llvm-project/libcxx/include/__algorithm/sort.h

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_SORT_H
#define _LIBCPP___ALGORITHM_SORT_H

#include <__algorithm/comp.h>
#include <__algorithm/comp_ref_type.h>
#include <__algorithm/min_element.h>
#include <__algorithm/partial_sort.h>
#include <__algorithm/unwrap_iter.h>
#include <__bits>
#include <__config>
#include <__functional/operations.h>
#include <__utility/swap.h>
#include <climits>
#include <memory>

#if defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
#  include <__algorithm/shuffle.h>
#endif

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

// stable, 2-3 compares, 0-2 swaps

template <class _Compare, class _ForwardIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z,
                                               _Compare __c) {
  unsigned __r = 0;
  if (!__c(*__y, *__x))   // if x <= y
  {
    if (!__c(*__z, *__y)) // if y <= z
      return __r;         // x <= y && y <= z
                          // x <= y && y > z
    swap(*__y, *__z);     // x <= z && y < z
    __r = 1;
    if (__c(*__y, *__x))  // if x > y
    {
      swap(*__x, *__y);   // x < y && y <= z
      __r = 2;
    }
    return __r;           // x <= y && y < z
  }
  if (__c(*__z, *__y))    // x > y, if y > z
  {
    swap(*__x, *__z);     // x < y && y < z
    __r = 1;
    return __r;
  }
  swap(*__x, *__y);       // x > y && y <= z
  __r = 1;                // x < y && x <= z
  if (__c(*__z, *__y))    // if y > z
  {
    swap(*__y, *__z);     // x <= y && y < z
    __r = 2;
  }
  return __r;
}                         // x <= y && y <= z

// stable, 3-6 compares, 0-5 swaps

template <class _Compare, class _ForwardIterator>
unsigned __sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3, _ForwardIterator __x4,
                 _Compare __c) {
  unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
  if (__c(*__x4, *__x3)) {
    swap(*__x3, *__x4);
    ++__r;
    if (__c(*__x3, *__x2)) {
      swap(*__x2, *__x3);
      ++__r;
      if (__c(*__x2, *__x1)) {
        swap(*__x1, *__x2);
        ++__r;
      }
    }
  }
  return __r;
}

// stable, 4-10 compares, 0-9 swaps

template <class _Compare, class _ForwardIterator>
_LIBCPP_HIDDEN unsigned __sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
                                _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c) {
  unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
  if (__c(*__x5, *__x4)) {
    swap(*__x4, *__x5);
    ++__r;
    if (__c(*__x4, *__x3)) {
      swap(*__x3, *__x4);
      ++__r;
      if (__c(*__x3, *__x2)) {
        swap(*__x2, *__x3);
        ++__r;
        if (__c(*__x2, *__x1)) {
          swap(*__x1, *__x2);
          ++__r;
        }
      }
    }
  }
  return __r;
}

template <class _Tp>
struct __is_simple_comparator : false_type {};
template <class _Tp>
struct __is_simple_comparator<__less<_Tp>&> : true_type {};
template <class _Tp>
struct __is_simple_comparator<less<_Tp>&> : true_type {};
template <class _Tp>
struct __is_simple_comparator<greater<_Tp>&> : true_type {};

template <class _Compare, class _Iter, class _Tp = typename iterator_traits<_Iter>::value_type>
using __use_branchless_sort =
    integral_constant<bool, __is_cpp17_contiguous_iterator<_Iter>::value && sizeof(_Tp) <= sizeof(void*) &&
                                is_arithmetic<_Tp>::value && __is_simple_comparator<_Compare>::value>;

// Ensures that __c(*__x, *__y) is true by swapping *__x and *__y if necessary.
template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI void __cond_swap(_RandomAccessIterator __x, _RandomAccessIterator __y, _Compare __c) {
  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
  bool __r = __c(*__x, *__y);
  value_type __tmp = __r ? *__x : *__y;
  *__y = __r ? *__y : *__x;
  *__x = __tmp;
}

