algorithm.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Documentation: https://www.etlcpp.com/algorithm.html
 
Copyright(c) 2014 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
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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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,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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******************************************************************************/
 
#ifndef ETL_ALGORITHM_INCLUDED
#define ETL_ALGORITHM_INCLUDED

 
#include "platform.h"
#include "error_handler.h"
#include "exception.h"
#include "functional.h"
#include "gcd.h"
#include "initializer_list.h"
#include "invoke.h"
#include "iterator.h"
#include "largest.h"
#include "ranges.h"
#include "type_traits.h"
#include "utility.h"
 
#include <stddef.h>
#include <string.h>
 
#include "private/minmax_push.h"
 
#if ETL_USING_STL
  #include <algorithm>
  #include <functional>
  #include <iterator>
  #include <numeric>
  #include <utility>
#endif
 
namespace etl
{
  // Declare prototypes of the ETL's sort functions
  template <typename TIterator>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    void
    shell_sort(TIterator first, TIterator last);
 
  template <typename TIterator, typename TCompare>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    void
    shell_sort(TIterator first, TIterator last, TCompare compare);
 
  template <typename TIterator>
  ETL_CONSTEXPR14 void insertion_sort(TIterator first, TIterator last);
 
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void insertion_sort(TIterator first, TIterator last, TCompare compare);
 
} // namespace etl
 
//*****************************************************************************
// Algorithms defined by the ETL
//*****************************************************************************
namespace etl
{
  struct stable_partition_exception : etl::exception
  {
    stable_partition_exception(string_type reason_, string_type file_, numeric_type line_)
      : etl::exception(reason_, file_, line_)
    {
    }
  };
 
  struct stable_partition_buffer_too_small : stable_partition_exception
  {
    stable_partition_buffer_too_small(string_type file_, numeric_type line_)
      : stable_partition_exception(ETL_ERROR_TEXT("stable_partition:buffer too small", ETL_ALGORITHM_FILE_ID"A"), file_, line_)
    {
    }
  };
 
  namespace private_algorithm
  {
    template <bool use_swap>
    struct swap_impl;
 
    // Generic swap
    template <>
    struct swap_impl<false>
    {
      template <typename TIterator1, typename TIterator2>
      static void do_swap(TIterator1 a, TIterator2 b)
      {
        typename etl::iterator_traits<TIterator1>::value_type tmp = *a;
        *a                                                        = *b;
        *b                                                        = tmp;
      }
    };
 
    // Specialised swap
    template <>
    struct swap_impl<true>
    {
      template <typename TIterator1, typename TIterator2>
      static void do_swap(TIterator1 a, TIterator2 b)
      {
        using ETL_OR_STD::swap; // Allow ADL
        swap(*a, *b);
      }
    };
  } // namespace private_algorithm
 
  //***************************************************************************
  // iter_swap
  //***************************************************************************
  template <typename TIterator1, typename TIterator2>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    void
    iter_swap(TIterator1 a, TIterator2 b)
  {
    typedef etl::iterator_traits<TIterator1> traits1;
    typedef etl::iterator_traits<TIterator2> traits2;
 
    typedef typename traits1::value_type v1;
    typedef typename traits2::value_type v2;
 
    typedef typename traits1::reference r1;
    typedef typename traits2::reference r2;
 
    const bool use_swap = etl::is_same<v1, v2>::value && etl::is_reference<r1>::value && etl::is_reference<r2>::value;
 
    private_algorithm::swap_impl<use_swap>::do_swap(a, b);
  }
 
  //***************************************************************************
  // swap_ranges
  //***************************************************************************
  template <typename TIterator1, typename TIterator2>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    TIterator2
    swap_ranges(TIterator1 first1, TIterator1 last1, TIterator2 first2)
  {
    while (first1 != last1)
    {
      etl::iter_swap(first1, first2);
      ++first1;
      ++first2;
    }
 
    return first2;
  }
 
  //***************************************************************************
  // generate
  template <typename TIterator, typename TFunction>
  ETL_CONSTEXPR14 void generate(TIterator db, TIterator de, TFunction funct)
  {
    while (db != de)
    {
      *db++ = funct();
    }
  }
 
  //***************************************************************************
  // copy
#if ETL_USING_STL && ETL_USING_CPP20
  // Use the STL constexpr implementation.
  template <typename TIterator1, typename TIterator2>
  constexpr TIterator2 copy(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    return std::copy(sb, se, db);
  }
#else
  // Non-pointer or not trivially copyable or not using builtin memcpy.
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 copy(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    while (sb != se)
    {
      *db = *sb;
      ++db;
      ++sb;
    }
 
    return db;
  }
#endif
 
  //***************************************************************************
  // reverse_copy
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator1, typename TIterator2>
  constexpr TIterator2 reverse_copy(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    return std::reverse_copy(sb, se, db);
  }
#else
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 reverse_copy(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    while (sb != se)
    {
      *db = *--se;
      ++db;
    }
 
    return db;
  }
#endif
 
  //***************************************************************************
  // copy_n
#if ETL_USING_STL && ETL_USING_CPP20
  // Use the STL implementation
  template <typename TIterator1, typename TSize, typename TIterator2>
  constexpr TIterator2 copy_n(TIterator1 sb, TSize count, TIterator2 db)
  {
    return std::copy_n(sb, count, db);
  }
#else
  // Non-pointer or not trivially copyable or not using builtin memcpy.
  template <typename TIterator1, typename TSize, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 copy_n(TIterator1 sb, TSize count, TIterator2 db)
  {
    while (count != 0)
    {
      *db = *sb;
      ++db;
      ++sb;
      --count;
    }
 
    return db;
  }
#endif
 
  //***************************************************************************
  // copy_backward
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator1, typename TIterator2>
  constexpr TIterator2 copy_backward(TIterator1 sb, TIterator1 se, TIterator2 de)
  {
    return std::copy_backward(sb, se, de);
  }
#else
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 copy_backward(TIterator1 sb, TIterator1 se, TIterator2 de)
  {
    while (se != sb)
    {
      *(--de) = *(--se);
    }
 
    return de;
  }
#endif
 
  //***************************************************************************
  // move
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator1, typename TIterator2>
  constexpr TIterator2 move(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    return std::move(sb, se, db);
  }
#elif ETL_USING_CPP11
  // For C++11
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 move(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    while (sb != se)
    {
      *db = etl::move(*sb);
      ++db;
      ++sb;
    }
 
    return db;
  }
#else
  // For C++03
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 move(TIterator1 sb, TIterator1 se, TIterator2 db)
  {
    return copy(sb, se, db);
  }
#endif
 
  //***************************************************************************
  // move_backward
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR20 TIterator2 move_backward(TIterator1 sb, TIterator1 se, TIterator2 de)
  {
  #include "etl/private/diagnostic_array_bounds_push.h"
    return std::move_backward(sb, se, de);
  #include "etl/private/diagnostic_pop.h"
  }
#elif ETL_USING_CPP11
  // For C++11
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 move_backward(TIterator1 sb, TIterator1 se, TIterator2 de)
  {
    while (sb != se)
    {
      *(--de) = etl::move(*(--se));
    }
 
    return de;
  }
#else
  // For C++03
  template <typename TIterator1, typename TIterator2>
  ETL_CONSTEXPR14 TIterator2 move_backward(TIterator1 sb, TIterator1 se, TIterator2 de)
  {
    return etl::copy_backward(sb, se, de);
  }
#endif
 
  //***************************************************************************
  // reverse
  //***************************************************************************
  // Pointers
  template <typename TIterator>
  ETL_CONSTEXPR14 typename etl::enable_if<etl::is_pointer<TIterator>::value, void>::type reverse(TIterator b, TIterator e)
  {
    if (b != e)
    {
      while (b < --e)
      {
        etl::iter_swap(b, e);
        ++b;
      }
    }
  }
 
  // Non-pointers
  template <typename TIterator>
  ETL_CONSTEXPR14 typename etl::enable_if<!etl::is_pointer<TIterator>::value, void>::type reverse(TIterator b, TIterator e)
  {
    while ((b != e) && (b != --e))
    {
      etl::iter_swap(b++, e);
    }
  }
 
  //***************************************************************************
  // lower_bound
  //***************************************************************************
  template <typename TIterator, typename TValue, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator lower_bound(TIterator first, TIterator last, const TValue& value, TCompare compare)
  {
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    difference_t count = etl::distance(first, last);
 
    while (count > 0)
    {
      TIterator    itr  = first;
      difference_t step = count / 2;
 
      etl::advance(itr, step);
 
      if (compare(*itr, value))
      {
        first = ++itr;
        count -= step + 1;
      }
      else
      {
        count = step;
      }
    }
 
    return first;
  }
 
  template <typename TIterator, typename TValue>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator lower_bound(TIterator first, TIterator last, const TValue& value)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return etl::lower_bound(first, last, value, compare());
  }
 
  //***************************************************************************
  // upper_bound
  //***************************************************************************
  template <typename TIterator, typename TValue, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator upper_bound(TIterator first, TIterator last, const TValue& value, TCompare compare)
  {
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    difference_t count = etl::distance(first, last);
 
    while (count > 0)
    {
      TIterator    itr  = first;
      difference_t step = count / 2;
 
      etl::advance(itr, step);
 
      if (!compare(value, *itr))
      {
        first = ++itr;
        count -= step + 1;
      }
      else
      {
        count = step;
      }
    }
 
    return first;
  }
 
  template <typename TIterator, typename TValue>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator upper_bound(TIterator first, TIterator last, const TValue& value)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return etl::upper_bound(first, last, value, compare());
  }
 
  //***************************************************************************
  // equal_range
  //***************************************************************************
  template <typename TIterator, typename TValue, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 ETL_OR_STD::pair<TIterator, TIterator> equal_range(TIterator first, TIterator last, const TValue& value, TCompare compare)
  {
    return ETL_OR_STD::make_pair(etl::lower_bound(first, last, value, compare), etl::upper_bound(first, last, value, compare));
  }
 
  template <typename TIterator, typename TValue>
  ETL_NODISCARD
  ETL_OR_STD::pair<TIterator, TIterator> equal_range(TIterator first, TIterator last, const TValue& value)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return ETL_OR_STD::make_pair(etl::lower_bound(first, last, value, compare()), etl::upper_bound(first, last, value, compare()));
  }
 
  //***************************************************************************
  // binary_search
  //***************************************************************************
  template <typename TIterator, typename T, typename Compare>
  ETL_NODISCARD ETL_CONSTEXPR14 bool binary_search(TIterator first, TIterator last, const T& value, Compare compare)
  {
    first = etl::lower_bound(first, last, value, compare);
 
    return (!(first == last) && !(compare(value, *first)));
  }
 
  template <typename TIterator, typename T>
  ETL_NODISCARD ETL_CONSTEXPR14 bool binary_search(TIterator first, TIterator last, const T& value)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return binary_search(first, last, value, compare());
  }
 
  //***************************************************************************
  // find_if
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator find_if(TIterator first, TIterator last, TUnaryPredicate predicate)
  {
    while (first != last)
    {
      if (predicate(*first))
      {
        return first;
      }
 
      ++first;
    }
 
    return last;
  }
 
  //***************************************************************************
  // find
  //***************************************************************************
  template <typename TIterator, typename T>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator find(TIterator first, TIterator last, const T& value)
  {
    while (first != last)
    {
      if (*first == value)
      {
        return first;
      }
 
      ++first;
    }
 
    return last;
  }
 
  //***************************************************************************
  // fill
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator, typename TValue>
  constexpr void fill(TIterator first, TIterator last, const TValue& value)
  {
    std::fill(first, last, value);
  }
#else
  template <typename TIterator, typename TValue>
  ETL_CONSTEXPR14 void fill(TIterator first, TIterator last, const TValue& value)
  {
    while (first != last)
    {
      // This cast is necessary because the signedness can differ
      *first = static_cast<typename etl::iterator_traits<TIterator>::value_type>(value);
      ++first;
    }
  }
#endif
 
  //***************************************************************************
  // fill_n
#if ETL_USING_STL && ETL_USING_CPP20
  template <typename TIterator, typename TSize, typename TValue>
  constexpr TIterator fill_n(TIterator first, TSize count, const TValue& value)
  {
    return std::fill_n(first, count, value);
  }
#else
  template <typename TIterator, typename TSize, typename TValue>
  ETL_CONSTEXPR14 TIterator fill_n(TIterator first, TSize count, const TValue& value)
  {
    while (count != 0)
    {
      *first++ = value;
      --count;
    }
 
    return first;
  }
#endif
 
  //***************************************************************************
  // count
  //***************************************************************************
  template <typename TIterator, typename T>
  ETL_NODISCARD ETL_CONSTEXPR14 typename etl::iterator_traits<TIterator>::difference_type count(TIterator first, TIterator last, const T& value)
  {
    typename iterator_traits<TIterator>::difference_type n = 0;
 
    while (first != last)
    {
      if (*first == value)
      {
        ++n;
      }
 
      ++first;
    }
 
    return n;
  }
 
  //***************************************************************************
  // count_if
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 typename etl::iterator_traits<TIterator>::difference_type count_if(TIterator first, TIterator last, TUnaryPredicate predicate)
  {
    typename iterator_traits<TIterator>::difference_type n = 0;
 
    while (first != last)
    {
      if (predicate(*first))
      {
        ++n;
      }
 
      ++first;
    }
 
    return n;
  }
 
  //***************************************************************************
  // equal
#if ETL_USING_STL && ETL_USING_CPP20
  // Three parameter
  template <typename TIterator1, typename TIterator2>
  [[nodiscard]]
  constexpr bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2)
  {
    return std::equal(first1, last1, first2);
  }
 
  // Three parameter + predicate
  template <typename TIterator1, typename TIterator2, typename TPredicate>
  [[nodiscard]]
  constexpr bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TPredicate predicate)
  {
    return std::equal(first1, last1, first2, predicate);
  }
 
  // Four parameter
  template <typename TIterator1, typename TIterator2>
  [[nodiscard]]
  constexpr bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2)
  {
    return std::equal(first1, last1, first2, last2);
  }
 
  // Four parameter + Predicate
  template <typename TIterator1, typename TIterator2, typename TPredicate>
  [[nodiscard]]
  constexpr bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2, TPredicate predicate)
  {
    return std::equal(first1, last1, first2, last2, predicate);
  }
 
#else
 
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2)
  {
    while (first1 != last1)
    {
      if (*first1 != *first2)
      {
        return false;
      }
 
      ++first1;
      ++first2;
    }
 
    return true;
  }
 
  // Predicate
  template <typename TIterator1, typename TIterator2, typename TPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TPredicate predicate)
  {
    while (first1 != last1)
    {
      if (!predicate(*first1, *first2))
      {
        return false;
      }
 
      ++first1;
      ++first2;
    }
 
    return true;
  }
 
  // Four parameter
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2)
  {
    while ((first1 != last1) && (first2 != last2))
    {
      if (*first1 != *first2)
      {
        return false;
      }
 
      ++first1;
      ++first2;
    }
 
    return (first1 == last1) && (first2 == last2);
  }
 
  // Four parameter, Predicate
  template <typename TIterator1, typename TIterator2, typename TPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool equal(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2, TPredicate predicate)
  {
    while ((first1 != last1) && (first2 != last2))
    {
      if (!predicate(*first1, *first2))
      {
        return false;
      }
 
      ++first1;
      ++first2;
    }
 
    return (first1 == last1) && (first2 == last2);
  }
#endif
 
  //***************************************************************************
  // lexicographical_compare
  //***************************************************************************
  template <typename TIterator1, typename TIterator2, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 bool lexicographical_compare(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2, TCompare compare)
  {
    while ((first1 != last1) && (first2 != last2))
    {
      if (compare(*first1, *first2))
      {
        return true;
      }
 
      if (compare(*first2, *first1))
      {
        return false;
      }
 
      ++first1;
      ++first2;
    }
 
    return (first1 == last1) && (first2 != last2);
  }
 
  // lexicographical_compare
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 bool lexicographical_compare(TIterator1 first1, TIterator1 last1, TIterator2 first2, TIterator2 last2)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator1>::value_type> compare;
 
    return etl::lexicographical_compare(first1, last1, first2, last2, compare());
  }
 
  //***************************************************************************
  // min
  //***************************************************************************
  template <typename T, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR const T& min(const T& a, const T& b, TCompare compare)
  {
    return (compare(a, b)) ? a : b;
  }
 
  template <typename T>
  ETL_NODISCARD ETL_CONSTEXPR const T& min(const T& a, const T& b)
  {
    typedef etl::less<T> compare;
 
    return etl::min(a, b, compare());
  }
 
  //***************************************************************************
  // max
  //***************************************************************************
  template <typename T, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR const T& max(const T& a, const T& b, TCompare compare)
  {
    return (compare(a, b)) ? b : a;
  }
 
  template <typename T>
  ETL_NODISCARD ETL_CONSTEXPR const T& max(const T& a, const T& b)
  {
    typedef etl::less<T> compare;
 
    return etl::max(a, b, compare());
  }
 
  //***************************************************************************
  // for_each
  //***************************************************************************
  template <typename TIterator, typename TUnaryOperation>
  ETL_CONSTEXPR14 TUnaryOperation for_each(TIterator first, TIterator last, TUnaryOperation unary_operation)
  {
    while (first != last)
    {
      unary_operation(*first);
      ++first;
    }
 
    return unary_operation;
  }
 
  //***************************************************************************
  // transform
  //***************************************************************************
  template <typename TIteratorIn, typename TIteratorOut, typename TUnaryOperation>
  ETL_CONSTEXPR14 TIteratorOut transform(TIteratorIn first1, TIteratorIn last1, TIteratorOut d_first, TUnaryOperation unary_operation)
  {
    while (first1 != last1)
    {
      *d_first = unary_operation(*first1);
 
      ++d_first;
      ++first1;
    }
 
    return d_first;
  }
 
  template <typename TIteratorIn1, typename TIteratorIn2, typename TIteratorOut, typename TBinaryOperation>
  ETL_CONSTEXPR14 TIteratorOut transform(TIteratorIn1 first1, TIteratorIn1 last1, TIteratorIn2 first2, TIteratorOut d_first,
                                   TBinaryOperation binary_operation)
  {
    while (first1 != last1)
    {
      *d_first = binary_operation(*first1, *first2);
 
      ++d_first;
      ++first1;
      ++first2;
    }
 
    return d_first;
  }
 
  //***************************************************************************
  // replace
  //***************************************************************************
  template <typename TIterator, typename T>
  ETL_CONSTEXPR14 void replace(TIterator first, TIterator last, const T& old_value, const T& new_value)
  {
    while (first != last)
    {
      if (*first == old_value)
      {
        *first = new_value;
      }
 
      ++first;
    }
  }
 
  //***************************************************************************
  // replace_if
  //***************************************************************************
  template <typename TIterator, typename TPredicate, typename T>
  ETL_CONSTEXPR14 void replace_if(TIterator first, TIterator last, TPredicate predicate, const T& new_value)
  {
    while (first != last)
    {
      if (predicate(*first))
      {
        *first = new_value;
      }
 
