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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___CXX03___MEMORY_UNINITIALIZED_ALGORITHMS_H
11#define _LIBCPP___CXX03___MEMORY_UNINITIALIZED_ALGORITHMS_H
12
13#include <__cxx03/__algorithm/copy.h>
14#include <__cxx03/__algorithm/move.h>
15#include <__cxx03/__algorithm/unwrap_iter.h>
16#include <__cxx03/__algorithm/unwrap_range.h>
17#include <__cxx03/__config>
18#include <__cxx03/__iterator/iterator_traits.h>
19#include <__cxx03/__iterator/reverse_iterator.h>
20#include <__cxx03/__memory/addressof.h>
21#include <__cxx03/__memory/allocator_traits.h>
22#include <__cxx03/__memory/construct_at.h>
23#include <__cxx03/__memory/pointer_traits.h>
24#include <__cxx03/__memory/voidify.h>
25#include <__cxx03/__type_traits/extent.h>
26#include <__cxx03/__type_traits/is_array.h>
27#include <__cxx03/__type_traits/is_constant_evaluated.h>
28#include <__cxx03/__type_traits/is_trivially_assignable.h>
29#include <__cxx03/__type_traits/is_trivially_constructible.h>
30#include <__cxx03/__type_traits/is_trivially_relocatable.h>
31#include <__cxx03/__type_traits/is_unbounded_array.h>
32#include <__cxx03/__type_traits/negation.h>
33#include <__cxx03/__type_traits/remove_const.h>
34#include <__cxx03/__type_traits/remove_extent.h>
35#include <__cxx03/__utility/exception_guard.h>
36#include <__cxx03/__utility/move.h>
37#include <__cxx03/__utility/pair.h>
38#include <__cxx03/new>
39
40#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
41# pragma GCC system_header
42#endif
43
44_LIBCPP_PUSH_MACROS
45#include <__cxx03/__undef_macros>
46
47_LIBCPP_BEGIN_NAMESPACE_STD
48
49struct __always_false {
50 template <class... _Args>
51 _LIBCPP_HIDE_FROM_ABI bool operator()(_Args&&...) const _NOEXCEPT {
52 return false;
53 }
54};
55
56// uninitialized_copy
57
58template <class _ValueType, class _InputIterator, class _Sentinel1, class _ForwardIterator, class _EndPredicate>
59inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator> __uninitialized_copy(
60 _InputIterator __ifirst, _Sentinel1 __ilast, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
61 _ForwardIterator __idx = __ofirst;
62#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
63 try {
64#endif
65 for (; __ifirst != __ilast && !__stop_copying(__idx); ++__ifirst, (void)++__idx)
66 ::new (std::__voidify(*__idx)) _ValueType(*__ifirst);
67#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
68 } catch (...) {
69 std::__destroy(__ofirst, __idx);
70 throw;
71 }
72#endif
73
74 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
75}
76
77template <class _InputIterator, class _ForwardIterator>
78_LIBCPP_HIDE_FROM_ABI _ForwardIterator
79uninitialized_copy(_InputIterator __ifirst, _InputIterator __ilast, _ForwardIterator __ofirst) {
80 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
81 auto __result = std::__uninitialized_copy<_ValueType>(
82 std::move(__ifirst), std::move(__ilast), std::move(__ofirst), __always_false());
83 return std::move(__result.second);
84}
85
86// uninitialized_copy_n
87
88template <class _ValueType, class _InputIterator, class _Size, class _ForwardIterator, class _EndPredicate>
89inline _LIBCPP_HIDE_FROM_ABI pair<_InputIterator, _ForwardIterator>
90__uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst, _EndPredicate __stop_copying) {
91 _ForwardIterator __idx = __ofirst;
92#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
93 try {
94#endif
95 for (; __n > 0 && !__stop_copying(__idx); ++__ifirst, (void)++__idx, (void)--__n)
96 ::new (std::__voidify(*__idx)) _ValueType(*__ifirst);
97#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
98 } catch (...) {
99 std::__destroy(__ofirst, __idx);
