fsfw/contrib/fsfw_contrib/etl-20.39.4/include/etl/reference_flat_multimap.h

///\file

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2017 John Wellbelove

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
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The above copyright notice and this permission notice shall be included in all
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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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 ETL_REFERENCE_FLAT_MULTIMAP_INCLUDED
#define ETL_REFERENCE_FLAT_MULTIMAP_INCLUDED

#include "platform.h"
#include "exception.h"
#include "error_handler.h"
#include "debug_count.h"
#include "vector.h"
#include "iterator.h"
#include "nth_type.h"
#include "type_traits.h"
#include "type_traits.h"

#include "private/comparator_is_transparent.h"

#include <stddef.h>

namespace etl
{
  //***************************************************************************
  ///\ingroup reference_flat_multimap
  /// Exception base for reference_flat_multimaps
  //***************************************************************************
  class flat_multimap_exception : public exception
  {
  public:

    flat_multimap_exception(string_type reason_, string_type file_name_, numeric_type line_number_)
      : exception(reason_, file_name_, line_number_)
    {
    }
  };

  //***************************************************************************
  ///\ingroup reference_flat_multimap
  /// Vector full exception.
  //***************************************************************************
  class flat_multimap_full : public flat_multimap_exception
  {
  public:

    flat_multimap_full(string_type file_name_, numeric_type line_number_)
      : flat_multimap_exception(ETL_ERROR_TEXT("flat_multimap:full", ETL_REFERENCE_FLAT_MULTIMAP_FILE_ID"A"), file_name_, line_number_)
    {
    }
  };

  //***************************************************************************
  /// The base class for specifically sized reference_flat_multimaps.
  /// Can be used as a reference type for all reference_flat_multimaps containing a specific type.
  ///\ingroup reference_flat_multimap
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare = etl::less<TKey> >
  class ireference_flat_multimap
  {
  public:

    typedef ETL_OR_STD::pair<const TKey, TMapped> value_type;

  protected:

    typedef etl::ivector<value_type*> lookup_t;

  public:

    typedef TKey              key_type;
    typedef TMapped           mapped_type;
    typedef TKeyCompare       key_compare;
    typedef value_type&       reference;
    typedef const value_type& const_reference;
    typedef value_type*       pointer;
    typedef const value_type* const_pointer;
    typedef size_t            size_type;

    //*************************************************************************
    class iterator : public etl::iterator<ETL_OR_STD::bidirectional_iterator_tag, value_type>
    {
    public:

      friend class ireference_flat_multimap;
      friend class const_iterator;

      iterator()
      {
      }

      iterator(typename lookup_t::iterator ilookup_)
        : ilookup(ilookup_)
      {
      }

      iterator(const iterator& other)
        : ilookup(other.ilookup)
      {
      }

      iterator& operator =(const iterator& other)
      {
        ilookup = other.ilookup;
        return *this;
      }

      iterator& operator ++()
      {
        ++ilookup;
        return *this;
      }

      iterator operator ++(int)
      {
        iterator temp(*this);
        ++ilookup;
        return temp;
      }

      iterator& operator --()
      {
        --ilookup;
        return *this;
      }

      iterator operator --(int)
      {
        iterator temp(*this);
        --ilookup;
        return temp;
      }

      reference operator *() const
      {
        return *(*ilookup);
      }

      pointer operator &() const
      {
        return etl::addressof(*(*ilookup));
      }

      pointer operator ->() const
      {
        return etl::addressof(*(*ilookup));
      }

      friend bool operator == (const iterator& lhs, const iterator& rhs)
      {
        return lhs.ilookup == rhs.ilookup;
      }

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

    private:

      typename lookup_t::iterator ilookup;
    };

    //*************************************************************************
    class const_iterator : public etl::iterator<ETL_OR_STD::bidirectional_iterator_tag, const value_type>
    {
    public:

      friend class ireference_flat_multimap;

      const_iterator()
      {
      }

      const_iterator(typename lookup_t::const_iterator ilookup_)
        : ilookup(ilookup_)
      {
      }

      const_iterator(const typename ireference_flat_multimap::iterator& other)
        : ilookup(other.ilookup)
      {
      }

      const_iterator(const const_iterator& other)
        : ilookup(other.ilookup)
      {
      }

      const_iterator& operator =(const iterator& other)
      {
        ilookup = other.ilookup;
        return *this;
      }

      const_iterator& operator =(const const_iterator& other)
      {
        ilookup = other.ilookup;
        return *this;
      }