      ++first;
    }
  }
 
  //***************************************************************************
  // Heap
  //***************************************************************************
  namespace private_heap
  {
    // Push Heap Helper
    template <typename TIterator, typename TDistance, typename TValue, typename TCompare>
    ETL_CONSTEXPR14 void push_heap(TIterator first, TDistance value_index, TDistance top_index, TValue value, TCompare compare)
    {
      TDistance parent = (value_index - 1) / 2;
 
#include "etl/private/diagnostic_array_bounds_push.h"
      while ((value_index > top_index) && compare(*(first + parent), value))
      {
        *(first + value_index) = ETL_MOVE(*(first + parent));
        value_index            = parent;
        parent                 = (value_index - 1) / 2;
      }
 
      *(first + value_index) = ETL_MOVE(value);
#include "etl/private/diagnostic_pop.h"
    }
 
    // Adjust Heap Helper
    template <typename TIterator, typename TDistance, typename TValue, typename TCompare>
    ETL_CONSTEXPR14 void adjust_heap(TIterator first, TDistance value_index, TDistance length, TValue value, TCompare compare)
    {
      TDistance top_index = value_index;
      TDistance child2nd  = (2 * value_index) + 2;
 
#include "etl/private/diagnostic_array_bounds_push.h"
      while (child2nd < length)
      {
        if (compare(*(first + child2nd), *(first + (child2nd - 1))))
        {
          --child2nd;
        }
 
        *(first + value_index) = ETL_MOVE(*(first + child2nd));
        value_index            = child2nd;
        child2nd               = 2 * (child2nd + 1);
      }
 
      if (child2nd == length)
      {
        *(first + value_index) = ETL_MOVE(*(first + (child2nd - 1)));
        value_index            = child2nd - 1;
      }
#include "etl/private/diagnostic_pop.h"
 
      push_heap(first, value_index, top_index, ETL_MOVE(value), compare);
    }
 
    // Is Heap Helper
    template <typename TIterator, typename TDistance, typename TCompare>
    ETL_CONSTEXPR14 bool is_heap(const TIterator first, const TDistance n, TCompare compare)
    {
      TDistance parent = 0;
 
      for (TDistance child = 1; child < n; ++child)
      {
        if (compare(*(first + parent), *(first + child)))
        {
          return false;
        }
 
        if ((child & 1) == 0)
        {
          ++parent;
        }
      }
 
      return true;
    }
  } // namespace private_heap
 
  // Pop Heap
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void pop_heap(TIterator first, TIterator last, TCompare compare)
  {
    typedef typename etl::iterator_traits<TIterator>::value_type      value_t;
    typedef typename etl::iterator_traits<TIterator>::difference_type distance_t;
 
    const distance_t n = last - first;
    if (n <= 1)
    {
      return;
    }
 
    value_t value = ETL_MOVE(*(last - 1));
    *(last - 1)   = ETL_MOVE(*first);
 
    private_heap::adjust_heap(first, distance_t(0), distance_t(last - first - 1), ETL_MOVE(value), compare);
  }
 
  // Pop Heap
  template <typename TIterator>
  ETL_CONSTEXPR14 void pop_heap(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    etl::pop_heap(first, last, compare());
  }
 
  // Push Heap
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void push_heap(TIterator first, TIterator last, TCompare compare)
  {
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
    typedef typename etl::iterator_traits<TIterator>::value_type      value_t;
 
    private_heap::push_heap(first, difference_t(last - first - 1), difference_t(0), value_t(ETL_MOVE(*(last - 1))), compare);
  }
 
  // Push Heap
  template <typename TIterator>
  ETL_CONSTEXPR14 void push_heap(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    etl::push_heap(first, last, compare());
  }
 
  // Make Heap
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void make_heap(TIterator first, TIterator last, TCompare compare)
  {
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    if ((last - first) < 2)
    {
      return;
    }
 
    difference_t length = last - first;
    difference_t parent = (length - 2) / 2;
 
    while (true)
    {
      private_heap::adjust_heap(first, parent, length, ETL_MOVE(*(first + parent)), compare);
 
      if (parent == 0)
      {
        return;
      }
 
      --parent;
    }
  }
 
  // Make Heap
  template <typename TIterator>
  ETL_CONSTEXPR14 void make_heap(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    etl::make_heap(first, last, compare());
  }
 
  // Is Heap
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_heap(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return private_heap::is_heap(first, last - first, compare());
  }
 
  // Is Heap
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_heap(TIterator first, TIterator last, TCompare compare)
  {
    return private_heap::is_heap(first, last - first, compare);
  }
 
  // Sort Heap
  template <typename TIterator>
  ETL_CONSTEXPR14 void sort_heap(TIterator first, TIterator last)
  {
    while (first != last)
    {
      etl::pop_heap(first, last);
      --last;
    }
  }
 
  // Sort Heap
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void sort_heap(TIterator first, TIterator last, TCompare compare)
  {
    while (first != last)
    {
      etl::pop_heap(first, last, compare);
      --last;
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void partial_sort(TIterator first, TIterator middle, TIterator last, TCompare compare)
  {
    if (first == middle)
    {
      return;
    }
 
    typedef typename etl::iterator_traits<TIterator>::value_type      value_t;
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    etl::make_heap(first, middle, compare);
 
    for (TIterator i = middle; i != last; ++i)
    {
      if (compare(*i, *first))
      {
        value_t value = ETL_MOVE(*i);
        *i            = ETL_MOVE(*first);
 
        private_heap::adjust_heap(first, difference_t(0), difference_t(middle - first), ETL_MOVE(value), compare);
      }
    }
 
    etl::sort_heap(first, middle, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 void partial_sort(TIterator first, TIterator middle, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    etl::partial_sort(first, middle, last, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TRandomAccessIterator, typename TCompare>
  ETL_CONSTEXPR14 TRandomAccessIterator partial_sort_copy(TInputIterator first, TInputIterator last, TRandomAccessIterator d_first,
                                                    TRandomAccessIterator d_last, TCompare compare)
  {
    typedef typename etl::iterator_traits<TRandomAccessIterator>::value_type      value_t;
    typedef typename etl::iterator_traits<TRandomAccessIterator>::difference_type difference_t;
 
    TRandomAccessIterator result = d_first;
 
    // Fill the destination range
    while ((first != last) && (result != d_last))
    {
      *result = *first;
      ++result;
      ++first;
    }
 
    if (result == d_first)
    {
      return result;
    }
 
    // Build a max-heap over the destination range
    etl::make_heap(d_first, result, compare);
 
    // Process remaining input elements
    for (TInputIterator i = first; i != last; ++i)
    {
      if (compare(*i, *d_first))
      {
        value_t value = *i;
        private_heap::adjust_heap(d_first, difference_t(0), difference_t(result - d_first), ETL_MOVE(value), compare);
      }
    }
 
    etl::sort_heap(d_first, result, compare);
 
    return result;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TRandomAccessIterator>
  ETL_CONSTEXPR14 TRandomAccessIterator partial_sort_copy(TInputIterator first, TInputIterator last, TRandomAccessIterator d_first,
                                                    TRandomAccessIterator d_last)
  {
    typedef etl::less< typename etl::iterator_traits<TRandomAccessIterator>::value_type> compare;
 
    return etl::partial_sort_copy(first, last, d_first, d_last, compare());
  }
 
  //***************************************************************************
  // Search
  //***************************************************************************
  template <typename TIterator1, typename TIterator2, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator1 search(TIterator1 first, TIterator1 last, TIterator2 search_first, TIterator2 search_last, TCompare compare)
  {
    while (true)
    {
      TIterator1 itr        = first;
      TIterator2 search_itr = search_first;
 
      while (true)
      {
        if (search_itr == search_last)
        {
          return first;
        }
 
        if (itr == last)
        {
          return last;
        }
 
        if (!compare(*itr, *search_itr))
        {
          break;
        }
 
        ++itr;
        ++search_itr;
      }
 
      ++first;
    }
  }
 
  // Search
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator1 search(TIterator1 first, TIterator1 last, TIterator2 search_first, TIterator2 search_last)
  {
    typedef etl::equal_to<typename etl::iterator_traits<TIterator1>::value_type> compare;
 
    return etl::search(first, last, search_first, search_last, compare());
  }
 
  //***************************************************************************
  // Rotate
  //***************************************************************************
  namespace private_algorithm
  {
    //*********************************
    // For random access iterators
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_random_access_iterator<TIterator>::value, TIterator>::type
      rotate_general(TIterator first, TIterator middle, TIterator last)
    {
      if (first == middle)
      {
        return last;
      }
 
      if (middle == last)
      {
        return first;
      }
 
      typedef typename etl::iterator_traits<TIterator>::value_type      value_type;
      typedef typename etl::iterator_traits<TIterator>::difference_type difference_type;
 
      difference_type n      = last - first;
      difference_type m      = middle - first;
      difference_type gcd_nm = (n == 0 || m == 0) ? n + m : etl::gcd(n, m);
      TIterator       result = first + (last - middle);
 
      for (difference_type i = 0; i < gcd_nm; i++)
      {
        value_type      temp = ETL_MOVE(*(first + i));
        difference_type j    = i;
 
        while (true)
        {
          difference_type k = j + m;
 
          if (k >= n)
          {
            k = k - n;
          }
 
          if (k == i)
          {
            break;
          }
 
          *(first + j) = ETL_MOVE(*(first + k));
          j            = k;
        }
 
        *(first + j) = ETL_MOVE(temp);
      }
 
      return result;
    }
 
    //*********************************
    // For bidirectional iterators
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_bidirectional_iterator<TIterator>::value, TIterator>::type
      rotate_general(TIterator first, TIterator middle, TIterator last)
    {
      if (first == middle)
      {
        return last;
      }
 
      if (middle == last)
      {
        return first;
      }
 
      TIterator result = first;
      etl::advance(result, etl::distance(middle, last));
 
      reverse(first, middle);
      reverse(middle, last);
      reverse(first, last);
 
      return result;
    }
 
    //*********************************
    // For forward iterators
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_forward_iterator<TIterator>::value, TIterator>::type rotate_general(TIterator first, TIterator middle,
                                                                                                                  TIterator last)
    {
      if (first == middle)
      {
        return last;
      }
 
      if (middle == last)
      {
        return first;
      }
 
      TIterator next   = middle;
      TIterator result = first;
      etl::advance(result, etl::distance(middle, last));
 
      while (first != next)
      {
        using ETL_OR_STD::swap;
        swap(*first++, *next++);
 
        if (next == last)
        {
          next = middle;
        }
        else if (first == middle)
        {
          middle = next;
        }
      }
 
      return result;
    }
 
    //*********************************
    // Simplified algorithm for rotate left by one
    template <typename TIterator>
    ETL_CONSTEXPR14 TIterator rotate_left_by_one(TIterator first, TIterator last)
    {
      typedef typename etl::iterator_traits<TIterator>::value_type value_type;
 
      // Save the first item.
      value_type temp(ETL_MOVE(*first));
 
      // Move the rest.
#include "etl/private/diagnostic_stringop_overread_push.h"
      TIterator result = etl::move(etl::next(first), last, first);
#include "etl/private/diagnostic_pop.h"
 
      // Restore the first item in its rotated position.
      *result = ETL_MOVE(temp);
 
      // The new position of the first item.
      return result;
    }
 
    //*********************************
    // Simplified for algorithm rotate right by one
    template <typename TIterator>
    ETL_CONSTEXPR14 TIterator rotate_right_by_one(TIterator first, TIterator last)
    {
      typedef typename etl::iterator_traits<TIterator>::value_type value_type;
 
      // Save the last item.
      TIterator  previous = etl::prev(last);
      value_type temp(ETL_MOVE(*previous));
 
      // Move the rest.
      TIterator result = etl::move_backward(first, previous, last);
 
      // Restore the last item in its rotated position.
      *first = ETL_MOVE(temp);
 
      // The new position of the first item.
      return result;
    }
  } // namespace private_algorithm
 
  //*********************************
  template <typename TIterator>
  ETL_CONSTEXPR14 TIterator rotate(TIterator first, TIterator middle, TIterator last)
  {
    if (first == middle)
    {
      return last;
    }
    if (middle == last)
    {
      return first;
    }
 
    if (etl::next(first) == middle)
    {
      return private_algorithm::rotate_left_by_one(first, last);
    }
 
#if ETL_USING_CPP20
    if (etl::next(middle) == last)
    {
      if ETL_IF_CONSTEXPR (etl::is_bidirectional_iterator_concept< TIterator>::value)
      {
        return private_algorithm::rotate_right_by_one(first, last);
      }
    }
#endif
 
    return private_algorithm::rotate_general(first, middle, last);
  }
 
  //***************************************************************************
  // find_end
  //***************************************************************************
  // Predicate
  template <typename TIterator1, typename TIterator2, typename TPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator1 find_end(TIterator1 b, TIterator1 e, TIterator2 sb, TIterator2 se, TPredicate predicate)
  {
    if (sb == se)
    {
      return e;
    }
 
    TIterator1 result = e;
 
    while (true)
    {
      TIterator1 new_result = etl::search(b, e, sb, se, predicate);
 
      if (new_result == e)
      {
        break;
      }
      else
      {
        result = new_result;
        b      = result;
        ++b;
      }
    }
    return result;
  }
 
  // Default
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator1 find_end(TIterator1 b, TIterator1 e, TIterator2 sb, TIterator2 se)
  {
    typedef etl::equal_to<typename etl::iterator_traits<TIterator1>::value_type> predicate;
 
    return find_end(b, e, sb, se, predicate());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator min_element(TIterator begin, TIterator end, TCompare compare)
  {
    TIterator minimum = begin;
 
    if (begin != end)
    {
      ++begin;
 
      while (begin != end)
      {
        if (compare(*begin, *minimum))
        {
          minimum = begin;
        }
 
        ++begin;
      }
    }
 
    return minimum;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator min_element(TIterator begin, TIterator end)
  {
    typedef typename etl::iterator_traits<TIterator>::value_type value_t;
 
    return etl::min_element(begin, end, etl::less<value_t>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator max_element(TIterator begin, TIterator end, TCompare compare)
  {
    TIterator maximum = begin;
 
    if (begin != end)
    {
      ++begin;
 
      while (begin != end)
      {
        if (compare(*maximum, *begin))
        {
          maximum = begin;
        }
 
        ++begin;
      }
    }
 
    return maximum;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator max_element(TIterator begin, TIterator end)
  {
    typedef typename etl::iterator_traits<TIterator>::value_type value_t;
 
    return etl::max_element(begin, end, etl::less<value_t>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 ETL_OR_STD::pair<TIterator, TIterator> minmax_element(TIterator begin, TIterator end, TCompare compare)
  {
    TIterator minimum = begin;
    TIterator maximum = begin;
 
    if (begin != end)
    {
      ++begin;
 
      while (begin != end)
      {
        if (compare(*begin, *minimum))
        {
          minimum = begin;
        }
 
        if (!compare(*begin, *maximum))
        {
          maximum = begin;
        }
 
        ++begin;
      }
    }
 
    return ETL_OR_STD::pair<TIterator, TIterator>(minimum, maximum);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 ETL_OR_STD::pair<TIterator, TIterator> minmax_element(TIterator begin, TIterator end)
  {
    typedef typename etl::iterator_traits<TIterator>::value_type value_t;
 
    return etl::minmax_element(begin, end, etl::less<value_t>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename T>
  ETL_NODISCARD ETL_CONSTEXPR14 ETL_OR_STD::pair<const T&, const T&> minmax(const T& a, const T& b)
  {
    return (b < a) ? ETL_OR_STD::pair<const T&, const T&>(b, a) : ETL_OR_STD::pair<const T&, const T&>(a, b);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename T, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 ETL_OR_STD::pair<const T&, const T&> minmax(const T& a, const T& b, TCompare compare)
  {
    return compare(b, a) ? ETL_OR_STD::pair<const T&, const T&>(b, a) : ETL_OR_STD::pair<const T&, const T&>(a, b);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator is_sorted_until(TIterator begin, TIterator end, TCompare compare)
  {
    if (begin != end)
    {
      TIterator next = begin;
 
      while (++next != end)
      {
        if (compare(*next, *begin))
        {
          return next;
        }
 
        ++begin;
      }
    }
 
    return end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator is_sorted_until(TIterator begin, TIterator end)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return etl::is_sorted_until(begin, end, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_sorted(TIterator begin, TIterator end)
  {
    return etl::is_sorted_until(begin, end) == end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_sorted(TIterator begin, TIterator end, TCompare compare)
  {
    return etl::is_sorted_until(begin, end, compare) == end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator is_unique_sorted_until(TIterator begin, TIterator end, TCompare compare)
  {
    if (begin != end)
    {
      TIterator next = begin;
 
      while (++next != end)
      {
        if (!compare(*begin, *next))
        {
          return next;
        }
 
        ++begin;
      }
    }
 
    return end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator is_unique_sorted_until(TIterator begin, TIterator end)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
 
    return etl::is_unique_sorted_until(begin, end, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_unique_sorted(TIterator begin, TIterator end)
  {
    return etl::is_unique_sorted_until(begin, end) == end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_unique_sorted(TIterator begin, TIterator end, TCompare compare)
  {
    return etl::is_unique_sorted_until(begin, end, compare) == end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator find_if_not(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (!predicate(*begin))
      {
        return begin;
      }
 
      ++begin;
    }
 
    return end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TBinaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator adjacent_find(TIterator first, TIterator last, TBinaryPredicate predicate)
  {
    if (first != last)
    {
      TIterator next = first;
      ++next;
 
      while (next != last)
      {
        if (predicate(*first, *next))
        {
          return first;
        }
 
