master
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
11#define _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H
12
13#include <__algorithm/copy.h>
14#include <__algorithm/move.h>
15#include <__algorithm/unwrap_iter.h>
16#include <__algorithm/unwrap_range.h>
17#include <__config>
18#include <__cstddef/size_t.h>
19#include <__fwd/memory.h>
20#include <__iterator/iterator_traits.h>
21#include <__iterator/reverse_iterator.h>
22#include <__memory/addressof.h>
23#include <__memory/allocator_traits.h>
24#include <__memory/construct_at.h>
25#include <__memory/destroy.h>
26#include <__memory/pointer_traits.h>
27#include <__type_traits/enable_if.h>
28#include <__type_traits/extent.h>
29#include <__type_traits/is_array.h>
30#include <__type_traits/is_constant_evaluated.h>
31#include <__type_traits/is_same.h>
32#include <__type_traits/is_trivially_assignable.h>
33#include <__type_traits/is_trivially_constructible.h>
34#include <__type_traits/is_trivially_relocatable.h>
35#include <__type_traits/is_unbounded_array.h>
36#include <__type_traits/remove_const.h>
37#include <__type_traits/remove_extent.h>
38#include <__utility/exception_guard.h>
39#include <__utility/move.h>
40#include <__utility/pair.h>
41
42#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
43# pragma GCC system_header
44#endif
45
46_LIBCPP_PUSH_MACROS
47#include <__undef_macros>
48
49_LIBCPP_BEGIN_NAMESPACE_STD
50
51struct __always_false {
52 template <class... _Args>
53 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR bool operator()(_Args&&...) const _NOEXCEPT {
54 return false;
55 }
56};
57
58// uninitialized_copy
59
60template <class _ValueType, class _InputIterator, class _Sentinel1, class _ForwardIterator, class _EndPredicate>
61inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_copy(
62 _InputIterator __ifirst, _Sentinel1 __ilast, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
63 _ForwardIterator __idx = __ofirst;
64#if _LIBCPP_HAS_EXCEPTIONS
65 try {
66#endif
67 for (; __ifirst != __ilast && !__stop_copying(__idx); ++__ifirst, (void)++__idx)
68 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(*__ifirst);
69#if _LIBCPP_HAS_EXCEPTIONS
70 } catch (...) {
71 std::__destroy(__ofirst, __idx);
72 throw;
73 }
74#endif
75
76 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
77}
78
79template <class _InputIterator, class _ForwardIterator>
80_LIBCPP_HIDE_FROM_ABI _ForwardIterator
81uninitialized_copy(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) {
82 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
83 auto __result = std::__uninitialized_copy<_ValueType>(
84 std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false());
85 return std::move(__result.second);
86}
87
88// uninitialized_copy_n
89
90template <class _ValueType, class _InputIterator, class _Size, class _ForwardIterator, class _EndPredicate>
91inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
92__uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
93 _ForwardIterator __idx = __ofirst;
94#if _LIBCPP_HAS_EXCEPTIONS
95 try {
96#endif
97 for (; __n > 0 && !__stop_copying(__idx); ++__ifirst, (void)++__idx, (void)--__n)
98 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(*__ifirst);
99#if _LIBCPP_HAS_EXCEPTIONS
100 } catch (...) {
101 std::__destroy(__ofirst, __idx);
102 throw;
103 }
104#endif
105
106 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
107}
108
109template <class _InputIterator, class _Size, class _ForwardIterator>
110inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
111uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
112 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
113 auto __result =
114 std::__uninitialized_copy_n<_ValueType>(std::move(__ifirst), __n, std::move(__ofirst), __always_false());
115 return std::move(__result.second);
116}
117
118// uninitialized_fill
119
120template <class _ValueType, class _ForwardIterator, class _Sentinel, class _Tp>
121inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
