File indexing completed on 2024-11-24 05:07:24

 /**
  * MIT License
  *
  * Copyright (c) 2017 Thibaut Goetghebuer-Planchon <tessil@gmx.com>
  *
  * 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_ROBIN_HASH_H
 #define TSL_ROBIN_HASH_H
 
 #include <algorithm>
 #include <cassert>
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
 #include <exception>
 #include <iterator>
 #include <limits>
 #include <memory>
 #include <new>
 #include <stdexcept>
 #include <tuple>
 #include <type_traits>
 #include <utility>
 #include <vector>
 
 #include "robin_growth_policy.h"
 
 namespace tsl {
 
 namespace detail_robin_hash {
 
 template <typename T>
 struct make_void {
   using type = void;
 };
 
 template <typename T, typename = void>
 struct has_is_transparent : std::false_type {};
 
 template <typename T>
 struct has_is_transparent<T,
                           typename make_void<typename T::is_transparent>::type>
     : std::true_type {};
 
 template <typename U>
 struct is_power_of_two_policy : std::false_type {};
 
 template <std::size_t GrowthFactor>
 struct is_power_of_two_policy<tsl::rh::power_of_two_growth_policy<GrowthFactor>>
     : std::true_type {};
 
 // Only available in C++17, we need to be compatible with C++11
 template <class T>
 const T& clamp(const T& v, const T& lo, const T& hi) {
   return std::min(hi, std::max(lo, v));
 }
 
 template <typename T, typename U>
 static T numeric_cast(U value,
                       const char* error_message = "numeric_cast() failed.") {
   T ret = static_cast<T>(value);
   if (static_cast<U>(ret) != value) {
     TSL_RH_THROW_OR_TERMINATE(std::runtime_error, error_message);
   }
 
   const bool is_same_signedness =
       (std::is_unsigned<T>::value && std::is_unsigned<U>::value) ||
       (std::is_signed<T>::value && std::is_signed<U>::value);
   if (!is_same_signedness && (ret < T{}) != (value < U{})) {
     TSL_RH_THROW_OR_TERMINATE(std::runtime_error, error_message);
   }
 
   return ret;
 }
 
 template <class T, class Deserializer>
 static T deserialize_value(Deserializer& deserializer) {
   // MSVC < 2017 is not conformant, circumvent the problem by removing the
   // template keyword
 #if defined(_MSC_VER) && _MSC_VER < 1910
   return deserializer.Deserializer::operator()<T>();
 #else
   return deserializer.Deserializer::template operator()<T>();
 #endif
 }
 
 /**
  * Fixed size type used to represent size_type values on serialization. Need to
  * be big enough to represent a std::size_t on 32 and 64 bits platforms, and
  * must be the same size on both platforms.
  */
 using slz_size_type = std::uint64_t;
 static_assert(std::numeric_limits<slz_size_type>::max() >=
                   std::numeric_limits<std::size_t>::max(),
               "slz_size_type must be >= std::size_t");
 
 using truncated_hash_type = std::uint32_t;
 
 /**
  * Helper class that stores a truncated hash if StoreHash is true and nothing
  * otherwise.
  */
 template <bool StoreHash>
 class bucket_entry_hash {
  public:
   bool bucket_hash_equal(std::size_t /*hash*/) const noexcept { return true; }
 
   truncated_hash_type truncated_hash() const noexcept { return 0; }
 
  protected:
   void set_hash(truncated_hash_type /*hash*/) noexcept {}
 };
 
 template <>
 class bucket_entry_hash<true> {
  public:
   bool bucket_hash_equal(std::size_t hash) const noexcept {
     return m_hash == truncated_hash_type(hash);
   }
 
   truncated_hash_type truncated_hash() const noexcept { return m_hash; }
 
  protected:
   void set_hash(truncated_hash_type hash) noexcept {
     m_hash = truncated_hash_type(hash);
   }
 
  private:
   truncated_hash_type m_hash;
 };
 
 /**
  * Each bucket entry has:
  * - A value of type `ValueType`.
  * - An integer to store how far the value of the bucket, if any, is from its
  * ideal bucket (ex: if the current bucket 5 has the value 'foo' and
  * `hash('foo') % nb_buckets` == 3, `dist_from_ideal_bucket()` will return 2 as
  * the current value of the bucket is two buckets away from its ideal bucket) If
  * there is no value in the bucket (i.e. `empty()` is true)
  * `dist_from_ideal_bucket()` will be < 0.
  * - A marker which tells us if the bucket is the last bucket of the bucket
  * array (useful for the iterator of the hash table).
  * - If `StoreHash` is true, 32 bits of the hash of the value, if any, are also
  * stored in the bucket. If the size of the hash is more than 32 bits, it is
  * truncated. We don't store the full hash as storing the hash is a potential
  * opportunity to use the unused space due to the alignment of the bucket_entry
  * structure. We can thus potentially store the hash without any extra space
  *   (which would not be possible with 64 bits of the hash).
  */
 template <typename ValueType, bool StoreHash>
 class bucket_entry : public bucket_entry_hash<StoreHash> {
   using bucket_hash = bucket_entry_hash<StoreHash>;
 
  public:
   using value_type = ValueType;
   using distance_type = std::int16_t;
 
   bucket_entry() noexcept
       : bucket_hash(),
         m_dist_from_ideal_bucket(EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET),
         m_last_bucket(false) {
     tsl_rh_assert(empty());
   }
 
   bucket_entry(bool last_bucket) noexcept
       : bucket_hash(),
         m_dist_from_ideal_bucket(EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET),
         m_last_bucket(last_bucket) {
     tsl_rh_assert(empty());
   }
 
   bucket_entry(const bucket_entry& other) noexcept(
       std::is_nothrow_copy_constructible<value_type>::value)
       : bucket_hash(other),
         m_dist_from_ideal_bucket(EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET),
         m_last_bucket(other.m_last_bucket) {
     if (!other.empty()) {
       ::new (static_cast<void*>(std::addressof(m_value)))
           value_type(other.value());
       m_dist_from_ideal_bucket = other.m_dist_from_ideal_bucket;
     }
     tsl_rh_assert(empty() == other.empty());
   }
 
   /**
    * Never really used, but still necessary as we must call resize on an empty
    * `std::vector<bucket_entry>`. and we need to support move-only types. See
    * robin_hash constructor for details.
    */
   bucket_entry(bucket_entry&& other) noexcept(
       std::is_nothrow_move_constructible<value_type>::value)
       : bucket_hash(std::move(other)),
         m_dist_from_ideal_bucket(EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET),
         m_last_bucket(other.m_last_bucket) {
     if (!other.empty()) {
       ::new (static_cast<void*>(std::addressof(m_value)))
           value_type(std::move(other.value()));
       m_dist_from_ideal_bucket = other.m_dist_from_ideal_bucket;
     }
     tsl_rh_assert(empty() == other.empty());
   }
 
   bucket_entry& operator=(const bucket_entry& other) noexcept(
       std::is_nothrow_copy_constructible<value_type>::value) {
     if (this != &other) {
       clear();
 
       bucket_hash::operator=(other);
       if (!other.empty()) {
         ::new (static_cast<void*>(std::addressof(m_value)))
             value_type(other.value());
       }
 
       m_dist_from_ideal_bucket = other.m_dist_from_ideal_bucket;
       m_last_bucket = other.m_last_bucket;
     }
 
     return *this;
   }
 
   bucket_entry& operator=(bucket_entry&&) = delete;
 
