See `max_key_size()` for an easy access to this limit.
 * 
 * The number of elements in the map is limited to `std::numeric_limits<IndexSizeT>::max()`.
 * That is 4 294 967 296 elements, but can be raised with the `IndexSizeT` template parameter. 
 * See `max_size()` for an easy access to this limit.
 * 
 * Iterators invalidation:
 *  - clear, operator=: always invalidate the iterators.
 *  - insert, emplace, operator[]: always invalidate the iterators.
 *  - erase: always invalidate the iterators.
 *  - shrink_to_fit: always invalidate the iterators.
 */    
template<class CharT,
         class T, 
         class Hash = tsl::ah::str_hash<CharT>,
         class KeyEqual = tsl::ah::str_equal<CharT>,
         bool StoreNullTerminator = true,
         class KeySizeT = std::uint16_t,
         class IndexSizeT = std::uint32_t,
         class GrowthPolicy = tsl::ah::power_of_two_growth_policy<2>>
class array_map {
private:
    using ht = tsl::detail_array_hash::array_hash<CharT, T, Hash, KeyEqual, StoreNullTerminator, 
                                                  KeySizeT, IndexSizeT, GrowthPolicy>;
    
public:
    using char_type = typename ht::char_type;
    using mapped_type = T;
    using key_size_type = typename ht::key_size_type;
    using index_size_type = typename ht::index_size_type;
    using size_type = typename ht::size_type;
    using hasher = typename ht::hasher;
    using key_equal = typename ht::key_equal;
    using iterator = typename ht::iterator;
    using const_iterator = typename ht::const_iterator;
 
public:
    array_map(): array_map(ht::DEFAULT_INIT_BUCKET_COUNT) {
    }
    
    explicit array_map(size_type bucket_count,
                       const Hash& hash = Hash()): m_ht(bucket_count, hash, ht::DEFAULT_MAX_LOAD_FACTOR) 
    {
    }
    
    template<class InputIt>
    array_map(InputIt first, InputIt last,
              size_type bucket_count = ht::DEFAULT_INIT_BUCKET_COUNT,
              const Hash& hash = Hash()): array_map(bucket_count, hash)
    {
        insert(first, last);
    }
    
    
    
#ifdef TSL_HAS_STRING_VIEW
    array_map(std::initializer_list<std::pair<nonstd::basic_string_view<CharT>, T>> init,
              size_type bucket_count = ht::DEFAULT_INIT_BUCKET_COUNT,
              const Hash& hash = Hash()): array_map(bucket_count, hash)
    {
        insert(init);
    }
#else    
    array_map(std::initializer_list<std::pair<const CharT*, T>> init,
              size_type bucket_count = ht::DEFAULT_INIT_BUCKET_COUNT,
              const Hash& hash = Hash()): array_map(bucket_count, hash)
    {
        insert(init);
    }
#endif
    
    

#ifdef TSL_HAS_STRING_VIEW
    array_map& operator=(std::initializer_list<std::pair<nonstd::basic_string_view<CharT>, T>> ilist) {
        clear();
        
        reserve(ilist.size());
        insert(ilist);
        
        return *this;
    }
#else
    array_map& operator=(std::initializer_list<std::pair<const CharT*, T>> ilist) {
        clear();
        
        reserve(ilist.size());
        insert(ilist);
        
        return *this;
    }
#endif     
    
    
    
    /*
     * Iterators
     */
    iterator begin() noexcept { return m_ht.begin(); }
    const_iterator begin() const noexcept { return m_ht.begin(); }
    const_iterator cbegin() const noexcept { return m_ht.cbegin(); }
    
    iterator end() noexcept { return m_ht.end(); }
    const_iterator end() const noexcept { return m_ht.end(); }
    const_iterator cend() const noexcept { return m_ht.cend(); }
    
    
    