122__uninitialized_fill(_ForwardIterator __first, _Sentinel __last, const _Tp& __x) {
123 _ForwardIterator __idx = __first;
124#if _LIBCPP_HAS_EXCEPTIONS
125 try {
126#endif
127 for (; __idx != __last; ++__idx)
128 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(__x);
129#if _LIBCPP_HAS_EXCEPTIONS
130 } catch (...) {
131 std::__destroy(__first, __idx);
132 throw;
133 }
134#endif
135
136 return __idx;
137}
138
139template <class _ForwardIterator, class _Tp>
140inline _LIBCPP_HIDE_FROM_ABI void
141uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __x) {
142 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
143 (void)std::__uninitialized_fill<_ValueType>(__first, __last, __x);
144}
145
146// uninitialized_fill_n
147
148template <class _ValueType, class _ForwardIterator, class _Size, class _Tp>
149inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
150__uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
151 _ForwardIterator __idx = __first;
152#if _LIBCPP_HAS_EXCEPTIONS
153 try {
154#endif
155 for (; __n > 0; ++__idx, (void)--__n)
156 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(__x);
157#if _LIBCPP_HAS_EXCEPTIONS
158 } catch (...) {
159 std::__destroy(__first, __idx);
160 throw;
161 }
162#endif
163
164 return __idx;
165}
166
167template <class _ForwardIterator, class _Size, class _Tp>
168inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
169uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
170 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
171 return std::__uninitialized_fill_n<_ValueType>(__first, __n, __x);
172}
173
174#if _LIBCPP_STD_VER >= 17
175
176// uninitialized_default_construct
177
178template <class _ValueType, class _ForwardIterator, class _Sentinel>
179inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
180__uninitialized_default_construct(_ForwardIterator __first, _Sentinel __last) {
181 auto __idx = __first;
182# if _LIBCPP_HAS_EXCEPTIONS
183 try {
184# endif
185 for (; __idx != __last; ++__idx)
186 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType;
187# if _LIBCPP_HAS_EXCEPTIONS
188 } catch (...) {
189 std::__destroy(__first, __idx);
190 throw;
191 }
192# endif
193
194 return __idx;
195}
196
197template <class _ForwardIterator>
198inline _LIBCPP_HIDE_FROM_ABI void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
199 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
200 (void)std::__uninitialized_default_construct<_ValueType>(std::move(__first), std::move(__last));
201}
202
203// uninitialized_default_construct_n
204
205template <class _ValueType, class _ForwardIterator, class _Size>
206inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
207 auto __idx = __first;
208# if _LIBCPP_HAS_EXCEPTIONS
209 try {
210# endif
211 for (; __n > 0; ++__idx, (void)--__n)
212 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType;
213# if _LIBCPP_HAS_EXCEPTIONS
214 } catch (...) {
215 std::__destroy(__first, __idx);
216 throw;
217 }
218# endif
219
220 return __idx;
221}
222
223template <class _ForwardIterator, class _Size>
224inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
225 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
226 return std::__uninitialized_default_construct_n<_ValueType>(std::move(__first), __n);
227}
228
229// uninitialized_value_construct
230
231template <class _ValueType, class _ForwardIterator, class _Sentinel>
232inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
233__uninitialized_value_construct(_ForwardIterator __first, _Sentinel __last) {
234 auto __idx = __first;
235# if _LIBCPP_HAS_EXCEPTIONS
236 try {
237# endif
238 for (; __idx != __last; ++__idx)
239 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType();
240# if _LIBCPP_HAS_EXCEPTIONS
241 } catch (...) {
242 std::__destroy(__first, __idx);
243 throw;
244 }
245# endif
246
247 return __idx;
248}
249
250template <class _ForwardIterator>
251inline _LIBCPP_HIDE_FROM_ABI void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
252 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