   ~bucket_entry() noexcept { clear(); }
 
   void clear() noexcept {
     if (!empty()) {
       destroy_value();
       m_dist_from_ideal_bucket = EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET;
     }
   }
 
   bool empty() const noexcept {
     return m_dist_from_ideal_bucket == EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET;
   }
 
   value_type& value() noexcept {
     tsl_rh_assert(!empty());
 #if defined(__cplusplus) && __cplusplus >= 201703L
     return *std::launder(
         reinterpret_cast<value_type*>(std::addressof(m_value)));
 #else
     return *reinterpret_cast<value_type*>(std::addressof(m_value));
 #endif
   }
 
   const value_type& value() const noexcept {
     tsl_rh_assert(!empty());
 #if defined(__cplusplus) && __cplusplus >= 201703L
     return *std::launder(
         reinterpret_cast<const value_type*>(std::addressof(m_value)));
 #else
     return *reinterpret_cast<const value_type*>(std::addressof(m_value));
 #endif
   }
 
   distance_type dist_from_ideal_bucket() const noexcept {
     return m_dist_from_ideal_bucket;
   }
 
   bool last_bucket() const noexcept { return m_last_bucket; }
 
   void set_as_last_bucket() noexcept { m_last_bucket = true; }
 
   template <typename... Args>
   void set_value_of_empty_bucket(distance_type dist_from_ideal_bucket,
                                  truncated_hash_type hash,
                                  Args&&... value_type_args) {
     tsl_rh_assert(dist_from_ideal_bucket >= 0);
     tsl_rh_assert(empty());
 
     ::new (static_cast<void*>(std::addressof(m_value)))
         value_type(std::forward<Args>(value_type_args)...);
     this->set_hash(hash);
     m_dist_from_ideal_bucket = dist_from_ideal_bucket;
 
     tsl_rh_assert(!empty());
   }
 
   void swap_with_value_in_bucket(distance_type& dist_from_ideal_bucket,
                                  truncated_hash_type& hash, value_type& value) {
     tsl_rh_assert(!empty());
     tsl_rh_assert(dist_from_ideal_bucket > m_dist_from_ideal_bucket);
 
     using std::swap;
     swap(value, this->value());
     swap(dist_from_ideal_bucket, m_dist_from_ideal_bucket);
 
     if (StoreHash) {
       const truncated_hash_type tmp_hash = this->truncated_hash();
       this->set_hash(hash);
       hash = tmp_hash;
     } else {
       // Avoid warning of unused variable if StoreHash is false
       TSL_RH_UNUSED(hash);
     }
   }
 
   static truncated_hash_type truncate_hash(std::size_t hash) noexcept {
     return truncated_hash_type(hash);
   }
 
  private:
   void destroy_value() noexcept {
     tsl_rh_assert(!empty());
     value().~value_type();
   }
 
  public:
   static const distance_type EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET = -1;
   static const distance_type DIST_FROM_IDEAL_BUCKET_LIMIT = 8192;
   static_assert(DIST_FROM_IDEAL_BUCKET_LIMIT <=
                     std::numeric_limits<distance_type>::max() - 1,
                 "DIST_FROM_IDEAL_BUCKET_LIMIT must be <= "
                 "std::numeric_limits<distance_type>::max() - 1.");
 
  private:
   distance_type m_dist_from_ideal_bucket;
   bool m_last_bucket;
   alignas(value_type) unsigned char m_value[sizeof(value_type)];
 };
 
 /**
  * Internal common class used by `robin_map` and `robin_set`.
  *
  * ValueType is what will be stored by `robin_hash` (usually `std::pair<Key, T>`
  * for map and `Key` for set).
  *
  * `KeySelect` should be a `FunctionObject` which takes a `ValueType` in
  * parameter and returns a reference to the key.
  *
  * `ValueSelect` should be a `FunctionObject` which takes a `ValueType` in
  * parameter and returns a reference to the value. `ValueSelect` should be void
  * if there is no value (in a set for example).
  *
  * The strong exception guarantee only holds if the expression
  * `std::is_nothrow_swappable<ValueType>::value &&
  * std::is_nothrow_move_constructible<ValueType>::value` is true.
  *
  * Behaviour is undefined if the destructor of `ValueType` throws.
  */
 template <class ValueType, class KeySelect, class ValueSelect, class Hash,
           class KeyEqual, class Allocator, bool StoreHash, class GrowthPolicy>
 class robin_hash : private Hash, private KeyEqual, private GrowthPolicy {
  private:
   template <typename U>
   using has_mapped_type =
       typename std::integral_constant<bool, !std::is_same<U, void>::value>;
 
   static_assert(
       noexcept(std::declval<GrowthPolicy>().bucket_for_hash(std::size_t(0))),
       "GrowthPolicy::bucket_for_hash must be noexcept.");
   static_assert(noexcept(std::declval<GrowthPolicy>().clear()),
                 "GrowthPolicy::clear must be noexcept.");
 
  public:
   template <bool IsConst>
   class robin_iterator;
 
   using key_type = typename KeySelect::key_type;
   using value_type = ValueType;
   using size_type = std::size_t;
   using difference_type = std::ptrdiff_t;
   using hasher = Hash;
   using key_equal = KeyEqual;
   using allocator_type = Allocator;
   using reference = value_type&;
   using const_reference = const value_type&;
   using pointer = value_type*;
   using const_pointer = const value_type*;
   using iterator = robin_iterator<false>;
   using const_iterator = robin_iterator<true>;
 
  private:
   /**
    * Either store the hash because we are asked by the `StoreHash` template
    * parameter or store the hash because it doesn't cost us anything in size and
    * can be used to speed up rehash.
    */
   static constexpr bool STORE_HASH =
       StoreHash ||
       ((sizeof(tsl::detail_robin_hash::bucket_entry<value_type, true>) ==
         sizeof(tsl::detail_robin_hash::bucket_entry<value_type, false>)) &&
        (sizeof(std::size_t) == sizeof(truncated_hash_type) ||
         is_power_of_two_policy<GrowthPolicy>::value) &&
        // Don't store the hash for primitive types with default hash.
        (!std::is_arithmetic<key_type>::value ||
         !std::is_same<Hash, std::hash<key_type>>::value));
 
   /**
    * Only use the stored hash on lookup if we are explicitly asked. We are not
    * sure how slow the KeyEqual operation is. An extra comparison may slow
    * things down with a fast KeyEqual.
    */
   static constexpr bool USE_STORED_HASH_ON_LOOKUP = StoreHash;
 