        ++first;
        ++next;
      }
    }
 
    return last;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator adjacent_find(TIterator first, TIterator last)
  {
    typedef etl::equal_to<typename etl::iterator_traits<TIterator>::value_type> predicate;
 
    return etl::adjacent_find(first, last, predicate());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_permutation(TIterator1 begin1, TIterator1 end1, TIterator2 begin2)
  {
    if (begin1 != end1)
    {
      TIterator2 end2 = begin2;
 
      etl::advance(end2, etl::distance(begin1, end1));
 
      for (TIterator1 i = begin1; i != end1; ++i)
      {
        if (i == etl::find(begin1, i, *i))
        {
          size_t n = static_cast<size_t>(etl::count(begin2, end2, *i));
 
          if (n == 0 || size_t(etl::count(i, end1, *i)) != n)
          {
            return false;
          }
        }
      }
    }
 
    return true;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator1, typename TIterator2, typename TBinaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_permutation(TIterator1 begin1, TIterator1 end1, TIterator2 begin2, TBinaryPredicate predicate)
  {
    if (begin1 != end1)
    {
      TIterator2 end2 = begin2;
 
      etl::advance(end2, etl::distance(begin1, end1));
 
      for (TIterator1 i = begin1; i != end1; ++i)
      {
        const typename etl::binder1st<TBinaryPredicate> predicate_is_i = etl::bind1st(predicate, *i);
        if (i == etl::find_if(begin1, i, predicate_is_i))
        {
          size_t n = static_cast<size_t>(etl::count_if(begin2, end2, predicate_is_i));
 
          if (n == 0 || size_t(etl::count_if(i, end1, predicate_is_i)) != n)
          {
            return false;
          }
        }
      }
    }
 
    return true;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator1, typename TIterator2>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_permutation(TIterator1 begin1, TIterator1 end1, TIterator2 begin2, TIterator2 end2)
  {
    if (etl::distance(begin1, end1) != etl::distance(begin2, end2))
    {
      return false;
    }
 
    if (begin1 != end1)
    {
      for (TIterator1 i = begin1; i != end1; ++i)
      {
        if (i == etl::find(begin1, i, *i))
        {
          size_t n = static_cast<size_t>(etl::count(begin2, end2, *i));
 
          if (n == 0 || size_t(etl::count(i, end1, *i)) != n)
          {
            return false;
          }
        }
      }
    }
 
    return true;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator1, typename TIterator2, typename TBinaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_permutation(TIterator1 begin1, TIterator1 end1, TIterator2 begin2, TIterator2 end2, TBinaryPredicate predicate)
  {
    if (etl::distance(begin1, end1) != etl::distance(begin2, end2))
    {
      return false;
    }
 
    if (begin1 != end1)
    {
      for (TIterator1 i = begin1; i != end1; ++i)
      {
        const typename etl::binder1st<TBinaryPredicate> predicate_is_i = etl::bind1st(predicate, *i);
        if (i == etl::find_if(begin1, i, predicate_is_i))
        {
          size_t n = static_cast<size_t>(etl::count_if(begin2, end2, predicate_is_i));
 
          if (n == 0 || size_t(etl::count_if(i, end1, predicate_is_i)) != n)
          {
            return false;
          }
        }
      }
    }
 
    return true;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 bool next_permutation(TIterator first, TIterator last, TCompare compare)
  {
    if (first == last)
    {
      return false;
    }
 
    TIterator i = last;
    --i;
 
    if (first == i)
    {
      return false;
    }
 
    while (true)
    {
      TIterator i1 = i;
      --i;
 
      if (compare(*i, *i1))
      {
        TIterator j = last;
        --j;
 
        while (!compare(*i, *j))
        {
          --j;
        }
 
        etl::iter_swap(i, j);
        etl::reverse(i1, last);
        return true;
      }
 
      if (i == first)
      {
        etl::reverse(first, last);
        return false;
      }
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 bool next_permutation(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
    return etl::next_permutation(first, last, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 bool prev_permutation(TIterator first, TIterator last, TCompare compare)
  {
    if (first == last)
    {
      return false;
    }
 
    TIterator i = last;
    --i;
 
    if (first == i)
    {
      return false;
    }
 
    while (true)
    {
      TIterator i1 = i;
      --i;
 
      if (compare(*i1, *i))
      {
        TIterator j = last;
        --j;
 
        while (!compare(*j, *i))
        {
          --j;
        }
 
        etl::iter_swap(i, j);
        etl::reverse(i1, last);
        return true;
      }
 
      if (i == first)
      {
        etl::reverse(first, last);
        return false;
      }
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 bool prev_permutation(TIterator first, TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare;
    return etl::prev_permutation(first, last, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool is_partitioned(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (!predicate(*begin))
      {
        break;
      }
 
      ++begin;
    }
 
    while (begin != end)
    {
      if (predicate(*begin))
      {
        return false;
      }
 
      ++begin;
    }
 
    return true;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator partition_point(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    // binary search on a partitioned range
    for (difference_t length = etl::distance(begin, end); 0 < length;)
    {
      difference_t half   = length / 2;
      TIterator    middle = etl::next(begin, half);
      if (predicate(*middle))
      {
        begin = etl::next(middle);
        length -= (half + 1);
      }
      else
      {
        length = half;
      }
    }
 
    return begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TSource, typename TDestinationTrue, typename TDestinationFalse, typename TUnaryPredicate>
  ETL_CONSTEXPR14 ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse> partition_copy(TSource begin, TSource end, TDestinationTrue destination_true,
                                                                                 TDestinationFalse destination_false, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (predicate(*begin))
      {
        *destination_true = *begin;
        ++destination_true;
      }
      else
      {
        *destination_false = *begin;
        ++destination_false;
      }
 
      ++begin;
    }
 
    return ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>(destination_true, destination_false);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TSource, typename TDestinationTrue, typename TDestinationFalse, typename TUnaryPredicate>
  ETL_CONSTEXPR14 ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse> partition_move(TSource begin, TSource end, TDestinationTrue destination_true,
                                                                                 TDestinationFalse destination_false, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (predicate(*begin))
      {
        *destination_true = etl::move(*begin);
        ++destination_true;
      }
      else
      {
        *destination_false = etl::move(*begin);
        ++destination_false;
      }
 
      ++begin;
    }
 
    return ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>(destination_true, destination_false);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TOutputIterator, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator copy_if(TIterator begin, TIterator end, TOutputIterator out, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (predicate(*begin))
      {
        *out = *begin;
        ++out;
      }
 
      ++begin;
    }
 
    return out;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool all_of(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    return etl::find_if_not(begin, end, predicate) == end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool any_of(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    return etl::find_if(begin, end, predicate) != end;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_NODISCARD ETL_CONSTEXPR14 bool none_of(TIterator begin, TIterator end, TUnaryPredicate predicate)
  {
    return etl::find_if(begin, end, predicate) == end;
  }
 
#if ETL_NOT_USING_STL
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  void sort(TIterator first, TIterator last, TCompare compare)
  {
    etl::shell_sort(first, last, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  void sort(TIterator first, TIterator last)
  {
    etl::shell_sort(first, last, etl::less<typename etl::iterator_traits<TIterator>::value_type>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  void stable_sort(TIterator first, TIterator last, TCompare compare)
  {
    etl::insertion_sort(first, last, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  void stable_sort(TIterator first, TIterator last)
  {
    etl::insertion_sort(first, last, etl::less<typename etl::iterator_traits<TIterator>::value_type>());
  }
#else
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  void sort(TIterator first, TIterator last, TCompare compare)
  {
    std::sort(first, last, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  void sort(TIterator first, TIterator last)
  {
    std::sort(first, last);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  void stable_sort(TIterator first, TIterator last, TCompare compare)
  {
    std::stable_sort(first, last, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  void stable_sort(TIterator first, TIterator last)
  {
    std::stable_sort(first, last);
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename T>
  ETL_CONSTEXPR14 T accumulate(TIterator first, TIterator last, T sum)
  {
    while (first != last)
    {
      sum = static_cast<T>(ETL_MOVE(sum) + static_cast<T>(*first));
      ++first;
    }
 
    return sum;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename T, typename TBinaryOperation>
  ETL_CONSTEXPR14 T accumulate(TIterator first, TIterator last, T sum, TBinaryOperation operation)
  {
    while (first != last)
    {
      sum = operation(ETL_MOVE(sum), *first);
      ++first;
    }
 
    return sum;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename T, typename TCompare>
  ETL_CONSTEXPR T clamp(const T& value, const T& low, const T& high, TCompare compare)
  {
    return compare(value, low) ? low : compare(high, value) ? high : value;
  }
 
  template <typename T>
  ETL_CONSTEXPR T clamp(const T& value, const T& low, const T& high)
  {
    return clamp(value, low, high, etl::less<T>());
  }
 
  template <typename T, T Low, T High, typename TCompare>
  ETL_CONSTEXPR T clamp(const T& value, TCompare compare)
  {
    return compare(value, Low) ? Low : compare(High, value) ? High : value;
  }
 
  template <typename T, T Low, T High>
  ETL_CONSTEXPR T clamp(const T& value)
  {
    return clamp<T, Low, High>(value, etl::less<T>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename T>
  ETL_CONSTEXPR14 TIterator remove(TIterator first, TIterator last, const T& value)
  {
    first = etl::find(first, last, value);
 
    if (first != last)
    {
      TIterator itr = first;
 
      while (++itr != last)
      {
        if (!(*itr == value))
        {
          *first++ = ETL_MOVE(*itr);
        }
      }
    }
 
    return first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TIterator remove_if(TIterator first, TIterator last, TUnaryPredicate predicate)
  {
    first = etl::find_if(first, last, predicate);
 
    if (first != last)
    {
      TIterator itr = first;
 
      while (++itr != last)
      {
        if (!predicate(*itr))
        {
          *first++ = ETL_MOVE(*itr);
        }
      }
    }
 
    return first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 TIterator unique(TIterator first, TIterator last)
  {
    if (first == last)
    {
      return last;
    }
 
    TIterator result = first;
 
    while (++first != last)
    {
      if (!(*result == *first) && (++result != first))
      {
        *result = ETL_MOVE(*first);
      }
    }
 
    return ++result;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TBinaryPredicate>
  ETL_CONSTEXPR14 TIterator unique(TIterator first, TIterator last, TBinaryPredicate predicate)
  {
    if (first == last)
    {
      return last;
    }
 
    TIterator result = first;
 
    while (++first != last)
    {
      if (!predicate(*result, *first) && (++result != first))
      {
        *result = ETL_MOVE(*first);
      }
    }
 
    return ++result;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  ETL_CONSTEXPR14 TOutputIterator unique_copy(TInputIterator first, TInputIterator last, TOutputIterator d_first)
  {
    if (first == last)
    {
      return d_first;
    }
 
    typename etl::iterator_traits<TInputIterator>::value_type prev = *first;
    *d_first                                                       = prev;
 
    while (++first != last)
    {
      if (!(prev == *first))
      {
        prev         = *first;
        *(++d_first) = prev;
      }
    }
 
    return ++d_first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator, typename TBinaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator unique_copy(TInputIterator first, TInputIterator last, TOutputIterator d_first, TBinaryPredicate predicate)
  {
    if (first == last)
    {
      return d_first;
    }
 
    typename etl::iterator_traits<TInputIterator>::value_type prev = *first;
    *d_first                                                       = prev;
 
    while (++first != last)
    {
      if (!predicate(prev, *first))
      {
        prev         = *first;
        *(++d_first) = prev;
      }
    }
 
    return ++d_first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator1, typename TInputIterator2, typename TOutputIterator, typename TCompare>
  ETL_CONSTEXPR14 TOutputIterator merge(TInputIterator1 first1, TInputIterator1 last1, TInputIterator2 first2, TInputIterator2 last2,
                                  TOutputIterator d_first, TCompare compare)
  {
    while ((first1 != last1) && (first2 != last2))
    {
      if (compare(*first2, *first1))
      {
        *d_first = *first2;
        ++first2;
      }
      else
      {
        *d_first = *first1;
        ++first1;
      }
      ++d_first;
    }
 
    d_first = etl::copy(first1, last1, d_first);
    d_first = etl::copy(first2, last2, d_first);
 
    return d_first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator1, typename TInputIterator2, typename TOutputIterator>
  ETL_CONSTEXPR14 TOutputIterator merge(TInputIterator1 first1, TInputIterator1 last1, TInputIterator2 first2, TInputIterator2 last2,
                                  TOutputIterator d_first)
  {
    typedef etl::less< typename etl::iterator_traits<TInputIterator1>::value_type> compare;
 
    return etl::merge(first1, last1, first2, last2, d_first, compare());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TBidirectionalIterator, typename TCompare>
  void inplace_merge(TBidirectionalIterator first, TBidirectionalIterator middle, TBidirectionalIterator last, TCompare compare)
  {
    typedef typename etl::iterator_traits<TBidirectionalIterator>::difference_type difference_type;
 
    difference_type len1 = etl::distance(first, middle);
    difference_type len2 = etl::distance(middle, last);
 
    while ((len1 != 0) && (len2 != 0))
    {
      // Find where the first element of the right half belongs in the left
      // half. All elements in [first, cut1) are <= *middle, so they are already
      // in place.
      TBidirectionalIterator cut1   = etl::upper_bound(first, middle, *middle, compare);
      difference_type        prefix = etl::distance(first, cut1);
      len1 -= prefix;
 
      // If the entire left half is <= *middle, we are done.
      if (len1 == 0)
      {
        return;
      }
 
      // Advance first past the already-placed prefix.
      first = cut1;
 
      // Find where the first element of the (remaining) left half belongs in
      // the right half.  All elements in [middle, cut2) are < *first, so they
      // need to be moved before *first.
      TBidirectionalIterator cut2 = etl::lower_bound(middle, last, *first, compare);
      difference_type        run  = etl::distance(middle, cut2);
      len2 -= run;
 
      // Rotate the block [first, middle, cut2) so that [middle, cut2) moves
      // before [first, middle).  After the rotate the elements from
      // [middle, cut2) (length = run) now occupy [first, first + run) and
      // are in their final position.
      etl::rotate(first, middle, cut2);
 
      // Advance past the block we just placed.
      etl::advance(first, run);
      middle = cut2;
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TBidirectionalIterator>
  void inplace_merge(TBidirectionalIterator first, TBidirectionalIterator middle, TBidirectionalIterator last)
  {
    typedef etl::less< typename etl::iterator_traits<TBidirectionalIterator>::value_type> compare;
 
    etl::inplace_merge(first, middle, last, compare());
  }
} // namespace etl
 
//*****************************************************************************
// ETL extensions to the STL algorithms.
//*****************************************************************************
namespace etl
{
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  ETL_CONSTEXPR14
    typename etl::enable_if< etl::is_random_iterator<TInputIterator>::value && etl::is_random_iterator<TOutputIterator>::value, TOutputIterator>::type
    copy_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end)
  {
    typedef typename iterator_traits<TInputIterator>::difference_type  s_size_type;
    typedef typename iterator_traits<TOutputIterator>::difference_type d_size_type;
 
#if ETL_USING_CPP11
    typedef typename etl::common_type<s_size_type, d_size_type>::type min_size_type;
#else
    typedef typename etl::largest_type<s_size_type, d_size_type>::type min_size_type;
#endif
 
    s_size_type   s_size   = etl::distance(i_begin, i_end);
    d_size_type   d_size   = etl::distance(o_begin, o_end);
    min_size_type min_size = etl::min<min_size_type>(s_size, d_size);
 
    return etl::copy(i_begin, i_begin + min_size, o_begin);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  ETL_CONSTEXPR14 typename etl::enable_if< !etl::is_random_iterator<TInputIterator>::value || !etl::is_random_iterator<TOutputIterator>::value,
                                     TOutputIterator>::type
    copy_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end)
  {
    while ((i_begin != i_end) && (o_begin != o_end))
    {
      *o_begin = *i_begin;
      ++o_begin;
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TSize, typename TOutputIterator>
  ETL_CONSTEXPR14 TOutputIterator copy_n_s(TInputIterator i_begin, TSize n, TOutputIterator o_begin, TOutputIterator o_end)
  {
    while ((n-- > 0) && (o_begin != o_end))
    {
      *o_begin = *i_begin;
      ++o_begin;
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TSize1, typename TOutputIterator, typename TSize2>
  ETL_CONSTEXPR14 TOutputIterator copy_n_s(TInputIterator i_begin, TSize1 n1, TOutputIterator o_begin, TSize2 n2)
  {
    while ((n1-- > 0) && (n2-- > 0))
    {
      *o_begin = *i_begin;
      ++o_begin;
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator copy_if_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end,
                                      TUnaryPredicate predicate)
  {
    while ((i_begin != i_end) && (o_begin != o_end))
    {
      if (predicate(*i_begin))
      {
        *o_begin = *i_begin;
        ++o_begin;
      }
 
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TSize, typename TOutputIterator, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator copy_n_if(TInputIterator i_begin, TSize n, TOutputIterator o_begin, TUnaryPredicate predicate)
  {
    while (n-- > 0)
    {
      if (predicate(*i_begin))
      {
        *o_begin = *i_begin;
        ++o_begin;
      }
 
      ++i_begin;
    }
 
    return o_begin;
  }
 
#if ETL_USING_CPP11
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  ETL_CONSTEXPR14
    typename etl::enable_if< etl::is_random_iterator<TInputIterator>::value && etl::is_random_iterator<TOutputIterator>::value, TOutputIterator>::type
    move_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end)
  {
    using s_size_type   = typename iterator_traits<TInputIterator>::difference_type;
    using d_size_type   = typename iterator_traits<TOutputIterator>::difference_type;
    using min_size_type = typename etl::common_type<s_size_type, d_size_type>::type;
 
    s_size_type   s_size   = etl::distance(i_begin, i_end);
    d_size_type   d_size   = etl::distance(o_begin, o_end);
    min_size_type min_size = etl::min<min_size_type>(s_size, d_size);
 
  #include "etl/private/diagnostic_null_dereference_push.h"
    return etl::move(i_begin, i_begin + min_size, o_begin);
  #include "etl/private/diagnostic_pop.h"
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  ETL_CONSTEXPR14 typename etl::enable_if< !etl::is_random_iterator<TInputIterator>::value || !etl::is_random_iterator<TOutputIterator>::value,
                                     TOutputIterator>::type
    move_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end)
  {
    while ((i_begin != i_end) && (o_begin != o_end))
    {
      *o_begin = etl::move(*i_begin);
      ++i_begin;
      ++o_begin;
    }
 
    return o_begin;
  }
#else
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator>
  TOutputIterator move_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end)
  {
    // Move not supported. Defer to copy.
    return etl::copy_s(i_begin, i_end, o_begin, o_end);
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TValue>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator binary_find(TIterator begin, TIterator end, const TValue& value)
  {
    TIterator it = etl::lower_bound(begin, end, value);
 
    if ((it == end) || (*it != value))
    {
      it = end;
    }
 
    return it;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TValue, typename TBinaryPredicate, typename TBinaryEquality>
  ETL_NODISCARD ETL_CONSTEXPR14 TIterator binary_find(TIterator begin, TIterator end, const TValue& value, TBinaryPredicate predicate, TBinaryEquality equality)
  {
    TIterator it = etl::lower_bound(begin, end, value, predicate);
 
    if ((it == end) || !equality(*it, value))
    {
      it = end;
    }
 
    return it;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TUnaryFunction, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TUnaryFunction for_each_if(TIterator begin, const TIterator end, TUnaryFunction function, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (predicate(*begin))
      {
        function(*begin);
      }
 
      ++begin;
    }
 
    return function;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TSize, typename TUnaryFunction>
  ETL_CONSTEXPR14 TIterator for_each_n(TIterator begin, TSize n, TUnaryFunction function)
  {
    while (n-- > 0)
    {
      function(*begin);
      ++begin;
    }
 
    return begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TSize, typename TUnaryFunction, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TIterator for_each_n_if(TIterator begin, TSize n, TUnaryFunction function, TUnaryPredicate predicate)
  {
    while (n-- > 0)
    {
      if (predicate(*begin))
      {
        function(*begin);
      }
 