    /*
     * Capacity
     */
    bool empty() const noexcept { return m_ht.empty(); }
    size_type size() const noexcept { return m_ht.size(); }
    size_type max_size() const noexcept { return m_ht.max_size(); }
    size_type max_key_size() const noexcept { return m_ht.max_key_size(); }
    void shrink_to_fit() { m_ht.shrink_to_fit(); }
    
    
    
    /*
     * Modifiers
     */
    void clear() noexcept { m_ht.clear(); }

    
    
#ifdef TSL_HAS_STRING_VIEW
    std::pair<iterator, bool> insert(const nonstd::basic_string_view<CharT>& key, const T& value) {
        return m_ht.emplace(key.data(), key.size(), value); 
    }
#else
    std::pair<iterator, bool> insert(const CharT* key, const T& value) {
        return m_ht.emplace(key, std::strlen(key), value);
    }
    
    std::pair<iterator, bool> insert(const std::basic_string<CharT>& key, const T& value) {
        return m_ht.emplace(key.data(), key.size(), value); 
    }
#endif
    std::pair<iterator, bool> insert_ks(const CharT* key, size_type key_size, const T& value) {
        return m_ht.emplace(key, key_size, value);
    }
    
    
   
#ifdef TSL_HAS_STRING_VIEW
    std::pair<iterator, bool> insert(const nonstd::basic_string_view<CharT>& key, T&& value) {
        return m_ht.emplace(key.data(), key.size(), std::move(value));
    }
#else
    std::pair<iterator, bool> insert(const CharT* key, T&& value) {
        return m_ht.emplace(key, std::strlen(key), std::move(value));
    }
    
    std::pair<iterator, bool> insert(const std::basic_string<CharT>& key, T&& value) {
        return m_ht.emplace(key.data(), key.size(), std::move(value));
    }
#endif    
    std::pair<iterator, bool> insert_ks(const CharT* key, size_type key_size, T&& value) {
        return m_ht.emplace(key, key_size, std::move(value));
    }
       
       
       
    template<class InputIt>
    void insert(InputIt first, InputIt last) {
        if(std::is_base_of<std::forward_iterator_tag, 
                           typename std::iterator_traits<InputIt>::iterator_category>::value) 
        {
            const auto nb_elements_insert = std::distance(first, last);
            const std::size_t nb_free_buckets = std::size_t(float(bucket_count())*max_load_factor()) - size();
            
            if(nb_elements_insert > 0 && nb_free_buckets < std::size_t(nb_elements_insert)) {
                reserve(size() + std::size_t(nb_elements_insert));
            }
        }
        
        for(auto it = first; it != last; ++it) {
            insert_pair(*it);
        }
    }
    
    

#ifdef TSL_HAS_STRING_VIEW
    void insert(std::initializer_list<std::pair<nonstd::basic_string_view<CharT>, T>> ilist) {
        insert(ilist.begin(), ilist.end());
    }
#else
    void insert(std::initializer_list<std::pair<const CharT*, T>> ilist) {
        insert(ilist.begin(), ilist.end());
    }
#endif
    
    
    
#ifdef TSL_HAS_STRING_VIEW
    template<class M>
    std::pair<iterator, bool> insert_or_assign(const nonstd::basic_string_view<CharT>& key, M&& obj) { 
        return m_ht.insert_or_assign(key.data(), key.size(), std::forward<M>(obj)); 
    }
#else
    template<class M>
    std::pair<iterator, bool> insert_or_assign(const CharT* key, M&& obj) { 
        return m_ht.insert_or_assign(key, std::strlen(key), std::forward<M>(obj)); 
    }
    
    template<class M>
    std::pair<iterator, bool> insert_or_assign(const std::basic_string<CharT>& key, M&& obj) { 
        return m_ht.insert_or_assign(key.data(), key.size(), std::forward<M>(obj)); 
    }
#endif 
    template<class M>
    std::pair<iterator, bool> insert_or_assign_ks(const CharT* key, size_type key_size, M&& obj) { 
        return m_ht.insert_or_assign(key, key_size, std::forward<M>(obj)); 
    }
    