   /**
    * We can only use the hash on rehash if the size of the hash type is the same
    * as the stored one or if we use a power of two modulo. In the case of the
    * power of two modulo, we just mask the least significant bytes, we just have
    * to check that the truncated_hash_type didn't truncated more bytes.
    */
   static bool USE_STORED_HASH_ON_REHASH(size_type bucket_count) {
     if (STORE_HASH && sizeof(std::size_t) == sizeof(truncated_hash_type)) {
       TSL_RH_UNUSED(bucket_count);
       return true;
     } else if (STORE_HASH && is_power_of_two_policy<GrowthPolicy>::value) {
       return bucket_count == 0 ||
              (bucket_count - 1) <=
                  std::numeric_limits<truncated_hash_type>::max();
     } else {
       TSL_RH_UNUSED(bucket_count);
       return false;
     }
   }
 
   using bucket_entry =
       tsl::detail_robin_hash::bucket_entry<value_type, STORE_HASH>;
   using distance_type = typename bucket_entry::distance_type;
 
   using buckets_allocator = typename std::allocator_traits<
       allocator_type>::template rebind_alloc<bucket_entry>;
   using buckets_container_type = std::vector<bucket_entry, buckets_allocator>;
 
  public:
   /**
    * The 'operator*()' and 'operator->()' methods return a const reference and
    * const pointer respectively to the stored value type.
    *
    * In case of a map, to get a mutable reference to the value associated to a
    * key (the '.second' in the stored pair), you have to call 'value()'.
    *
    * The main reason for this is that if we returned a `std::pair<Key, T>&`
    * instead of a `const std::pair<Key, T>&`, the user may modify the key which
    * will put the map in a undefined state.
    */
   template <bool IsConst>
   class robin_iterator {
     friend class robin_hash;
 
    private:
     using bucket_entry_ptr =
         typename std::conditional<IsConst, const bucket_entry*,
                                   bucket_entry*>::type;
 
     robin_iterator(bucket_entry_ptr bucket) noexcept : m_bucket(bucket) {}
 
    public:
     using iterator_category = std::forward_iterator_tag;
     using value_type = const typename robin_hash::value_type;
     using difference_type = std::ptrdiff_t;
     using reference = value_type&;
     using pointer = value_type*;
 
     robin_iterator() noexcept {}
 
     // Copy constructor from iterator to const_iterator.
     template <bool TIsConst = IsConst,
               typename std::enable_if<TIsConst>::type* = nullptr>
     robin_iterator(const robin_iterator<!TIsConst>& other) noexcept
         : m_bucket(other.m_bucket) {}
 
     robin_iterator(const robin_iterator& other) = default;
     robin_iterator(robin_iterator&& other) = default;
     robin_iterator& operator=(const robin_iterator& other) = default;
     robin_iterator& operator=(robin_iterator&& other) = default;
 
     const typename robin_hash::key_type& key() const {
       return KeySelect()(m_bucket->value());
     }
 
     template <class U = ValueSelect,
               typename std::enable_if<has_mapped_type<U>::value &&
                                       IsConst>::type* = nullptr>
     const typename U::value_type& value() const {
       return U()(m_bucket->value());
     }
 
     template <class U = ValueSelect,
               typename std::enable_if<has_mapped_type<U>::value &&
                                       !IsConst>::type* = nullptr>
     typename U::value_type& value() const {
       return U()(m_bucket->value());
     }
 
     reference operator*() const { return m_bucket->value(); }
 
     pointer operator->() const { return std::addressof(m_bucket->value()); }
 
     robin_iterator& operator++() {
       while (true) {
         if (m_bucket->last_bucket()) {
           ++m_bucket;
           return *this;
         }
 
         ++m_bucket;
         if (!m_bucket->empty()) {
           return *this;
         }
       }
     }
 
     robin_iterator operator++(int) {
       robin_iterator tmp(*this);
       ++*this;
 
       return tmp;
     }
 
     friend bool operator==(const robin_iterator& lhs,
                            const robin_iterator& rhs) {
       return lhs.m_bucket == rhs.m_bucket;
     }
 
     friend bool operator!=(const robin_iterator& lhs,
                            const robin_iterator& rhs) {
       return !(lhs == rhs);
     }
 
    private:
     bucket_entry_ptr m_bucket;
   };
 
  public:
 #if defined(__cplusplus) && __cplusplus >= 201402L
   robin_hash(size_type bucket_count, const Hash& hash, const KeyEqual& equal,
              const Allocator& alloc,
              float min_load_factor = DEFAULT_MIN_LOAD_FACTOR,
              float max_load_factor = DEFAULT_MAX_LOAD_FACTOR)
       : Hash(hash),
         KeyEqual(equal),
         GrowthPolicy(bucket_count),
         m_buckets_data(bucket_count, alloc),
         m_buckets(m_buckets_data.empty() ? static_empty_bucket_ptr()
                                          : m_buckets_data.data()),
         m_bucket_count(bucket_count),
         m_nb_elements(0),
         m_grow_on_next_insert(false),
         m_try_shrink_on_next_insert(false) {
     if (bucket_count > max_bucket_count()) {
       TSL_RH_THROW_OR_TERMINATE(std::length_error,
                                 "The map exceeds its maximum bucket count.");
     }
 
     if (m_bucket_count > 0) {
       tsl_rh_assert(!m_buckets_data.empty());
       m_buckets_data.back().set_as_last_bucket();
     }
 
     this->min_load_factor(min_load_factor);
     this->max_load_factor(max_load_factor);
   }
 #else
   /**
    * C++11 doesn't support the creation of a std::vector with a custom allocator
    * and 'count' default-inserted elements. The needed contructor `explicit
    * vector(size_type count, const Allocator& alloc = Allocator());` is only
    * available in C++14 and later. We thus must resize after using the
    * `vector(const Allocator& alloc)` constructor.
    *
    * We can't use `vector(size_type count, const T& value, const Allocator&
    * alloc)` as it requires the value T to be copyable.
    */
   robin_hash(size_type bucket_count, const Hash& hash, const KeyEqual& equal,
              const Allocator& alloc,
              float min_load_factor = DEFAULT_MIN_LOAD_FACTOR,
              float max_load_factor = DEFAULT_MAX_LOAD_FACTOR)
       : Hash(hash),
         KeyEqual(equal),
         GrowthPolicy(bucket_count),
         m_buckets_data(alloc),
         m_buckets(static_empty_bucket_ptr()),
         m_bucket_count(bucket_count),
         m_nb_elements(0),
         m_grow_on_next_insert(false),
         m_try_shrink_on_next_insert(false) {
     if (bucket_count > max_bucket_count()) {
       TSL_RH_THROW_OR_TERMINATE(std::length_error,
                                 "The map exceeds its maximum bucket count.");
     }
 
     if (m_bucket_count > 0) {
       m_buckets_data.resize(m_bucket_count);
       m_buckets = m_buckets_data.data();
 
       tsl_rh_assert(!m_buckets_data.empty());
       m_buckets_data.back().set_as_last_bucket();
     }
 
     this->min_load_factor(min_load_factor);
     this->max_load_factor(max_load_factor);
   }
 #endif
 
