libstdc++
stl_uninitialized.h
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1// Raw memory manipulators -*- C++ -*-
2
3// Copyright (C) 2001-2022 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
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25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
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37 *
38 *
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40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
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49 */
50
51/** @file bits/stl_uninitialized.h
52 * This is an internal header file, included by other library headers.
53 * Do not attempt to use it directly. @headername{memory}
54 */
55
56#ifndef _STL_UNINITIALIZED_H
57#define _STL_UNINITIALIZED_H 1
58
59#if __cplusplus >= 201103L
60#include <type_traits>
61#endif
62
63#include <bits/stl_algobase.h> // copy
64#include <ext/alloc_traits.h> // __alloc_traits
65
66#if __cplusplus >= 201703L
67#include <bits/stl_pair.h>
68#endif
69
70namespace std _GLIBCXX_VISIBILITY(default)
71{
72_GLIBCXX_BEGIN_NAMESPACE_VERSION
73
74 /** @addtogroup memory
75 * @{
76 */
77
78 /// @cond undocumented
79
80#if __cplusplus >= 201103L
81 template<typename _ValueType, typename _Tp>
82 constexpr bool
83 __check_constructible()
84 {
85 // Trivial types can have deleted constructors, but std::copy etc.
86 // only use assignment (or memmove) not construction, so we need an
87 // explicit check that construction from _Tp is actually valid,
88 // otherwise some ill-formed uses of std::uninitialized_xxx would
89 // compile without errors. This gives a nice clear error message.
90 static_assert(is_constructible<_ValueType, _Tp>::value,
91 "result type must be constructible from input type");
92
93 return true;
94 }
95
96// If the type is trivial we don't need to construct it, just assign to it.
97// But trivial types can still have deleted or inaccessible assignment,
98// so don't try to use std::copy or std::fill etc. if we can't assign.
99# define _GLIBCXX_USE_ASSIGN_FOR_INIT(T, U) \
100 __is_trivial(T) && __is_assignable(T&, U) \
101 && std::__check_constructible<T, U>()
102#else
103// No need to check if is_constructible<T, U> for C++98. Trivial types have
104// no user-declared constructors, so if the assignment is valid, construction
105// should be too.
106# define _GLIBCXX_USE_ASSIGN_FOR_INIT(T, U) \
107 __is_trivial(T) && __is_assignable(T&, U)
108#endif
109
110 template<typename _InputIterator, typename _ForwardIterator>
111 _GLIBCXX20_CONSTEXPR
112 _ForwardIterator
113 __do_uninit_copy(_InputIterator __first, _InputIterator __last,
114 _ForwardIterator __result)
115 {
116 _ForwardIterator __cur = __result;
117 __try
118 {
119 for (; __first != __last; ++__first, (void)++__cur)
120 std::_Construct(std::__addressof(*__cur), *__first);
121 return __cur;
122 }
123 __catch(...)
124 {
125 std::_Destroy(__result, __cur);
126 __throw_exception_again;
127 }
128 }
129
130 template<bool _TrivialValueTypes>
131 struct __uninitialized_copy
132 {
133 template<typename _InputIterator, typename _ForwardIterator>
134 static _ForwardIterator
135 __uninit_copy(_InputIterator __first, _InputIterator __last,
136 _ForwardIterator __result)
137 { return std::__do_uninit_copy(__first, __last, __result); }
138 };
139
140 template<>
141 struct __uninitialized_copy<true>
142 {
143 template<typename _InputIterator, typename _ForwardIterator>
144 static _ForwardIterator
145 __uninit_copy(_InputIterator __first, _InputIterator __last,
146 _ForwardIterator __result)
147 { return std::copy(__first, __last, __result); }
148 };
149
150 /// @endcond
151
152 /**
153 * @brief Copies the range [first,last) into result.
154 * @param __first An input iterator.
155 * @param __last An input iterator.
156 * @param __result An output iterator.
157 * @return __result + (__first - __last)
158 *
159 * Like copy(), but does not require an initialized output range.
160 */
161 template<typename _InputIterator, typename _ForwardIterator>
162 inline _ForwardIterator
163 uninitialized_copy(_InputIterator __first, _InputIterator __last,
164 _ForwardIterator __result)
165 {
167 _ValueType1;
169 _ValueType2;
170
171 // _ValueType1 must be trivially-copyable to use memmove, so don't
172 // bother optimizing to std::copy if it isn't.
173 // XXX Unnecessary because std::copy would check it anyway?