    
    
#ifdef TSL_HAS_STRING_VIEW
    template<class... Args>
    std::pair<iterator, bool> emplace(const nonstd::basic_string_view<CharT>& key, Args&&... args) {
        return m_ht.emplace(key.data(), key.size(), std::forward<Args>(args)...);
    }
#else
    template<class... Args>
    std::pair<iterator, bool> emplace(const CharT* key, Args&&... args) {
        return m_ht.emplace(key, std::strlen(key), std::forward<Args>(args)...);
    }
    
    template<class... Args>
    std::pair<iterator, bool> emplace(const std::basic_string<CharT>& key, Args&&... args) {
        return m_ht.emplace(key.data(), key.size(), std::forward<Args>(args)...);
    }
#endif    
    template<class... Args>
    std::pair<iterator, bool> emplace_ks(const CharT* key, size_type key_size, Args&&... args) {
        return m_ht.emplace(key, key_size, std::forward<Args>(args)...);
    }
    
    
    
    /**
     * Erase has an amortized O(1) runtime complexity, but even if it removes the key immediatly,
     * it doesn't do the same for the associated value T.
     * 
     * T will only be removed when the ratio between the size of the map and 
     * the size of the map + the number of deleted values still stored is low enough.
     * 
     * To force the deletion you can call shrink_to_fit.
     */
    iterator erase(const_iterator pos) { return m_ht.erase(pos); }
    
    /**
     * @copydoc erase(const_iterator pos)
     */
    iterator erase(const_iterator first, const_iterator last) { return m_ht.erase(first, last); }

    
    
#ifdef TSL_HAS_STRING_VIEW 
    /**
     * @copydoc erase(const_iterator pos)
     */
    size_type erase(const nonstd::basic_string_view<CharT>& key) {
        return m_ht.erase(key.data(), key.size());
    }
#else    
    /**
     * @copydoc erase(const_iterator pos)
     */
    size_type erase(const CharT* key) {
        return m_ht.erase(key, std::strlen(key));
    }
    
    /**
     * @copydoc erase(const_iterator pos)
     */
    size_type erase(const std::basic_string<CharT>& key) {
        return m_ht.erase(key.data(), key.size());
    }
#endif    
    /**
     * @copydoc erase(const_iterator pos)
     */
    size_type erase_ks(const CharT* key, size_type key_size) {
        return m_ht.erase(key, key_size);
    }
    
    

#ifdef TSL_HAS_STRING_VIEW 
    /**
     * @copydoc erase_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    size_type erase(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.erase(key.data(), key.size(), precalculated_hash);
    }
#else    
    /**
     * @copydoc erase_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    size_type erase(const CharT* key, std::size_t precalculated_hash) {
        return m_ht.erase(key, std::strlen(key), precalculated_hash);
    }
    
    /**
     * @copydoc erase_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    size_type erase(const std::basic_string<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.erase(key.data(), key.size(), precalculated_hash);
    }
#endif    
    /**
     * @copydoc erase(const_iterator pos)
     * 
     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
     * as hash_function()(key). Usefull to speed-up the lookup to the value if you already have the hash.
     */
    size_type erase_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) {
        return m_ht.erase(key, key_size, precalculated_hash);
    }
    
    
    
    void swap(array_map& other) { other.m_ht.swap(m_ht); }
    
    
    
    /*
     * Lookup
     */
#ifdef TSL_HAS_STRING_VIEW    
    T& at(const nonstd::basic_string_view<CharT>& key) { 
        return m_ht.at(key.data(), key.size()); 
    }
    
    const T& at(const nonstd::basic_string_view<CharT>& key) const { 
        return m_ht.at(key.data(), key.size()); 
    }
#else    
    T& at(const CharT* key) { 
        return m_ht.at(key, std::strlen(key)); 
    }
    
    const T& at(const CharT* key) const { 
        return m_ht.at(key, std::strlen(key)); 
    }
    