   robin_hash(const robin_hash& other)
       : Hash(other),
         KeyEqual(other),
         GrowthPolicy(other),
         m_buckets_data(other.m_buckets_data),
         m_buckets(m_buckets_data.empty() ? static_empty_bucket_ptr()
                                          : m_buckets_data.data()),
         m_bucket_count(other.m_bucket_count),
         m_nb_elements(other.m_nb_elements),
         m_load_threshold(other.m_load_threshold),
         m_min_load_factor(other.m_min_load_factor),
         m_max_load_factor(other.m_max_load_factor),
         m_grow_on_next_insert(other.m_grow_on_next_insert),
         m_try_shrink_on_next_insert(other.m_try_shrink_on_next_insert) {}
 
   robin_hash(robin_hash&& other) noexcept(
       std::is_nothrow_move_constructible<
           Hash>::value&& std::is_nothrow_move_constructible<KeyEqual>::value&&
           std::is_nothrow_move_constructible<GrowthPolicy>::value&&
               std::is_nothrow_move_constructible<buckets_container_type>::value)
       : Hash(std::move(static_cast<Hash&>(other))),
         KeyEqual(std::move(static_cast<KeyEqual&>(other))),
         GrowthPolicy(std::move(static_cast<GrowthPolicy&>(other))),
         m_buckets_data(std::move(other.m_buckets_data)),
         m_buckets(m_buckets_data.empty() ? static_empty_bucket_ptr()
                                          : m_buckets_data.data()),
         m_bucket_count(other.m_bucket_count),
         m_nb_elements(other.m_nb_elements),
         m_load_threshold(other.m_load_threshold),
         m_min_load_factor(other.m_min_load_factor),
         m_max_load_factor(other.m_max_load_factor),
         m_grow_on_next_insert(other.m_grow_on_next_insert),
         m_try_shrink_on_next_insert(other.m_try_shrink_on_next_insert) {
     other.clear_and_shrink();
   }
 
   robin_hash& operator=(const robin_hash& other) {
     if (&other != this) {
       Hash::operator=(other);
       KeyEqual::operator=(other);
       GrowthPolicy::operator=(other);
 
       m_buckets_data = other.m_buckets_data;
       m_buckets = m_buckets_data.empty() ? static_empty_bucket_ptr()
                                          : m_buckets_data.data();
       m_bucket_count = other.m_bucket_count;
       m_nb_elements = other.m_nb_elements;
 
       m_load_threshold = other.m_load_threshold;
       m_min_load_factor = other.m_min_load_factor;
       m_max_load_factor = other.m_max_load_factor;
 
       m_grow_on_next_insert = other.m_grow_on_next_insert;
       m_try_shrink_on_next_insert = other.m_try_shrink_on_next_insert;
     }
 
     return *this;
   }
 
   robin_hash& operator=(robin_hash&& other) {
     other.swap(*this);
     other.clear_and_shrink();
 
     return *this;
   }
 
   allocator_type get_allocator() const {
     return m_buckets_data.get_allocator();
   }
 
   /*
    * Iterators
    */
   iterator begin() noexcept {
     std::size_t i = 0;
     while (i < m_bucket_count && m_buckets[i].empty()) {
       i++;
     }
 
     return iterator(m_buckets + i);
   }
 
   const_iterator begin() const noexcept { return cbegin(); }
 
   const_iterator cbegin() const noexcept {
     std::size_t i = 0;
     while (i < m_bucket_count && m_buckets[i].empty()) {
       i++;
     }
 
     return const_iterator(m_buckets + i);
   }
 
   iterator end() noexcept { return iterator(m_buckets + m_bucket_count); }
 
   const_iterator end() const noexcept { return cend(); }
 
   const_iterator cend() const noexcept {
     return const_iterator(m_buckets + m_bucket_count);
   }
 
   /*
    * Capacity
    */
   bool empty() const noexcept { return m_nb_elements == 0; }
 
   size_type size() const noexcept { return m_nb_elements; }
 
   size_type max_size() const noexcept { return m_buckets_data.max_size(); }
 
   /*
    * Modifiers
    */
   void clear() noexcept {
     if (m_min_load_factor > 0.0f) {
       clear_and_shrink();
     } else {
       for (auto& bucket : m_buckets_data) {
         bucket.clear();
       }
 
       m_nb_elements = 0;
       m_grow_on_next_insert = false;
     }
   }
 
   template <typename P>
   std::pair<iterator, bool> insert(P&& value) {
     return insert_impl(KeySelect()(value), std::forward<P>(value));
   }
 
   template <typename P>
   iterator insert_hint(const_iterator hint, P&& value) {
     if (hint != cend() &&
         compare_keys(KeySelect()(*hint), KeySelect()(value))) {
       return mutable_iterator(hint);
     }
 
     return insert(std::forward<P>(value)).first;
   }
 
   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 size_type nb_free_buckets = m_load_threshold - size();
       tsl_rh_assert(m_load_threshold >= size());
 
       if (nb_elements_insert > 0 &&
           nb_free_buckets < size_type(nb_elements_insert)) {
         reserve(size() + size_type(nb_elements_insert));
       }
     }
 
     for (; first != last; ++first) {
       insert(*first);
     }
   }
 
   template <class K, class M>
   std::pair<iterator, bool> insert_or_assign(K&& key, M&& obj) {
     auto it = try_emplace(std::forward<K>(key), std::forward<M>(obj));
     if (!it.second) {
       it.first.value() = std::forward<M>(obj);
     }
 
     return it;
   }
 
   template <class K, class M>
   iterator insert_or_assign(const_iterator hint, K&& key, M&& obj) {
     if (hint != cend() && compare_keys(KeySelect()(*hint), key)) {
       auto it = mutable_iterator(hint);
       it.value() = std::forward<M>(obj);
 
       return it;
     }
 
     return insert_or_assign(std::forward<K>(key), std::forward<M>(obj)).first;
   }
 
   template <class... Args>
   std::pair<iterator, bool> emplace(Args&&... args) {
     return insert(value_type(std::forward<Args>(args)...));
   }
 
   template <class... Args>
   iterator emplace_hint(const_iterator hint, Args&&... args) {
     return insert_hint(hint, value_type(std::forward<Args>(args)...));
   }
 
   template <class K, class... Args>
   std::pair<iterator, bool> try_emplace(K&& key, Args&&... args) {
     return insert_impl(key, std::piecewise_construct,
                        std::forward_as_tuple(std::forward<K>(key)),
                        std::forward_as_tuple(std::forward<Args>(args)...));
   }
 
   template <class K, class... Args>
   iterator try_emplace_hint(const_iterator hint, K&& key, Args&&... args) {
     if (hint != cend() && compare_keys(KeySelect()(*hint), key)) {
       return mutable_iterator(hint);
     }
 
     return try_emplace(std::forward<K>(key), std::forward<Args>(args)...).first;
   }
 
   /**
    * Here to avoid `template<class K> size_type erase(const K& key)` being used
    * when we use an `iterator` instead of a `const_iterator`.
    */
   iterator erase(iterator pos) {
     erase_from_bucket(pos);
 
