1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___ALGORITHM_SORT_H
10 #define _LIBCPP___ALGORITHM_SORT_H
11 
12 #include <__algorithm/comp.h>
13 #include <__algorithm/comp_ref_type.h>
14 #include <__algorithm/min_element.h>
15 #include <__algorithm/partial_sort.h>
16 #include <__algorithm/unwrap_iter.h>
17 #include <__bits>
18 #include <__config>
19 #include <__debug>
20 #include <__functional/operations.h>
21 #include <__iterator/iterator_traits.h>
22 #include <__utility/swap.h>
23 #include <climits>
24 #include <memory>
25 
26 #if defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
27 #  include <__algorithm/shuffle.h>
28 #endif
29 
30 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
31 #  pragma GCC system_header
32 #endif
33 
34 _LIBCPP_BEGIN_NAMESPACE_STD
35 
36 // stable, 2-3 compares, 0-2 swaps
37 
38 template <class _Compare, class _ForwardIterator>
39 _LIBCPP_CONSTEXPR_AFTER_CXX11 unsigned __sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z,
40                                                _Compare __c) {
41   unsigned __r = 0;
42   if (!__c(*__y, *__x))   // if x <= y
43   {
44     if (!__c(*__z, *__y)) // if y <= z
45       return __r;         // x <= y && y <= z
46                           // x <= y && y > z
47     swap(*__y, *__z);     // x <= z && y < z
48     __r = 1;
49     if (__c(*__y, *__x))  // if x > y
50     {
51       swap(*__x, *__y);   // x < y && y <= z
52       __r = 2;
53     }
54     return __r;           // x <= y && y < z
55   }
56   if (__c(*__z, *__y))    // x > y, if y > z
57   {
58     swap(*__x, *__z);     // x < y && y < z
59     __r = 1;
60     return __r;
61   }
62   swap(*__x, *__y);       // x > y && y <= z
63   __r = 1;                // x < y && x <= z
64   if (__c(*__z, *__y))    // if y > z
65   {
66     swap(*__y, *__z);     // x <= y && y < z
67     __r = 2;
68   }
69   return __r;
70 }                         // x <= y && y <= z
71 
72 // stable, 3-6 compares, 0-5 swaps
73 
74 template <class _Compare, class _ForwardIterator>
75 unsigned __sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3, _ForwardIterator __x4,
76                  _Compare __c) {
77   unsigned __r = _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
78   if (__c(*__x4, *__x3)) {
79     swap(*__x3, *__x4);
80     ++__r;
81     if (__c(*__x3, *__x2)) {
82       swap(*__x2, *__x3);
83       ++__r;
84       if (__c(*__x2, *__x1)) {
85         swap(*__x1, *__x2);
86         ++__r;
87       }
88     }
89   }
90   return __r;
91 }
92 
93 // stable, 4-10 compares, 0-9 swaps
94 
95 template <class _Compare, class _ForwardIterator>
96 _LIBCPP_HIDDEN unsigned __sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
97                                 _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c) {
98   unsigned __r = _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
99   if (__c(*__x5, *__x4)) {
100     swap(*__x4, *__x5);
101     ++__r;
102     if (__c(*__x4, *__x3)) {
103       swap(*__x3, *__x4);
104       ++__r;
105       if (__c(*__x3, *__x2)) {
106         swap(*__x2, *__x3);
107         ++__r;
108         if (__c(*__x2, *__x1)) {
109           swap(*__x1, *__x2);
110           ++__r;
111         }
112       }
113     }
114   }
115   return __r;
116 }
117 
118 template <class _Tp>
119 struct __is_simple_comparator : false_type {};
120 template <class _Tp>
121 struct __is_simple_comparator<__less<_Tp>&> : true_type {};
122 template <class _Tp>
123 struct __is_simple_comparator<less<_Tp>&> : true_type {};
124 template <class _Tp>
125 struct __is_simple_comparator<greater<_Tp>&> : true_type {};
126 
127 template <class _Compare, class _Iter, class _Tp = typename iterator_traits<_Iter>::value_type>
128 using __use_branchless_sort =
129     integral_constant<bool, __is_cpp17_contiguous_iterator<_Iter>::value && sizeof(_Tp) <= sizeof(void*) &&
130                                 is_arithmetic<_Tp>::value && __is_simple_comparator<_Compare>::value>;
131 
132 // Ensures that __c(*__x, *__y) is true by swapping *__x and *__y if necessary.