// Ensures that *__x, *__y and *__z are ordered according to the comparator __c,
// under the assumption that *__y and *__z are already ordered.
template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI void __partially_sorted_swap(_RandomAccessIterator __x, _RandomAccessIterator __y,
                                                          _RandomAccessIterator __z, _Compare __c) {
  using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
  bool __r = __c(*__z, *__x);
  value_type __tmp = __r ? *__z : *__x;
  *__z = __r ? *__x : *__z;
  __r = __c(__tmp, *__y);
  *__x = __r ? *__x : *__y;
  *__y = __r ? *__y : __tmp;
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _Compare __c) {
  _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
  _VSTD::__partially_sorted_swap<_Compare>(__x1, __x2, __x3, __c);
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _Compare __c) {
  _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _RandomAccessIterator __x4, _Compare __c) {
  _VSTD::__cond_swap<_Compare>(__x1, __x3, __c);
  _VSTD::__cond_swap<_Compare>(__x2, __x4, __c);
  _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
  _VSTD::__cond_swap<_Compare>(__x3, __x4, __c);
  _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _RandomAccessIterator __x4, _Compare __c) {
  _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
  _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
  _VSTD::__cond_swap<_Compare>(__x4, __x5, __c);
  _VSTD::__partially_sorted_swap<_Compare>(__x3, __x4, __x5, __c);
  _VSTD::__cond_swap<_Compare>(__x2, __x5, __c);
  _VSTD::__partially_sorted_swap<_Compare>(__x1, __x3, __x4, __c);
  _VSTD::__partially_sorted_swap<_Compare>(__x2, __x3, __x4, __c);
}

template <class _Compare, class _RandomAccessIterator>
inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
__sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
                         _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
  _VSTD::__sort5<_Compare>(__x1, __x2, __x3, __x4, __x5, __c);
}

// Assumes size > 0
template <class _Compare, class _BidirectionalIterator>
_LIBCPP_CONSTEXPR_AFTER_CXX11 void __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last,
                                                    _Compare __comp) {
  _BidirectionalIterator __lm1 = __last;
  for (--__lm1; __first != __lm1; ++__first) {
    _BidirectionalIterator __i = _VSTD::min_element(__first, __last, __comp);
    if (__i != __first)
      swap(*__first, *__i);
  }
}

template <class _Compare, class _BidirectionalIterator>
void __insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) {
  typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
  if (__first != __last) {
    _BidirectionalIterator __i = __first;
    for (++__i; __i != __last; ++__i) {
      _BidirectionalIterator __j = __i;
      value_type __t(_VSTD::move(*__j));
      for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t, *--__k); --__j)
        *__j = _VSTD::move(*__k);
      *__j = _VSTD::move(__t);
    }
  }
}

template <class _Compare, class _RandomAccessIterator>
void __insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
  _RandomAccessIterator __j = __first + difference_type(2);
  _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
  for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
    if (__comp(*__i, *__j)) {
      value_type __t(_VSTD::move(*__i));
      _RandomAccessIterator __k = __j;
      __j = __i;
      do {
        *__j = _VSTD::move(*__k);
        __j = __k;
      } while (__j != __first && __comp(__t, *--__k));
      *__j = _VSTD::move(__t);
    }
    __j = __i;
  }
}

template <class _Compare, class _RandomAccessIterator>
bool __insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
  switch (__last - __first) {
  case 0:
  case 1:
    return true;
  case 2:
    if (__comp(*--__last, *__first))
      swap(*__first, *__last);
    return true;
  case 3:
    _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
    return true;
  case 4:
    _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
                                              --__last, __comp);
    return true;
  case 5:
    _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
                                              __first + difference_type(3), --__last, __comp);
    return true;
  }
  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
  _RandomAccessIterator __j = __first + difference_type(2);
  _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
  const unsigned __limit = 8;
  unsigned __count = 0;
  for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
    if (__comp(*__i, *__j)) {
      value_type __t(_VSTD::move(*__i));
      _RandomAccessIterator __k = __j;
      __j = __i;
      do {
        *__j = _VSTD::move(*__k);
        __j = __k;
      } while (__j != __first && __comp(__t, *--__k));
      *__j = _VSTD::move(__t);
      if (++__count == __limit)
        return ++__i == __last;
    }
    __j = __i;
  }
  return true;
}