      ++begin;
    }
 
    return begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator, typename TUnaryFunction>
  ETL_CONSTEXPR14 TOutputIterator transform_s(TInputIterator i_begin, TInputIterator i_end, TOutputIterator o_begin, TOutputIterator o_end,
                                        TUnaryFunction function)
  {
    while ((i_begin != i_end) && (o_begin != o_end))
    {
      *o_begin = function(*i_begin);
      ++i_begin;
      ++o_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TSize, typename TOutputIterator, typename TUnaryFunction>
  ETL_CONSTEXPR14 void transform_n(TInputIterator i_begin, TSize n, TOutputIterator o_begin, TUnaryFunction function)
  {
    TInputIterator i_end(i_begin);
    etl::advance(i_end, n);
 
    etl::transform(i_begin, i_end, o_begin, function);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator1, typename TInputIterator2, typename TSize, typename TOutputIterator, typename TBinaryFunction>
  ETL_CONSTEXPR14 void transform_n(TInputIterator1 i_begin1, TInputIterator2 i_begin2, TSize n, TOutputIterator o_begin, TBinaryFunction function)
  {
    TInputIterator1 i_end1(i_begin1);
    etl::advance(i_end1, n);
 
    etl::transform(i_begin1, i_end1, i_begin2, o_begin, function);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TOutputIterator, typename TUnaryFunction, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator transform_if(TInputIterator i_begin, const TInputIterator i_end, TOutputIterator o_begin, TUnaryFunction function,
                                         TUnaryPredicate predicate)
  {
    while (i_begin != i_end)
    {
      if (predicate(*i_begin))
      {
        *o_begin = function(*i_begin);
        ++o_begin;
      }
 
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator1, typename TInputIterator2, typename TOutputIterator, typename TBinaryFunction, typename TBinaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator transform_if(TInputIterator1 i_begin1, const TInputIterator1 i_end1, TInputIterator2 i_begin2, TOutputIterator o_begin,
                                         TBinaryFunction function, TBinaryPredicate predicate)
  {
    while (i_begin1 != i_end1)
    {
      if (predicate(*i_begin1, *i_begin2))
      {
        *o_begin = function(*i_begin1, *i_begin2);
        ++o_begin;
      }
 
      ++i_begin1;
      ++i_begin2;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator, typename TSize, typename TOutputIterator, typename TUnaryFunction, typename TUnaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator transform_n_if(TInputIterator i_begin, TSize n, TOutputIterator o_begin, TUnaryFunction function,
                                           TUnaryPredicate predicate)
  {
    while (n-- > 0)
    {
      if (predicate(*i_begin))
      {
        *o_begin = function(*i_begin);
        ++o_begin;
      }
 
      ++i_begin;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TInputIterator1, typename TInputIterator2, typename TSize, typename TOutputIterator, typename TBinaryFunction,
            typename TBinaryPredicate>
  ETL_CONSTEXPR14 TOutputIterator transform_n_if(TInputIterator1 i_begin1, TInputIterator2 i_begin2, TSize n, TOutputIterator o_begin,
                                           TBinaryFunction function, TBinaryPredicate predicate)
  {
    while (n-- > 0)
    {
      if (predicate(*i_begin1, *i_begin2))
      {
        *o_begin++ = function(*i_begin1, *i_begin2);
      }
 
      ++i_begin1;
      ++i_begin2;
    }
 
    return o_begin;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TSource, typename TDestinationTrue, typename TDestinationFalse, typename TUnaryFunctionTrue, typename TUnaryFunctionFalse,
            typename TUnaryPredicate>
  ETL_CONSTEXPR14 ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>
    partition_transform(TSource begin, TSource end, TDestinationTrue destination_true, TDestinationFalse destination_false,
                        TUnaryFunctionTrue function_true, TUnaryFunctionFalse function_false, TUnaryPredicate predicate)
  {
    while (begin != end)
    {
      if (predicate(*begin))
      {
        *destination_true = function_true(*begin);
        ++destination_true;
      }
      else
      {
        *destination_false = function_false(*begin);
        ++destination_false;
      }
 
      ++begin;
    }
 
    return ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>(destination_true, destination_false);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TSource1, typename TSource2, typename TDestinationTrue, typename TDestinationFalse, typename TBinaryFunctionTrue,
            typename TBinaryFunctionFalse, typename TBinaryPredicate>
  ETL_CONSTEXPR14 ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>
    partition_transform(TSource1 begin1, TSource1 end1, TSource2 begin2, TDestinationTrue destination_true, TDestinationFalse destination_false,
                        TBinaryFunctionTrue function_true, TBinaryFunctionFalse function_false, TBinaryPredicate predicate)
  {
    while (begin1 != end1)
    {
      if (predicate(*begin1, *begin2))
      {
        *destination_true = function_true(*begin1, *begin2);
        ++destination_true;
      }
      else
      {
        *destination_false = function_false(*begin1, *begin2);
        ++destination_false;
      }
 
      ++begin1;
      ++begin2;
    }
 
    return ETL_OR_STD::pair<TDestinationTrue, TDestinationFalse>(destination_true, destination_false);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    void
    shell_sort(TIterator first, TIterator last, TCompare compare)
  {
    if (first == last)
    {
      return;
    }
 
    typedef typename etl::iterator_traits<TIterator>::difference_type difference_t;
 
    difference_t n = etl::distance(first, last);
 
    for (difference_t i = n / 2; i > 0; i /= 2)
    {
      for (difference_t j = i; j < n; ++j)
      {
        for (difference_t k = j - i; k >= 0; k -= i)
        {
          TIterator itr1 = first;
          TIterator itr2 = first;
 
          etl::advance(itr1, k);
          etl::advance(itr2, k + i);
 
          if (compare(*itr2, *itr1))
          {
            etl::iter_swap(itr1, itr2);
          }
        }
      }
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
#if ETL_USING_STD_NAMESPACE
  ETL_CONSTEXPR20
#else
  ETL_CONSTEXPR14
#endif
    void
    shell_sort(TIterator first, TIterator last)
  {
    etl::shell_sort(first, last, etl::less<typename etl::iterator_traits<TIterator>::value_type>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void insertion_sort(TIterator first, TIterator last, TCompare compare)
  {
    for (TIterator itr = first; itr != last; ++itr)
    {
      etl::rotate(etl::upper_bound(first, itr, *itr, compare), itr, etl::next(itr));
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 void insertion_sort(TIterator first, TIterator last)
  {
    etl::insertion_sort(first, last, etl::less<typename etl::iterator_traits<TIterator>::value_type>());
  }
 
  //***************************************************************************
  namespace private_algorithm
  {
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_forward_iterator<TIterator>::value, TIterator>::type get_before_last(TIterator first_, TIterator last_)
    {
      TIterator last      = first_;
      TIterator lastplus1 = first_;
      ++lastplus1;
 
      while (lastplus1 != last_)
      {
        ++last;
        ++lastplus1;
      }
 
      return last;
    }
 
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_bidirectional_iterator<TIterator>::value, TIterator>::type get_before_last(TIterator /*first_*/,
                                                                                                                         TIterator last_)
    {
      TIterator last = last_;
      --last;
 
      return last;
    }
 
    template <typename TIterator>
    ETL_CONSTEXPR14 typename etl::enable_if<etl::is_random_access_iterator<TIterator>::value, TIterator>::type get_before_last(TIterator /*first_*/,
                                                                                                                         TIterator last_)
    {
      return last_ - 1;
    }
  } // namespace private_algorithm
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR20 void selection_sort(TIterator first, TIterator last, TCompare compare)
  {
    if (first == last)
    {
      return;
    }
 
    TIterator       min;
    const TIterator ilast = private_algorithm::get_before_last(first, last);
    const TIterator jlast = last;
 
    for (TIterator i = first; i != ilast; ++i)
    {
      min = i;
 
      TIterator j = i;
      ++j;
 
      for (; j != jlast; ++j)
      {
        if (compare(*j, *min))
        {
          min = j;
        }
      }
 
      using ETL_OR_STD::swap; // Allow ADL
      if (min != i)
      {
        swap(*i, *min);
      }
    }
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR20 void selection_sort(TIterator first, TIterator last)
  {
    selection_sort(first, last, etl::less<typename etl::iterator_traits<TIterator>::value_type>());
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TCompare>
  ETL_CONSTEXPR14 void heap_sort(TIterator first, TIterator last, TCompare compare)
  {
    etl::make_heap(first, last, compare);
    etl::sort_heap(first, last, compare);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator>
  ETL_CONSTEXPR14 void heap_sort(TIterator first, TIterator last)
  {
    etl::make_heap(first, last);
    etl::sort_heap(first, last);
  }
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename T>
  ETL_NODISCARD
  constexpr const T& multimax(const T& a, const T& b)
  {
    return a < b ? b : a;
  }
 
  template <typename T, typename... Tx>
  ETL_NODISCARD
  constexpr const T& multimax(const T& t, const Tx&... tx)
  {
    return multimax(t, multimax(tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TCompare, typename T>
  ETL_NODISCARD
  constexpr const T& multimax_compare(TCompare compare, const T& a, const T& b)
  {
    return compare(a, b) ? b : a;
  }
 
  template <typename TCompare, typename T, typename... Tx>
  ETL_NODISCARD
  constexpr const T& multimax_compare(TCompare compare, const T& t, const Tx&... tx)
  {
    return multimax_compare(compare, t, multimax_compare(compare, tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename T>
  ETL_NODISCARD
  constexpr const T& multimin(const T& a, const T& b)
  {
    return a < b ? a : b;
  }
 
  template <typename T, typename... Tx>
  ETL_NODISCARD
  constexpr const T& multimin(const T& t, const Tx&... tx)
  {
    return multimin(t, multimin(tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TCompare, typename T>
  ETL_NODISCARD
  constexpr const T& multimin_compare(TCompare compare, const T& a, const T& b)
  {
    return compare(a, b) ? a : b;
  }
 
  template <typename TCompare, typename T, typename... Tx>
  ETL_NODISCARD
  constexpr const T& multimin_compare(TCompare compare, const T& t, const Tx&... tx)
  {
    return multimin_compare(compare, t, multimin_compare(compare, tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TIterator>
  ETL_NODISCARD
  constexpr const TIterator& multimax_iter(const TIterator& a, const TIterator& b)
  {
    return *a < *b ? b : a;
  }
 
  template <typename TIterator, typename... TIteratorx>
  ETL_NODISCARD
  constexpr const TIterator& multimax_iter(const TIterator& t, const TIteratorx&... tx)
  {
    return multimax_iter(t, multimax_iter(tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TCompare, typename TIterator>
  ETL_NODISCARD
  constexpr const TIterator& multimax_iter_compare(TCompare compare, const TIterator& a, const TIterator& b)
  {
    return compare(*a, *b) ? b : a;
  }
 
  template <typename TCompare, typename TIterator, typename... TIteratorx>
  ETL_NODISCARD
  constexpr const TIterator& multimax_iter_compare(TCompare compare, const TIterator& t, const TIteratorx&... tx)
  {
    return multimax_iter_compare(compare, t, multimax_iter_compare(compare, tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TIterator>
  ETL_NODISCARD
  constexpr const TIterator& multimin_iter(const TIterator& a, const TIterator& b)
  {
    return *a < *b ? a : b;
  }
 
  template <typename TIterator, typename... Tx>
  ETL_NODISCARD
  constexpr const TIterator& multimin_iter(const TIterator& t, const Tx&... tx)
  {
    return multimin_iter(t, multimin_iter(tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
#if ETL_USING_CPP11
  template <typename TCompare, typename TIterator>
  ETL_NODISCARD
  constexpr const TIterator& multimin_iter_compare(TCompare compare, const TIterator& a, const TIterator& b)
  {
    return compare(*a, *b) ? a : b;
  }
 
  template <typename TCompare, typename TIterator, typename... Tx>
  ETL_NODISCARD
  constexpr const TIterator& multimin_iter_compare(TCompare compare, const TIterator& t, const Tx&... tx)
  {
    return multimin_iter_compare(compare, t, multimin_iter_compare(compare, tx...));
  }
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TPredicate>
  ETL_CONSTEXPR14 typename etl::enable_if<etl::is_forward_iterator<TIterator>::value, TIterator>::type partition(TIterator first, TIterator last,
                                                                                                           TPredicate predicate)
  {
    first = etl::find_if_not(first, last, predicate);
 
    if (first == last)
    {
      return first;
    }
 
    for (TIterator i = etl::next(first); i != last; ++i)
    {
      if (predicate(*i))
      {
        using ETL_OR_STD::swap;
        swap(*i, *first);
        ++first;
      }
    }
 
    return first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TPredicate>
  ETL_CONSTEXPR14 typename etl::enable_if< etl::is_bidirectional_iterator_concept<TIterator>::value, TIterator>::type
    partition(TIterator first, TIterator last, TPredicate predicate)
  {
    while (first != last)
    {
      first = etl::find_if_not(first, last, predicate);
 
      if (first == last)
      {
        break;
      }
 
      last = etl::find_if(etl::reverse_iterator<TIterator>(last), etl::reverse_iterator<TIterator>(first), predicate).base();
 
      if (first == last)
      {
        break;
      }
 
      --last;
      using ETL_OR_STD::swap;
      swap(*first, *last);
      ++first;
    }
 
    return first;
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TPredicate>
  ETL_CONSTEXPR14 TIterator stable_partition(TIterator first, TIterator last, TPredicate predicate)
  {
    typename etl::iterator_traits<TIterator>::difference_type n = etl::distance(first, last);
 
    if (n <= 1)
    {
      // Empty or single-element range: trivially partitioned either way.
      return first;
    }
 
    TIterator mid = first;
    etl::advance(mid, n / 2);
 
    etl::stable_partition(first, mid, predicate);
    etl::stable_partition(mid, last, predicate);
 
    TIterator left_partition_start  = etl::find_if_not(first, last, predicate);
    TIterator right_partition_start = etl::find_if(left_partition_start, last, predicate);
    TIterator right_partition_end   = etl::find_if_not(right_partition_start, last, predicate);
 
    return etl::rotate(left_partition_start, right_partition_start, right_partition_end);
  }
 
  //***************************************************************************
  //***************************************************************************
  template <typename TIterator, typename TPredicate>
  ETL_CONSTEXPR14 TIterator stable_partition(TIterator first, TIterator last, TIterator buffer_first, TIterator buffer_last, TPredicate predicate)
  {
    typename etl::iterator_traits<TIterator>::difference_type n = etl::distance(first, last);
 
    ETL_ASSERT((n <= etl::distance(buffer_first, buffer_last)), ETL_ERROR(stable_partition_buffer_too_small));
 
    if (n <= 1)
    {
      // Empty or single-element range.
      return first;
    }
 
    TIterator input_first = first;
    TIterator buffer_true = buffer_first;
 
    // Find where the partition point will be in the buffer.
    typename etl::iterator_traits<TIterator>::difference_type true_count   = etl::count_if(first, last, predicate);
    TIterator                                                 buffer_false = buffer_first + true_count;
 
    // Move them to the correct places in the temporary buffer.
    while (first != last)
    {
      if (predicate(*first))
      {
        *buffer_true++ = etl::move(*first);
      }
      else
      {
        *buffer_false++ = etl::move(*first);
      }
 
      ++first;
    }
 
    // Move them back to the original range.
    TIterator buffer_end = buffer_first;
    etl::advance(buffer_end, n);
    etl::move(buffer_first, buffer_end, input_first);
 
    etl::advance(input_first, true_count);
 
    return input_first;
  }
 
  //*********************************************************
  namespace private_algorithm
  {
    using ETL_OR_STD::swap;
 
    template <typename TIterator, typename TCompare>
#if (ETL_USING_CPP20 && ETL_USING_STL) || (ETL_USING_CPP14 && ETL_NOT_USING_STL && !defined(ETL_IN_UNIT_TEST))
    constexpr
#endif
      TIterator
      nth_partition(TIterator first, TIterator last, TCompare compare)
    {
      typedef typename etl::iterator_traits<TIterator>::value_type value_type;
 
      value_type pivot_value = ETL_MOVE(*last);
 
      TIterator i = first;
 
      for (TIterator j = first; j < last; ++j)
      {
        if (!compare(pivot_value, *j)) // Hack to get '*j <= pivot_value' in
                                       // terms of 'pivot_value < *j'
        {
          swap(*i, *j);
          ++i;
        }
      }
 
      swap(*i, *last);
 
      return i;
    }
  } // namespace private_algorithm
 
  //*********************************************************
  //*********************************************************
#if ETL_USING_CPP11
  template <typename TIterator, typename TCompare = etl::less<typename etl::iterator_traits<TIterator>::value_type>>
  #if (ETL_USING_CPP20 && ETL_USING_STL) || (ETL_USING_CPP14 && ETL_NOT_USING_STL && !defined(ETL_IN_UNIT_TEST))
  constexpr
  #endif
    typename etl::enable_if< etl::is_random_access_iterator_concept<TIterator>::value, void>::type
    nth_element(TIterator first, TIterator nth, TIterator last, TCompare compare = TCompare())
  {
    if (first == last)
    {
      return;
    }
 
    // 'last' must point to the actual last value.
    --last;
 
    while (first <= last)
    {
      TIterator p = private_algorithm::nth_partition(first, last, compare);
 
      if (p == nth)
      {
        return;
      }
      else if (p > nth)
      {
        last = p - 1;
      }
      else
      {
        first = p + 1;
      }
    }
  }
 
#else
 
  //*********************************************************
  template <typename TIterator, typename TCompare>
  typename etl::enable_if< etl::is_random_access_iterator_concept<TIterator>::value, void>::type nth_element(TIterator first, TIterator nth,
                                                                                                             TIterator last, TCompare compare)
  {
    if (first == last)
    {
      return;
    }
 
    // 'last' must point to the actual last value.
    --last;
 
    while (first <= last)
    {
      TIterator p = private_algorithm::nth_partition(first, last, compare);
 
      if (p == nth)
      {
        return;
      }
      else if (p > nth)
      {
        last = p - 1;
      }
      else
      {
        first = p + 1;
      }
    }
  }
 