253 (void)std::__uninitialized_value_construct<_ValueType>(std::move(__first), std::move(__last));
254}
255
256// uninitialized_value_construct_n
257
258template <class _ValueType, class _ForwardIterator, class _Size>
259inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator __uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
260 auto __idx = __first;
261# if _LIBCPP_HAS_EXCEPTIONS
262 try {
263# endif
264 for (; __n > 0; ++__idx, (void)--__n)
265 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType();
266# if _LIBCPP_HAS_EXCEPTIONS
267 } catch (...) {
268 std::__destroy(__first, __idx);
269 throw;
270 }
271# endif
272
273 return __idx;
274}
275
276template <class _ForwardIterator, class _Size>
277inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
278 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
279 return std::__uninitialized_value_construct_n<_ValueType>(std::move(__first), __n);
280}
281
282// uninitialized_move
283
284template <class _ValueType,
285 class _InputIterator,
286 class _Sentinel1,
287 class _ForwardIterator,
288 class _EndPredicate,
289 class _IterMove>
290inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move(
291 _InputIterator __ifirst,
292 _Sentinel1 __ilast,
293 _ForwardIterator __ofirst,
294 _EndPredicate __stop_moving,
295 _IterMove __iter_move) {
296 auto __idx = __ofirst;
297# if _LIBCPP_HAS_EXCEPTIONS
298 try {
299# endif
300 for (; __ifirst != __ilast && !__stop_moving(__idx); ++__idx, (void)++__ifirst) {
301 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(__iter_move(__ifirst));
302 }
303# if _LIBCPP_HAS_EXCEPTIONS
304 } catch (...) {
305 std::__destroy(__ofirst, __idx);
306 throw;
307 }
308# endif
309
310 return {std::move(__ifirst), std::move(__idx)};
311}
312
313template <class _InputIterator, class _ForwardIterator>
314inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
315uninitialized_move(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) {
316 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
317 auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); };
318
319 auto __result = std::__uninitialized_move<_ValueType>(
320 std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false(), __iter_move);
321 return std::move(__result.second);
322}
323
324// uninitialized_move_n
325
326template <class _ValueType,
327 class _InputIterator,
328 class _Size,
329 class _ForwardIterator,
330 class _EndPredicate,
331 class _IterMove>
332inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_move_n(
333 _InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_moving, _IterMove __iter_move) {
334 auto __idx = __ofirst;
335# if _LIBCPP_HAS_EXCEPTIONS
336 try {
337# endif
338 for (; __n > 0 && !__stop_moving(__idx); ++__idx, (void)++__ifirst, --__n)
339 ::new (static_cast<void*>(std::addressof(*__idx))) _ValueType(__iter_move(__ifirst));
340# if _LIBCPP_HAS_EXCEPTIONS
341 } catch (...) {
342 std::__destroy(__ofirst, __idx);
343 throw;
344 }
345# endif
346
347 return {std::move(__ifirst), std::move(__idx)};
348}
349
350template <class _InputIterator, class _Size, class _ForwardIterator>
351inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
352uninitialized_move_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
353 using _ValueType = typename iterator_traits<_ForwardIterator>::value_type;
354 auto __iter_move = [](auto&& __iter) -> decltype(auto) { return std::move(*__iter); };
355
356 return std::__uninitialized_move_n<_ValueType>(
357 std::move(__ifirst), __n, std::move(__ofirst), __always_false(), __iter_move);
358}
359
360// TODO: Rewrite this to iterate left to right and use reverse_iterators when calling
361// Destroys every element in the range [first, last) FROM RIGHT TO LEFT using allocator
362// destruction. If elements are themselves C-style arrays, they are recursively destroyed
363// in the same manner.
364//
365// This function assumes that destructors do not throw, and that the allocator is bound to
366// the correct type.