     /**
      * Erase bucket used a backward shift after clearing the bucket.
      * Check if there is a new value in the bucket, if not get the next
      * non-empty.
      */
     if (pos.m_bucket->empty()) {
       ++pos;
     }
 
     m_try_shrink_on_next_insert = true;
 
     return pos;
   }
 
   iterator erase(const_iterator pos) { return erase(mutable_iterator(pos)); }
 
   iterator erase(const_iterator first, const_iterator last) {
     if (first == last) {
       return mutable_iterator(first);
     }
 
     auto first_mutable = mutable_iterator(first);
     auto last_mutable = mutable_iterator(last);
     for (auto it = first_mutable.m_bucket; it != last_mutable.m_bucket; ++it) {
       if (!it->empty()) {
         it->clear();
         m_nb_elements--;
       }
     }
 
     if (last_mutable == end()) {
       m_try_shrink_on_next_insert = true;
       return end();
     }
 
     /*
      * Backward shift on the values which come after the deleted values.
      * We try to move the values closer to their ideal bucket.
      */
     std::size_t icloser_bucket =
         static_cast<std::size_t>(first_mutable.m_bucket - m_buckets);
     std::size_t ito_move_closer_value =
         static_cast<std::size_t>(last_mutable.m_bucket - m_buckets);
     tsl_rh_assert(ito_move_closer_value > icloser_bucket);
 
     const std::size_t ireturn_bucket =
         ito_move_closer_value -
         std::min(
             ito_move_closer_value - icloser_bucket,
             std::size_t(
                 m_buckets[ito_move_closer_value].dist_from_ideal_bucket()));
 
     while (ito_move_closer_value < m_bucket_count &&
            m_buckets[ito_move_closer_value].dist_from_ideal_bucket() > 0) {
       icloser_bucket =
           ito_move_closer_value -
           std::min(
               ito_move_closer_value - icloser_bucket,
               std::size_t(
                   m_buckets[ito_move_closer_value].dist_from_ideal_bucket()));
 
       tsl_rh_assert(m_buckets[icloser_bucket].empty());
       const distance_type new_distance = distance_type(
           m_buckets[ito_move_closer_value].dist_from_ideal_bucket() -
           (ito_move_closer_value - icloser_bucket));
       m_buckets[icloser_bucket].set_value_of_empty_bucket(
           new_distance, m_buckets[ito_move_closer_value].truncated_hash(),
           std::move(m_buckets[ito_move_closer_value].value()));
       m_buckets[ito_move_closer_value].clear();
 
       ++icloser_bucket;
       ++ito_move_closer_value;
     }
 
     m_try_shrink_on_next_insert = true;
 
     return iterator(m_buckets + ireturn_bucket);
   }
 
   template <class K>
   size_type erase(const K& key) {
     return erase(key, hash_key(key));
   }
 
   template <class K>
   size_type erase(const K& key, std::size_t hash) {
     auto it = find(key, hash);
     if (it != end()) {
       erase_from_bucket(it);
       m_try_shrink_on_next_insert = true;
 
       return 1;
     } else {
       return 0;
     }
   }
 
   void swap(robin_hash& other) {
     using std::swap;
 
     swap(static_cast<Hash&>(*this), static_cast<Hash&>(other));
     swap(static_cast<KeyEqual&>(*this), static_cast<KeyEqual&>(other));
     swap(static_cast<GrowthPolicy&>(*this), static_cast<GrowthPolicy&>(other));
     swap(m_buckets_data, other.m_buckets_data);
     swap(m_buckets, other.m_buckets);
     swap(m_bucket_count, other.m_bucket_count);
     swap(m_nb_elements, other.m_nb_elements);
     swap(m_load_threshold, other.m_load_threshold);
     swap(m_min_load_factor, other.m_min_load_factor);
     swap(m_max_load_factor, other.m_max_load_factor);
     swap(m_grow_on_next_insert, other.m_grow_on_next_insert);
     swap(m_try_shrink_on_next_insert, other.m_try_shrink_on_next_insert);
   }
 
   /*
    * Lookup
    */
   template <class K, class U = ValueSelect,
             typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
   typename U::value_type& at(const K& key) {
     return at(key, hash_key(key));
   }
 
   template <class K, class U = ValueSelect,
             typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
   typename U::value_type& at(const K& key, std::size_t hash) {
     return const_cast<typename U::value_type&>(
         static_cast<const robin_hash*>(this)->at(key, hash));
   }
 
   template <class K, class U = ValueSelect,
             typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
   const typename U::value_type& at(const K& key) const {
     return at(key, hash_key(key));
   }
 
   template <class K, class U = ValueSelect,
             typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
   const typename U::value_type& at(const K& key, std::size_t hash) const {
     auto it = find(key, hash);
     if (it != cend()) {
       return it.value();
     } else {
       TSL_RH_THROW_OR_TERMINATE(std::out_of_range, "Couldn't find key.");
     }
   }
 
   template <class K, class U = ValueSelect,
             typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
   typename U::value_type& operator[](K&& key) {
     return try_emplace(std::forward<K>(key)).first.value();
   }
 
   template <class K>
   size_type count(const K& key) const {
     return count(key, hash_key(key));
   }
 
   template <class K>
   size_type count(const K& key, std::size_t hash) const {
     if (find(key, hash) != cend()) {
       return 1;
     } else {
       return 0;
     }
   }
 
   template <class K>
   iterator find(const K& key) {
     return find_impl(key, hash_key(key));
   }
 
   template <class K>
   iterator find(const K& key, std::size_t hash) {
     return find_impl(key, hash);
   }
 
   template <class K>
   const_iterator find(const K& key) const {
     return find_impl(key, hash_key(key));
   }
 
   template <class K>
   const_iterator find(const K& key, std::size_t hash) const {
     return find_impl(key, hash);
   }
 
   template <class K>
   bool contains(const K& key) const {
     return contains(key, hash_key(key));
   }
 
   template <class K>
   bool contains(const K& key, std::size_t hash) const {
     return count(key, hash) != 0;
   }
 
   template <class K>
   std::pair<iterator, iterator> equal_range(const K& key) {
     return equal_range(key, hash_key(key));
   }
 
   template <class K>
   std::pair<iterator, iterator> equal_range(const K& key, std::size_t hash) {
     iterator it = find(key, hash);
     return std::make_pair(it, (it == end()) ? it : std::next(it));
   }
 
   template <class K>
   std::pair<const_iterator, const_iterator> equal_range(const K& key) const {
     return equal_range(key, hash_key(key));
   }
 
   template <class K>
   std::pair<const_iterator, const_iterator> equal_range(
       const K& key, std::size_t hash) const {
     const_iterator it = find(key, hash);
     return std::make_pair(it, (it == cend()) ? it : std::next(it));
   }
 
   /*
    * Bucket interface
    */
   size_type bucket_count() const { return m_bucket_count; }
 
   size_type max_bucket_count() const {
     return std::min(GrowthPolicy::max_bucket_count(),
                     m_buckets_data.max_size());
   }
 