  //*********************************************************
  template <typename TIterator>
  typename etl::enable_if< etl::is_random_access_iterator_concept<TIterator>::value, void>::type nth_element(TIterator first, TIterator nth,
                                                                                                             TIterator last)
  {
    typedef etl::less<typename etl::iterator_traits<TIterator>::value_type> compare_t;
 
    nth_element(first, nth, last, compare_t());
  }
#endif
 
#if ETL_USING_CPP17
 
  namespace ranges
  {
    template <class I, class F>
    struct in_fun_result
    {
      ETL_NO_UNIQUE_ADDRESS I in;
      ETL_NO_UNIQUE_ADDRESS F fun;
 
      template <class I2, class F2>
      constexpr operator in_fun_result<I2, F2>() const&
      {
        return {in, fun};
      }
 
      template <class I2, class F2>
      constexpr operator in_fun_result<I2, F2>() &&
      {
        return {etl::move(in), etl::move(fun)};
      }
    };
 
    template <class I1, class I2>
    struct in_in_result
    {
      ETL_NO_UNIQUE_ADDRESS I1 in1;
      ETL_NO_UNIQUE_ADDRESS I2 in2;
 
      template <class II1, class II2>
      constexpr operator in_in_result<II1, II2>() const&
      {
        return {in1, in2};
      }
 
      template <class II1, class II2>
      constexpr operator in_in_result<II1, II2>() &&
      {
        return {etl::move(in1), etl::move(in2)};
      }
    };
 
    template <class I, class O>
    struct in_out_result
    {
      ETL_NO_UNIQUE_ADDRESS I in;
      ETL_NO_UNIQUE_ADDRESS O out;
 
      template <class I2, class O2>
      constexpr operator in_out_result<I2, O2>() const&
      {
        return {in, out};
      }
 
      template <class I2, class O2>
      constexpr operator in_out_result<I2, O2>() &&
      {
        return {etl::move(in), etl::move(out)};
      }
    };
 
    template <class I1, class I2, class O>
    struct in_in_out_result
    {
      ETL_NO_UNIQUE_ADDRESS I1 in1;
      ETL_NO_UNIQUE_ADDRESS I2 in2;
      ETL_NO_UNIQUE_ADDRESS O  out;
 
      template <class II1, class II2, class OO>
      constexpr operator in_in_out_result<II1, II2, OO>() const&
      {
        return {in1, in2, out};
      }
 
      template <class II1, class II2, class OO>
      constexpr operator in_in_out_result<II1, II2, OO>() &&
      {
        return {etl::move(in1), etl::move(in2), etl::move(out)};
      }
    };
 
    template <class I, class O1, class O2>
    struct in_out_out_result
    {
      ETL_NO_UNIQUE_ADDRESS I  in;
      ETL_NO_UNIQUE_ADDRESS O1 out1;
      ETL_NO_UNIQUE_ADDRESS O2 out2;
 
      template <class II, class OO1, class OO2>
      constexpr operator in_out_out_result<II, OO1, OO2>() const&
      {
        return {in, out1, out2};
      }
 
      template <class II, class OO1, class OO2>
      constexpr operator in_out_out_result<II, OO1, OO2>() &&
      {
        return {etl::move(in), etl::move(out1), etl::move(out2)};
      }
    };
 
    template <class I>
    struct in_found_result
    {
      ETL_NO_UNIQUE_ADDRESS I in;
      bool                    found;
 
      template <class I2>
      constexpr operator in_found_result<I2>() const&
      {
        return {in, found};
      }
 
      template <class I2>
      constexpr operator in_found_result<I2>() &&
      {
        return {etl::move(in), found};
      }
    };
 
    template <class O, class T>
    struct out_value_result
    {
      ETL_NO_UNIQUE_ADDRESS O out;
      ETL_NO_UNIQUE_ADDRESS T value;
 
      template <class O2, class T2>
      constexpr operator out_value_result<O2, T2>() const&
      {
        return {out, value};
      }
 
      template <class O2, class T2>
      constexpr operator out_value_result<O2, T2>() &&
      {
        return {etl::move(out), etl::move(value)};
      }
    };
 
    template <class O, class T>
    using iota_result = out_value_result<O, T>;
 
    template <class I, class O>
    using copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using copy_n_result = in_out_result<I, O>;
 
    template <class I, class O>
    using copy_if_result = in_out_result<I, O>;
 
    template <class I, class O>
    using copy_backward_result = in_out_result<I, O>;
 
    template <class I, class O>
    using uninitialized_copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using uninitialized_copy_n_result = in_out_result<I, O>;
 
    template <class I, class O>
    using uninitialized_move_result = in_out_result<I, O>;
 
    template <class I, class O>
    using uninitialized_move_n_result = in_out_result<I, O>;
 
    template <class I, class O>
    using move_result = in_out_result<I, O>;
 
    template <class I, class O>
    using move_backward_result = in_out_result<I, O>;
 
    template <class I1, class I2>
    using mismatch_result = in_in_result<I1, I2>;
 
    template <class I1, class I2>
    using swap_ranges_result = in_in_result<I1, I2>;
 
    template <class I, class O>
    using unary_transform_result = in_out_result<I, O>;
 
    template <class I1, class I2, class O>
    using binary_transform_result = in_in_out_result<I1, I2, O>;
 
    template <class I, class O>
    using replace_copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using replace_copy_if_result = in_out_result<I, O>;
 
    template <class I, class O>
    using remove_copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using unique_copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using rotate_copy_result = in_out_result<I, O>;
 
    template <class I, class O>
    using partial_sort_copy_result = in_out_result<I, O>;
 
    template <class I, class O1, class O2>
    using partition_copy_result = in_out_out_result<I, O1, O2>;
 
    template <class I1, class I2, class O>
    using set_union_result = in_in_out_result<I1, I2, O>;
 
    template <class I1, class I2, class O>
    using set_intersection_result = in_in_out_result<I1, I2, O>;
 
    template <class I, class O>
    using set_difference_result = in_out_result<I, O>;
 
    template <class I1, class I2, class O>
    using set_symmetric_difference_result = in_in_out_result<I1, I2, O>;
 
    template <class I1, class I2, class O>
    using merge_result = in_in_out_result<I1, I2, O>;
 
    template <class I>
    using next_permutation_result = in_found_result<I>;
 
    template <class I>
    using prev_permutation_result = in_found_result<I>;
 
    template <class T>
    struct min_max_result
    {
      T min;
      T max;
 
      template <class T2>
      constexpr operator min_max_result<T2>() const&
      {
        return {min, max};
      }
 
      template <class T2>
      constexpr operator min_max_result<T2>() &&
      {
        return {etl::move(min), etl::move(max)};
      }
    };
 
    template <class T>
    using minmax_result = min_max_result<T>;
 
    template <class I>
    using minmax_element_result = min_max_result<I>;
 
    template <class I, class F>
    using for_each_result = in_fun_result<I, F>;
 
    struct for_each_fn
    {
      template <class I, class S, class Fun, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::for_each_result<I, Fun> operator()(I first, S last, Fun f, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          etl::invoke(f, etl::invoke(proj, *first));
        }
        return {etl::move(first), etl::move(f)};
      }
 
      template <class R, class Fun, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::for_each_result<ranges::borrowed_iterator_t<R>, Fun> operator()(R&& r, Fun f, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(f), etl::ref(proj));
      }
    };
 
    inline constexpr for_each_fn for_each;
 
    template <class I, class F>
    using for_each_n_result = in_fun_result<I, F>;
 
    struct for_each_n_fn
    {
      template <class I, class Fun, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr for_each_n_result<I, Fun> operator()(I first, etl::iter_difference_t<I> n, Fun fun, Proj proj = Proj{}) const
      {
        for (; n-- > 0; ++first)
        {
          etl::invoke(fun, etl::invoke(proj, *first));
        }
        return {etl::move(first), etl::move(fun)};
      }
    };
 
    inline constexpr for_each_n_fn for_each_n{};
 
    struct find_fn
    {
      template <class I, class S, class T, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, const T& value, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(proj, *first) == value)
          {
            return first;
          }
        }
        return first;
      }
 
      template <class R, class T, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, const T& value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::ref(proj));
      }
    };
 
    inline constexpr find_fn find;
 
    struct find_if_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            return first;
          }
        }
        return first;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr find_if_fn find_if;
 
    struct find_if_not_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (!etl::invoke(pred, etl::invoke(proj, *first)))
          {
            return first;
          }
        }
        return first;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr find_if_not_fn find_if_not;
 
    struct search_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::subrange<I1> operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (;; ++first1)
        {
          I1 it1 = first1;
          for (I2 it2 = first2;; ++it1, ++it2)
          {
            if (it2 == last2)
            {
              return {first1, it1};
            }
            if (it1 == last1)
            {
              return {it1, it1};
            }
            if (!etl::invoke(pred, etl::invoke(proj1, *it1), etl::invoke(proj2, *it2)))
            {
              break;
            }
          }
        }
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::borrowed_subrange_t<R1> operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr search_fn search{};
 
    struct search_n_fn
    {
      template <class I, class S, class T = etl::iter_value_t<I>, class Pred = ranges::equal_to, class Proj = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, etl::iter_difference_t<I> count, const T& value, Pred pred = {}, Proj proj = {}) const
      {
        if (count <= 0)
        {
          return {first, first};
        }
 
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first), value))
          {
            I                         start = first;
            etl::iter_difference_t<I> n     = 1;
 
            for (;;)
            {
              if (n >= count)
              {
                return {start, ++first};
              }
              ++first;
              if (first == last)
              {
                return {first, first};
              }
              if (!etl::invoke(pred, etl::invoke(proj, *first), value))
              {
                break;
              }
              ++n;
            }
          }
        }
        return {first, first};
      }
 
      template <class R, class T = etl::ranges::range_value_t<R>, class Pred = ranges::equal_to, class Proj = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, ranges::range_difference_t<R> count, const T& value, Pred pred = {},
                                                          Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), count, value, etl::move(pred), etl::move(proj));
      }
    };
 
    inline constexpr search_n_fn search_n{};
 
    struct find_end_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::subrange<I1> operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        if (first2 == last2)
        {
          auto last_it = ranges::next(first1, last1);
          return {last_it, last_it};
        }
        auto result = ranges::search(etl::move(first1), last1, first2, last2, pred, proj1, proj2);
 
        if (result.empty())
        {
          return result;
        }
 
        for (;;)
        {
          auto new_result = ranges::search(etl::next(result.begin()), last1, first2, last2, pred, proj1, proj2);
          if (new_result.empty())
          {
            return result;
          }
          else
          {
            result = etl::move(new_result);
          }
        }
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::borrowed_subrange_t<R1> operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr find_end_fn find_end{};
 
    struct find_first_of_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr I1 operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (; first1 != last1; ++first1)
        {
          for (auto i = first2; i != last2; ++i)
          {
            if (etl::invoke(pred, etl::invoke(proj1, *first1), etl::invoke(proj2, *i)))
            {
              return first1;
            }
          }
        }
        return first1;
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::borrowed_iterator_t<R1> operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr find_first_of_fn find_first_of{};
 
    struct adjacent_find_fn
    {
      template <class I, class S, class Proj = etl::identity, class Pred = ranges::equal_to, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Pred pred = {}, Proj proj = {}) const
      {
        if (first == last)
        {
          return first;
        }
        auto next_it = ranges::next(first);
        for (; next_it != last; ++next_it, ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first), etl::invoke(proj, *next_it)))
          {
            return first;
          }
        }
        return next_it;
      }
 
      template <class R, class Proj = etl::identity, class Pred = ranges::equal_to, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Pred pred = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr adjacent_find_fn adjacent_find;
 
    struct count_fn
    {
      template <class I, class S, class Proj = etl::identity, class T = etl::projected_value_t<I, Proj>,
                typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr etl::iter_difference_t<I> operator()(I first, S last, const T& value, Proj proj = {}) const
      {
        etl::iter_difference_t<I> counter = 0;
        for (; first != last; ++first)
        {
          if (etl::invoke(proj, *first) == value)
          {
            ++counter;
          }
        }
        return counter;
      }
 
      template <class R, class Proj = etl::identity, class T = etl::projected_value_t<ranges::iterator_t<R>, Proj>,
                typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::range_difference_t<R> operator()(R&& r, const T& value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::ref(proj));
      }
    };
 
    inline constexpr count_fn count;
 
    struct count_if_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr etl::iter_difference_t<I> operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        etl::iter_difference_t<I> counter = 0;
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            ++counter;
          }
        }
        return counter;
      }
 
      template <class R, class Proj = etl::identity, class Pred, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::range_difference_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr count_if_fn count_if;
 
    struct all_of_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        return ranges::find_if_not(first, last, etl::ref(pred), etl::ref(proj)) == last;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return operator()(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr all_of_fn all_of;
 
    struct any_of_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        return ranges::find_if(first, last, etl::ref(pred), etl::ref(proj)) != last;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return operator()(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr any_of_fn any_of;
 
    struct none_of_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        return ranges::find_if(first, last, etl::ref(pred), etl::ref(proj)) == last;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return operator()(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr none_of_fn none_of;
 
    struct mismatch_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::mismatch_result<I1, I2> operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {},
                                                           Proj2 proj2 = {}) const
      {
        for (; first1 != last1 && first2 != last2; ++first1, ++first2)
        {
          if (!etl::invoke(pred, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            break;
          }
        }
        return {etl::move(first1), etl::move(first2)};
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::mismatch_result<ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>>
        operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr mismatch_fn mismatch{};
 
    struct equal_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (; first1 != last1 && first2 != last2; ++first1, ++first2)
        {
          if (!etl::invoke(pred, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            return false;
          }
        }
        return first1 == last1 && first2 == last2;
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr bool operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr equal_fn equal{};
 
    struct is_permutation_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        // Skip common prefix
        for (; first1 != last1 && first2 != last2; ++first1, ++first2)
        {
          if (!etl::invoke(pred, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            break;
          }
        }
 
        if (first1 == last1)
        {
          return first2 == last2;
        }
 
        if (first2 == last2)
        {
          return false;
        }
 
        // Check remaining elements
        for (I1 i = first1; i != last1; ++i)
        {
          // Check if we already counted this element
          bool already_seen = false;
          for (I1 j = first1; j != i; ++j)
          {
            if (etl::invoke(pred, etl::invoke(proj1, *i), etl::invoke(proj1, *j)))
            {
              already_seen = true;
              break;
            }
          }
 
          if (already_seen)
          {
            continue;
          }
 
          // Count occurrences in range2
          auto count2 = etl::iter_difference_t<I2>(0);
          for (I2 k = first2; k != last2; ++k)
          {
            if (etl::invoke(pred, etl::invoke(proj1, *i), etl::invoke(proj2, *k)))
            {
              ++count2;
            }
          }
 
          if (count2 == 0)
          {
            return false;
          }
 
          // Count occurrences in range1
          auto count1 = etl::iter_difference_t<I1>(0);
          for (I1 k = i; k != last1; ++k)
          {
            if (etl::invoke(pred, etl::invoke(proj1, *i), etl::invoke(proj1, *k)))
            {
              ++count1;
            }
          }
 
          if (count1 != count2)
          {
            return false;
          }
        }
 
        return true;
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr bool operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr is_permutation_fn is_permutation{};
 
    struct starts_with_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (; first2 != last2; ++first1, ++first2)
        {
          if (first1 == last1 || !etl::invoke(pred, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            return false;
          }
        }
        return true;
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr bool operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr starts_with_fn starts_with{};
 
    struct ends_with_fn
    {
      template <class I1, class S1, class I2, class S2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        auto n1 = etl::distance(first1, last1);
        auto n2 = etl::distance(first2, last2);
 
        if (n2 > n1)
        {
          return false;
        }
 
        ranges::advance(first1, n1 - n2);
 
        return starts_with(first1, last1, first2, last2, etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
 
      template <class R1, class R2, class Pred = ranges::equal_to, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr bool operator()(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(pred), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr ends_with_fn ends_with{};
 
    struct lexicographical_compare_fn
    {
      template <class I1, class S1, class I2, class S2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (; first1 != last1 && first2 != last2; ++first1, ++first2)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            return true;
          }
 
          if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            return false;
          }
        }
        return first1 == last1 && first2 != last2;
      }
 
      template <class R1, class R2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr bool operator()(R1&& r1, R2&& r2, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(comp), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr lexicographical_compare_fn lexicographical_compare{};
 
    template <class I, class T>
    struct in_value_result
    {
      ETL_NO_UNIQUE_ADDRESS I in;
      ETL_NO_UNIQUE_ADDRESS T value;
 
      template <class I2, class T2>
      constexpr operator in_value_result<I2, T2>() const&
      {
        return {in, value};
      }
 
      template <class I2, class T2>
      constexpr operator in_value_result<I2, T2>() &&
      {
        return {etl::move(in), etl::move(value)};
      }
    };
 
    template <class I, class T>
    using fold_left_with_iter_result = in_value_result<I, T>;
 
    struct fold_left_fn
    {
      template <class I, class S, class T, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, T init, F f) const -> etl::decay_t<etl::invoke_result_t<F&, T, etl::iter_reference_t<I>>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, T, etl::iter_reference_t<I>>>;
        U accum = etl::move(init);
        for (; first != last; ++first)
        {
          accum = etl::invoke(f, etl::move(accum), *first);
        }
        return accum;
      }
 
      template <class R, class T, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto operator()(R&& r, T init, F f) const -> etl::decay_t< etl::invoke_result_t<F&, T, etl::ranges::range_reference_t<R>>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(init), etl::move(f));
      }
    };
 
    inline constexpr fold_left_fn fold_left{};
 
    struct fold_left_with_iter_fn
    {
      template <class I, class S, class T, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, T init,
                                F f) const -> fold_left_with_iter_result< I, etl::decay_t<etl::invoke_result_t<F&, T, etl::iter_reference_t<I>>>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, T, etl::iter_reference_t<I>>>;
        U accum = etl::move(init);
        for (; first != last; ++first)
        {
          accum = etl::invoke(f, etl::move(accum), *first);
        }
        return {etl::move(first), etl::move(accum)};
      }
 
      template <class R, class T, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto operator()(R&& r, T init, F f) const
        -> fold_left_with_iter_result< ranges::borrowed_iterator_t<R>, etl::decay_t< etl::invoke_result_t<F&, T, etl::ranges::range_reference_t<R>>>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(init), etl::move(f));
      }
    };
 
    inline constexpr fold_left_with_iter_fn fold_left_with_iter{};
 
    struct fold_left_first_fn
    {
      template <class I, class S, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, F f) const -> etl::decay_t<etl::invoke_result_t<F&, etl::iter_value_t<I>, etl::iter_reference_t<I>>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, etl::iter_value_t<I>, etl::iter_reference_t<I>>>;
        if (first == last)
        {
          return U{};
        }
        U accum = *first;
        ++first;
        for (; first != last; ++first)
        {
          accum = etl::invoke(f, etl::move(accum), *first);
        }
        return accum;
      }
 
      template <class R, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto operator()(R&& r,
                                F f) const -> etl::decay_t<etl::invoke_result_t<F&, etl::ranges::range_value_t<R>, etl::ranges::range_reference_t<R>>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(f));
      }
    };
 
    inline constexpr fold_left_first_fn fold_left_first{};
 
    struct fold_left_first_with_iter_fn
    {
      template <class I, class S, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, F f) const
        -> fold_left_with_iter_result< I, etl::decay_t<etl::invoke_result_t<F&, etl::iter_value_t<I>, etl::iter_reference_t<I>>>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, etl::iter_value_t<I>, etl::iter_reference_t<I>>>;
        if (first == last)
        {
          return {etl::move(first), U{}};
        }
        U accum = *first;
        ++first;
        for (; first != last; ++first)
        {
          accum = etl::invoke(f, etl::move(accum), *first);
        }
        return {etl::move(first), etl::move(accum)};
      }
 
      template <class R, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto operator()(R&& r, F f) const
        -> fold_left_with_iter_result< ranges::borrowed_iterator_t<R>,
                                       etl::decay_t<etl::invoke_result_t<F&, etl::ranges::range_value_t<R>, etl::ranges::range_reference_t<R>>>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(f));
      }
    };
 