174 const bool __can_memmove = __is_trivial(_ValueType1);
175
176#if __cplusplus < 201103L
177 typedef typename iterator_traits<_InputIterator>::reference _From;
178#else
179 using _From = decltype(*__first);
180#endif
181 const bool __assignable
182 = _GLIBCXX_USE_ASSIGN_FOR_INIT(_ValueType2, _From);
183
184 return std::__uninitialized_copy<__can_memmove && __assignable>::
185 __uninit_copy(__first, __last, __result);
186 }
187
188 /// @cond undocumented
189
190 template<typename _ForwardIterator, typename _Tp>
191 _GLIBCXX20_CONSTEXPR void
192 __do_uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
193 const _Tp& __x)
194 {
195 _ForwardIterator __cur = __first;
196 __try
197 {
198 for (; __cur != __last; ++__cur)
199 std::_Construct(std::__addressof(*__cur), __x);
200 }
201 __catch(...)
202 {
203 std::_Destroy(__first, __cur);
204 __throw_exception_again;
205 }
206 }
207
208 template<bool _TrivialValueType>
209 struct __uninitialized_fill
210 {
211 template<typename _ForwardIterator, typename _Tp>
212 static void
213 __uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
214 const _Tp& __x)
215 { std::__do_uninit_fill(__first, __last, __x); }
216 };
217
218 template<>
219 struct __uninitialized_fill<true>
220 {
221 template<typename _ForwardIterator, typename _Tp>
222 static void
223 __uninit_fill(_ForwardIterator __first, _ForwardIterator __last,
224 const _Tp& __x)
225 { std::fill(__first, __last, __x); }
226 };
227
228 /// @endcond
229
230 /**
231 * @brief Copies the value x into the range [first,last).
232 * @param __first An input iterator.
233 * @param __last An input iterator.
234 * @param __x The source value.
235 * @return Nothing.
236 *
237 * Like fill(), but does not require an initialized output range.
238 */
239 template<typename _ForwardIterator, typename _Tp>
240 inline void
241 uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last,
242 const _Tp& __x)
243 {
245 _ValueType;
246
247 // Trivial types do not need a constructor to begin their lifetime,
248 // so try to use std::fill to benefit from its memset optimization.
249 const bool __can_fill
250 = _GLIBCXX_USE_ASSIGN_FOR_INIT(_ValueType, const _Tp&);
251
252 std::__uninitialized_fill<__can_fill>::
253 __uninit_fill(__first, __last, __x);
254 }
255
256 /// @cond undocumented
257
258 template<typename _ForwardIterator, typename _Size, typename _Tp>
259 _GLIBCXX20_CONSTEXPR
260 _ForwardIterator
261 __do_uninit_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
262 {
263 _ForwardIterator __cur = __first;
264 __try
265 {
266 for (; __n > 0; --__n, (void) ++__cur)
267 std::_Construct(std::__addressof(*__cur), __x);
268 return __cur;
269 }
270 __catch(...)
271 {
272 std::_Destroy(__first, __cur);
273 __throw_exception_again;
274 }
275 }
276
277 template<bool _TrivialValueType>
278 struct __uninitialized_fill_n
279 {
280 template<typename _ForwardIterator, typename _Size, typename _Tp>
281 static _ForwardIterator
282 __uninit_fill_n(_ForwardIterator __first, _Size __n,
283 const _Tp& __x)
284 { return std::__do_uninit_fill_n(__first, __n, __x); }
285 };
286
287 template<>
288 struct __uninitialized_fill_n<true>
289 {
290 template<typename _ForwardIterator, typename _Size, typename _Tp>
291 static _ForwardIterator
292 __uninit_fill_n(_ForwardIterator __first, _Size __n,
293 const _Tp& __x)
294 { return std::fill_n(__first, __n, __x); }
295 };
296
297 /// @endcond
298
299 // _GLIBCXX_RESOLVE_LIB_DEFECTS
300 // DR 1339. uninitialized_fill_n should return the end of its range
301 /**
302 * @brief Copies the value x into the range [first,first+n).
303 * @param __first An input iterator.
304 * @param __n The number of copies to make.
305 * @param __x The source value.
306 * @return Nothing.
307 *
308 * Like fill_n(), but does not require an initialized output range.
309 */
310 template<typename _ForwardIterator, typename _Size, typename _Tp>
311 inline _ForwardIterator
312 uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp& __x)
313 {
315 _ValueType;
316
317 // Trivial types do not need a constructor to begin their lifetime,
318 // so try to use std::fill_n to benefit from its optimizations.
319 const bool __can_fill
320 = _GLIBCXX_USE_ASSIGN_FOR_INIT(_ValueType, const _Tp&)
321 // For arbitrary class types and floating point types we can't assume
322 // that __n > 0 and std::__size_to_integer(__n) > 0 are equivalent,
323 // so only use std::fill_n when _Size is already an integral type.
324 && __is_integer<_Size>::__value;
325
326 return __uninitialized_fill_n<__can_fill>::
327 __uninit_fill_n(__first, __n, __x);
328 }
329
330#undef _GLIBCXX_USE_ASSIGN_FOR_INIT
331
332 /// @cond undocumented
333
334 // Extensions: versions of uninitialized_copy, uninitialized_fill,
335 // and uninitialized_fill_n that take an allocator parameter.