    T& at(const std::basic_string<CharT>& key) { 
        return m_ht.at(key.data(), key.size()); 
    }
    
    const T& at(const std::basic_string<CharT>& key) const { 
        return m_ht.at(key.data(), key.size()); 
    }
#endif    
    T& at_ks(const CharT* key, size_type key_size) { 
        return m_ht.at(key, key_size); 
    }
    
    const T& at_ks(const CharT* key, size_type key_size) const { 
        return m_ht.at(key, key_size); 
    }
    
    
    
#ifdef TSL_HAS_STRING_VIEW    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    T& at(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) { 
        return m_ht.at(key.data(), key.size(), precalculated_hash); 
    }
    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const T& at(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) const { 
        return m_ht.at(key.data(), key.size(), precalculated_hash); 
    }
#else    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    T& at(const CharT* key, std::size_t precalculated_hash) { 
        return m_ht.at(key, std::strlen(key), precalculated_hash); 
    }
    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const T& at(const CharT* key, std::size_t precalculated_hash) const { 
        return m_ht.at(key, std::strlen(key), precalculated_hash); 
    }
    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    T& at(const std::basic_string<CharT>& key, std::size_t precalculated_hash) { 
        return m_ht.at(key.data(), key.size(), precalculated_hash); 
    }
    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const T& at(const std::basic_string<CharT>& key, std::size_t precalculated_hash) const { 
        return m_ht.at(key.data(), key.size(), precalculated_hash); 
    }
#endif  
    /**
     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
     * as hash_function()(key). Usefull to speed-up the lookup to the value if you already have the hash.
     */
    T& at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) { 
        return m_ht.at(key, key_size, precalculated_hash); 
    }
    
    /**
     * @copydoc at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const T& at_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const { 
        return m_ht.at(key, key_size, precalculated_hash); 
    }
    
    

#ifdef TSL_HAS_STRING_VIEW 
    T& operator[](const nonstd::basic_string_view<CharT>& key) { return m_ht.access_operator(key.data(), key.size()); }
#else
    T& operator[](const CharT* key) { return m_ht.access_operator(key, std::strlen(key)); }
    T& operator[](const std::basic_string<CharT>& key) { return m_ht.access_operator(key.data(), key.size()); }
#endif    
    
    
    
#ifdef TSL_HAS_STRING_VIEW 
    size_type count(const nonstd::basic_string_view<CharT>& key) const { 
        return m_ht.count(key.data(), key.size()); 
    }
#else
    size_type count(const CharT* key) const { 
        return m_ht.count(key, std::strlen(key)); 
    }
    
    size_type count(const std::basic_string<CharT>& key) const { 
        return m_ht.count(key.data(), key.size()); 
    }
#endif
    size_type count_ks(const CharT* key, size_type key_size) const { 
        return m_ht.count(key, key_size); 
    }
    
    
    
#ifdef TSL_HAS_STRING_VIEW 
    /**
     * @copydoc count_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const
     */
    size_type count(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) const { 
        return m_ht.count(key.data(), key.size(), precalculated_hash); 
    }
#else
    /**
     * @copydoc count_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const
     */
    size_type count(const CharT* key, std::size_t precalculated_hash) const { 
        return m_ht.count(key, std::strlen(key), precalculated_hash); 
    }
    
    /**
     * @copydoc count_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const
     */
    size_type count(const std::basic_string<CharT>& key, std::size_t precalculated_hash) const { 
        return m_ht.count(key.data(), key.size(), precalculated_hash); 
    }
#endif
    /**
     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
     * as hash_function()(key). Usefull to speed-up the lookup to the value if you already have the hash.
     */
    size_type count_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const { 
        return m_ht.count(key, key_size, precalculated_hash); 
    }
    
    