133 template <class _Compare, class _RandomAccessIterator>
134 inline _LIBCPP_HIDE_FROM_ABI void __cond_swap(_RandomAccessIterator __x, _RandomAccessIterator __y, _Compare __c) {
135   using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
136   bool __r = __c(*__x, *__y);
137   value_type __tmp = __r ? *__x : *__y;
138   *__y = __r ? *__y : *__x;
139   *__x = __tmp;
140 }
141 
142 // Ensures that *__x, *__y and *__z are ordered according to the comparator __c,
143 // under the assumption that *__y and *__z are already ordered.
144 template <class _Compare, class _RandomAccessIterator>
145 inline _LIBCPP_HIDE_FROM_ABI void __partially_sorted_swap(_RandomAccessIterator __x, _RandomAccessIterator __y,
146                                                           _RandomAccessIterator __z, _Compare __c) {
147   using value_type = typename iterator_traits<_RandomAccessIterator>::value_type;
148   bool __r = __c(*__z, *__x);
149   value_type __tmp = __r ? *__z : *__x;
150   *__z = __r ? *__x : *__z;
151   __r = __c(__tmp, *__y);
152   *__x = __r ? *__x : *__y;
153   *__y = __r ? *__y : __tmp;
154 }
155 
156 template <class _Compare, class _RandomAccessIterator>
157 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
158 __sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
159                          _Compare __c) {
160   _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
161   _VSTD::__partially_sorted_swap<_Compare>(__x1, __x2, __x3, __c);
162 }
163 
164 template <class _Compare, class _RandomAccessIterator>
165 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
166 __sort3_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
167                          _Compare __c) {
168   _VSTD::__sort3<_Compare>(__x1, __x2, __x3, __c);
169 }
170 
171 template <class _Compare, class _RandomAccessIterator>
172 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
173 __sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
174                          _RandomAccessIterator __x4, _Compare __c) {
175   _VSTD::__cond_swap<_Compare>(__x1, __x3, __c);
176   _VSTD::__cond_swap<_Compare>(__x2, __x4, __c);
177   _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
178   _VSTD::__cond_swap<_Compare>(__x3, __x4, __c);
179   _VSTD::__cond_swap<_Compare>(__x2, __x3, __c);
180 }
181 
182 template <class _Compare, class _RandomAccessIterator>
183 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
184 __sort4_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
185                          _RandomAccessIterator __x4, _Compare __c) {
186   _VSTD::__sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
187 }
188 
189 template <class _Compare, class _RandomAccessIterator>
190 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
191 __sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
192                          _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
193   _VSTD::__cond_swap<_Compare>(__x1, __x2, __c);
194   _VSTD::__cond_swap<_Compare>(__x4, __x5, __c);
195   _VSTD::__partially_sorted_swap<_Compare>(__x3, __x4, __x5, __c);
196   _VSTD::__cond_swap<_Compare>(__x2, __x5, __c);
197   _VSTD::__partially_sorted_swap<_Compare>(__x1, __x3, __x4, __c);
198   _VSTD::__partially_sorted_swap<_Compare>(__x2, __x3, __x4, __c);
199 }
200 
201 template <class _Compare, class _RandomAccessIterator>
202 inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!__use_branchless_sort<_Compare, _RandomAccessIterator>::value, void>
203 __sort5_maybe_branchless(_RandomAccessIterator __x1, _RandomAccessIterator __x2, _RandomAccessIterator __x3,
204                          _RandomAccessIterator __x4, _RandomAccessIterator __x5, _Compare __c) {
205   _VSTD::__sort5<_Compare>(__x1, __x2, __x3, __x4, __x5, __c);
206 }
207 
208 // Assumes size > 0
209 template <class _Compare, class _BidirectionalIterator>
210 _LIBCPP_CONSTEXPR_AFTER_CXX11 void __selection_sort(_BidirectionalIterator __first, _BidirectionalIterator __last,
211                                                     _Compare __comp) {
212   _BidirectionalIterator __lm1 = __last;
213   for (--__lm1; __first != __lm1; ++__first) {
214     _BidirectionalIterator __i = _VSTD::min_element(__first, __last, __comp);
215     if (__i != __first)
216       swap(*__first, *__i);
217   }
218 }
219 
220 template <class _Compare, class _BidirectionalIterator>
221 void __insertion_sort(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp) {
222   typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
223   if (__first != __last) {
224     _BidirectionalIterator __i = __first;
225     for (++__i; __i != __last; ++__i) {
226       _BidirectionalIterator __j = __i;
227       value_type __t(_VSTD::move(*__j));
228       for (_BidirectionalIterator __k = __i; __k != __first && __comp(__t, *--__k); --__j)
229         *__j = _VSTD::move(*__k);
230       *__j = _VSTD::move(__t);
231     }
232   }
233 }
234 
235 template <class _Compare, class _RandomAccessIterator>
236 void __insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
237   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