      const_iterator& operator ++()
      {
        ++ilookup;
        return *this;
      }

      const_iterator operator ++(int)
      {
        const_iterator temp(*this);
        ++ilookup;
        return temp;
      }

      const_iterator& operator --()
      {
        --ilookup;
        return *this;
      }

      const_iterator operator --(int)
      {
        const_iterator temp(*this);
        --ilookup;
        return temp;
      }

      const_reference operator *() const
      {
        return *(*ilookup);
      }

      const_pointer operator &() const
      {
        return etl::addressof(*(*ilookup));
      }

      const_pointer operator ->() const
      {
        return etl::addressof(*(*ilookup));
      }

      friend bool operator == (const const_iterator& lhs, const const_iterator& rhs)
      {
        return lhs.ilookup == rhs.ilookup;
      }

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

    private:

      typename lookup_t::const_iterator ilookup;
    };

    typedef ETL_OR_STD::reverse_iterator<iterator>       reverse_iterator;
    typedef ETL_OR_STD::reverse_iterator<const_iterator> const_reverse_iterator;
    typedef typename etl::iterator_traits<iterator>::difference_type difference_type;

  protected:

    typedef const TKey& key_parameter_t;

  private:

    //*********************************************************************
    /// How to compare elements and keys.
    //*********************************************************************
    class Compare
    {
    public:

      bool operator ()(const value_type& element, key_type key) const
      {
        return comp(element.first, key);
      }

      bool operator ()(key_type key, const value_type& element) const
      {
        return comp(key, element.first);
      }

#if ETL_USING_CPP11
      template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
      bool operator ()(const value_type& element, const K& key) const
      {
        return comp(element.first, key);
      }

      template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
      bool operator ()(const K& key, const value_type& element) const
      {
        return comp(key, element.first);
      }
#endif

      key_compare comp;
    };

  public:

    //*********************************************************************
    /// Returns an iterator to the beginning of the reference_flat_multimap.
    ///\return An iterator to the beginning of the reference_flat_multimap.
    //*********************************************************************
    iterator begin()
    {
      return iterator(lookup.begin());
    }

    //*********************************************************************
    /// Returns a const_iterator to the beginning of the reference_flat_multimap.
    ///\return A const iterator to the beginning of the reference_flat_multimap.
    //*********************************************************************
    const_iterator begin() const
    {
      return const_iterator(lookup.begin());
    }

    //*********************************************************************
    /// Returns an iterator to the end of the reference_flat_multimap.
    ///\return An iterator to the end of the reference_flat_multimap.
    //*********************************************************************
    iterator end()
    {
      return iterator(lookup.end());
    }

    //*********************************************************************
    /// Returns a const_iterator to the end of the reference_flat_multimap.
    ///\return A const iterator to the end of the reference_flat_multimap.
    //*********************************************************************
    const_iterator end() const
    {
      return const_iterator(lookup.end());
    }

    //*********************************************************************
    /// Returns a const_iterator to the beginning of the reference_flat_multimap.
    ///\return A const iterator to the beginning of the reference_flat_multimap.
    //*********************************************************************
    const_iterator cbegin() const
    {
      return const_iterator(lookup.cbegin());
    }

    //*********************************************************************
    /// Returns a const_iterator to the end of the reference_flat_multimap.
    ///\return A const iterator to the end of the reference_flat_multimap.
    //*********************************************************************
    const_iterator cend() const
    {
      return const_iterator(lookup.cend());
    }

    //*********************************************************************
    /// Returns an reverse iterator to the reverse beginning of the reference_flat_multimap.
    ///\return Iterator to the reverse beginning of the reference_flat_multimap.
    //*********************************************************************
    reverse_iterator rbegin()
    {
      return reverse_iterator(lookup.rbegin());
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the reverse beginning of the reference_flat_multimap.
    ///\return Const iterator to the reverse beginning of the reference_flat_multimap.
    //*********************************************************************
    const_reverse_iterator rbegin() const
    {
      return const_reverse_iterator(lookup.rbegin());
    }

    //*********************************************************************
    /// Returns a reverse iterator to the end + 1 of the reference_flat_multimap.
    ///\return Reverse iterator to the end + 1 of the reference_flat_multimap.
    //*********************************************************************
    reverse_iterator rend()
    {
      return reverse_iterator(lookup.rend());
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the end + 1 of the reference_flat_multimap.
    ///\return Const reverse iterator to the end + 1 of the reference_flat_multimap.
    //*********************************************************************
    const_reverse_iterator rend() const
    {
      return const_reverse_iterator(lookup.rend());
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the reverse beginning of the reference_flat_multimap.
    ///\return Const reverse iterator to the reverse beginning of the reference_flat_multimap.
    //*********************************************************************
    const_reverse_iterator crbegin() const
    {
      return const_reverse_iterator(lookup.crbegin());
    }