   /*
    * Hash policy
    */
   float load_factor() const {
     if (bucket_count() == 0) {
       return 0;
     }
 
     return float(m_nb_elements) / float(bucket_count());
   }
 
   float min_load_factor() const { return m_min_load_factor; }
 
   float max_load_factor() const { return m_max_load_factor; }
 
   void min_load_factor(float ml) {
     m_min_load_factor = clamp(ml, float(MINIMUM_MIN_LOAD_FACTOR),
                               float(MAXIMUM_MIN_LOAD_FACTOR));
   }
 
   void max_load_factor(float ml) {
     m_max_load_factor = clamp(ml, float(MINIMUM_MAX_LOAD_FACTOR),
                               float(MAXIMUM_MAX_LOAD_FACTOR));
     m_load_threshold = size_type(float(bucket_count()) * m_max_load_factor);
     tsl_rh_assert(bucket_count() == 0 || m_load_threshold < bucket_count());
   }
 
   void rehash(size_type count_) {
     count_ = std::max(count_,
                       size_type(std::ceil(float(size()) / max_load_factor())));
     rehash_impl(count_);
   }
 
   void reserve(size_type count_) {
     rehash(size_type(std::ceil(float(count_) / max_load_factor())));
   }
 
   /*
    * Observers
    */
   hasher hash_function() const { return static_cast<const Hash&>(*this); }
 
   key_equal key_eq() const { return static_cast<const KeyEqual&>(*this); }
 
   /*
    * Other
    */
   iterator mutable_iterator(const_iterator pos) {
     return iterator(const_cast<bucket_entry*>(pos.m_bucket));
   }
 
   template <class Serializer>
   void serialize(Serializer& serializer) const {
     serialize_impl(serializer);
   }
 
   template <class Deserializer>
   void deserialize(Deserializer& deserializer, bool hash_compatible) {
     deserialize_impl(deserializer, hash_compatible);
   }
 
  private:
   template <class K>
   std::size_t hash_key(const K& key) const {
     return Hash::operator()(key);
   }
 
   template <class K1, class K2>
   bool compare_keys(const K1& key1, const K2& key2) const {
     return KeyEqual::operator()(key1, key2);
   }
 
   std::size_t bucket_for_hash(std::size_t hash) const {
     const std::size_t bucket = GrowthPolicy::bucket_for_hash(hash);
     tsl_rh_assert(bucket < m_bucket_count ||
                   (bucket == 0 && m_bucket_count == 0));
 
     return bucket;
   }
 
   template <class U = GrowthPolicy,
             typename std::enable_if<is_power_of_two_policy<U>::value>::type* =
                 nullptr>
   std::size_t next_bucket(std::size_t index) const noexcept {
     tsl_rh_assert(index < bucket_count());
 
     return (index + 1) & this->m_mask;
   }
 
   template <class U = GrowthPolicy,
             typename std::enable_if<!is_power_of_two_policy<U>::value>::type* =
                 nullptr>
   std::size_t next_bucket(std::size_t index) const noexcept {
     tsl_rh_assert(index < bucket_count());
 
     index++;
     return (index != bucket_count()) ? index : 0;
   }
 
   template <class K>
   iterator find_impl(const K& key, std::size_t hash) {
     return mutable_iterator(
         static_cast<const robin_hash*>(this)->find(key, hash));
   }
 
   template <class K>
   const_iterator find_impl(const K& key, std::size_t hash) const {
     std::size_t ibucket = bucket_for_hash(hash);
     distance_type dist_from_ideal_bucket = 0;
 
     while (dist_from_ideal_bucket <=
            m_buckets[ibucket].dist_from_ideal_bucket()) {
       if (TSL_RH_LIKELY(
               (!USE_STORED_HASH_ON_LOOKUP ||
                m_buckets[ibucket].bucket_hash_equal(hash)) &&
               compare_keys(KeySelect()(m_buckets[ibucket].value()), key))) {
         return const_iterator(m_buckets + ibucket);
       }
 
       ibucket = next_bucket(ibucket);
       dist_from_ideal_bucket++;
     }
 
     return cend();
   }
 
   void erase_from_bucket(iterator pos) {
     pos.m_bucket->clear();
     m_nb_elements--;
 
     /**
      * Backward shift, swap the empty bucket, previous_ibucket, with the values
      * on its right, ibucket, until we cross another empty bucket or if the
      * other bucket has a distance_from_ideal_bucket == 0.
      *
      * We try to move the values closer to their ideal bucket.
      */
     std::size_t previous_ibucket =
         static_cast<std::size_t>(pos.m_bucket - m_buckets);
     std::size_t ibucket = next_bucket(previous_ibucket);
 
     while (m_buckets[ibucket].dist_from_ideal_bucket() > 0) {
       tsl_rh_assert(m_buckets[previous_ibucket].empty());
 
       const distance_type new_distance =
           distance_type(m_buckets[ibucket].dist_from_ideal_bucket() - 1);
       m_buckets[previous_ibucket].set_value_of_empty_bucket(
           new_distance, m_buckets[ibucket].truncated_hash(),
           std::move(m_buckets[ibucket].value()));
       m_buckets[ibucket].clear();
 
       previous_ibucket = ibucket;
       ibucket = next_bucket(ibucket);
     }
   }
 
   template <class K, class... Args>
   std::pair<iterator, bool> insert_impl(const K& key,
                                         Args&&... value_type_args) {
     const std::size_t hash = hash_key(key);
 
     std::size_t ibucket = bucket_for_hash(hash);
     distance_type dist_from_ideal_bucket = 0;
 
     while (dist_from_ideal_bucket <=
            m_buckets[ibucket].dist_from_ideal_bucket()) {
       if ((!USE_STORED_HASH_ON_LOOKUP ||
            m_buckets[ibucket].bucket_hash_equal(hash)) &&
           compare_keys(KeySelect()(m_buckets[ibucket].value()), key)) {
         return std::make_pair(iterator(m_buckets + ibucket), false);
       }
 
       ibucket = next_bucket(ibucket);
       dist_from_ideal_bucket++;
     }
 
     while (rehash_on_extreme_load(dist_from_ideal_bucket)) {
       ibucket = bucket_for_hash(hash);
       dist_from_ideal_bucket = 0;
 
       while (dist_from_ideal_bucket <=
              m_buckets[ibucket].dist_from_ideal_bucket()) {
         ibucket = next_bucket(ibucket);
         dist_from_ideal_bucket++;
       }
     }
 
     if (m_buckets[ibucket].empty()) {
       m_buckets[ibucket].set_value_of_empty_bucket(
           dist_from_ideal_bucket, bucket_entry::truncate_hash(hash),
           std::forward<Args>(value_type_args)...);
     } else {
       insert_value(ibucket, dist_from_ideal_bucket,
                    bucket_entry::truncate_hash(hash),
                    std::forward<Args>(value_type_args)...);
     }
 
     m_nb_elements++;
     /*
      * The value will be inserted in ibucket in any case, either because it was
      * empty or by stealing the bucket (robin hood).
      */
     return std::make_pair(iterator(m_buckets + ibucket), true);
   }
 
   template <class... Args>
   void insert_value(std::size_t ibucket, distance_type dist_from_ideal_bucket,
                     truncated_hash_type hash, Args&&... value_type_args) {
     value_type value(std::forward<Args>(value_type_args)...);
     insert_value_impl(ibucket, dist_from_ideal_bucket, hash, value);
   }
 
   void insert_value(std::size_t ibucket, distance_type dist_from_ideal_bucket,
                     truncated_hash_type hash, value_type&& value) {
     insert_value_impl(ibucket, dist_from_ideal_bucket, hash, value);
   }
 