100 throw;
101 }
102#endif
103
104 return pair<_InputIterator, _ForwardIterator>(std::move(__ifirst), std::move(__idx));
105}
106
107template <class _InputIterator, class _Size, class _ForwardIterator>
108inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
109uninitialized_copy_n(_InputIterator __ifirst, _Size __n, _ForwardIterator __ofirst) {
110 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
111 auto __result =
112 std::__uninitialized_copy_n<_ValueType>(std::move(__ifirst), __n, std::move(__ofirst), __always_false());
113 return std::move(__result.second);
114}
115
116// uninitialized_fill
117
118template <class _ValueType, class _ForwardIterator, class _Sentinel, class _Tp>
119inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
120__uninitialized_fill(_ForwardIterator __first, _Sentinel __last, const _Tp& __x) {
121 _ForwardIterator __idx = __first;
122#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
123 try {
124#endif
125 for (; __idx != __last; ++__idx)
126 ::new (std::__voidify(*__idx)) _ValueType(__x);
127#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
128 } catch (...) {
129 std::__destroy(__first, __idx);
130 throw;
131 }
132#endif
133
134 return __idx;
135}
136
137template <class _ForwardIterator, class _Tp>
138inline _LIBCPP_HIDE_FROM_ABI void
139uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __x) {
140 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
141 (void)std::__uninitialized_fill<_ValueType>(__first, __last, __x);
142}
143
144// uninitialized_fill_n
145
146template <class _ValueType, class _ForwardIterator, class _Size, class _Tp>
147inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
148__uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
149 _ForwardIterator __idx = __first;
150#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
151 try {
152#endif
153 for (; __n > 0; ++__idx, (void)--__n)
154 ::new (std::__voidify(*__idx)) _ValueType(__x);
155#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
156 } catch (...) {
157 std::__destroy(__first, __idx);
158 throw;
159 }
160#endif
161
162 return __idx;
163}
164
165template <class _ForwardIterator, class _Size, class _Tp>
166inline _LIBCPP_HIDE_FROM_ABI _ForwardIterator
167uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x) {
168 typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType;
169 return std::__uninitialized_fill_n<_ValueType>(__first, __n, __x);
170}
171
172// Destroy all elements in [__first, __last) from left to right using allocator destruction.
173template <class _Alloc, class _Iter, class _Sent>
174_LIBCPP_HIDE_FROM_ABI void __allocator_destroy(_Alloc& __alloc, _Iter __first, _Sent __last) {
175 for (; __first != __last; ++__first)
176 allocator_traits<_Alloc>::destroy(__alloc, std::__to_address(__first));
177}
178
179template <class _Alloc, class _Iter>
180class _AllocatorDestroyRangeReverse {
181public:
182 _LIBCPP_HIDE_FROM_ABI _AllocatorDestroyRangeReverse(_Alloc& __alloc, _Iter& __first, _Iter& __last)
183 : __alloc_(__alloc), __first_(__first), __last_(__last) {}
184
185 _LIBCPP_HIDE_FROM_ABI void operator()() const {
186 std::__allocator_destroy(__alloc_, std::reverse_iterator<_Iter>(__last_), std::reverse_iterator<_Iter>(__first_));
187 }
188
189private:
190 _Alloc& __alloc_;
191 _Iter& __first_;
192 _Iter& __last_;
193};
194
195// Copy-construct [__first1, __last1) in [__first2, __first2 + N), where N is distance(__first1, __last1).
196//
197// The caller has to ensure that __first2 can hold at least N uninitialized elements. If an exception is thrown the
198// already copied elements are destroyed in reverse order of their construction.
