/**

 * 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_ORDERED_SET_H

#define TSL_ORDERED_SET_H

#include <cstddef>

#include <cstdint>

#include <deque>

#include <functional>

#include <initializer_list>

#include <memory>

#include <type_traits>

#include <utility>

#include <vector>

#include "ordered_hash.h"

namespace tsl {

/**

 * Implementation of an hash set using open addressing with robin hood with

 * backshift delete to resolve collisions.

 *

 * The particularity of this hash set is that it remembers the order in which

 * the elements were added and provide a way to access the structure which

 * stores these values through the 'values_container()' method. The used

 * container is defined by ValueTypeContainer, by default a std::deque is used

 * (grows faster) but a std::vector may be used. In this case the set provides a

 * 'data()' method which give a direct access to the memory used to store the

 * values (which can be useful to communicate with C API's).

 *

 * The Key must be copy constructible and/or move constructible. To use

 * `unordered_erase` it also must be swappable.

 *

 * The behaviour of the hash set is undefined if the destructor of Key throws an

 * exception.

 *

 * By default the maximum size of a set is limited to 2^32 - 1 values, if needed

 * this can be changed through the IndexType template parameter. Using an

 * `uint64_t` will raise this limit to 2^64 - 1 values but each bucket will use

 * 16 bytes instead of 8 bytes in addition to the space needed to store the

 * values.

 *

 * Iterators invalidation:

 *  - clear, operator=, reserve, rehash: always invalidate the iterators (also

 * invalidate end()).

 *  - insert, emplace, emplace_hint, operator[]: when a std::vector is used as

 * ValueTypeContainer and if size() < capacity(), only end(). Otherwise all the

 * iterators are invalidated if an insert occurs.

 *  - erase, unordered_erase: when a std::vector is used as ValueTypeContainer

 * invalidate the iterator of the erased element and all the ones after the

 * erased element (including end()). Otherwise all the iterators are invalidated

 * if an erase occurs.

 */

template <class Key, class Hash = std::hash<Key>,

          class KeyEqual = std::equal_to<Key>,

          class Allocator = std::allocator<Key>,

          class ValueTypeContainer = std::deque<Key, Allocator>,

          class IndexType = std::uint_least32_t>

class ordered_set {

 private:

  template <typename U>

  using has_is_transparent = tsl::detail_ordered_hash::has_is_transparent<U>;

  class KeySelect {

   public:

    using key_type = Key;

    const key_type& operator()(const Key& key) const noexcept { return key; }

Unexecuted instantiation: tsl::ordered_set<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::deque<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, unsigned int>::KeySelect::operator()(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const

Unexecuted instantiation: tsl::ordered_set<int, std::__1::hash<int>, std::__1::equal_to<int>, std::__1::allocator<int>, std::__1::deque<int, std::__1::allocator<int> >, unsigned int>::KeySelect::operator()(int const&) const

    key_type& operator()(Key& key) noexcept { return key; }

Unexecuted instantiation: tsl::ordered_set<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::deque<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, unsigned int>::KeySelect::operator()(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >&)

Unexecuted instantiation: tsl::ordered_set<int, std::__1::hash<int>, std::__1::equal_to<int>, std::__1::allocator<int>, std::__1::deque<int, std::__1::allocator<int> >, unsigned int>::KeySelect::operator()(int&)

  };

  using ht = detail_ordered_hash::ordered_hash<Key, KeySelect, void, Hash,

                                               KeyEqual, Allocator,

                                               ValueTypeContainer, IndexType>;

 public:

  using key_type = typename ht::key_type;

  using value_type = typename ht::value_type;

  using size_type = typename ht::size_type;

  using difference_type = typename ht::difference_type;

  using hasher = typename ht::hasher;

  using key_equal = typename ht::key_equal;

  using allocator_type = typename ht::allocator_type;

  using reference = typename ht::reference;

  using const_reference = typename ht::const_reference;

  using pointer = typename ht::pointer;

  using const_pointer = typename ht::const_pointer;

  using iterator = typename ht::iterator;

  using const_iterator = typename ht::const_iterator;

  using reverse_iterator = typename ht::reverse_iterator;

  using const_reverse_iterator = typename ht::const_reverse_iterator;

  using values_container_type = typename ht::values_container_type;

  /*

   * Constructors

   */

  ordered_set() : ordered_set(ht::DEFAULT_INIT_BUCKETS_SIZE) {}

Unexecuted instantiation: tsl::ordered_set<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::deque<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, unsigned int>::ordered_set()