238   typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
239   _RandomAccessIterator __j = __first + difference_type(2);
240   _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
241   for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
242     if (__comp(*__i, *__j)) {
243       value_type __t(_VSTD::move(*__i));
244       _RandomAccessIterator __k = __j;
245       __j = __i;
246       do {
247         *__j = _VSTD::move(*__k);
248         __j = __k;
249       } while (__j != __first && __comp(__t, *--__k));
250       *__j = _VSTD::move(__t);
251     }
252     __j = __i;
253   }
254 }
255 
256 template <class _Compare, class _RandomAccessIterator>
257 bool __insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
258   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
259   switch (__last - __first) {
260   case 0:
261   case 1:
262     return true;
263   case 2:
264     if (__comp(*--__last, *__first))
265       swap(*__first, *__last);
266     return true;
267   case 3:
268     _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
269     return true;
270   case 4:
271     _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
272                                               --__last, __comp);
273     return true;
274   case 5:
275     _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
276                                               __first + difference_type(3), --__last, __comp);
277     return true;
278   }
279   typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
280   _RandomAccessIterator __j = __first + difference_type(2);
281   _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), __j, __comp);
282   const unsigned __limit = 8;
283   unsigned __count = 0;
284   for (_RandomAccessIterator __i = __j + difference_type(1); __i != __last; ++__i) {
285     if (__comp(*__i, *__j)) {
286       value_type __t(_VSTD::move(*__i));
287       _RandomAccessIterator __k = __j;
288       __j = __i;
289       do {
290         *__j = _VSTD::move(*__k);
291         __j = __k;
292       } while (__j != __first && __comp(__t, *--__k));
293       *__j = _VSTD::move(__t);
294       if (++__count == __limit)
295         return ++__i == __last;
296     }
297     __j = __i;
298   }
299   return true;
300 }
301 
302 template <class _Compare, class _BidirectionalIterator>
303 void __insertion_sort_move(_BidirectionalIterator __first1, _BidirectionalIterator __last1,
304                            typename iterator_traits<_BidirectionalIterator>::value_type* __first2, _Compare __comp) {
305   typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
306   if (__first1 != __last1) {
307     __destruct_n __d(0);
308     unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
309     value_type* __last2 = __first2;
310     ::new ((void*)__last2) value_type(_VSTD::move(*__first1));
311     __d.template __incr<value_type>();
312     for (++__last2; ++__first1 != __last1; ++__last2) {
313       value_type* __j2 = __last2;
314       value_type* __i2 = __j2;
315       if (__comp(*__first1, *--__i2)) {
316         ::new ((void*)__j2) value_type(_VSTD::move(*__i2));
317         __d.template __incr<value_type>();
318         for (--__j2; __i2 != __first2 && __comp(*__first1, *--__i2); --__j2)
319           *__j2 = _VSTD::move(*__i2);
320         *__j2 = _VSTD::move(*__first1);
321       } else {
322         ::new ((void*)__j2) value_type(_VSTD::move(*__first1));
323         __d.template __incr<value_type>();
324       }
325     }
326     __h.release();
327   }
328 }
329 
330 template <class _Compare, class _RandomAccessIterator>
331 void __introsort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
332                  typename iterator_traits<_RandomAccessIterator>::difference_type __depth) {
333   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
334   typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
335   const difference_type __limit =
336       is_trivially_copy_constructible<value_type>::value && is_trivially_copy_assignable<value_type>::value ? 30 : 6;
337   while (true) {
338   __restart:
339     difference_type __len = __last - __first;
340     switch (__len) {
341     case 0:
342     case 1:
343       return;
344     case 2:
345       if (__comp(*--__last, *__first))
346         swap(*__first, *__last);
347       return;
348     case 3:
349       _VSTD::__sort3_maybe_branchless<_Compare>(__first, __first + difference_type(1), --__last, __comp);
350       return;
351     case 4:
352       _VSTD::__sort4_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
353                                                 --__last, __comp);
354       return;
355     case 5:
356       _VSTD::__sort5_maybe_branchless<_Compare>(__first, __first + difference_type(1), __first + difference_type(2),
357                                                 __first + difference_type(3), --__last, __comp);
358       return;
359     }
360     if (__len <= __limit) {
361       _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
362       return;
363     }
364     // __len > 5
365     if (__depth == 0) {
366       // Fallback to heap sort as Introsort suggests.