   /*
    * We don't use `value_type&& value` as last argument due to a bug in MSVC
    * when `value_type` is a pointer, The compiler is not able to see the
    * difference between `std::string*` and `std::string*&&` resulting in a
    * compilation error.
    *
    * The `value` will be in a moved state at the end of the function.
    */
   void insert_value_impl(std::size_t ibucket,
                          distance_type dist_from_ideal_bucket,
                          truncated_hash_type hash, value_type& value) {
     tsl_rh_assert(dist_from_ideal_bucket >
                   m_buckets[ibucket].dist_from_ideal_bucket());
     m_buckets[ibucket].swap_with_value_in_bucket(dist_from_ideal_bucket, hash,
                                                  value);
     ibucket = next_bucket(ibucket);
     dist_from_ideal_bucket++;
 
     while (!m_buckets[ibucket].empty()) {
       if (dist_from_ideal_bucket >
           m_buckets[ibucket].dist_from_ideal_bucket()) {
         if (dist_from_ideal_bucket >
             bucket_entry::DIST_FROM_IDEAL_BUCKET_LIMIT) {
           /**
            * The number of probes is really high, rehash the map on the next
            * insert. Difficult to do now as rehash may throw an exception.
            */
           m_grow_on_next_insert = true;
         }
 
         m_buckets[ibucket].swap_with_value_in_bucket(dist_from_ideal_bucket,
                                                      hash, value);
       }
 
       ibucket = next_bucket(ibucket);
       dist_from_ideal_bucket++;
     }
 
     m_buckets[ibucket].set_value_of_empty_bucket(dist_from_ideal_bucket, hash,
                                                  std::move(value));
   }
 
   void rehash_impl(size_type count_) {
     robin_hash new_table(count_, static_cast<Hash&>(*this),
                          static_cast<KeyEqual&>(*this), get_allocator(),
                          m_min_load_factor, m_max_load_factor);
     tsl_rh_assert(size() <= new_table.m_load_threshold);
 
     const bool use_stored_hash =
         USE_STORED_HASH_ON_REHASH(new_table.bucket_count());
     for (auto& bucket : m_buckets_data) {
       if (bucket.empty()) {
         continue;
       }
 
       const std::size_t hash =
           use_stored_hash ? bucket.truncated_hash()
                           : new_table.hash_key(KeySelect()(bucket.value()));
 
       new_table.insert_value_on_rehash(new_table.bucket_for_hash(hash), 0,
                                        bucket_entry::truncate_hash(hash),
                                        std::move(bucket.value()));
     }
 
     new_table.m_nb_elements = m_nb_elements;
     new_table.swap(*this);
   }
 
   void clear_and_shrink() noexcept {
     GrowthPolicy::clear();
     m_buckets_data.clear();
     m_buckets = static_empty_bucket_ptr();
     m_bucket_count = 0;
     m_nb_elements = 0;
     m_load_threshold = 0;
     m_grow_on_next_insert = false;
     m_try_shrink_on_next_insert = false;
   }
 
   void insert_value_on_rehash(std::size_t ibucket,
                               distance_type dist_from_ideal_bucket,
                               truncated_hash_type hash, value_type&& value) {
     while (true) {
       if (dist_from_ideal_bucket >
           m_buckets[ibucket].dist_from_ideal_bucket()) {
         if (m_buckets[ibucket].empty()) {
           m_buckets[ibucket].set_value_of_empty_bucket(dist_from_ideal_bucket,
                                                        hash, std::move(value));
           return;
         } else {
           m_buckets[ibucket].swap_with_value_in_bucket(dist_from_ideal_bucket,
                                                        hash, value);
         }
       }
 
       dist_from_ideal_bucket++;
       ibucket = next_bucket(ibucket);
     }
   }
 
   /**
    * Grow the table if m_grow_on_next_insert is true or we reached the
    * max_load_factor. Shrink the table if m_try_shrink_on_next_insert is true
    * (an erase occurred) and we're below the min_load_factor.
    *
    * Return true if the table has been rehashed.
    */
   bool rehash_on_extreme_load(distance_type curr_dist_from_ideal_bucket) {
     if (m_grow_on_next_insert ||
         curr_dist_from_ideal_bucket >
             bucket_entry::DIST_FROM_IDEAL_BUCKET_LIMIT ||
         size() >= m_load_threshold) {
       rehash_impl(GrowthPolicy::next_bucket_count());
       m_grow_on_next_insert = false;
 
       return true;
     }
 
     if (m_try_shrink_on_next_insert) {
       m_try_shrink_on_next_insert = false;
       if (m_min_load_factor != 0.0f && load_factor() < m_min_load_factor) {
         reserve(size() + 1);
 
         return true;
       }
     }
 
     return false;
   }
 
   template <class Serializer>
   void serialize_impl(Serializer& serializer) const {
     const slz_size_type version = SERIALIZATION_PROTOCOL_VERSION;
     serializer(version);
 
     // Indicate if the truncated hash of each bucket is stored. Use a
     // std::int16_t instead of a bool to avoid the need for the serializer to
     // support an extra 'bool' type.
     const std::int16_t hash_stored_for_bucket =
         static_cast<std::int16_t>(STORE_HASH);
     serializer(hash_stored_for_bucket);
 
     const slz_size_type nb_elements = m_nb_elements;
     serializer(nb_elements);
 
     const slz_size_type bucket_count = m_buckets_data.size();
     serializer(bucket_count);
 
     const float min_load_factor = m_min_load_factor;
     serializer(min_load_factor);
 
     const float max_load_factor = m_max_load_factor;
     serializer(max_load_factor);
 
     for (const bucket_entry& bucket : m_buckets_data) {
       if (bucket.empty()) {
         const std::int16_t empty_bucket =
             bucket_entry::EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET;
         serializer(empty_bucket);
       } else {
         const std::int16_t dist_from_ideal_bucket =
             bucket.dist_from_ideal_bucket();
         serializer(dist_from_ideal_bucket);
         if (STORE_HASH) {
           const std::uint32_t truncated_hash = bucket.truncated_hash();
           serializer(truncated_hash);
         }
         serializer(bucket.value());
       }
     }
   }
 
   template <class Deserializer>
   void deserialize_impl(Deserializer& deserializer, bool hash_compatible) {
     tsl_rh_assert(m_buckets_data.empty());  // Current hash table must be empty
 
     const slz_size_type version =
         deserialize_value<slz_size_type>(deserializer);
     // For now we only have one version of the serialization protocol.
     // If it doesn't match there is a problem with the file.
     if (version != SERIALIZATION_PROTOCOL_VERSION) {
       TSL_RH_THROW_OR_TERMINATE(std::runtime_error,
                                 "Can't deserialize the ordered_map/set. "
                                 "The protocol version header is invalid.");
     }
 