Unexecuted instantiation: tsl::ordered_set<int, std::__1::hash<int>, std::__1::equal_to<int>, std::__1::allocator<int>, std::__1::deque<int, std::__1::allocator<int> >, unsigned int>::ordered_set()

  explicit ordered_set(size_type bucket_count, const Hash& hash = Hash(),

                       const KeyEqual& equal = KeyEqual(),

                       const Allocator& alloc = Allocator())

      : m_ht(bucket_count, hash, equal, alloc, ht::DEFAULT_MAX_LOAD_FACTOR) {}

Unexecuted instantiation: tsl::ordered_set<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::deque<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, unsigned int>::ordered_set(unsigned long, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > const&, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > const&, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > const&)

Unexecuted instantiation: tsl::ordered_set<int, std::__1::hash<int>, std::__1::equal_to<int>, std::__1::allocator<int>, std::__1::deque<int, std::__1::allocator<int> >, unsigned int>::ordered_set(unsigned long, std::__1::hash<int> const&, std::__1::equal_to<int> const&, std::__1::allocator<int> const&)

  ordered_set(size_type bucket_count, const Allocator& alloc)

      : ordered_set(bucket_count, Hash(), KeyEqual(), alloc) {}

  ordered_set(size_type bucket_count, const Hash& hash, const Allocator& alloc)

      : ordered_set(bucket_count, hash, KeyEqual(), alloc) {}

  explicit ordered_set(const Allocator& alloc)

      : ordered_set(ht::DEFAULT_INIT_BUCKETS_SIZE, alloc) {}

  template <class InputIt>

  ordered_set(InputIt first, InputIt last,

              size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,

              const Hash& hash = Hash(), const KeyEqual& equal = KeyEqual(),

              const Allocator& alloc = Allocator())

      : ordered_set(bucket_count, hash, equal, alloc) {

    insert(first, last);

  }

  template <class InputIt>

  ordered_set(InputIt first, InputIt last, size_type bucket_count,

              const Allocator& alloc)

      : ordered_set(first, last, bucket_count, Hash(), KeyEqual(), alloc) {}

  template <class InputIt>

  ordered_set(InputIt first, InputIt last, size_type bucket_count,

              const Hash& hash, const Allocator& alloc)

      : ordered_set(first, last, bucket_count, hash, KeyEqual(), alloc) {}

  ordered_set(std::initializer_list<value_type> init,

              size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,

              const Hash& hash = Hash(), const KeyEqual& equal = KeyEqual(),

              const Allocator& alloc = Allocator())

      : ordered_set(init.begin(), init.end(), bucket_count, hash, equal,

                    alloc) {}

  ordered_set(std::initializer_list<value_type> init, size_type bucket_count,

              const Allocator& alloc)

      : ordered_set(init.begin(), init.end(), bucket_count, Hash(), KeyEqual(),

                    alloc) {}

  ordered_set(std::initializer_list<value_type> init, size_type bucket_count,

              const Hash& hash, const Allocator& alloc)

      : ordered_set(init.begin(), init.end(), bucket_count, hash, KeyEqual(),

                    alloc) {}

  ordered_set& operator=(std::initializer_list<value_type> ilist) {

    m_ht.clear();

    m_ht.reserve(ilist.size());

    m_ht.insert(ilist.begin(), ilist.end());

    return *this;

  }

  allocator_type get_allocator() const { return m_ht.get_allocator(); }

  /*

   * 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(); }

  reverse_iterator rbegin() noexcept { return m_ht.rbegin(); }

  const_reverse_iterator rbegin() const noexcept { return m_ht.rbegin(); }

  const_reverse_iterator rcbegin() const noexcept { return m_ht.rcbegin(); }

  reverse_iterator rend() noexcept { return m_ht.rend(); }

  const_reverse_iterator rend() const noexcept { return m_ht.rend(); }

  const_reverse_iterator rcend() const noexcept { return m_ht.rcend(); }

  /*

   * 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(); }

  /*

   * Modifiers

   */

  void clear() noexcept { m_ht.clear(); }

  std::pair<iterator, bool> insert(const value_type& value) {

    return m_ht.insert(value);

  }

Unexecuted instantiation: tsl::ordered_set<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::hash<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::equal_to<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::deque<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > >, unsigned int>::insert(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)

Unexecuted instantiation: tsl::ordered_set<int, std::__1::hash<int>, std::__1::equal_to<int>, std::__1::allocator<int>, std::__1::deque<int, std::__1::allocator<int> >, unsigned int>::insert(int const&)

  std::pair<iterator, bool> insert(value_type&& value) {

    return m_ht.insert(std::move(value));