#ifdef TSL_HAS_STRING_VIEW 
    iterator find(const nonstd::basic_string_view<CharT>& key) {
        return m_ht.find(key.data(), key.size());
    }
    
    const_iterator find(const nonstd::basic_string_view<CharT>& key) const {
        return m_ht.find(key.data(), key.size());
    }
#else
    iterator find(const CharT* key) {
        return m_ht.find(key, std::strlen(key));
    }
    
    const_iterator find(const CharT* key) const {
        return m_ht.find(key, std::strlen(key));
    }
    
    iterator find(const std::basic_string<CharT>& key) {
        return m_ht.find(key.data(), key.size());
    }
    
    const_iterator find(const std::basic_string<CharT>& key) const {
        return m_ht.find(key.data(), key.size());
    }
#endif    
    iterator find_ks(const CharT* key, size_type key_size) {
        return m_ht.find(key, key_size);
    }
    
    const_iterator find_ks(const CharT* key, size_type key_size) const {
        return m_ht.find(key, key_size);
    }
    
    

#ifdef TSL_HAS_STRING_VIEW 
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    iterator find(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.find(key.data(), key.size(), precalculated_hash);
    }
    
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const_iterator find(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) const {
        return m_ht.find(key.data(), key.size(), precalculated_hash);
    }
#else
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    iterator find(const CharT* key, std::size_t precalculated_hash) {
        return m_ht.find(key, std::strlen(key), precalculated_hash);
    }
    
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const_iterator find(const CharT* key, std::size_t precalculated_hash) const {
        return m_ht.find(key, std::strlen(key), precalculated_hash);
    }
    
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    iterator find(const std::basic_string<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.find(key.data(), key.size(), precalculated_hash);
    }
    
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const_iterator find(const std::basic_string<CharT>& key, std::size_t precalculated_hash) const {
        return m_ht.find(key.data(), key.size(), precalculated_hash);
    }
#endif    
    /**
     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
     * as hash_function()(key). Usefull to speed-up the lookup to the value if you already have the hash.
     */
    iterator find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) {
        return m_ht.find(key, key_size, precalculated_hash);
    }
    
    /**
     * @copydoc find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    const_iterator find_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const {
        return m_ht.find(key, key_size, precalculated_hash);
    }
    

    
#ifdef TSL_HAS_STRING_VIEW 
    std::pair<iterator, iterator> equal_range(const nonstd::basic_string_view<CharT>& key) {
        return m_ht.equal_range(key.data(), key.size());
    }
    
    std::pair<const_iterator, const_iterator> equal_range(const nonstd::basic_string_view<CharT>& key) const {
        return m_ht.equal_range(key.data(), key.size());
    }
#else
    std::pair<iterator, iterator> equal_range(const CharT* key) {
        return m_ht.equal_range(key, std::strlen(key));
    }
    
    std::pair<const_iterator, const_iterator> equal_range(const CharT* key) const {
        return m_ht.equal_range(key, std::strlen(key));
    }
    
    std::pair<iterator, iterator> equal_range(const std::basic_string<CharT>& key) {
        return m_ht.equal_range(key.data(), key.size());
    }
    
    std::pair<const_iterator, const_iterator> equal_range(const std::basic_string<CharT>& key) const {
        return m_ht.equal_range(key.data(), key.size());
    }
#endif    
    std::pair<iterator, iterator> equal_range_ks(const CharT* key, size_type key_size) {
        return m_ht.equal_range(key, key_size);
    }
    
    std::pair<const_iterator, const_iterator> equal_range_ks(const CharT* key, size_type key_size) const {
        return m_ht.equal_range(key, key_size);
    }
    

    
#ifdef TSL_HAS_STRING_VIEW 
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<iterator, iterator> equal_range(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.equal_range(key.data(), key.size(), precalculated_hash);
    }
    
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<const_iterator, const_iterator> equal_range(const nonstd::basic_string_view<CharT>& key, std::size_t precalculated_hash) const {
        return m_ht.equal_range(key.data(), key.size(), precalculated_hash);
    }
#else
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<iterator, iterator> equal_range(const CharT* key, std::size_t precalculated_hash) {
        return m_ht.equal_range(key, std::strlen(key), precalculated_hash);
    }
    