367template <class _Alloc,
368 class _BidirIter,
369 __enable_if_t<__has_bidirectional_iterator_category<_BidirIter>::value, int> = 0>
370_LIBCPP_HIDE_FROM_ABI constexpr void
371__allocator_destroy_multidimensional(_Alloc& __alloc, _BidirIter __first, _BidirIter __last) noexcept {
372 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
373 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _ValueType>,
374 "The allocator should already be rebound to the correct type");
375
376 if (__first == __last)
377 return;
378
379 if constexpr (is_array_v<_ValueType>) {
380 static_assert(!__is_unbounded_array_v<_ValueType>,
381 "arrays of unbounded arrays don't exist, but if they did we would mess up here");
382
383 using _Element = remove_extent_t<_ValueType>;
384 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
385 do {
386 --__last;
387 decltype(auto) __array = *__last;
388 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + extent_v<_ValueType>);
389 } while (__last != __first);
390 } else {
391 do {
392 --__last;
393 allocator_traits<_Alloc>::destroy(__alloc, std::addressof(*__last));
394 } while (__last != __first);
395 }
396}
397
398// Constructs the object at the given location using the allocator's construct method.
399//
400// If the object being constructed is an array, each element of the array is allocator-constructed,
401// recursively. If an exception is thrown during the construction of an array, the initialized
402// elements are destroyed in reverse order of initialization using allocator destruction.
403//
404// This function assumes that the allocator is bound to the correct type.
405template <class _Alloc, class _Tp>
406_LIBCPP_HIDE_FROM_ABI constexpr void __allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc) {
407 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
408 "The allocator should already be rebound to the correct type");
409
410 if constexpr (is_array_v<_Tp>) {
411 using _Element = remove_extent_t<_Tp>;
412 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
413 size_t __i = 0;
414 _Tp& __array = *__loc;
415
416 // If an exception is thrown, destroy what we have constructed so far in reverse order.
417 auto __guard = std::__make_exception_guard([&]() {
418 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i);
419 });
420
421 for (; __i != extent_v<_Tp>; ++__i) {
422 std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i]));
423 }
424 __guard.__complete();
425 } else {
426 allocator_traits<_Alloc>::construct(__alloc, __loc);
427 }
428}
429
430// Constructs the object at the given location using the allocator's construct method, passing along
431// the provided argument.
432//
433// If the object being constructed is an array, the argument is also assumed to be an array. Each
434// each element of the array being constructed is allocator-constructed from the corresponding
435// element of the argument array. If an exception is thrown during the construction of an array,
436// the initialized elements are destroyed in reverse order of initialization using allocator
437// destruction.
438//
439// This function assumes that the allocator is bound to the correct type.
440template <class _Alloc, class _Tp, class _Arg>
441_LIBCPP_HIDE_FROM_ABI constexpr void
442__allocator_construct_at_multidimensional(_Alloc& __alloc, _Tp* __loc, _Arg const& __arg) {
443 static_assert(is_same_v<typename allocator_traits<_Alloc>::value_type, _Tp>,
444 "The allocator should already be rebound to the correct type");
445
446 if constexpr (is_array_v<_Tp>) {
447 static_assert(is_array_v<_Arg>,
448 "Provided non-array initialization argument to __allocator_construct_at_multidimensional when "
449 "trying to construct an array.");
450
451 using _Element = remove_extent_t<_Tp>;
452 __allocator_traits_rebind_t<_Alloc, _Element> __elem_alloc(__alloc);
453 size_t __i = 0;
454 _Tp& __array = *__loc;
455
456 // If an exception is thrown, destroy what we have constructed so far in reverse order.
457 auto __guard = std::__make_exception_guard([&]() {
458 std::__allocator_destroy_multidimensional(__elem_alloc, __array, __array + __i);
459 });
460 for (; __i != extent_v<_Tp>; ++__i) {
461 std::__allocator_construct_at_multidimensional(__elem_alloc, std::addressof(__array[__i]), __arg[__i]);
462 }
463 __guard.__complete();
464 } else {
465 allocator_traits<_Alloc>::construct(__alloc, __loc, __arg);
466 }
467}
468
469// Given a range starting at it and containing n elements, initializes each element in the
470// range from left to right using the construct method of the allocator (rebound to the
471// correct type).