    inline constexpr fold_left_first_with_iter_fn fold_left_first_with_iter{};
 
    struct fold_right_fn
    {
      template <class I, class S, class T, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, T init, F f) const -> etl::decay_t<etl::invoke_result_t<F&, etl::iter_reference_t<I>, T>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, etl::iter_reference_t<I>, T>>;
        U accum = etl::move(init);
        I tail  = ranges::next(first, last);
        while (tail != first)
        {
          tail  = ranges::prev(tail);
          accum = etl::invoke(f, *tail, etl::move(accum));
        }
        return accum;
      }
 
      template <class R, class T, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto operator()(R&& r, T init, F f) const -> etl::decay_t< etl::invoke_result_t<F&, etl::ranges::range_reference_t<R>, T>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(init), etl::move(f));
      }
    };
 
    inline constexpr fold_right_fn fold_right{};
 
    struct fold_right_last_fn
    {
      template <class I, class S, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr auto operator()(I first, S last, F f) const -> etl::decay_t<etl::invoke_result_t<F&, etl::iter_reference_t<I>, etl::iter_value_t<I>>>
      {
        using U = etl::decay_t<etl::invoke_result_t<F&, etl::iter_reference_t<I>, etl::iter_value_t<I>>>;
        I tail  = ranges::next(first, last);
        if (tail == first)
        {
          return U{};
        }
        tail    = ranges::prev(tail);
        U accum = *tail;
        while (tail != first)
        {
          tail  = ranges::prev(tail);
          accum = etl::invoke(f, *tail, etl::move(accum));
        }
        return accum;
      }
 
      template <class R, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr auto
        operator()(R&& r, F f) const -> etl::decay_t<etl::invoke_result_t< F&, etl::ranges::range_reference_t<R>, etl::ranges::range_value_t<R>>>
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(f));
      }
    };
 
    inline constexpr fold_right_last_fn fold_right_last{};
 
    struct copy_fn
    {
      template <class I, class S, class O, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::copy_result<I, O> operator()(I first, S last, O result) const
      {
        for (; first != last; ++first, ++result)
        {
          *result = *first;
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr copy_fn copy{};
 
    struct copy_n_fn
    {
      template <class I, class O>
      constexpr ranges::copy_n_result<I, O> operator()(I first, etl::iter_difference_t<I> n, O result) const
      {
        for (etl::iter_difference_t<I> i = 0; i < n; ++i, ++first, ++result)
        {
          *result = *first;
        }
        return {etl::move(first), etl::move(result)};
      }
    };
 
    inline constexpr copy_n_fn copy_n{};
 
    struct copy_if_fn
    {
      template <class I, class S, class O, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::copy_if_result<I, O> operator()(I first, S last, O result, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            *result = *first;
            ++result;
          }
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::copy_if_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr copy_if_fn copy_if{};
 
    struct copy_backward_fn
    {
      template <class I1, class S1, class I2, typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::copy_backward_result<I1, I2> operator()(I1 first, S1 last, I2 result) const
      {
        I1 last_it = ranges::next(first, last);
        I1 tail    = last_it;
        while (first != tail)
        {
          *(--result) = *(--tail);
        }
        return {etl::move(last_it), etl::move(result)};
      }
 
      template <class R, class I, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::copy_backward_result<ranges::borrowed_iterator_t<R>, I> operator()(R&& r, I result) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr copy_backward_fn copy_backward{};
 
    struct move_fn
    {
      template <class I, class S, class O, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::move_result<I, O> operator()(I first, S last, O result) const
      {
        for (; first != last; ++first, ++result)
        {
          *result = etl::move(*first);
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::move_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr move_fn move{};
 
    struct move_backward_fn
    {
      template <class I1, class S1, class I2, typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::move_backward_result<I1, I2> operator()(I1 first, S1 last, I2 result) const
      {
        I1 last_it = ranges::next(first, last);
        I1 tail    = last_it;
        while (first != tail)
        {
          *(--result) = etl::move(*(--tail));
        }
        return {etl::move(last_it), etl::move(result)};
      }
 
      template <class R, class I, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::move_backward_result<ranges::borrowed_iterator_t<R>, I> operator()(R&& r, I result) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr move_backward_fn move_backward{};
 
    struct swap_ranges_fn
    {
      template <class I1, class S1, class I2, class S2, typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::swap_ranges_result<I1, I2> operator()(I1 first1, S1 last1, I2 first2, S2 last2) const
      {
        for (; first1 != last1 && first2 != last2; ++first1, ++first2)
        {
          etl::iter_swap(first1, first2);
        }
        return {etl::move(first1), etl::move(first2)};
      }
 
      template <class R1, class R2, typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::swap_ranges_result<ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>> operator()(R1&& r1, R2&& r2) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2));
      }
    };
 
    inline constexpr swap_ranges_fn swap_ranges{};
 
    struct replace_fn
    {
      template <class I, class S, class T1, class T2, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, const T1& old_value, const T2& new_value, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(proj, *first) == old_value)
          {
            *first = new_value;
          }
        }
        return first;
      }
 
      template <class R, class T1, class T2, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, const T1& old_value, const T2& new_value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), old_value, new_value, etl::ref(proj));
      }
    };
 
    inline constexpr replace_fn replace{};
 
    struct replace_if_fn
    {
      template <class I, class S, class Pred, class T, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Pred pred, const T& new_value, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            *first = new_value;
          }
        }
        return first;
      }
 
      template <class R, class Pred, class T, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Pred pred, const T& new_value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), new_value, etl::ref(proj));
      }
    };
 
    inline constexpr replace_if_fn replace_if{};
 
    struct replace_copy_fn
    {
      template <class I, class S, class O, class T1, class T2, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::replace_copy_result<I, O> operator()(I first, S last, O result, const T1& old_value, const T2& new_value,
                                                             Proj proj = {}) const
      {
        for (; first != last; ++first, ++result)
        {
          if (etl::invoke(proj, *first) == old_value)
          {
            *result = new_value;
          }
          else
          {
            *result = *first;
          }
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, class T1, class T2, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::replace_copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, const T1& old_value, const T2& new_value,
                                                                                          Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), old_value, new_value, etl::ref(proj));
      }
    };
 
    inline constexpr replace_copy_fn replace_copy{};
 
    struct replace_copy_if_fn
    {
      template <class I, class S, class O, class Pred, class T, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::replace_copy_if_result<I, O> operator()(I first, S last, O result, Pred pred, const T& new_value, Proj proj = {}) const
      {
        for (; first != last; ++first, ++result)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            *result = new_value;
          }
          else
          {
            *result = *first;
          }
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, class Pred, class T, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::replace_copy_if_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, Pred pred, const T& new_value,
                                                                                             Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), etl::ref(pred), new_value, etl::ref(proj));
      }
    };
 
    inline constexpr replace_copy_if_fn replace_copy_if{};
 
    struct remove_fn
    {
      template <class I, class S, class T, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, const T& value, Proj proj = {}) const
      {
        first = ranges::find(first, last, value, etl::ref(proj));
 
        if (first != last)
        {
          I result = first;
 
          for (I it = result; ++it != last;)
          {
            if (!(etl::invoke(proj, *it) == value))
            {
              *result = etl::move(*it);
              ++result;
            }
          }
 
          return {result, last};
        }
 
        return {first, last};
      }
 
      template <class R, class T, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, const T& value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::ref(proj));
      }
    };
 
    inline constexpr remove_fn remove{};
 
    struct remove_if_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        first = ranges::find_if(first, last, etl::ref(pred), etl::ref(proj));
 
        if (first != last)
        {
          I result = first;
 
          for (I it = result; ++it != last;)
          {
            if (!etl::invoke(pred, etl::invoke(proj, *it)))
            {
              *result = etl::move(*it);
              ++result;
            }
          }
 
          return {result, last};
        }
 
        return {first, last};
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr remove_if_fn remove_if{};
 
    struct remove_copy_fn
    {
      template <class I, class S, class O, class T, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::remove_copy_result<I, O> operator()(I first, S last, O result, const T& value, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (!(etl::invoke(proj, *first) == value))
          {
            *result = *first;
            ++result;
          }
        }
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, class T, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::remove_copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, const T& value, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), value, etl::ref(proj));
      }
    };
 
    inline constexpr remove_copy_fn remove_copy{};
 
    struct fill_fn
    {
      template <class I, class S, class T, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, const T& value) const
      {
        for (; first != last; ++first)
        {
          *first = value;
        }
        return first;
      }
 
      template <class R, class T, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, const T& value) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value);
      }
    };
 
    inline constexpr fill_fn fill{};
 
    struct fill_n_fn
    {
      template <class I, class T>
      constexpr I operator()(I first, etl::iter_difference_t<I> n, const T& value) const
      {
        for (; n-- > 0; ++first)
        {
          *first = value;
        }
        return first;
      }
    };
 
    inline constexpr fill_n_fn fill_n{};
 
    struct generate_fn
    {
      template <class I, class S, class F, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, F gen) const
      {
        for (; first != last; ++first)
        {
          *first = gen();
        }
        return first;
      }
 
      template <class R, class F, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, F gen) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(gen));
      }
    };
 
    inline constexpr generate_fn generate{};
 
    struct generate_n_fn
    {
      template <class I, class F>
      constexpr I operator()(I first, etl::iter_difference_t<I> n, F gen) const
      {
        for (; n-- > 0; ++first)
        {
          *first = gen();
        }
        return first;
      }
    };
 
    inline constexpr generate_n_fn generate_n{};
 
    struct iota_fn
    {
      template <class O, class S, class T, typename = etl::enable_if_t<!etl::is_range_v<O>>>
      constexpr ranges::iota_result<O, T> operator()(O first, S last, T value) const
      {
        while (first != last)
        {
          *first = value;
          ++first;
          ++value;
        }
        return {etl::move(first), etl::move(value)};
      }
 
      template <class R, class T, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::iota_result<ranges::borrowed_iterator_t<R>, T> operator()(R&& r, T value) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(value));
      }
    };
 
    inline constexpr iota_fn iota{};
 
    struct unique_fn
    {
      template <class I, class S, class Pred = ranges::equal_to, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, Pred pred = {}, Proj proj = {}) const
      {
        first = ranges::adjacent_find(first, last, etl::ref(pred), etl::ref(proj));
 
        if (first != last)
        {
          I result = first;
          ++first;
 
          while (++first != last)
          {
            if (!etl::invoke(pred, etl::invoke(proj, *result), etl::invoke(proj, *first)))
            {
              *++result = etl::move(*first);
            }
          }
 
          return {++result, last};
        }
 
        return {first, last};
      }
 
      template <class R, class Pred = ranges::equal_to, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, Pred pred = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr unique_fn unique{};
 
    struct unique_copy_fn
    {
      template <class I, class S, class O, class Pred = ranges::equal_to, class Proj = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::unique_copy_result<I, O> operator()(I first, S last, O result, Pred pred = {}, Proj proj = {}) const
      {
        if (first != last)
        {
          *result = *first;
          ++result;
 
          auto previous = first;
          ++first;
 
          for (; first != last; ++first)
          {
            if (!etl::invoke(pred, etl::invoke(proj, *previous), etl::invoke(proj, *first)))
            {
              *result = *first;
              ++result;
            }
            previous = first;
          }
        }
 
        return {etl::move(first), etl::move(result)};
      }
 
      template <class R, class O, class Pred = ranges::equal_to, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::unique_copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, Pred pred = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr unique_copy_fn unique_copy{};
 
    struct transform_fn
    {
      // Unary: iterator + sentinel
      template <class I, class S, class O, class F, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::unary_transform_result<I, O> operator()(I first, S last, O result, F op, Proj proj = {}) const
      {
        for (; first != last; ++first, ++result)
        {
          *result = etl::invoke(op, etl::invoke(proj, *first));
        }
        return {etl::move(first), etl::move(result)};
      }
 
      // Unary: range
      template < class R, class O, class F, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R> && !etl::is_range_v<O>>>
      constexpr ranges::unary_transform_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result, F op, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result), etl::ref(op), etl::ref(proj));
      }
 
      // Binary: iterator + sentinel
      template <class I1, class S1, class I2, class S2, class O, class F, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::binary_transform_result<I1, I2, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, F op, Proj1 proj1 = {},
                                                                      Proj2 proj2 = {}) const
      {
        for (; first1 != last1 && first2 != last2; ++first1, ++first2, ++result)
        {
          *result = etl::invoke(op, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2));
        }
        return {etl::move(first1), etl::move(first2), etl::move(result)};
      }
 
      // Binary: range
      template < class R1, class R2, class O, class F, class Proj1 = etl::identity, class Proj2 = etl::identity,
                 typename = etl::enable_if_t<etl::is_range_v<R1> && etl::is_range_v<R2>>>
      constexpr ranges::binary_transform_result< ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result, F op, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::ref(op), etl::ref(proj1),
                       etl::ref(proj2));
      }
    };
 
    inline constexpr transform_fn transform{};
 
    struct reverse_fn
    {
      template <class I, class S, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last) const
      {
        I tail   = ranges::next(first, last);
        I result = tail;
 
        for (; first != tail && first != --tail; ++first)
        {
          etl::iter_swap(first, tail);
        }
 
        return result;
      }
 
      template <class R, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r) const
      {
        return (*this)(ranges::begin(r), ranges::end(r));
      }
    };
 
    inline constexpr reverse_fn reverse{};
 
    template <class I, class O>
    using reverse_copy_result = in_out_result<I, O>;
 
    struct reverse_copy_fn
    {
      template <class I, class S, class O, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::reverse_copy_result<I, O> operator()(I first, S last, O result) const
      {
        I tail   = ranges::next(first, last);
        I end_it = tail;
 
        while (tail != first)
        {
          *result = *--tail;
          ++result;
        }
 
        return {etl::move(end_it), etl::move(result)};
      }
 
      template <class R, class O, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::reverse_copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, O result) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr reverse_copy_fn reverse_copy{};
 
    template <class I>
    using rotate_result = ranges::subrange<I>;
 
    struct rotate_fn
    {
      template <class I, class S, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::rotate_result<I> operator()(I first, I middle, S last) const
      {
        if (first == middle)
        {
          I last_it = ranges::next(first, last);
          return {last_it, last_it};
        }
 
        I last_it = ranges::next(first, last);
 
        if (middle == last_it)
        {
          return {first, last_it};
        }
 
        I new_first = etl::rotate(first, middle, last_it);
        return {etl::move(new_first), etl::move(last_it)};
      }
 
      template <class R, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::rotate_result<ranges::borrowed_iterator_t<R>> operator()(R&& r, ranges::iterator_t<R> middle) const
      {
        return (*this)(ranges::begin(r), etl::move(middle), ranges::end(r));
      }
    };
 
    inline constexpr rotate_fn rotate{};
 
    struct rotate_copy_fn
    {
      template <class I, class S, class O, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::rotate_copy_result<I, O> operator()(I first, I middle, S last, O result) const
      {
        I last_it = ranges::next(first, last);
        O end_out = etl::copy(middle, last_it, result);
        end_out   = etl::copy(first, middle, end_out);
        return {etl::move(last_it), etl::move(end_out)};
      }
 
      template <class R, class O, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::rotate_copy_result<ranges::borrowed_iterator_t<R>, O> operator()(R&& r, ranges::iterator_t<R> middle, O result) const
      {
        return (*this)(ranges::begin(r), etl::move(middle), ranges::end(r), etl::move(result));
      }
    };
 
    inline constexpr rotate_copy_fn rotate_copy{};
 
    struct shift_left_fn
    {
      template <class I, class S, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, etl::iter_difference_t<I> n) const
      {
        I last_it = ranges::next(first, last);
 
        if (n <= 0)
        {
          return {first, last_it};
        }
 
        I mid = first;
        if (ranges::advance(mid, n, last_it) != 0)
        {
          return {first, first};
        }
 
        I result = ranges::move(mid, last_it, first).out;
        return {first, etl::move(result)};
      }
 
      template <class R, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, etl::ranges::range_difference_t<R> n) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), n);
      }
    };
 
    inline constexpr shift_left_fn shift_left{};
 
    struct shift_right_fn
    {
      template <class I, class S, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, etl::iter_difference_t<I> n) const
      {
        I last_it = ranges::next(first, last);
 
        if (n <= 0)
        {
          return {first, last_it};
        }
 
        I trail = last_it;
        if (ranges::advance(trail, -n, first) != 0)
        {
          return {last_it, last_it};
        }
 
        I new_first = ranges::move_backward(first, trail, last_it).out;
        return {etl::move(new_first), etl::move(last_it)};
      }
 
      template <class R, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, etl::ranges::range_difference_t<R> n) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), n);
      }
    };
 
    inline constexpr shift_right_fn shift_right{};
 
    struct shuffle_fn
    {
      template <class I, class S, class Gen, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      I operator()(I first, S last, Gen&& gen) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "shuffle requires random access iterators");
 
        using diff_t    = etl::iter_difference_t<I>;
        using udiff_t   = etl::make_unsigned_t<diff_t>;
        using gen_t     = etl::remove_reference_t<Gen>;
        using uresult_t = decltype(gen());
 
        I      last_it = ranges::next(first, last);
        diff_t n       = last_it - first;
 
        if (n <= 1)
        {
          return last_it;
        }
 
        for (diff_t i = n - 1; i > 0; --i)
        {
          // Generate a uniformly distributed random index in [0, i]
          // using rejection sampling to avoid modulo bias.
          udiff_t             range  = static_cast<udiff_t>(i);
          constexpr uresult_t gmin   = gen_t::min();
          constexpr uresult_t gmax   = gen_t::max();
          constexpr uresult_t grange = gmax - gmin;
 
          uresult_t j;
 
          if ETL_IF_CONSTEXPR (grange == static_cast<uresult_t>(-1))
          {
            // Generator covers full range of uresult_t, just use modulo with
            // rejection
            uresult_t limit = (static_cast<uresult_t>(-1) / (static_cast<uresult_t>(range) + 1)) * (static_cast<uresult_t>(range) + 1);
            do {
              j = static_cast<uresult_t>(gen() - gmin);
            } while (j >= limit);
            j %= (static_cast<uresult_t>(range) + 1);
          }
          else
          {
            uresult_t limit = (grange / (static_cast<uresult_t>(range) + 1)) * (static_cast<uresult_t>(range) + 1);
            do {
              j = static_cast<uresult_t>(gen() - gmin);
            } while (j >= limit);
            j %= (static_cast<uresult_t>(range) + 1);
          }
 
          etl::iter_swap(first + i, first + static_cast<diff_t>(j));
        }
 
        return last_it;
      }
 
      template <class R, class Gen, typename = etl::enable_if_t<etl::is_range_v<R>>>
      ranges::borrowed_iterator_t<R> operator()(R&& r, Gen&& gen) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<ranges::iterator_t<R>>::value, "shuffle requires a range with random access iterators");
 
        return (*this)(ranges::begin(r), ranges::end(r), static_cast<Gen&&>(gen));
      }
    };
 
    inline constexpr shuffle_fn shuffle{};
 
    struct sample_fn
    {
      template <class I, class S, class O, class Gen, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      O operator()(I first, S last, O out, etl::iter_difference_t<I> n, Gen&& gen) const
      {
        using diff_t    = etl::iter_difference_t<I>;
        using udiff_t   = etl::make_unsigned_t<diff_t>;
        using gen_t     = etl::remove_reference_t<Gen>;
        using uresult_t = decltype(gen());
 
        if (n <= 0)
        {
          return out;
        }
 
        // Compute the size of [first, last).
        I      first_copy = first;
        diff_t pop_size   = 0;
        for (I it = first_copy; it != last; ++it)
        {
          ++pop_size;
        }
 
        if (pop_size <= n)
        {
          // Copy all elements.
          for (; first != last; ++first, ++out)
          {
            *out = *first;
          }
          return out;
        }
 