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<const_iterator, const_iterator> equal_range(const CharT* key, std::size_t precalculated_hash) const {
        return m_ht.equal_range(key, std::strlen(key), precalculated_hash);
    }
    
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<iterator, iterator> equal_range(const std::basic_string<CharT>& key, std::size_t precalculated_hash) {
        return m_ht.equal_range(key.data(), key.size(), precalculated_hash);
    }
    
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<const_iterator, const_iterator> equal_range(const std::basic_string<CharT>& key, std::size_t precalculated_hash) const {
        return m_ht.equal_range(key.data(), key.size(), precalculated_hash);
    }
#endif    
    /**
     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
     * as hash_function()(key). Usefull to speed-up the lookup to the value if you already have the hash.
     */
    std::pair<iterator, iterator> equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) {
        return m_ht.equal_range(key, key_size, precalculated_hash);
    }
    
    /**
     * @copydoc equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash)
     */
    std::pair<const_iterator, const_iterator> equal_range_ks(const CharT* key, size_type key_size, std::size_t precalculated_hash) const {
        return m_ht.equal_range(key, key_size, precalculated_hash);
    }
    
    
    
    /*
     * Bucket interface 
     */
    size_type bucket_count() const { return m_ht.bucket_count(); }
    size_type max_bucket_count() const { return m_ht.max_bucket_count(); }
    
    
    /*
     *  Hash policy 
     */
    float load_factor() const { return m_ht.load_factor(); }
    float max_load_factor() const { return m_ht.max_load_factor(); }
    void max_load_factor(float ml) { m_ht.max_load_factor(ml); }
    
    void rehash(size_type count) { m_ht.rehash(count); }
    void reserve(size_type count) { m_ht.reserve(count); }
    
    
    /*
     * Observers
     */
    hasher hash_function() const { return m_ht.hash_function(); }
    key_equal key_eq() const { return m_ht.key_eq(); }
        
        
    /*
     * Other
     */
    iterator mutable_iterator(const_iterator it) noexcept { return m_ht.mutable_iterator(it); }
    
    friend bool operator==(const array_map& lhs, const array_map& rhs) {
        if(lhs.size() != rhs.size()) {
            return false;
        }
        
        for(auto it = lhs.cbegin(); it != lhs.cend(); ++it) {
            const auto it_element_rhs = rhs.find_ks(it.key(), it.key_size());
            if(it_element_rhs == rhs.cend() || it.value() != it_element_rhs.value()) {
                return false;
            }
        }
        
        return true;
    }

    friend bool operator!=(const array_map& lhs, const array_map& rhs) {
        return !operator==(lhs, rhs);
    }

    friend void swap(array_map& lhs, array_map& rhs) {
        lhs.swap(rhs);
    }
    
private:
    template<class U, class V>
    void insert_pair(const std::pair<U, V>& value) {
        insert(value.first, value.second);
    }
    
    template<class U, class V>
    void insert_pair(std::pair<U, V>&& value) {
        insert(value.first, std::move(value.second));
    }    
    
public:
    static const size_type MAX_KEY_SIZE = ht::MAX_KEY_SIZE;
    
private:
    ht m_ht;
};


/**
 * Same as 
 * `tsl::array_map<CharT, T, Hash, KeyEqual, StoreNullTerminator, KeySizeT, IndexSizeT, tsl::ah::prime_growth_policy>`.
 */
template<class CharT,
         class T, 
         class Hash = tsl::ah::str_hash<CharT>,
         class KeyEqual = tsl::ah::str_equal<CharT>,
         bool StoreNullTerminator = true,
         class KeySizeT = std::uint16_t,
         class IndexSizeT = std::uint32_t>         
using array_pg_map = array_map<CharT, T, Hash, KeyEqual, StoreNullTerminator, 
                               KeySizeT, IndexSizeT, tsl::ah::prime_growth_policy>;

} //end namespace tsl

#endif