199template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
200_LIBCPP_HIDE_FROM_ABI _Iter2
201__uninitialized_allocator_copy_impl(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
202 auto __destruct_first = __first2;
203 auto __guard =
204 std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Iter2>(__alloc, __destruct_first, __first2));
205 while (__first1 != __last1) {
206 allocator_traits<_Alloc>::construct(__alloc, std::__to_address(__first2), *__first1);
207 ++__first1;
208 ++__first2;
209 }
210 __guard.__complete();
211 return __first2;
212}
213
214template <class _Alloc, class _Type>
215struct __allocator_has_trivial_copy_construct : _Not<__has_construct<_Alloc, _Type*, const _Type&> > {};
216
217template <class _Type>
218struct __allocator_has_trivial_copy_construct<allocator<_Type>, _Type> : true_type {};
219
220template <class _Alloc,
221 class _In,
222 class _RawTypeIn = __remove_const_t<_In>,
223 class _Out,
224 __enable_if_t<
225 // using _RawTypeIn because of the allocator<T const> extension
226 is_trivially_copy_constructible<_RawTypeIn>::value && is_trivially_copy_assignable<_RawTypeIn>::value &&
227 is_same<__remove_const_t<_In>, __remove_const_t<_Out> >::value &&
228 __allocator_has_trivial_copy_construct<_Alloc, _RawTypeIn>::value,
229 int> = 0>
230_LIBCPP_HIDE_FROM_ABI _Out* __uninitialized_allocator_copy_impl(_Alloc&, _In* __first1, _In* __last1, _Out* __first2) {
231 // TODO: Remove the const_cast once we drop support for std::allocator<T const>
232 if (__libcpp_is_constant_evaluated()) {
233 while (__first1 != __last1) {
234 std::__construct_at(std::__to_address(__first2), *__first1);
235 ++__first1;
236 ++__first2;
237 }
238 return __first2;
239 } else {
240 return std::copy(__first1, __last1, const_cast<_RawTypeIn*>(__first2));
241 }
242}
243
244template <class _Alloc, class _Iter1, class _Sent1, class _Iter2>
245_LIBCPP_HIDE_FROM_ABI _Iter2
246__uninitialized_allocator_copy(_Alloc& __alloc, _Iter1 __first1, _Sent1 __last1, _Iter2 __first2) {
247 auto __unwrapped_range = std::__unwrap_range(__first1, __last1);
248 auto __result = std::__uninitialized_allocator_copy_impl(
249 __alloc, __unwrapped_range.first, __unwrapped_range.second, std::__unwrap_iter(__first2));
250 return std::__rewrap_iter(__first2, __result);
251}
252
253template <class _Alloc, class _Type>
254struct __allocator_has_trivial_move_construct : _Not<__has_construct<_Alloc, _Type*, _Type&&> > {};
255
256template <class _Type>
257struct __allocator_has_trivial_move_construct<allocator<_Type>, _Type> : true_type {};
258
259template <class _Alloc, class _Tp>
260struct __allocator_has_trivial_destroy : _Not<__has_destroy<_Alloc, _Tp*> > {};
261
262template <class _Tp, class _Up>
263struct __allocator_has_trivial_destroy<allocator<_Tp>, _Up> : true_type {};
264
265// __uninitialized_allocator_relocate relocates the objects in [__first, __last) into __result.
266// Relocation means that the objects in [__first, __last) are placed into __result as-if by move-construct and destroy,
267// except that the move constructor and destructor may never be called if they are known to be equivalent to a memcpy.
268//
269// Preconditions: __result doesn't contain any objects and [__first, __last) contains objects
270// Postconditions: __result contains the objects from [__first, __last) and
271// [__first, __last) doesn't contain any objects
272//
273// The strong exception guarantee is provided if any of the following are true:
274// - is_nothrow_move_constructible<_Tp>
275// - is_copy_constructible<_Tp>
276// - __libcpp_is_trivially_relocatable<_Tp>
277template <class _Alloc, class _Tp>
278_LIBCPP_HIDE_FROM_ABI void
279__uninitialized_allocator_relocate(_Alloc& __alloc, _Tp* __first, _Tp* __last, _Tp* __result) {
280 static_assert(__is_cpp17_move_insertable<_Alloc>::value,
281 "The specified type does not meet the requirements of Cpp17MoveInsertable");
282 if (__libcpp_is_constant_evaluated() || !__libcpp_is_trivially_relocatable<_Tp>::value ||
283 !__allocator_has_trivial_move_construct<_Alloc, _Tp>::value ||
284 !__allocator_has_trivial_destroy<_Alloc, _Tp>::value) {
285 auto __destruct_first = __result;
286 auto __guard =
287 std::__make_exception_guard(_AllocatorDestroyRangeReverse<_Alloc, _Tp*>(__alloc, __destruct_first, __result));
288 auto __iter = __first;
289 while (__iter != __last) {
290#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
291 allocator_traits<_Alloc>::construct(__alloc, __result, std::move_if_noexcept(*__iter));
292#else
293 allocator_traits<_Alloc>::construct(__alloc, __result, std::move(*__iter));
294#endif
295 ++__iter;
296 ++__result;
297 }
298 __guard.__complete();
299 std::__allocator_destroy(__alloc, __first, __last);
300 } else {
301 // Casting to void* to suppress clang complaining that this is technically UB.
302 __builtin_memcpy(static_cast<void*>(__result), __first, sizeof(_Tp) * (__last - __first));
303 }
304}
305
306_LIBCPP_END_NAMESPACE_STD
307
308_LIBCPP_POP_MACROS
309
310#endif // _LIBCPP___CXX03___MEMORY_UNINITIALIZED_ALGORITHMS_H
311

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source code of libcxx/include/__cxx03/__memory/uninitialized_algorithms.h