472//
473// If an exception is thrown, the initialized elements are destroyed in reverse order of
474// initialization using allocator_traits destruction. If the elements in the range are C-style
475// arrays, they are initialized element-wise using allocator construction, and recursively so.
476template <class _Alloc,
477 class _BidirIter,
478 class _Tp,
479 class _Size = typename iterator_traits<_BidirIter>::difference_type>
480_LIBCPP_HIDE_FROM_ABI constexpr void
481__uninitialized_allocator_fill_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n, _Tp const& __value) {
482 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
483 __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
484 _BidirIter __begin = __it;
485
486 // If an exception is thrown, destroy what we have constructed so far in reverse order.
487 auto __guard =
488 std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
489 for (; __n != 0; --__n, ++__it) {
490 std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it), __value);
491 }
492 __guard.__complete();
493}
494
495// Same as __uninitialized_allocator_fill_n_multidimensional, but doesn't pass any initialization argument
496// to the allocator's construct method, which results in value initialization.
497template <class _Alloc, class _BidirIter, class _Size = typename iterator_traits<_BidirIter>::difference_type>
498_LIBCPP_HIDE_FROM_ABI constexpr void
499__uninitialized_allocator_value_construct_n_multidimensional(_Alloc& __alloc, _BidirIter __it, _Size __n) {
500 using _ValueType = typename iterator_traits<_BidirIter>::value_type;
501 __allocator_traits_rebind_t<_Alloc, _ValueType> __value_alloc(__alloc);
502 _BidirIter __begin = __it;
503
504 // If an exception is thrown, destroy what we have constructed so far in reverse order.
505 auto __guard =
506 std::__make_exception_guard([&]() { std::__allocator_destroy_multidimensional(__value_alloc, __begin, __it); });
507 for (; __n != 0; --__n, ++__it) {
508 std::__allocator_construct_at_multidimensional(__value_alloc, std::addressof(*__it));
509 }
510 __guard.__complete();
511}
512
513#endif // _LIBCPP_STD_VER >= 17
514
515template <class _Alloc, class _Iter>
516class _AllocatorDestroyRangeReverse {
517public:
518 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
519 _AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last)
520 : __alloc_(__alloc), __first_(__first), __last_(__last) {}
521
522 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void operator()() const {
523 std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_));
524 }
525
526private:
527 _Alloc& __alloc_;
528 _Iter& __first_;
529 _Iter& __last_;
530};
531
532// Copy-construct [__first1, __last1) in [__first2, __first2 + N), where N is distance(__first1, __last1).
533//
534// The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the
535// already copied elements are destroyed in reverse order of their construction.
536template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
537_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
538__uninitialized_allocator_copy_impl(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
539 auto __destruct_first = __first2;
540 auto __guard =
541 std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
542 while (__first1 != __last1) {
543 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), *__first1);
544 ++__first1;
545 ++__first2;
546 }
547 __guard.__complete();
548 return __first2;
549}
550
551template <class _Alloc, class _Type>
552inline const bool __allocator_has_trivial_copy_construct_v = !__has_construct_v<_Alloc, _Type*, const _Type&>;
553
554template <class _Type>
555inline const bool __allocator_has_trivial_copy_construct_v<allocator<_Type>, _Type> = true;
556
557template <class _Alloc,
558 class _In,
559 class _Out,
560 __enable_if_t<is_trivially_copy_constructible<_In>::value && is_trivially_copy_assignable<_In>::value &&
561 is_same<__remove_const_t<_In>, __remove_const_t<_Out> >::value &&
562 __allocator_has_trivial_copy_construct_v<_Alloc, _In>,
563 int> = 0>