336 // We dispatch back to the standard versions when we're given the
337 // default allocator. For nondefault allocators we do not use
338 // any of the POD optimizations.
339
340 template<typename _InputIterator, typename _ForwardIterator,
341 typename _Allocator>
342 _GLIBCXX20_CONSTEXPR
343 _ForwardIterator
344 __uninitialized_copy_a(_InputIterator __first, _InputIterator __last,
345 _ForwardIterator __result, _Allocator& __alloc)
346 {
347 _ForwardIterator __cur = __result;
348 __try
349 {
351 for (; __first != __last; ++__first, (void)++__cur)
352 __traits::construct(__alloc, std::__addressof(*__cur), *__first);
353 return __cur;
354 }
355 __catch(...)
356 {
357 std::_Destroy(__result, __cur, __alloc);
358 __throw_exception_again;
359 }
360 }
361
362 template<typename _InputIterator, typename _ForwardIterator, typename _Tp>
363 _GLIBCXX20_CONSTEXPR
364 inline _ForwardIterator
365 __uninitialized_copy_a(_InputIterator __first, _InputIterator __last,
366 _ForwardIterator __result, allocator<_Tp>&)
367 {
368#ifdef __cpp_lib_is_constant_evaluated
370 return std::__do_uninit_copy(__first, __last, __result);
371#endif
372 return std::uninitialized_copy(__first, __last, __result);
373 }
374
375 template<typename _InputIterator, typename _ForwardIterator,
376 typename _Allocator>
377 _GLIBCXX20_CONSTEXPR
378 inline _ForwardIterator
379 __uninitialized_move_a(_InputIterator __first, _InputIterator __last,
380 _ForwardIterator __result, _Allocator& __alloc)
381 {
382 return std::__uninitialized_copy_a(_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
383 _GLIBCXX_MAKE_MOVE_ITERATOR(__last),
384 __result, __alloc);
385 }
386
387 template<typename _InputIterator, typename _ForwardIterator,
388 typename _Allocator>
389 _GLIBCXX20_CONSTEXPR
390 inline _ForwardIterator
391 __uninitialized_move_if_noexcept_a(_InputIterator __first,
392 _InputIterator __last,
393 _ForwardIterator __result,
394 _Allocator& __alloc)
395 {
396 return std::__uninitialized_copy_a
397 (_GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__first),
398 _GLIBCXX_MAKE_MOVE_IF_NOEXCEPT_ITERATOR(__last), __result, __alloc);
399 }
400
401 template<typename _ForwardIterator, typename _Tp, typename _Allocator>
402 _GLIBCXX20_CONSTEXPR
403 void
404 __uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
405 const _Tp& __x, _Allocator& __alloc)
406 {
407 _ForwardIterator __cur = __first;
408 __try
409 {
411 for (; __cur != __last; ++__cur)
412 __traits::construct(__alloc, std::__addressof(*__cur), __x);
413 }
414 __catch(...)
415 {
416 std::_Destroy(__first, __cur, __alloc);
417 __throw_exception_again;
418 }
419 }
420
421 template<typename _ForwardIterator, typename _Tp, typename _Tp2>
422 _GLIBCXX20_CONSTEXPR
423 inline void
424 __uninitialized_fill_a(_ForwardIterator __first, _ForwardIterator __last,
425 const _Tp& __x, allocator<_Tp2>&)
426 {
427#ifdef __cpp_lib_is_constant_evaluated
429 return std::__do_uninit_fill(__first, __last, __x);
430#endif
431 std::uninitialized_fill(__first, __last, __x);
432 }
433
434 template<typename _ForwardIterator, typename _Size, typename _Tp,
435 typename _Allocator>
436 _GLIBCXX20_CONSTEXPR
437 _ForwardIterator
438 __uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
439 const _Tp& __x, _Allocator& __alloc)
440 {
441 _ForwardIterator __cur = __first;
442 __try
443 {
445 for (; __n > 0; --__n, (void) ++__cur)
446 __traits::construct(__alloc, std::__addressof(*__cur), __x);
447 return __cur;
448 }
449 __catch(...)
450 {
451 std::_Destroy(__first, __cur, __alloc);
452 __throw_exception_again;
453 }
454 }
455
456 template<typename _ForwardIterator, typename _Size, typename _Tp,
457 typename _Tp2>
458 _GLIBCXX20_CONSTEXPR
459 inline _ForwardIterator
460 __uninitialized_fill_n_a(_ForwardIterator __first, _Size __n,
461 const _Tp& __x, allocator<_Tp2>&)
462 {
463#ifdef __cpp_lib_is_constant_evaluated
465 return std::__do_uninit_fill_n(__first, __n, __x);
466#endif
467 return std::uninitialized_fill_n(__first, __n, __x);
468 }
469
470
471 // Extensions: __uninitialized_copy_move, __uninitialized_move_copy,
472 // __uninitialized_fill_move, __uninitialized_move_fill.