367       _VSTD::__partial_sort<_Compare>(__first, __last, __last, __comp);
368       return;
369     }
370     --__depth;
371     _RandomAccessIterator __m = __first;
372     _RandomAccessIterator __lm1 = __last;
373     --__lm1;
374     unsigned __n_swaps;
375     {
376       difference_type __delta;
377       if (__len >= 1000) {
378         __delta = __len / 2;
379         __m += __delta;
380         __delta /= 2;
381         __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m + __delta, __lm1, __comp);
382       } else {
383         __delta = __len / 2;
384         __m += __delta;
385         __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
386       }
387     }
388     // *__m is median
389     // partition [__first, __m) < *__m and *__m <= [__m, __last)
390     // (this inhibits tossing elements equivalent to __m around unnecessarily)
391     _RandomAccessIterator __i = __first;
392     _RandomAccessIterator __j = __lm1;
393     // j points beyond range to be tested, *__m is known to be <= *__lm1
394     // The search going up is known to be guarded but the search coming down isn't.
395     // Prime the downward search with a guard.
396     if (!__comp(*__i, *__m)) // if *__first == *__m
397     {
398       // *__first == *__m, *__first doesn't go in first part
399       // manually guard downward moving __j against __i
400       while (true) {
401         if (__i == --__j) {
402           // *__first == *__m, *__m <= all other elements
403           // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
404           ++__i; // __first + 1
405           __j = __last;
406           if (!__comp(*__first, *--__j)) // we need a guard if *__first == *(__last-1)
407           {
408             while (true) {
409               if (__i == __j)
410                 return; // [__first, __last) all equivalent elements
411               if (__comp(*__first, *__i)) {
412                 swap(*__i, *__j);
413                 ++__n_swaps;
414                 ++__i;
415                 break;
416               }
417               ++__i;
418             }
419           }
420           // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
421           if (__i == __j)
422             return;
423           while (true) {
424             while (!__comp(*__first, *__i))
425               ++__i;
426             while (__comp(*__first, *--__j))
427               ;
428             if (__i >= __j)
429               break;
430             swap(*__i, *__j);
431             ++__n_swaps;
432             ++__i;
433           }
434           // [__first, __i) == *__first and *__first < [__i, __last)
435           // The first part is sorted, sort the second part
436           // _VSTD::__sort<_Compare>(__i, __last, __comp);
437           __first = __i;
438           goto __restart;
439         }
440         if (__comp(*__j, *__m)) {
441           swap(*__i, *__j);
442           ++__n_swaps;
443           break; // found guard for downward moving __j, now use unguarded partition
444         }
445       }
446     }
447     // It is known that *__i < *__m
448     ++__i;
449     // j points beyond range to be tested, *__m is known to be <= *__lm1
450     // if not yet partitioned...