    //*********************************************************************
    /// Returns a const reverse iterator to the end + 1 of the reference_flat_multimap.
    ///\return Const reverse iterator to the end + 1 of the reference_flat_multimap.
    //*********************************************************************
    const_reverse_iterator crend() const
    {
      return const_reverse_iterator(lookup.crend());
    }

    //*********************************************************************
    /// Assigns values to the reference_flat_multimap.
    /// If asserts or exceptions are enabled, emits reference_flat_multimap_full if the reference_flat_multimap does not have enough free space.
    /// If asserts or exceptions are enabled, emits reference_flat_multimap_iterator if the iterators are reversed.
    ///\param first The iterator to the first element.
    ///\param last  The iterator to the last element + 1.
    //*********************************************************************
    template <typename TIterator>
    void assign(TIterator first, TIterator last)
    {
#if ETL_IS_DEBUG_BUILD
      difference_type d = etl::distance(first, last);
      ETL_ASSERT(d <= difference_type(capacity()), ETL_ERROR(flat_multimap_full));
#endif

      clear();

      while (first != last)
      {
        insert(*first);
        ++first;
      }
    }

    //*********************************************************************
    /// Inserts a value to the reference_flat_multimap.
    /// If asserts or exceptions are enabled, emits reference_flat_multimap_full if the reference_flat_multimap is already full.
    ///\param value    The value to insert.
    //*********************************************************************
    ETL_OR_STD::pair<iterator, bool> insert(value_type& value)
    {
      ETL_ASSERT(!lookup.full(), ETL_ERROR(flat_multimap_full));

      ETL_OR_STD::pair<iterator, bool> result(end(), false);

      iterator i_element = upper_bound(value.first);

      return insert_at(i_element, value);
    }

    //*********************************************************************
    /// Inserts a value to the flat_multi.
    /// If asserts or exceptions are enabled, emits flat_map_full if the flat_map is already full.
    ///\param position The position to insert at.
    ///\param value    The value to insert.
    //*********************************************************************
    iterator insert(const_iterator /*position*/, const value_type& value)
    {
      return insert(value).first;
    }

    //*********************************************************************
    /// Inserts a range of values to the reference_flat_multimap.
    /// If asserts or exceptions are enabled, emits reference_flat_multimap_full if the reference_flat_multimap does not have enough free space.
    ///\param position The position to insert at.
    ///\param first    The first element to add.
    ///\param last     The last + 1 element to add.
    //*********************************************************************
    template <class TIterator>
    void insert(TIterator first, TIterator last)
    {
      while (first != last)
      {
        insert(*first);
        ++first;
      }
    }

    //*********************************************************************
    /// Erases an element.
    ///\param key The key to erase.
    ///\return The number of elements erased. 0 or 1.
    //*********************************************************************
    size_t erase(key_parameter_t key)
    {
      ETL_OR_STD::pair<iterator, iterator> range = equal_range(key);

      if (range.first == end())
      {
        return 0;
      }
      else
      {
        size_t d = etl::distance(range.first, range.second);
        erase(range.first, range.second);
        return d;
      }
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    size_t erase(K&& key)
    {
      ETL_OR_STD::pair<iterator, iterator> range = equal_range(key);

      if (range.first == end())
      {
        return 0U;
      }
      else
      {
        size_t d = etl::distance(range.first, range.second);
        erase(range.first, range.second);
        return d;
      }
    }
#endif

    //*********************************************************************
    /// Erases an element.
    ///\param i_element Iterator to the element.
    //*********************************************************************
    iterator erase(iterator i_element)
    {
      return lookup.erase(i_element.ilookup);
    }

    //*********************************************************************
    /// Erases an element.
    ///\param i_element Iterator to the element.
    //*********************************************************************
    iterator erase(const_iterator i_element)
    {
      return lookup.erase(i_element.ilookup);
    }

    //*********************************************************************
    /// Erases a range of elements.
    /// The range includes all the elements between first and last, including the
    /// element pointed by first, but not the one pointed by last.
    ///\param first Iterator to the first element.
    ///\param last  Iterator to the last element.
    //*********************************************************************
    iterator erase(const_iterator first, const_iterator last)
    {
      return lookup.erase(first.ilookup, last.ilookup);
    }