  }

  iterator insert(const_iterator hint, const value_type& value) {

    return m_ht.insert_hint(hint, value);

  }

  iterator insert(const_iterator hint, value_type&& value) {

    return m_ht.insert_hint(hint, std::move(value));

  }

  template <class InputIt>

  void insert(InputIt first, InputIt last) {

    m_ht.insert(first, last);

  }

  void insert(std::initializer_list<value_type> ilist) {

    m_ht.insert(ilist.begin(), ilist.end());

  }

  /**

   * Due to the way elements are stored, emplace will need to move or copy the

   * key-value once. The method is equivalent to

   * insert(value_type(std::forward<Args>(args)...));

   *

   * Mainly here for compatibility with the std::unordered_map interface.

   */

  template <class... Args>

  std::pair<iterator, bool> emplace(Args&&... args) {

    return m_ht.emplace(std::forward<Args>(args)...);

  }

  /**

   * Due to the way elements are stored, emplace_hint will need to move or copy

   * the key-value once. The method is equivalent to insert(hint,

   * value_type(std::forward<Args>(args)...));

   *

   * Mainly here for compatibility with the std::unordered_map interface.

   */

  template <class... Args>

  iterator emplace_hint(const_iterator hint, Args&&... args) {

    return m_ht.emplace_hint(hint, std::forward<Args>(args)...);

  }

  /**

   * When erasing an element, the insert order will be preserved and no holes

   * will be present in the container returned by 'values_container()'.

   *

   * The method is in O(bucket_count()), if the order is not important

   * 'unordered_erase(...)' method is faster with an O(1) average complexity.

   */

  iterator erase(iterator pos) { return m_ht.erase(pos); }

  /**

   * @copydoc erase(iterator pos)

   */

  iterator erase(const_iterator pos) { return m_ht.erase(pos); }

  /**

   * @copydoc erase(iterator pos)

   */

  iterator erase(const_iterator first, const_iterator last) {

    return m_ht.erase(first, last);

  }

  /**

   * @copydoc erase(iterator pos)

   */

  size_type erase(const key_type& key) { return m_ht.erase(key); }

  /**

   * @copydoc erase(iterator pos)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup to the value if you already have the hash.

   */

  size_type erase(const key_type& key, std::size_t precalculated_hash) {

    return m_ht.erase(key, precalculated_hash);

  }

  /**

   * @copydoc erase(iterator pos)

   *

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type erase(const K& key) {

    return m_ht.erase(key);

  }

  /**

   * @copydoc erase(const key_type& key, std::size_t precalculated_hash)

   *

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type erase(const K& key, std::size_t precalculated_hash) {

    return m_ht.erase(key, precalculated_hash);

  }

  /**

   * @copydoc erase(iterator pos)

   *

   * Erases all elements that satisfy the predicate pred. The method is in

   * O(n). Note that the function only has the strong exception guarantee if

   * the Predicate, Hash, and Key predicates and moves of keys and values do

   * not throw. If an exception is raised, the object is in an invalid state.

   * It can still be cleared and destroyed without leaking memory.

   */

  template <class Predicate>

  friend size_type erase_if(ordered_set &set, Predicate pred) {

    return set.m_ht.erase_if(pred);

  }

  void swap(ordered_set& other) { other.m_ht.swap(m_ht); }

  /*

   * Lookup

   */

  size_type count(const Key& key) const { return m_ht.count(key); }

  /**

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  size_type count(const Key& key, std::size_t precalculated_hash) const {

    return m_ht.count(key, precalculated_hash);

  }

  /**

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type count(const K& key) const {

    return m_ht.count(key);

  }

  /**

   * @copydoc count(const K& key) const

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type count(const K& key, std::size_t precalculated_hash) const {

    return m_ht.count(key, precalculated_hash);

  }

  iterator find(const Key& key) { return m_ht.find(key); }

  /**

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  iterator find(const Key& key, std::size_t precalculated_hash) {

    return m_ht.find(key, precalculated_hash);

  }

  const_iterator find(const Key& key) const { return m_ht.find(key); }

  /**

   * @copydoc find(const Key& key, std::size_t precalculated_hash)

   */

  const_iterator find(const Key& key, std::size_t precalculated_hash) const {

    return m_ht.find(key, precalculated_hash);

  }

  /**

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  iterator find(const K& key) {

    return m_ht.find(key);

  }

  /**

   * @copydoc find(const K& key)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  iterator find(const K& key, std::size_t precalculated_hash) {

    return m_ht.find(key, precalculated_hash);

  }

  /**

   * @copydoc find(const K& key)