        // Selection sampling (Algorithm S / Vitter).
        // For each element, decide whether to include it.
        diff_t remaining = pop_size;
        diff_t needed    = n;
 
        for (; first != last && needed > 0; ++first, --remaining)
        {
          // Generate a uniformly distributed random number in [0, remaining).
          udiff_t             range  = static_cast<udiff_t>(remaining - 1);
          constexpr uresult_t gmin   = gen_t::min();
          constexpr uresult_t gmax   = gen_t::max();
          constexpr uresult_t grange = gmax - gmin;
 
          uresult_t j;
 
          if ETL_IF_CONSTEXPR (grange == static_cast<uresult_t>(-1))
          {
            if (range == 0)
            {
              j = 0;
            }
            else
            {
              uresult_t limit = (static_cast<uresult_t>(-1) / (static_cast<uresult_t>(range) + 1)) * (static_cast<uresult_t>(range) + 1);
              do {
                j = static_cast<uresult_t>(gen() - gmin);
              } while (j >= limit);
              j %= (static_cast<uresult_t>(range) + 1);
            }
          }
          else
          {
            if (range == 0)
            {
              j = 0;
            }
            else
            {
              uresult_t limit = (grange / (static_cast<uresult_t>(range) + 1)) * (static_cast<uresult_t>(range) + 1);
              do {
                j = static_cast<uresult_t>(gen() - gmin);
              } while (j >= limit);
              j %= (static_cast<uresult_t>(range) + 1);
            }
          }
 
          if (static_cast<diff_t>(j) < needed)
          {
            *out = *first;
            ++out;
            --needed;
          }
        }
 
        return out;
      }
 
      template <class R, class O, class Gen, typename = etl::enable_if_t<etl::is_range_v<R>>>
      O operator()(R&& r, O out, etl::ranges::range_difference_t<R> n, Gen&& gen) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(out), n, static_cast<Gen&&>(gen));
      }
    };
 
    inline constexpr sample_fn sample{};
 
    struct sort_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "sort requires random access iterators");
 
        I last_it = ranges::next(first, last);
 
        if (first == last_it)
        {
          return last_it;
        }
 
        // Shell sort with projection support
        auto n = etl::distance(first, last_it);
 
        for (auto gap = n / 2; gap > 0; gap /= 2)
        {
          for (auto i = gap; i < n; ++i)
          {
            auto temp = etl::move(*(first + i));
            auto j    = i;
 
            while (j >= gap && etl::invoke(comp, etl::invoke(proj, temp), etl::invoke(proj, *(first + (j - gap)))))
            {
              *(first + j) = etl::move(*(first + (j - gap)));
              j -= gap;
            }
 
            *(first + j) = etl::move(temp);
          }
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<ranges::iterator_t<R>>::value, "sort requires a range with random access iterators");
 
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr sort_fn sort{};
 
    struct stable_sort_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        I last_it = ranges::next(first, last);
 
        if (first == last_it)
        {
          return last_it;
        }
 
        // Insertion sort with projection support (stable)
        for (I i = ranges::next(first); i != last_it; ++i)
        {
          auto temp = etl::move(*i);
          I    j    = i;
 
          while (j != first)
          {
            I prev_j = ranges::prev(j);
            if (etl::invoke(comp, etl::invoke(proj, temp), etl::invoke(proj, *prev_j)))
            {
              *j = etl::move(*prev_j);
              j  = prev_j;
            }
            else
            {
              break;
            }
          }
 
          *j = etl::move(temp);
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr stable_sort_fn stable_sort{};
 
    struct partial_sort_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, I middle, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "partial_sort requires random access iterators");
 
  #include "etl/private/diagnostic_array_bounds_push.h"
 
        I last_it = ranges::next(first, last);
 
        if (first == middle || first == last_it)
        {
          return last_it;
        }
 
        // Build a max-heap on [first, middle)
        auto heap_size = etl::distance(first, middle);
 
        // Heapify: process from the last parent down to 0
        for (auto start = (heap_size - 1) / 2; start >= 0; --start)
        {
          sift_down(first, start, heap_size, comp, proj);
        }
 
        // For each element in [middle, last_it), if it is smaller than the heap
        // root, swap it in and re-heapify
        for (I it = middle; it != last_it; ++it)
        {
          if (etl::invoke(comp, etl::invoke(proj, *it), etl::invoke(proj, *first)))
          {
            etl::iter_swap(it, first);
            sift_down(first, decltype(heap_size){0}, heap_size, comp, proj);
          }
        }
 
        // Sort the heap to produce a sorted [first, middle)
        // Repeatedly extract the max from the heap
        for (auto heap_end = heap_size - 1; heap_end > 0; --heap_end)
        {
          etl::iter_swap(first, first + heap_end);
          sift_down(first, decltype(heap_size){0}, heap_end, comp, proj);
        }
 
        return last_it;
 
  #include "etl/private/diagnostic_pop.h"
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, ranges::iterator_t<R> middle, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<ranges::iterator_t<R>>::value, "partial_sort requires a range with random access iterators");
 
        return (*this)(ranges::begin(r), etl::move(middle), ranges::end(r), etl::move(comp), etl::move(proj));
      }
 
    private:
 
      template <class I, class DiffType, class Comp, class Proj>
      static constexpr void sift_down(I first, DiffType index, DiffType heap_size, Comp& comp, Proj& proj)
      {
        while (true)
        {
          auto largest = index;
          auto left    = 2 * index + 1;
          auto right   = 2 * index + 2;
 
          if (left < heap_size && etl::invoke(comp, etl::invoke(proj, *(first + largest)), etl::invoke(proj, *(first + left))))
          {
            largest = left;
          }
 
          if (right < heap_size && etl::invoke(comp, etl::invoke(proj, *(first + largest)), etl::invoke(proj, *(first + right))))
          {
            largest = right;
          }
 
          if (largest == index)
          {
            break;
          }
 
          etl::iter_swap(first + index, first + largest);
          index = largest;
        }
      }
    };
 
    inline constexpr partial_sort_fn partial_sort{};
 
    struct partial_sort_copy_fn
    {
      template <class I1, class S1, class I2, class S2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::partial_sort_copy_result<I1, I2> operator()(I1 first, S1 last, I2 result_first, S2 result_last, Comp comp = {},
                                                                    Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I2>::value, "partial_sort_copy requires the output to be random access iterators");
 
  #include "etl/private/diagnostic_array_bounds_push.h"
 
        I1 in_last  = ranges::next(first, last);
        I2 out_last = ranges::next(result_first, result_last);
 
        I2 r = result_first;
 
        // Copy elements from the input range into the output range
        for (I1 it = first; it != in_last && r != out_last; ++it, ++r)
        {
          *r = *it;
        }
 
        auto heap_size = etl::distance(result_first, r);
 
        if (heap_size == 0)
        {
          return {etl::move(in_last), etl::move(r)};
        }
 
        // Build a max-heap on [result_first, r)
        for (auto start = (heap_size - 1) / 2; start >= 0; --start)
        {
          sift_down(result_first, start, heap_size, comp, proj2);
        }
 
        // For remaining elements in [first + heap_size, in_last), if smaller
        // than the heap root, swap it in and re-heapify
        I1 it = first;
        etl::advance(it, heap_size);
        for (; it != in_last; ++it)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *it), etl::invoke(proj2, *result_first)))
          {
            *result_first = *it;
            sift_down(result_first, decltype(heap_size){0}, heap_size, comp, proj2);
          }
        }
 
        // Sort the heap to produce a sorted output range
        for (auto heap_end = heap_size - 1; heap_end > 0; --heap_end)
        {
          etl::iter_swap(result_first, result_first + heap_end);
          sift_down(result_first, decltype(heap_size){0}, heap_end, comp, proj2);
        }
  #include "etl/private/diagnostic_pop.h"
 
        return {etl::move(in_last), etl::move(r)};
      }
 
      template <class R1, class R2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::partial_sort_copy_result< ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>>
        operator()(R1&& r, R2&& result_r, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<ranges::iterator_t<R2>>::value,
                          "partial_sort_copy requires the output range to have random access iterators");
 
        return (*this)(ranges::begin(r), ranges::end(r), ranges::begin(result_r), ranges::end(result_r), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
 
    private:
 
      template <class I, class DiffType, class Comp, class Proj>
      static constexpr void sift_down(I first, DiffType index, DiffType heap_size, Comp& comp, Proj& proj)
      {
        while (true)
        {
          auto largest = index;
          auto left    = 2 * index + 1;
          auto right   = 2 * index + 2;
 
          if (left < heap_size && etl::invoke(comp, etl::invoke(proj, *(first + largest)), etl::invoke(proj, *(first + left))))
          {
            largest = left;
          }
 
          if (right < heap_size && etl::invoke(comp, etl::invoke(proj, *(first + largest)), etl::invoke(proj, *(first + right))))
          {
            largest = right;
          }
 
          if (largest == index)
          {
            break;
          }
 
          etl::iter_swap(first + index, first + largest);
          index = largest;
        }
      }
    };
 
    inline constexpr partial_sort_copy_fn partial_sort_copy{};
 
    struct nth_element_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, I nth, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "nth_element requires random access iterators");
 
        I last_it = ranges::next(first, last);
 
        if (first == last_it || ranges::next(first) == last_it)
        {
          return last_it;
        }
 
        I lo = first;
        I hi = ranges::prev(last_it);
 
        while (lo <= hi)
        {
          I p = nth_partition(lo, hi, comp, proj);
 
          if (p == nth)
          {
            return last_it;
          }
          else if (p > nth)
          {
            hi = ranges::prev(p);
          }
          else
          {
            lo = ranges::next(p);
          }
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, ranges::iterator_t<R> nth, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<ranges::iterator_t<R>>::value, "nth_element requires a range with random access iterators");
 
        return (*this)(ranges::begin(r), etl::move(nth), ranges::end(r), etl::move(comp), etl::move(proj));
      }
 
    private:
 
      template <class I, class Comp, class Proj>
      static constexpr I nth_partition(I first, I last, Comp& comp, Proj& proj)
      {
        if (first == last)
        {
          return first;
        }
 
        if (last - first == 1)
        {
          if (etl::invoke(comp, etl::invoke(proj, *last), etl::invoke(proj, *first)))
          {
            etl::iter_swap(first, last);
          }
          return first;
        }
 
        // Median-of-three pivot selection
        I mid = first + (last - first) / 2;
 
        if (etl::invoke(comp, etl::invoke(proj, *mid), etl::invoke(proj, *first)))
        {
          etl::iter_swap(first, mid);
        }
 
        if (etl::invoke(comp, etl::invoke(proj, *last), etl::invoke(proj, *first)))
        {
          etl::iter_swap(first, last);
        }
 
        if (etl::invoke(comp, etl::invoke(proj, *mid), etl::invoke(proj, *last)))
        {
          etl::iter_swap(mid, last);
        }
 
        // Pivot is now at *last
        I i = first;
        I j = last;
 
        while (true)
        {
          while (etl::invoke(comp, etl::invoke(proj, *i), etl::invoke(proj, *last)))
          {
            ++i;
          }
 
          --j;
 
          while (i < j && etl::invoke(comp, etl::invoke(proj, *last), etl::invoke(proj, *j)))
          {
            --j;
          }
 
          if (i >= j)
          {
            break;
          }
 
          etl::iter_swap(i, j);
          ++i;
        }
 
        etl::iter_swap(i, last);
        return i;
      }
    };
 
    inline constexpr nth_element_fn nth_element{};
 
    struct partition_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        first = ranges::find_if_not(first, last, etl::ref(pred), etl::ref(proj));
 
        if (first == last)
        {
          return {first, first};
        }
 
        for (I i = ranges::next(first); i != last; ++i)
        {
          if (etl::invoke(pred, etl::invoke(proj, *i)))
          {
            etl::iter_swap(i, first);
            ++first;
          }
        }
 
        return {first, ranges::next(first, last)};
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr partition_fn partition{};
 
    struct is_partitioned_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (!etl::invoke(pred, etl::invoke(proj, *first)))
          {
            break;
          }
        }
 
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            return false;
          }
        }
 
        return true;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr is_partitioned_fn is_partitioned{};
 
    struct partition_copy_fn
    {
      template <class I, class S, class O1, class O2, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::partition_copy_result<I, O1, O2> operator()(I first, S last, O1 out_true, O2 out_false, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (etl::invoke(pred, etl::invoke(proj, *first)))
          {
            *out_true = *first;
            ++out_true;
          }
          else
          {
            *out_false = *first;
            ++out_false;
          }
        }
 
        return {etl::move(first), etl::move(out_true), etl::move(out_false)};
      }
 
      template <class R, class O1, class O2, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::partition_copy_result<ranges::borrowed_iterator_t<R>, O1, O2> operator()(R&& r, O1 out_true, O2 out_false, Pred pred,
                                                                                                 Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(out_true), etl::move(out_false), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr partition_copy_fn partition_copy{};
 
    struct partition_point_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        for (; first != last; ++first)
        {
          if (!etl::invoke(pred, etl::invoke(proj, *first)))
          {
            return first;
          }
        }
 
        return first;
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
    };
 
    inline constexpr partition_point_fn partition_point{};
 
    struct stable_partition_fn
    {
      template <class I, class S, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, Pred pred, Proj proj = {}) const
      {
        // Find the first element that does not satisfy the predicate
        first = ranges::find_if_not(first, last, etl::ref(pred), etl::ref(proj));
 
        if (first == last)
        {
          return {first, first};
        }
 
        I last_it = ranges::next(first, last);
 
        I pp = stable_partition_impl(first, last_it, etl::ref(pred), etl::ref(proj), etl::distance(first, last_it));
 
        return {pp, last_it};
      }
 
      template <class R, class Pred, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, Pred pred, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::ref(pred), etl::ref(proj));
      }
 
    private:
 
      template <class I, class Pred, class Proj>
      static constexpr I stable_partition_impl(I first, I last, Pred pred, Proj proj, typename etl::iterator_traits<I>::difference_type len)
      {
        if (len == 0)
        {
          return first;
        }
 
        if (len == 1)
        {
          return etl::invoke(pred, etl::invoke(proj, *first)) ? ranges::next(first) : first;
        }
 
        I middle = ranges::next(first, len / 2);
 
        I left_partition  = stable_partition_impl(first, middle, etl::ref(pred), etl::ref(proj), len / 2);
        I right_partition = stable_partition_impl(middle, last, etl::ref(pred), etl::ref(proj), len - len / 2);
 
        if (left_partition == middle)
        {
          return right_partition;
        }
 
        if (middle == right_partition)
        {
          return left_partition;
        }
 
        return etl::rotate(left_partition, middle, right_partition);
      }
    };
 
    inline constexpr stable_partition_fn stable_partition{};
 
    struct is_sorted_until_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        if (first != last)
        {
          I next_it = ranges::next(first);
 
          while (next_it != last)
          {
            if (etl::invoke(comp, etl::invoke(proj, *next_it), etl::invoke(proj, *first)))
            {
              return next_it;
            }
 
            first = next_it;
            ++next_it;
          }
        }
 
        return ranges::next(first, last);
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr is_sorted_until_fn is_sorted_until{};
 
    struct is_sorted_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        return ranges::is_sorted_until(first, last, etl::ref(comp), etl::ref(proj)) == last;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr is_sorted_fn is_sorted{};
 
    struct lower_bound_fn
    {
      template <class I, class S, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        auto len = etl::distance(first, last);
 
        while (len > 0)
        {
          auto half   = len / 2;
          I    middle = ranges::next(first, half);
 
          if (etl::invoke(comp, etl::invoke(proj, *middle), value))
          {
            first = ranges::next(middle);
            len -= half + 1;
          }
          else
          {
            len = half;
          }
        }
 
        return first;
      }
 
      template <class R, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr lower_bound_fn lower_bound{};
 
    struct upper_bound_fn
    {
      template <class I, class S, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        auto len = etl::distance(first, last);
 
        while (len > 0)
        {
          auto half   = len / 2;
          I    middle = ranges::next(first, half);
 
          if (!etl::invoke(comp, value, etl::invoke(proj, *middle)))
          {
            first = ranges::next(middle);
            len -= half + 1;
          }
          else
          {
            len = half;
          }
        }
 
        return first;
      }
 
      template <class R, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr upper_bound_fn upper_bound{};
 
    struct equal_range_fn
    {
      template <class I, class S, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::subrange<I> operator()(I first, S last, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        return {ranges::lower_bound(first, last, value, etl::ref(comp), etl::ref(proj)),
                ranges::upper_bound(first, last, value, etl::ref(comp), etl::ref(proj))};
      }
 
      template <class R, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_subrange_t<R> operator()(R&& r, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr equal_range_fn equal_range{};
 
    struct binary_search_fn
    {
      template <class I, class S, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      ETL_NODISCARD
      constexpr bool operator()(I first, S last, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        first = ranges::lower_bound(first, last, value, etl::ref(comp), etl::ref(proj));
 
        return (!(first == last) && !(etl::invoke(comp, value, etl::invoke(proj, *first))));
      }
 
      template <class R, class T, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      ETL_NODISCARD
      constexpr bool operator()(R&& r, const T& value, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), value, etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr binary_search_fn binary_search{};
 
    struct includes_fn
    {
      template <class I1, class S1, class I2, class S2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      ETL_NODISCARD
      constexpr bool operator()(I1 first1, S1 last1, I2 first2, S2 last2, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        for (; first2 != last2; ++first1)
        {
          if (first1 == last1)
          {
            return false;
          }
 
          if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            return false;
          }
 
          if (!etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            ++first2;
          }
        }
 
        return true;
      }
 
      template <class R1, class R2, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      ETL_NODISCARD
      constexpr bool operator()(R1&& r1, R2&& r2, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(comp), etl::move(proj1), etl::move(proj2));
      }
    };
 
    inline constexpr includes_fn includes{};
 
    struct merge_fn
    {
      template <class I1, class S1, class I2, class S2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::merge_result<I1, I2, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {}, Proj1 proj1 = {},
                                                           Proj2 proj2 = {}) const
      {
        while (first1 != last1 && first2 != last2)
        {
          if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            *result = *first2;
            ++first2;
          }
          else
          {
            *result = *first1;
            ++first1;
          }
          ++result;
        }
 
        while (first1 != last1)
        {
          *result = *first1;
          ++first1;
          ++result;
        }
 
        while (first2 != last2)
        {
          *result = *first2;
          ++first2;
          ++result;
        }
 
        return {etl::move(first1), etl::move(first2), etl::move(result)};
      }
 
      template <class R1, class R2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::merge_result<ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
    };
 
    inline constexpr merge_fn merge{};
 
    struct inplace_merge_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, I middle, S last, Comp comp = {}, Proj proj = {}) const
      {
        I last_it = ranges::next(first, last);
 
        if (first == middle || middle == last_it)
        {
          return last_it;
        }
 
        inplace_merge_impl(first, middle, last_it, comp, proj, etl::distance(first, middle), etl::distance(middle, last_it));
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, ranges::iterator_t<R> middle, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), etl::move(middle), ranges::end(r), etl::move(comp), etl::move(proj));
      }
 
    private:
 
      template <class I, class Comp, class Proj>
      static constexpr void inplace_merge_impl(I first, I middle, I last, Comp& comp, Proj& proj,
                                               typename etl::iterator_traits<I>::difference_type len1,
                                               typename etl::iterator_traits<I>::difference_type len2)
      {
        if (len1 == 0 || len2 == 0)
        {
          return;
        }
 
        if (len1 + len2 == 2)
        {
          if (etl::invoke(comp, etl::invoke(proj, *middle), etl::invoke(proj, *first)))
          {
            etl::iter_swap(first, middle);
          }
          return;
        }
 