    //*************************************************************************
    /// Clears the reference_flat_multimap.
    //*************************************************************************
    void clear()
    {
      lookup.clear();
    }

    //*********************************************************************
    /// Finds an element.
    ///\param key The key to search for.
    ///\return An iterator pointing to the element or end() if not found.
    //*********************************************************************
    iterator find(key_parameter_t key)
    {
      iterator itr = lower_bound(key);

      if (itr != end())
      {
        if (!key_compare()(itr->first, key) && !key_compare()(key, itr->first))
        {
          return itr;
        }
        else
        {
          return end();
        }
      }

      return end();
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    iterator find(const K& key)
    {
      iterator itr = lower_bound(key);

      if (itr != end())
      {
        if (!key_compare()(itr->first, key) && !key_compare()(key, itr->first))
        {
          return itr;
        }
        else
        {
          return end();
        }
      }

      return end();
    }
#endif

    //*********************************************************************
    /// Finds an element.
    ///\param key The key to search for.
    ///\return An iterator pointing to the element or end() if not found.
    //*********************************************************************
    const_iterator find(key_parameter_t key) const
    {
      const_iterator itr = lower_bound(key);

      if (itr != end())
      {
        if (!key_compare()(itr->first, key) && !key_compare()(key, itr->first))
        {
          return itr;
        }
        else
        {
          return end();
        }
      }

      return end();
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    const_iterator find(const K& key) const
    {
      const_iterator itr = lower_bound(key);

      if (itr != end())
      {
        if (!key_compare()(itr->first, key) && !key_compare()(key, itr->first))
        {
          return itr;
        }
        else
        {
          return end();
        }
      }

      return end();
    }
#endif

    //*********************************************************************
    /// Counts an element.
    ///\param key The key to search for.
    ///\return 1 if the key exists, otherwise 0.
    //*********************************************************************
    size_t count(key_parameter_t key) const
    {
      ETL_OR_STD::pair<const_iterator, const_iterator> range = equal_range(key);

      return etl::distance(range.first, range.second);
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    size_t count(const K& key) const
    {
      ETL_OR_STD::pair<const_iterator, const_iterator> range = equal_range(key);

      return etl::distance(range.first, range.second);
    }
#endif

    //*********************************************************************
    /// Finds the lower bound of a key
    ///\param key The key to search for.
    ///\return An iterator.
    //*********************************************************************
    iterator lower_bound(key_parameter_t key)
    {
      return etl::lower_bound(begin(), end(), key, compare);
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    iterator lower_bound(const K& key)
    {
      return etl::lower_bound(begin(), end(), key, compare);
    }
#endif

    //*********************************************************************
    /// Finds the lower bound of a key
    ///\param key The key to search for.
    ///\return An iterator.
    //*********************************************************************
    const_iterator lower_bound(key_parameter_t key) const
    {
      return etl::lower_bound(cbegin(), cend(), key, compare);
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    const_iterator lower_bound(const K& key) const
    {
      return etl::lower_bound(cbegin(), cend(), key, compare);
    }
#endif

    //*********************************************************************
    /// Finds the upper bound of a key
    ///\param key The key to search for.
    ///\return An iterator.
    //*********************************************************************
    iterator upper_bound(key_parameter_t key)
    {
      return etl::upper_bound(begin(), end(), key, compare);
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    iterator upper_bound(const K& key)
    {
      return etl::upper_bound(begin(), end(), key, compare);
    }
#endif

    //*********************************************************************
    /// Finds the upper bound of a key
    ///\param key The key to search for.
    ///\return An iterator.
    //*********************************************************************
    const_iterator upper_bound(key_parameter_t key) const
    {
      return etl::upper_bound(begin(), end(), key, compare);
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    const_iterator upper_bound(const K& key) const
    {
      return etl::upper_bound(begin(), end(), key, compare);
    }
#endif

    //*********************************************************************
    /// Finds the range of equal elements of a key
    ///\param key The key to search for.
    ///\return An iterator pair.
    //*********************************************************************
    ETL_OR_STD::pair<iterator, iterator> equal_range(key_parameter_t key)
    {
      iterator i_lower = etl::lower_bound(begin(), end(), key, compare);

      return ETL_OR_STD::make_pair(i_lower, etl::upper_bound(i_lower, end(), key, compare));
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    ETL_OR_STD::pair<iterator, iterator> equal_range(const K& key)
    {
      iterator i_lower = etl::lower_bound(begin(), end(), key, compare);

      return ETL_OR_STD::make_pair(i_lower, etl::upper_bound(i_lower, end(), key, compare));
    }
#endif