     const bool hash_stored_for_bucket =
         deserialize_value<std::int16_t>(deserializer) ? true : false;
     if (hash_compatible && STORE_HASH != hash_stored_for_bucket) {
       TSL_RH_THROW_OR_TERMINATE(
           std::runtime_error,
           "Can't deserialize a map with a different StoreHash "
           "than the one used during the serialization when "
           "hash compatibility is used");
     }
 
     const slz_size_type nb_elements =
         deserialize_value<slz_size_type>(deserializer);
     const slz_size_type bucket_count_ds =
         deserialize_value<slz_size_type>(deserializer);
     const float min_load_factor = deserialize_value<float>(deserializer);
     const float max_load_factor = deserialize_value<float>(deserializer);
 
     if (min_load_factor < MINIMUM_MIN_LOAD_FACTOR ||
         min_load_factor > MAXIMUM_MIN_LOAD_FACTOR) {
       TSL_RH_THROW_OR_TERMINATE(
           std::runtime_error,
           "Invalid min_load_factor. Check that the serializer "
           "and deserializer support floats correctly as they "
           "can be converted implicitly to ints.");
     }
 
     if (max_load_factor < MINIMUM_MAX_LOAD_FACTOR ||
         max_load_factor > MAXIMUM_MAX_LOAD_FACTOR) {
       TSL_RH_THROW_OR_TERMINATE(
           std::runtime_error,
           "Invalid max_load_factor. Check that the serializer "
           "and deserializer support floats correctly as they "
           "can be converted implicitly to ints.");
     }
 
     this->min_load_factor(min_load_factor);
     this->max_load_factor(max_load_factor);
 
     if (bucket_count_ds == 0) {
       tsl_rh_assert(nb_elements == 0);
       return;
     }
 
     if (!hash_compatible) {
       reserve(numeric_cast<size_type>(nb_elements,
                                       "Deserialized nb_elements is too big."));
       for (slz_size_type ibucket = 0; ibucket < bucket_count_ds; ibucket++) {
         const distance_type dist_from_ideal_bucket =
             deserialize_value<std::int16_t>(deserializer);
         if (dist_from_ideal_bucket !=
             bucket_entry::EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET) {
           if (hash_stored_for_bucket) {
             TSL_RH_UNUSED(deserialize_value<std::uint32_t>(deserializer));
           }
 
           insert(deserialize_value<value_type>(deserializer));
         }
       }
 
       tsl_rh_assert(nb_elements == size());
     } else {
       m_bucket_count = numeric_cast<size_type>(
           bucket_count_ds, "Deserialized bucket_count is too big.");
 
       GrowthPolicy::operator=(GrowthPolicy(m_bucket_count));
       // GrowthPolicy should not modify the bucket count we got from
       // deserialization
       if (m_bucket_count != bucket_count_ds) {
         TSL_RH_THROW_OR_TERMINATE(std::runtime_error,
                                   "The GrowthPolicy is not the same even "
                                   "though hash_compatible is true.");
       }
 
       m_nb_elements = numeric_cast<size_type>(
           nb_elements, "Deserialized nb_elements is too big.");
       m_buckets_data.resize(m_bucket_count);
       m_buckets = m_buckets_data.data();
 
       for (bucket_entry& bucket : m_buckets_data) {
         const distance_type dist_from_ideal_bucket =
             deserialize_value<std::int16_t>(deserializer);
         if (dist_from_ideal_bucket !=
             bucket_entry::EMPTY_MARKER_DIST_FROM_IDEAL_BUCKET) {
           truncated_hash_type truncated_hash = 0;
           if (hash_stored_for_bucket) {
             tsl_rh_assert(hash_stored_for_bucket);
             truncated_hash = deserialize_value<std::uint32_t>(deserializer);
           }
 
           bucket.set_value_of_empty_bucket(
               dist_from_ideal_bucket, truncated_hash,
               deserialize_value<value_type>(deserializer));
         }
       }
 
       if (!m_buckets_data.empty()) {
         m_buckets_data.back().set_as_last_bucket();
       }
     }
   }
 
  public:
   static const size_type DEFAULT_INIT_BUCKETS_SIZE = 0;
 
   static constexpr float DEFAULT_MAX_LOAD_FACTOR = 0.5f;
   static constexpr float MINIMUM_MAX_LOAD_FACTOR = 0.2f;
   static constexpr float MAXIMUM_MAX_LOAD_FACTOR = 0.95f;
 
   static constexpr float DEFAULT_MIN_LOAD_FACTOR = 0.0f;
   static constexpr float MINIMUM_MIN_LOAD_FACTOR = 0.0f;
   static constexpr float MAXIMUM_MIN_LOAD_FACTOR = 0.15f;
 
   static_assert(MINIMUM_MAX_LOAD_FACTOR < MAXIMUM_MAX_LOAD_FACTOR,
                 "MINIMUM_MAX_LOAD_FACTOR should be < MAXIMUM_MAX_LOAD_FACTOR");
   static_assert(MINIMUM_MIN_LOAD_FACTOR < MAXIMUM_MIN_LOAD_FACTOR,
                 "MINIMUM_MIN_LOAD_FACTOR should be < MAXIMUM_MIN_LOAD_FACTOR");
   static_assert(MAXIMUM_MIN_LOAD_FACTOR < MINIMUM_MAX_LOAD_FACTOR,
                 "MAXIMUM_MIN_LOAD_FACTOR should be < MINIMUM_MAX_LOAD_FACTOR");
 
  private:
   /**
    * Protocol version currenlty used for serialization.
    */
   static const slz_size_type SERIALIZATION_PROTOCOL_VERSION = 1;
 
   /**
    * Return an always valid pointer to an static empty bucket_entry with
    * last_bucket() == true.
    */
   bucket_entry* static_empty_bucket_ptr() noexcept {
     static bucket_entry empty_bucket(true);
     tsl_rh_assert(empty_bucket.empty());
     return &empty_bucket;
   }
 
  private:
   buckets_container_type m_buckets_data;
 
   /**
    * Points to m_buckets_data.data() if !m_buckets_data.empty() otherwise points
    * to static_empty_bucket_ptr. This variable is useful to avoid the cost of
    * checking if m_buckets_data is empty when trying to find an element.
    *
    * TODO Remove m_buckets_data and only use a pointer instead of a
    * pointer+vector to save some space in the robin_hash object. Manage the
    * Allocator manually.
    */
   bucket_entry* m_buckets;
 
   /**
    * Used a lot in find, avoid the call to m_buckets_data.size() which is a bit
    * slower.
    */
   size_type m_bucket_count;
 
   size_type m_nb_elements;
 
   size_type m_load_threshold;
 
   float m_min_load_factor;
   float m_max_load_factor;
 
   bool m_grow_on_next_insert;
 
   /**
    * We can't shrink down the map on erase operations as the erase methods need
    * to return the next iterator. Shrinking the map would invalidate all the
    * iterators and we could not return the next iterator in a meaningful way, On
    * erase, we thus just indicate on erase that we should try to shrink the hash
    * table on the next insert if we go below the min_load_factor.
    */
   bool m_try_shrink_on_next_insert;
 };
 
 }  // namespace detail_robin_hash
 
 }  // namespace tsl
 
 #endif