        I                                                 first_cut;
        I                                                 second_cut;
        typename etl::iterator_traits<I>::difference_type new_len1;
        typename etl::iterator_traits<I>::difference_type new_len2;
 
        if (len1 > len2)
        {
          new_len1   = len1 / 2;
          first_cut  = ranges::next(first, new_len1);
          second_cut = ranges::lower_bound(middle, last, etl::invoke(proj, *first_cut), etl::ref(comp), etl::ref(proj));
          new_len2   = etl::distance(middle, second_cut);
        }
        else
        {
          new_len2   = len2 / 2;
          second_cut = ranges::next(middle, new_len2);
          first_cut  = ranges::upper_bound(first, middle, etl::invoke(proj, *second_cut), etl::ref(comp), etl::ref(proj));
          new_len1   = etl::distance(first, first_cut);
        }
 
        I new_middle;
        // Due to a non-standard etl::rotate implementation, we need to handle
        // the case where one of the cuts is the middle separately to avoid
        // returning an iterator outside of [first, last)
        // As soon as etl::rotate is fixed to return an iterator in the middle
        // of the rotated range, this can be simplified to just calling
        // etl::rotate
        if (first_cut == middle)
        {
          new_middle = second_cut;
        }
        else if (second_cut == middle)
        {
          new_middle = first_cut;
        }
        else
        {
          new_middle = etl::rotate(first_cut, middle, second_cut);
        }
 
        inplace_merge_impl(first, first_cut, new_middle, comp, proj, new_len1, new_len2);
        inplace_merge_impl(new_middle, second_cut, last, comp, proj, len1 - new_len1, len2 - new_len2);
      }
    };
 
    inline constexpr inplace_merge_fn inplace_merge{};
 
    struct set_union_fn
    {
      template <class I1, class S1, class I2, class S2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::set_union_result<I1, I2, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {}, Proj1 proj1 = {},
                                                               Proj2 proj2 = {}) const
      {
        while (first1 != last1 && first2 != last2)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            *result = *first1;
            ++first1;
          }
          else if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            *result = *first2;
            ++first2;
          }
          else
          {
            *result = *first1;
            ++first1;
            ++first2;
          }
          ++result;
        }
 
        while (first1 != last1)
        {
          *result = *first1;
          ++first1;
          ++result;
        }
 
        while (first2 != last2)
        {
          *result = *first2;
          ++first2;
          ++result;
        }
 
        return {etl::move(first1), etl::move(first2), etl::move(result)};
      }
 
      template <class R1, class R2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::set_union_result<ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
    };
 
    inline constexpr set_union_fn set_union{};
 
    struct set_intersection_fn
    {
      template <class I1, class S1, class I2, class S2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::set_intersection_result<I1, I2, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {},
                                                                      Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        while (first1 != last1 && first2 != last2)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            ++first1;
          }
          else if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            ++first2;
          }
          else
          {
            *result = *first1;
            ++first1;
            ++first2;
            ++result;
          }
        }
 
        return {etl::move(first1), etl::move(first2), etl::move(result)};
      }
 
      template <class R1, class R2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::set_intersection_result< ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
    };
 
    inline constexpr set_intersection_fn set_intersection{};
 
    struct set_difference_fn
    {
      template <class I1, class S1, class I2, class S2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::set_difference_result<I1, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {}, Proj1 proj1 = {},
                                                                Proj2 proj2 = {}) const
      {
        while (first1 != last1 && first2 != last2)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            *result = *first1;
            ++first1;
            ++result;
          }
          else if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            ++first2;
          }
          else
          {
            ++first1;
            ++first2;
          }
        }
 
        while (first1 != last1)
        {
          *result = *first1;
          ++first1;
          ++result;
        }
 
        return {etl::move(first1), etl::move(result)};
      }
 
      template <class R1, class R2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::set_difference_result<ranges::borrowed_iterator_t<R1>, O> operator()(R1&& r1, R2&& r2, O result, Comp comp = {},
                                                                                             Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
    };
 
    inline constexpr set_difference_fn set_difference{};
 
    struct set_symmetric_difference_fn
    {
      template <class I1, class S1, class I2, class S2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<!etl::is_range_v<I1>>>
      constexpr ranges::set_symmetric_difference_result<I1, I2, O> operator()(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {},
                                                                              Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        while (first1 != last1 && first2 != last2)
        {
          if (etl::invoke(comp, etl::invoke(proj1, *first1), etl::invoke(proj2, *first2)))
          {
            *result = *first1;
            ++first1;
            ++result;
          }
          else if (etl::invoke(comp, etl::invoke(proj2, *first2), etl::invoke(proj1, *first1)))
          {
            *result = *first2;
            ++first2;
            ++result;
          }
          else
          {
            ++first1;
            ++first2;
          }
        }
 
        while (first1 != last1)
        {
          *result = *first1;
          ++first1;
          ++result;
        }
 
        while (first2 != last2)
        {
          *result = *first2;
          ++first2;
          ++result;
        }
 
        return {etl::move(first1), etl::move(first2), etl::move(result)};
      }
 
      template <class R1, class R2, class O, class Comp = ranges::less, class Proj1 = etl::identity, class Proj2 = etl::identity,
                typename = etl::enable_if_t<etl::is_range_v<R1>>>
      constexpr ranges::set_symmetric_difference_result< ranges::borrowed_iterator_t<R1>, ranges::borrowed_iterator_t<R2>, O>
        operator()(R1&& r1, R2&& r2, O result, Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}) const
      {
        return (*this)(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2), etl::move(result), etl::move(comp), etl::move(proj1),
                       etl::move(proj2));
      }
    };
 
    inline constexpr set_symmetric_difference_fn set_symmetric_difference{};
 
    struct make_heap_fn
    {
    private:
 
      template <class I, class Comp, class Proj>
      static constexpr void sift_down(I first, typename etl::iterator_traits<I>::difference_type index,
                                      typename etl::iterator_traits<I>::difference_type length, Comp& comp, Proj& proj)
      {
        while (true)
        {
          auto child = 2 * index + 1;
 
          if (child >= length)
          {
            break;
          }
 
          if ((child + 1 < length) && etl::invoke(comp, etl::invoke(proj, *(first + child)), etl::invoke(proj, *(first + (child + 1)))))
          {
            ++child;
          }
 
          if (!etl::invoke(comp, etl::invoke(proj, *(first + index)), etl::invoke(proj, *(first + child))))
          {
            break;
          }
 
          etl::iter_swap(first + index, first + child);
          index = child;
        }
      }
 
    public:
 
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        I last_it = ranges::next(first, last);
 
        auto length = etl::distance(first, last_it);
 
        if (length < 2)
        {
          return last_it;
        }
 
        auto parent = (length - 2) / 2;
 
        while (true)
        {
          sift_down(first, parent, length, comp, proj);
 
          if (parent == 0)
          {
            break;
          }
 
          --parent;
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr make_heap_fn make_heap{};
 
    struct push_heap_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "push_heap requires random access iterators");
 
        I last_it = ranges::next(first, last);
 
        auto length = etl::distance(first, last_it);
 
        if (length < 2)
        {
          return last_it;
        }
 
        auto value_index = length - 1;
        auto parent      = (value_index - 1) / 2;
        auto value       = etl::move(*(first + value_index));
 
        while ((value_index > 0) && etl::invoke(comp, etl::invoke(proj, *(first + parent)), etl::invoke(proj, value)))
        {
          *(first + value_index) = etl::move(*(first + parent));
          value_index            = parent;
          parent                 = (value_index - 1) / 2;
        }
 
        *(first + value_index) = etl::move(value);
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr push_heap_fn push_heap{};
 
    struct pop_heap_fn
    {
    private:
 
      template <class I, class Comp, class Proj>
      static constexpr void sift_down(I first, typename etl::iterator_traits<I>::difference_type index,
                                      typename etl::iterator_traits<I>::difference_type length, Comp& comp, Proj& proj)
      {
        while (true)
        {
          auto child = 2 * index + 1;
 
          if (child >= length)
          {
            break;
          }
 
          if ((child + 1 < length) && etl::invoke(comp, etl::invoke(proj, *(first + child)), etl::invoke(proj, *(first + (child + 1)))))
          {
            ++child;
          }
 
          if (!etl::invoke(comp, etl::invoke(proj, *(first + index)), etl::invoke(proj, *(first + child))))
          {
            break;
          }
 
          etl::iter_swap(first + index, first + child);
          index = child;
        }
      }
 
    public:
 
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "pop_heap requires random access iterators");
 
  #include "etl/private/diagnostic_array_bounds_push.h"
 
        I last_it = ranges::next(first, last);
 
        auto length = etl::distance(first, last_it);
 
        if (length < 2)
        {
          return last_it;
        }
 
        --last_it;
 
        etl::iter_swap(first, last_it);
 
        sift_down(first, decltype(length)(0), etl::distance(first, last_it), comp, proj);
 
        return ranges::next(first, last);
 
  #include "etl/private/diagnostic_pop.h"
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr pop_heap_fn pop_heap{};
 
    struct is_heap_until_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "is_heap_until requires random access iterators");
 
        I last_it = ranges::next(first, last);
 
        auto length = etl::distance(first, last_it);
 
        decltype(length) parent = 0;
 
        for (decltype(length) child = 1; child < length; ++child)
        {
          if (etl::invoke(comp, etl::invoke(proj, *(first + parent)), etl::invoke(proj, *(first + child))))
          {
            return first + child;
          }
 
          if ((child & 1) == 0)
          {
            ++parent;
          }
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr is_heap_until_fn is_heap_until{};
 
    struct is_heap_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr bool operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        return ranges::is_heap_until(first, last, etl::ref(comp), etl::ref(proj)) == last;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr bool operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr is_heap_fn is_heap{};
 
    struct sort_heap_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        ETL_STATIC_ASSERT(etl::is_random_access_iterator<I>::value, "sort_heap requires random access iterators");
 
        I last_it      = ranges::next(first, last);
        I current_last = last_it;
 
        while (first != current_last)
        {
          ranges::pop_heap(first, current_last, comp, proj);
          --current_last;
        }
 
        return last_it;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr sort_heap_fn sort_heap{};
 
    struct min_fn
    {
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr const T& operator()(const T& a, const T& b, Comp comp = {}, Proj proj = {}) const
      {
        return etl::invoke(comp, etl::invoke(proj, b), etl::invoke(proj, a)) ? b : a;
      }
 
  #if ETL_HAS_INITIALIZER_LIST
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr T operator()(std::initializer_list<T> r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = r.begin();
        auto last  = r.end();
 
        auto smallest = first;
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
        }
        return *smallest;
      }
  #endif
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::range_value_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = ranges::begin(r);
        auto last  = ranges::end(r);
 
        auto smallest = first;
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
        }
        return *smallest;
      }
    };
 
    inline constexpr min_fn min{};
 
    struct min_element_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        if (first == last)
        {
          return first;
        }
 
        I smallest = first;
        ++first;
 
        for (; first != last; ++first)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
        }
 
        return smallest;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr min_element_fn min_element{};
 
    struct max_fn
    {
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr const T& operator()(const T& a, const T& b, Comp comp = {}, Proj proj = {}) const
      {
        return etl::invoke(comp, etl::invoke(proj, a), etl::invoke(proj, b)) ? b : a;
      }
 
  #if ETL_HAS_INITIALIZER_LIST
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr T operator()(std::initializer_list<T> r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = r.begin();
        auto last  = r.end();
 
        auto largest = first;
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
        return *largest;
      }
  #endif
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::range_value_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = ranges::begin(r);
        auto last  = ranges::end(r);
 
        auto largest = first;
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
        return *largest;
      }
    };
 
    inline constexpr max_fn max{};
 
    struct max_element_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr I operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        if (first == last)
        {
          return first;
        }
 
        I largest = first;
        ++first;
 
        for (; first != last; ++first)
        {
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
 
        return largest;
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::borrowed_iterator_t<R> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr max_element_fn max_element{};
 
    struct minmax_fn
    {
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr ranges::minmax_result<const T&> operator()(const T& a, const T& b, Comp comp = {}, Proj proj = {}) const
      {
        if (etl::invoke(comp, etl::invoke(proj, b), etl::invoke(proj, a)))
        {
          return {b, a};
        }
        return {a, b};
      }
 
  #if ETL_HAS_INITIALIZER_LIST
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr ranges::minmax_result<T> operator()(std::initializer_list<T> r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = r.begin();
        auto last  = r.end();
 
        auto smallest = first;
        auto largest  = first;
 
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
        return {*smallest, *largest};
      }
  #endif
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::minmax_result<ranges::range_value_t<R>> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        auto first = ranges::begin(r);
        auto last  = ranges::end(r);
 
        auto smallest = first;
        auto largest  = first;
 
        while (++first != last)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
        return {*smallest, *largest};
      }
    };
 
    inline constexpr minmax_fn minmax{};
 
    struct minmax_element_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::minmax_element_result<I> operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        if (first == last)
        {
          return {first, first};
        }
 
        I smallest = first;
        I largest  = first;
        ++first;
 
        for (; first != last; ++first)
        {
          if (etl::invoke(comp, etl::invoke(proj, *first), etl::invoke(proj, *smallest)))
          {
            smallest = first;
          }
          if (etl::invoke(comp, etl::invoke(proj, *largest), etl::invoke(proj, *first)))
          {
            largest = first;
          }
        }
 
        return {smallest, largest};
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::minmax_element_result<ranges::borrowed_iterator_t<R>> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr minmax_element_fn minmax_element{};
 
    struct clamp_fn
    {
      template <class T, class Comp = ranges::less, class Proj = etl::identity>
      constexpr const T& operator()(const T& value, const T& low, const T& high, Comp comp = {}, Proj proj = {}) const
      {
        auto&& projected_value = etl::invoke(proj, value);
 
        return etl::invoke(comp, projected_value, etl::invoke(proj, low))    ? low
               : etl::invoke(comp, etl::invoke(proj, high), projected_value) ? high
                                                                             : value;
      }
    };
 
    inline constexpr clamp_fn clamp{};
 
    struct next_permutation_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::next_permutation_result<I> operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        I last_it = ranges::next(first, last);
 
        // Empty or single-element range: already at last permutation
        if (first == last_it)
        {
          return {etl::move(last_it), false};
        }
 
        I i = last_it;
        --i;
 
        if (i == first)
        {
          return {etl::move(last_it), false};
        }
 
        for (;;)
        {
          I i1 = i;
          --i;
 
          // Find the rightmost element where projected *i < projected *i1
          if (etl::invoke(comp, etl::invoke(proj, *i), etl::invoke(proj, *i1)))
          {
            // Find the rightmost element j where projected *j > projected *i
            I j = last_it;
            while (!etl::invoke(comp, etl::invoke(proj, *i), etl::invoke(proj, *--j)))
            {
            }
 
            etl::iter_swap(i, j);
 
            // Reverse from i1 to last
            I left  = i1;
            I right = last_it;
            while (left != right && left != --right)
            {
              etl::iter_swap(left, right);
              ++left;
            }
 
            return {etl::move(last_it), true};
          }
 
          if (i == first)
          {
            // Already at last (ascending) permutation: wrap to first
            // (descending)
            I left  = first;
            I right = last_it;
            while (left != right && left != --right)
            {
              etl::iter_swap(left, right);
              ++left;
            }
 
            return {etl::move(last_it), false};
          }
        }
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::next_permutation_result<ranges::borrowed_iterator_t<R>> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr next_permutation_fn next_permutation{};
 
    struct prev_permutation_fn
    {
      template <class I, class S, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<!etl::is_range_v<I>>>
      constexpr ranges::prev_permutation_result<I> operator()(I first, S last, Comp comp = {}, Proj proj = {}) const
      {
        I last_it = ranges::next(first, last);
 
        // Empty or single-element range: already at last permutation
        if (first == last_it)
        {
          return {etl::move(last_it), false};
        }
 
        I i = last_it;
        --i;
 
        if (i == first)
        {
          return {etl::move(last_it), false};
        }
 
        for (;;)
        {
          I i1 = i;
          --i;
 
          // Find the rightmost element where projected *i > projected *i1
          if (etl::invoke(comp, etl::invoke(proj, *i1), etl::invoke(proj, *i)))
          {
            // Find the rightmost element j where projected *j < projected *i
            I j = last_it;
            while (!etl::invoke(comp, etl::invoke(proj, *--j), etl::invoke(proj, *i)))
            {
            }
 
            etl::iter_swap(i, j);
 
            // Reverse from i1 to last
            I left  = i1;
            I right = last_it;
            while (left != right && left != --right)
            {
              etl::iter_swap(left, right);
              ++left;
            }
 
            return {etl::move(last_it), true};
          }
 
          if (i == first)
          {
            // Already at last (descending) permutation: wrap to first
            // (ascending)
            I left  = first;
            I right = last_it;
            while (left != right && left != --right)
            {
              etl::iter_swap(left, right);
              ++left;
            }
 
            return {etl::move(last_it), false};
          }
        }
      }
 
      template <class R, class Comp = ranges::less, class Proj = etl::identity, typename = etl::enable_if_t<etl::is_range_v<R>>>
      constexpr ranges::prev_permutation_result<ranges::borrowed_iterator_t<R>> operator()(R&& r, Comp comp = {}, Proj proj = {}) const
      {
        return (*this)(ranges::begin(r), ranges::end(r), etl::move(comp), etl::move(proj));
      }
    };
 
    inline constexpr prev_permutation_fn prev_permutation{};
  } // namespace ranges
#endif
 
} // namespace etl
 
#include "private/minmax_pop.h"
 
#endif