    //*********************************************************************
    /// Finds the range of equal elements of a key
    ///\param key The key to search for.
    ///\return An iterator pair.
    //*********************************************************************
    ETL_OR_STD::pair<const_iterator, const_iterator> equal_range(key_parameter_t key) const
    {
      const_iterator i_lower = etl::lower_bound(cbegin(), cend(), key, compare);

      return ETL_OR_STD::make_pair(i_lower, etl::upper_bound(i_lower, cend(), key, compare));
    }

#if ETL_USING_CPP11
    //*********************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    ETL_OR_STD::pair<const_iterator, const_iterator> equal_range(const K& key) const
    {
      const_iterator i_lower = etl::lower_bound(cbegin(), cend(), key, compare);

      return ETL_OR_STD::make_pair(i_lower, etl::upper_bound(i_lower, cend(), key, compare));
    }
#endif

    //*************************************************************************
    /// Check if the map contains the key.
    //*************************************************************************
    bool contains(const TKey& key) const
    {
      return find(key) != end();
    }

#if ETL_USING_CPP11
    //*************************************************************************
    template <typename K, typename KC = TKeyCompare, etl::enable_if_t<comparator_is_transparent<KC>::value, int> = 0>
    bool contains(const K& k) const
    {
      return find(k) != end();
    }
#endif

    //*************************************************************************
    /// Gets the current size of the flat_multiset.
    ///\return The current size of the flat_multiset.
    //*************************************************************************
    size_type size() const
    {
      return lookup.size();
    }

    //*************************************************************************
    /// Checks the 'empty' state of the flat_multiset.
    ///\return <b>true</b> if empty.
    //*************************************************************************
    bool empty() const
    {
      return lookup.empty();
    }

    //*************************************************************************
    /// Checks the 'full' state of the flat_multiset.
    ///\return <b>true</b> if full.
    //*************************************************************************
    bool full() const
    {
      return lookup.full();
    }

    //*************************************************************************
    /// Returns the capacity of the flat_multiset.
    ///\return The capacity of the flat_multiset.
    //*************************************************************************
    size_type capacity() const
    {
      return lookup.capacity();
    }

    //*************************************************************************
    /// Returns the maximum possible size of the flat_multiset.
    ///\return The maximum size of the flat_multiset.
    //*************************************************************************
    size_type max_size() const
    {
      return lookup.max_size();
    }

    //*************************************************************************
    /// Returns the remaining capacity.
    ///\return The remaining capacity.
    //*************************************************************************
    size_t available() const
    {
      return lookup.available();
    }

  protected:

    //*********************************************************************
    /// Constructor.
    //*********************************************************************
    ireference_flat_multimap(lookup_t& lookup_)
      : lookup(lookup_)
    {
    }

    //*********************************************************************
    /// Inserts a value to the reference_flat_multimap.
    ///\param i_element The place to insert.
    ///\param value     The value to insert.
    //*********************************************************************
    ETL_OR_STD::pair<iterator, bool> insert_at(iterator i_element, value_type& value)
    {
      ETL_OR_STD::pair<iterator, bool> result(end(), false);

      if (i_element == end())
      {
        // At the end.
        lookup.push_back(&value);
        result.first = --end();
        result.second = true;
      }
      else
      {
        // Not at the end.
        lookup.insert(i_element.ilookup, &value);
        result.first = i_element;
        result.second = true;
      }

      return result;
    }

  private:

    // Disable copy construction and assignment.
    ireference_flat_multimap(const ireference_flat_multimap&);
    ireference_flat_multimap& operator = (const ireference_flat_multimap&);

    lookup_t&  lookup;

    Compare compare;

    //*************************************************************************
    /// Destructor.
    //*************************************************************************
#if defined(ETL_POLYMORPHIC_REFERENCE_FLAT_MULTIMAP) || defined(ETL_POLYMORPHIC_CONTAINERS)
  public:
    virtual ~ireference_flat_multimap()
    {
    }
#else
  protected:
    ~ireference_flat_multimap()
    {
    }
#endif
  };