564_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Out*
565__uninitialized_allocator_copy_impl(_Alloc&, _In* __first1, _In* __last1, _Out* __first2) {
566 if (__libcpp_is_constant_evaluated()) {
567 while (__first1 != __last1) {
568 std::__construct_at(std::__to_address(__first2), *__first1);
569 ++__first1;
570 ++__first2;
571 }
572 return __first2;
573 } else {
574 return std::copy(__first1, __last1, __first2);
575 }
576}
577
578template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
579_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter2
580__uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
581 auto __unwrapped_range = std::__unwrap_range(std::move(__first1), std::move(__last1));
582 auto __result = std::__uninitialized_allocator_copy_impl(
583 __alloc, std::move(__unwrapped_range.first), std::move(__unwrapped_range.second), std::__unwrap_iter(__first2));
584 return std::__rewrap_iter(__first2, __result);
585}
586
587template <class _Alloc, class _Type>
588inline const bool __allocator_has_trivial_move_construct_v = !__has_construct_v<_Alloc, _Type*, _Type&&>;
589
590template <class _Type>
591inline const bool __allocator_has_trivial_move_construct_v<allocator<_Type>, _Type> = true;
592
593template <class _Alloc, class _Tp>
594inline const bool __allocator_has_trivial_destroy_v = !__has_destroy_v<_Alloc, _Tp*>;
595
596template <class _Tp, class _Up>
597inline const bool __allocator_has_trivial_destroy_v<allocator<_Tp>, _Up> = true;
598
599// __uninitialized_allocator_relocate relocates the objects in [__first, __last) into __result.
600// Relocation means that the objects in [__first, __last) are placed into __result as-if by move-construct and destroy,
601// except that the move constructor and destructor may never be called if they are known to be equivalent to a memcpy.
602//
603// Preconditions: __result doesn't contain any objects and [__first, __last) contains objects
604// Postconditions: __result contains the objects from [__first, __last) and
605// [__first, __last) doesn't contain any objects
606//
607// The strong exception guarantee is provided if any of the following are true:
608// - is_nothrow_move_constructible<_ValueType>
609// - is_copy_constructible<_ValueType>
610// - __libcpp_is_trivially_relocatable<_ValueType>
611template <class _Alloc, class _ContiguousIterator>
612_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void __uninitialized_allocator_relocate(
613 _Alloc& __alloc, _ContiguousIterator __first, _ContiguousIterator __last, _ContiguousIterator __result) {
614 static_assert(__libcpp_is_contiguous_iterator<_ContiguousIterator>::value, "");
615 using _ValueType = typename iterator_traits<_ContiguousIterator>::value_type;
616 static_assert(
617 __is_cpp17_move_insertable_v<_Alloc>, "The specified type does not meet the requirements of Cpp17MoveInsertable");
618 if (__libcpp_is_constant_evaluated() || !__libcpp_is_trivially_relocatable<_ValueType>::value ||
619 !__allocator_has_trivial_move_construct_v<_Alloc, _ValueType> ||
620 !__allocator_has_trivial_destroy_v<_Alloc, _ValueType>) {
621 auto __destruct_first = __result;
622 auto __guard = std::__make_exception_guard(
623 _AllocatorDestroyRangeReverse<_Alloc, _ContiguousIterator>(__alloc, __destruct_first, __result));
624 auto __iter = __first;
625 while (__iter != __last) {
626#if _LIBCPP_HAS_EXCEPTIONS
627 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__result), std::move_if_noexcept(*__iter));
628#else
629 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__result), std::move(*__iter));
630#endif
631 ++__iter;
632 ++__result;
633 }
634 __guard.__complete();
635 std::__allocator_destroy(__alloc, __first, __last);
636 } else {
637 // Casting to void* to suppress clang complaining that this is technically UB.
638 __builtin_memcpy(static_cast<void*>(std::__to_address(__result)),
639 std::__to_address(__first),
640 sizeof(_ValueType) * (__last - __first));
641 }
642}
643
644_LIBCPP_END_NAMESPACE_STD
645
646_LIBCPP_POP_MACROS
647
648#endif // _LIBCPP___MEMORY_UNINITIALIZED_ALGORITHMS_H