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  const_iterator find(const K& key) const {

    return m_ht.find(key);

  }

  /**

   * @copydoc find(const K& key)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  const_iterator find(const K& key, std::size_t precalculated_hash) const {

    return m_ht.find(key, precalculated_hash);

  }

  bool contains(const Key& key) const { return m_ht.contains(key); }

  /**

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  bool contains(const Key& key, std::size_t precalculated_hash) const {

    return m_ht.contains(key, precalculated_hash);

  }

  /**

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  bool contains(const K& key) const {

    return m_ht.contains(key);

  }

  /**

   * @copydoc contains(const K& key) const

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  bool contains(const K& key, std::size_t precalculated_hash) const {

    return m_ht.contains(key, precalculated_hash);

  }

  std::pair<iterator, iterator> equal_range(const Key& key) {

    return m_ht.equal_range(key);

  }

  /**

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  std::pair<iterator, iterator> equal_range(const Key& key,

                                            std::size_t precalculated_hash) {

    return m_ht.equal_range(key, precalculated_hash);

  }

  std::pair<const_iterator, const_iterator> equal_range(const Key& key) const {

    return m_ht.equal_range(key);

  }

  /**

   * @copydoc equal_range(const Key& key, std::size_t precalculated_hash)

   */

  std::pair<const_iterator, const_iterator> equal_range(

      const Key& key, std::size_t precalculated_hash) const {

    return m_ht.equal_range(key, precalculated_hash);

  }

  /**

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  std::pair<iterator, iterator> equal_range(const K& key) {

    return m_ht.equal_range(key);

  }

  /**

   * @copydoc equal_range(const K& key)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  std::pair<iterator, iterator> equal_range(const K& key,

                                            std::size_t precalculated_hash) {

    return m_ht.equal_range(key, precalculated_hash);

  }

  /**

   * @copydoc equal_range(const K& key)

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  std::pair<const_iterator, const_iterator> equal_range(const K& key) const {

    return m_ht.equal_range(key);

  }

  /**

   * @copydoc equal_range(const K& key, std::size_t precalculated_hash)

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  std::pair<const_iterator, const_iterator> equal_range(

      const K& key, std::size_t precalculated_hash) const {

    return m_ht.equal_range(key, 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

   */

  /**

   * Convert a const_iterator to an iterator.

   */

  iterator mutable_iterator(const_iterator pos) {

    return m_ht.mutable_iterator(pos);

  }

  /**

   * Requires index <= size().

   *

   * Return an iterator to the element at index. Return end() if index ==

   * size().

   */

  iterator nth(size_type index) { return m_ht.nth(index); }

  /**

   * @copydoc nth(size_type index)

   */

  const_iterator nth(size_type index) const { return m_ht.nth(index); }

  /**

   * Return const_reference to the first element. Requires the container to not

   * be empty.

   */

  const_reference front() const { return m_ht.front(); }

  /**

   * Return const_reference to the last element. Requires the container to not

   * be empty.

   */

  const_reference back() const { return m_ht.back(); }

  /**

   * Only available if ValueTypeContainer is a std::vector. Same as calling

   * 'values_container().data()'.

   */

  template <class U = values_container_type,

            typename std::enable_if<

                tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>

  const typename values_container_type::value_type* data() const noexcept {

    return m_ht.data();

  }

  /**

   * Return the container in which the values are stored. The values are in the

   * same order as the insertion order and are contiguous in the structure, no

   * holes (size() == values_container().size()).

   */

  const values_container_type& values_container() const noexcept {

    return m_ht.values_container();

  }

  /**

   * Release the container in which the values are stored.

   *

   * The set is empty after this operation.

   */

  values_container_type release() { return m_ht.release(); }

  template <class U = values_container_type,

            typename std::enable_if<

                tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>

  size_type capacity() const noexcept {

    return m_ht.capacity();

  }

  void shrink_to_fit() { m_ht.shrink_to_fit(); }

  /**

   * Insert the value before pos shifting all the elements on the right of pos

   * (including pos) one position to the right.

   *

   * O(bucket_count()) runtime complexity.

   */

  std::pair<iterator, bool> insert_at_position(const_iterator pos,

                                               const value_type& value) {

    return m_ht.insert_at_position(pos, value);

  }

  /**

   * @copydoc insert_at_position(const_iterator pos, const value_type& value)

   */

  std::pair<iterator, bool> insert_at_position(const_iterator pos,

                                               value_type&& value) {

    return m_ht.insert_at_position(pos, std::move(value));

  }

  /**

   * @copydoc insert_at_position(const_iterator pos, const value_type& value)

   *

   * Same as insert_at_position(pos, value_type(std::forward<Args>(args)...),

   * mainly here for coherence.