  //***************************************************************************
  /// Equal operator.
  ///\param lhs Reference to the first reference_flat_multimap.
  ///\param rhs Reference to the second reference_flat_multimap.
  ///\return <b>true</b> if the arrays are equal, otherwise <b>false</b>
  ///\ingroup reference_flat_multimap
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare>
  bool operator ==(const etl::ireference_flat_multimap<TKey, TMapped, TKeyCompare>& lhs, const etl::ireference_flat_multimap<TKey, TMapped, TKeyCompare>& rhs)
  {
    return (lhs.size() == rhs.size()) && etl::equal(lhs.begin(), lhs.end(), rhs.begin());
  }

  //***************************************************************************
  /// Not equal operator.
  ///\param lhs Reference to the first reference_flat_multimap.
  ///\param rhs Reference to the second reference_flat_multimap.
  ///\return <b>true</b> if the arrays are not equal, otherwise <b>false</b>
  ///\ingroup reference_flat_multimap
  //***************************************************************************
  template <typename TKey, typename TMapped, typename TKeyCompare>
  bool operator !=(const etl::ireference_flat_multimap<TKey, TMapped, TKeyCompare>& lhs, const etl::ireference_flat_multimap<TKey, TMapped, TKeyCompare>& rhs)
  {
    return !(lhs == rhs);
  }

  //***************************************************************************
  /// A reference_flat_multimap implementation that uses a fixed size buffer.
  ///\tparam TKey     The key type.
  ///\tparam TValue   The value type.
  ///\tparam TCompare The type to compare keys. Default = etl::less<TKey>
  ///\tparam MAX_SIZE_ The maximum number of elements that can be stored.
  ///\ingroup reference_flat_multimap
  //***************************************************************************
  template <typename TKey, typename TValue, const size_t MAX_SIZE_, typename TCompare = etl::less<TKey> >
  class reference_flat_multimap : public ireference_flat_multimap<TKey, TValue, TCompare>
  {
  public:

    static ETL_CONSTANT size_t MAX_SIZE = MAX_SIZE_;

    //*************************************************************************
    /// Constructor.
    //*************************************************************************
    reference_flat_multimap()
      : ireference_flat_multimap<TKey, TValue, TCompare>(lookup)
    {
    }

    //*************************************************************************
    /// Copy constructor.
    //*************************************************************************
    reference_flat_multimap(const reference_flat_multimap& other)
      : ireference_flat_multimap<TKey, TValue, TCompare>(lookup)
    {
      ireference_flat_multimap<TKey, TValue, TCompare>::assign(other.cbegin(), other.cend());
    }

    //*************************************************************************
    /// Constructor, from an iterator range.
    ///\tparam TIterator The iterator type.
    ///\param first The iterator to the first element.
    ///\param last  The iterator to the last element + 1.
    //*************************************************************************
    template <typename TIterator>
    reference_flat_multimap(TIterator first, TIterator last)
      : ireference_flat_multimap<TKey, TValue, TCompare>(lookup)
    {
      ireference_flat_multimap<TKey, TValue, TCompare>::assign(first, last);
    }

    //*************************************************************************
    /// Destructor.
    //*************************************************************************
    ~reference_flat_multimap()
    {
      ireference_flat_multimap<TKey, TValue, TCompare>::clear();
    }

  private:

    typedef typename ireference_flat_multimap<TKey, TValue, TCompare>::value_type node_t;

    // The vector that stores pointers to the nodes.
    etl::vector<node_t*, MAX_SIZE> lookup;
  };

  template <typename TKey, typename TValue, const size_t MAX_SIZE_, typename TCompare>
  ETL_CONSTANT size_t reference_flat_multimap< TKey, TValue, MAX_SIZE_, TCompare>::MAX_SIZE;

  //*************************************************************************
  /// Template deduction guides.
  //*************************************************************************
#if ETL_USING_CPP17 && ETL_HAS_INITIALIZER_LIST
  template <typename... TPairs>
  reference_flat_multimap(TPairs...) -> reference_flat_multimap<typename etl::nth_type_t<0, TPairs...>::first_type,
                                                                typename etl::nth_type_t<0, TPairs...>::second_type,
                                                                sizeof...(TPairs)>;
#endif

  //*************************************************************************
  /// Make
  //*************************************************************************
#if ETL_USING_CPP11 && ETL_HAS_INITIALIZER_LIST
  template <typename TKey, typename TMapped, typename TKeyCompare = etl::less<TKey>, typename... TPairs>
  constexpr auto make_reference_flat_multimap(TPairs&&... pairs) -> etl::reference_flat_multimap<TKey, TMapped, sizeof...(TPairs), TKeyCompare>
  {
    return { etl::forward<TPairs>(pairs)... };
  }
#endif
}

#endif