451     if (__i < __j) {
452       // known that *(__i - 1) < *__m
453       // known that __i <= __m
454       while (true) {
455         // __m still guards upward moving __i
456         while (__comp(*__i, *__m))
457           ++__i;
458         // It is now known that a guard exists for downward moving __j
459         while (!__comp(*--__j, *__m))
460           ;
461         if (__i > __j)
462           break;
463         swap(*__i, *__j);
464         ++__n_swaps;
465         // It is known that __m != __j
466         // If __m just moved, follow it
467         if (__m == __i)
468           __m = __j;
469         ++__i;
470       }
471     }
472     // [__first, __i) < *__m and *__m <= [__i, __last)
473     if (__i != __m && __comp(*__m, *__i)) {
474       swap(*__i, *__m);
475       ++__n_swaps;
476     }
477     // [__first, __i) < *__i and *__i <= [__i+1, __last)
478     // If we were given a perfect partition, see if insertion sort is quick...
479     if (__n_swaps == 0) {
480       bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
481       if (_VSTD::__insertion_sort_incomplete<_Compare>(__i + difference_type(1), __last, __comp)) {
482         if (__fs)
483           return;
484         __last = __i;
485         continue;
486       } else {
487         if (__fs) {
488           __first = ++__i;
489           continue;
490         }
491       }
492     }
493     // sort smaller range with recursive call and larger with tail recursion elimination
494     if (__i - __first < __last - __i) {
495       _VSTD::__introsort<_Compare>(__first, __i, __comp, __depth);
496       __first = ++__i;
497     } else {
498       _VSTD::__introsort<_Compare>(__i + difference_type(1), __last, __comp, __depth);
499       __last = __i;
500     }
501   }
502 }
503 
504 template <typename _Number>
505 inline _LIBCPP_HIDE_FROM_ABI _Number __log2i(_Number __n) {
506   if (__n == 0)
507     return 0;
508   if (sizeof(__n) <= sizeof(unsigned))
509     return sizeof(unsigned) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned>(__n));
510   if (sizeof(__n) <= sizeof(unsigned long))
511     return sizeof(unsigned long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long>(__n));
512   if (sizeof(__n) <= sizeof(unsigned long long))
513     return sizeof(unsigned long long) * CHAR_BIT - 1 - __libcpp_clz(static_cast<unsigned long long>(__n));
514 
515   _Number __log2 = 0;
516   while (__n > 1) {
517     __log2++;
518     __n >>= 1;
519   }
520   return __log2;
521 }
522 
523 template <class _Compare, class _RandomAccessIterator>
524 void __sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
525   typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
526   difference_type __depth_limit = 2 * __log2i(__last - __first);
527   _VSTD::__introsort<_Compare>(__first, __last, __comp, __depth_limit);
528 }
529 
530 template <class _Compare, class _Tp>
531 inline _LIBCPP_INLINE_VISIBILITY void __sort(_Tp** __first, _Tp** __last, __less<_Tp*>&) {
532   __less<uintptr_t> __comp;
533   _VSTD::__sort<__less<uintptr_t>&, uintptr_t*>((uintptr_t*)__first, (uintptr_t*)__last, __comp);
534 }
535 
536 extern template _LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&);
537 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
538 extern template _LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
539 #endif
540 extern template _LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&);
541 extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&);
542 extern template _LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&);
543 extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&);
544 extern template _LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&);
545 extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&);
546 extern template _LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&);
547 extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&);
548 extern template _LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&);
549 extern template _LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&);
550 extern template _LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&);
551 extern template _LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&);
552 extern template _LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
553 
554 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&);
555 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
556 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
557 #endif
558 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&);
559 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&);
560 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&);
561 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&);
562 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&);
563 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&);
564 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&);
565 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&);
566 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&);
567 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>&);
568 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&);
569 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&);
570 extern template _LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
571 
572 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>&);
573 
574 template <class _RandomAccessIterator, class _Compare>
575 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void
576 sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp) {
577   _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last);
578   typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
579   if (__libcpp_is_constant_evaluated()) {
580     _VSTD::__partial_sort<_Comp_ref>(__first, __last, __last, _Comp_ref(__comp));
581   } else {
582     _VSTD::__sort<_Comp_ref>(_VSTD::__unwrap_iter(__first), _VSTD::__unwrap_iter(__last), _Comp_ref(__comp));
583   }
584 }
585 
586 template <class _RandomAccessIterator>
587 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 void sort(_RandomAccessIterator __first,
588                                                                          _RandomAccessIterator __last) {
589   _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
590 }
591 
592 _LIBCPP_END_NAMESPACE_STD
593 
594 #endif // _LIBCPP___ALGORITHM_SORT_H
595