template <class _Compare, class _BidirectionalIterator>
void __insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1,
                           typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp) {
  typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
  if (__first1 != __last1) {
    __destruct_n __d(0);
    unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
    value_type* __last2 = __first2;
    ::new ((void*)__last2) value_type(_VSTD::move(*__first1));
    __d.template __incr<value_type>();
    for (++__last2; ++__first1 != __last1; ++__last2) {
      value_type* __j2 = __last2;
      value_type* __i2 = __j2;
      if (__comp(*__first1, *--__i2)) {
        ::new ((void*)__j2) value_type(_VSTD::move(*__i2));
        __d.template __incr<value_type>();
        for (--__j2; __i2 != __first2 && __comp(*__first1, *--__i2); --__j2)
          *__j2 = _VSTD::move(*__i2);
        *__j2 = _VSTD::move(*__first1);
      } else {
        ::new ((void*)__j2) value_type(_VSTD::move(*__first1));
        __d.template __incr<value_type>();
      }
    }
    __h.release();
  }
}

template <class _Compare, class _RandomAccessIterator>
void __introsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
                 typename iterator_traits<_RandomAccessIterator>::difference_type __depth) {
  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
  typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
  const difference_type __limit =
      is_trivially_copy_constructible<value_type>::value && is_trivially_copy_assignable<value_type>::value ? 30 : 6;
  while (true) {
  __restart:
    difference_type __len = __last - __first;
    switch (__len) {
    case 0:
    case 1:
      return;
    case 2:
      if (__comp(*--__last, *__first))
        swap(*__first, *__last);
      return;
    case 3:
      _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
      return;
    case 4:
      _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
                                                --__last, __comp);
      return;
    case 5:
      _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
                                                __first + difference_type(3), --__last, __comp);
      return;
    }
    if (__len <= __limit) {
      _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
      return;
    }
    // __len > 5
    if (__depth == 0) {
      // Fallback to heap sort as Introsort suggests.
      _VSTD::__partial_sort<_Compare>(__first, __last, __last, __comp);
      return;
    }
    --__depth;
    _RandomAccessIterator __m = __first;
    _RandomAccessIterator __lm1 = __last;
    --__lm1;
    unsigned __n_swaps;
    {
      difference_type __delta;
      if (__len >= 1000) {
        __delta = __len / 2;
        __m += __delta;
        __delta /= 2;
        __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m + __delta, __lm1, __comp);
      } else {
        __delta = __len / 2;
        __m += __delta;
        __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
      }
    }
    // *__m is median
    // partition [__first, __m) < *__m and *__m <= [__m, __last)
    // (this inhibits tossing elements equivalent to __m around unnecessarily)
    _RandomAccessIterator __i = __first;
    _RandomAccessIterator __j = __lm1;
    // j points beyond range to be tested, *__m is known to be <= *__lm1
    // The search going up is known to be guarded but the search coming down isn't.
    // Prime the downward search with a guard.
    if (!__comp(*__i, *__m)) // if *__first == *__m
    {
      // *__first == *__m, *__first doesn't go in first part
      // manually guard downward moving __j against __i
      while (true) {
        if (__i == --__j) {
          // *__first == *__m, *__m <= all other elements
          // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
          ++__i; // __first + 1
          __j = __last;
          if (!__comp(*__first, *--__j)) // we need a guard if *__first == *(__last-1)
          {
            while (true) {
              if (__i == __j)
                return; // [__first, __last) all equivalent elements
              if (__comp(*__first, *__i)) {
                swap(*__i, *__j);
                ++__n_swaps;
                ++__i;
                break;
              }
              ++__i;
            }
          }
          // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
          if (__i == __j)
            return;
          while (true) {
            while (!__comp(*__first, *__i))
              ++__i;
            while (__comp(*__first, *--__j))
              ;
            if (__i >= __j)
              break;
            swap(*__i, *__j);
            ++__n_swaps;
            ++__i;
          }
          // [__first, __i) == *__first and *__first < [__i, __last)
          // The first part is sorted, sort the second part
          // _VSTD::__sort<_Compare>(__i, __last, __comp);
          __first = __i;
          goto __restart;
        }
        if (__comp(*__j, *__m)) {
          swap(*__i, *__j);
          ++__n_swaps;
          break; // found guard for downward moving __j, now use unguarded partition
        }
      }
    }
    // It is known that *__i < *__m
    ++__i;
    // j points beyond range to be tested, *__m is known to be <= *__lm1
    // if not yet partitioned...
    if (__i < __j) {
      // known that *(__i - 1) < *__m
      // known that __i <= __m
      while (true) {
        // __m still guards upward moving __i
        while (__comp(*__i, *__m))
          ++__i;
        // It is now known that a guard exists for downward moving __j
        while (!__comp(*--__j, *__m))
          ;
        if (__i > __j)
          break;
        swap(*__i, *__j);
        ++__n_swaps;
        // It is known that __m != __j
        // If __m just moved, follow it
        if (__m == __i)
          __m = __j;
        ++__i;
      }
    }
    // [__first, __i) < *__m and *__m <= [__i, __last)
    if (__i != __m && __comp(*__m, *__i)) {
      swap(*__i, *__m);
      ++__n_swaps;
    }
    // [__first, __i) < *__i and *__i <= [__i+1, __last)
    // If we were given a perfect partition, see if insertion sort is quick...
    if (__n_swaps == 0) {
      bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
      if (_VSTD::__insertion_sort_incomplete<_Compare>(__i + difference_type(1), __last, __comp)) {
        if (__fs)
          return;
        __last = __i;
        continue;
      } else {
        if (__fs) {
          __first = ++__i;
          continue;
        }
      }
    }
    // sort smaller range with recursive call and larger with tail recursion elimination
    if (__i - __first < __last - __i) {
      _VSTD::__introsort<_Compare>(__first, __i, __comp, __depth);
      __first = ++__i;
    } else {
      _VSTD::__introsort<_Compare>(__i + difference_type(1), __last, __comp, __depth);
      __last = __i;
    }
  }
}