   */

  template <class... Args>

  std::pair<iterator, bool> emplace_at_position(const_iterator pos,

                                                Args&&... args) {

    return m_ht.emplace_at_position(pos, std::forward<Args>(args)...);

  }

  void pop_back() { m_ht.pop_back(); }

  /**

   * Faster erase operation with an O(1) average complexity but it doesn't

   * preserve the insertion order.

   *

   * If an erasure occurs, the last element of the map will take the place of

   * the erased element.

   */

  iterator unordered_erase(iterator pos) { return m_ht.unordered_erase(pos); }

  /**

   * @copydoc unordered_erase(iterator pos)

   */

  iterator unordered_erase(const_iterator pos) {

    return m_ht.unordered_erase(pos);

  }

  /**

   * @copydoc unordered_erase(iterator pos)

   */

  size_type unordered_erase(const key_type& key) {

    return m_ht.unordered_erase(key);

  }

  /**

   * @copydoc unordered_erase(iterator pos)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  size_type unordered_erase(const key_type& key,

                            std::size_t precalculated_hash) {

    return m_ht.unordered_erase(key, precalculated_hash);

  }

  /**

   * @copydoc unordered_erase(iterator pos)

   *

   * This overload only participates in the overload resolution if the typedef

   * KeyEqual::is_transparent exists. If so, K must be hashable and comparable

   * to Key.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type unordered_erase(const K& key) {

    return m_ht.unordered_erase(key);

  }

  /**

   * @copydoc unordered_erase(const K& key)

   *

   * Use the hash value 'precalculated_hash' instead of hashing the key. The

   * hash value should be the same as hash_function()(key). Useful to speed-up

   * the lookup if you already have the hash.

   */

  template <

      class K, class KE = KeyEqual,

      typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>

  size_type unordered_erase(const K& key, std::size_t precalculated_hash) {

    return m_ht.unordered_erase(key, precalculated_hash);

  }

  /**

   * Serialize the set through the `serializer` parameter.

   *

   * The `serializer` parameter must be a function object that supports the

   * following call:

   *  - `void operator()(const U& value);` where the types `std::uint64_t`,

   * `float` and `Key` must be supported for U.

   *

   * The implementation leaves binary compatibility (endianness, IEEE 754 for

   * floats, ...) of the types it serializes in the hands of the `Serializer`

   * function object if compatibility is required.

   */

  template <class Serializer>

  void serialize(Serializer& serializer) const {

    m_ht.serialize(serializer);

  }

  /**

   * Deserialize a previously serialized set through the `deserializer`

   * parameter.

   *

   * The `deserializer` parameter must be a function object that supports the

   * following calls:

   *  - `template<typename U> U operator()();` where the types `std::uint64_t`,

   * `float` and `Key` must be supported for U.

   *

   * If the deserialized hash set type is hash compatible with the serialized

   * set, the deserialization process can be sped up by setting

   * `hash_compatible` to true. To be hash compatible, the Hash and KeyEqual

   * must behave the same way than the ones used on the serialized map. The

   * `std::size_t` must also be of the same size as the one on the platform used

   * to serialize the map, the same apply for `IndexType`. If these criteria are

   * not met, the behaviour is undefined with `hash_compatible` sets to true.

   *

   * The behaviour is undefined if the type `Key` of the `ordered_set` is not

   * the same as the type used during serialization.

   *

   * The implementation leaves binary compatibility (endianness, IEEE 754 for

   * floats, size of int, ...) of the types it deserializes in the hands of the

   * `Deserializer` function object if compatibility is required.

   */

  template <class Deserializer>

  static ordered_set deserialize(Deserializer& deserializer,

                                 bool hash_compatible = false) {

    ordered_set set(0);

    set.m_ht.deserialize(deserializer, hash_compatible);

    return set;

  }

  friend bool operator==(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht == rhs.m_ht;

  }

  friend bool operator!=(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht != rhs.m_ht;

  }

  friend bool operator<(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht < rhs.m_ht;

  }

  friend bool operator<=(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht <= rhs.m_ht;

  }

  friend bool operator>(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht > rhs.m_ht;

  }

  friend bool operator>=(const ordered_set& lhs, const ordered_set& rhs) {

    return lhs.m_ht >= rhs.m_ht;

  }

  friend void swap(ordered_set& lhs, ordered_set& rhs) { lhs.swap(rhs); }

 private:

  ht m_ht;

};

}  // end namespace tsl

#endif