template <typename _Number>
inline _LIBCPP_HIDE_FROM_ABI _Number __log2i(_Number __n) {
  if (__n == 0)
    return 0;
  if (sizeof(__n) <= sizeof(unsigned))
    return sizeof(unsigned) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned>(__n));
  if (sizeof(__n) <= sizeof(unsigned long))
    return sizeof(unsigned long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long>(__n));
  if (sizeof(__n) <= sizeof(unsigned long long))
    return sizeof(unsigned long long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long long>(__n));

  _Number __log2 = 0;
  while (__n > 1) {
    __log2++;
    __n >>= 1;
  }
  return __log2;
}

template <class _Compare, class _RandomAccessIterator>
void __sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
  typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
  difference_type __depth_limit = 2 * __log2i(__last - __first);
  _VSTD::__introsort<_Compare>(__first, __last, __comp, __depth_limit);
}

template <class _Compare, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY void __sort(_Tp** __first, _Tp** __last, __less<_Tp*>&) {
  __less<uintptr_t> __comp;
  _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp);
}

_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
#endif
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))

_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
#endif
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))

_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&))

template <class _RandomAccessIterator, class _Compare>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void
sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
  _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last);
  typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
  if (__libcpp_is_constant_evaluated()) {
    _VSTD::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp));
  } else {
    _VSTD::__sort<_Comp_ref>(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _Comp_ref(__comp));
  }
}

template <class _RandomAccessIterator>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void sort(_RandomAccessIterator __first,
                                                                         _RandomAccessIterator __last) {
  _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
}

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___ALGORITHM_SORT_H