473 // All of these algorithms take a user-supplied allocator, which is used
474 // for construction and destruction.
475
476 // __uninitialized_copy_move
477 // Copies [first1, last1) into [result, result + (last1 - first1)), and
478 // move [first2, last2) into
479 // [result, result + (last1 - first1) + (last2 - first2)).
480 template<typename _InputIterator1, typename _InputIterator2,
481 typename _ForwardIterator, typename _Allocator>
482 inline _ForwardIterator
483 __uninitialized_copy_move(_InputIterator1 __first1,
484 _InputIterator1 __last1,
485 _InputIterator2 __first2,
486 _InputIterator2 __last2,
487 _ForwardIterator __result,
488 _Allocator& __alloc)
489 {
490 _ForwardIterator __mid = std::__uninitialized_copy_a(__first1, __last1,
491 __result,
492 __alloc);
493 __try
494 {
495 return std::__uninitialized_move_a(__first2, __last2, __mid, __alloc);
496 }
497 __catch(...)
498 {
499 std::_Destroy(__result, __mid, __alloc);
500 __throw_exception_again;
501 }
502 }
503
504 // __uninitialized_move_copy
505 // Moves [first1, last1) into [result, result + (last1 - first1)), and
506 // copies [first2, last2) into
507 // [result, result + (last1 - first1) + (last2 - first2)).
508 template<typename _InputIterator1, typename _InputIterator2,
509 typename _ForwardIterator, typename _Allocator>
510 inline _ForwardIterator
511 __uninitialized_move_copy(_InputIterator1 __first1,
512 _InputIterator1 __last1,
513 _InputIterator2 __first2,
514 _InputIterator2 __last2,
515 _ForwardIterator __result,
516 _Allocator& __alloc)
517 {
518 _ForwardIterator __mid = std::__uninitialized_move_a(__first1, __last1,
519 __result,
520 __alloc);
521 __try
522 {
523 return std::__uninitialized_copy_a(__first2, __last2, __mid, __alloc);
524 }
525 __catch(...)
526 {
527 std::_Destroy(__result, __mid, __alloc);
528 __throw_exception_again;
529 }
530 }
531
532 // __uninitialized_fill_move
533 // Fills [result, mid) with x, and moves [first, last) into
534 // [mid, mid + (last - first)).
535 template<typename _ForwardIterator, typename _Tp, typename _InputIterator,
536 typename _Allocator>
537 inline _ForwardIterator
538 __uninitialized_fill_move(_ForwardIterator __result, _ForwardIterator __mid,
539 const _Tp& __x, _InputIterator __first,
540 _InputIterator __last, _Allocator& __alloc)
541 {
542 std::__uninitialized_fill_a(__result, __mid, __x, __alloc);
543 __try
544 {
545 return std::__uninitialized_move_a(__first, __last, __mid, __alloc);
546 }
547 __catch(...)
548 {
549 std::_Destroy(__result, __mid, __alloc);
550 __throw_exception_again;
551 }
552 }
553
554 // __uninitialized_move_fill
555 // Moves [first1, last1) into [first2, first2 + (last1 - first1)), and
556 // fills [first2 + (last1 - first1), last2) with x.
557 template<typename _InputIterator, typename _ForwardIterator, typename _Tp,
558 typename _Allocator>
559 inline void
560 __uninitialized_move_fill(_InputIterator __first1, _InputIterator __last1,
561 _ForwardIterator __first2,
562 _ForwardIterator __last2, const _Tp& __x,
563 _Allocator& __alloc)
564 {
565 _ForwardIterator __mid2 = std::__uninitialized_move_a(__first1, __last1,
566 __first2,
567 __alloc);
568 __try
569 {
570 std::__uninitialized_fill_a(__mid2, __last2, __x, __alloc);
571 }
572 __catch(...)
573 {
574 std::_Destroy(__first2, __mid2, __alloc);
575 __throw_exception_again;
576 }
577 }
578
579 /// @endcond
580
581#if __cplusplus >= 201103L
582 /// @cond undocumented
583
584 // Extensions: __uninitialized_default, __uninitialized_default_n,
585 // __uninitialized_default_a, __uninitialized_default_n_a.
586
587 template<bool _TrivialValueType>
588 struct __uninitialized_default_1
589 {
590 template<typename _ForwardIterator>
591 static void
592 __uninit_default(_ForwardIterator __first, _ForwardIterator __last)
593 {
594 _ForwardIterator __cur = __first;
595 __try
596 {
597 for (; __cur != __last; ++__cur)
599 }
600 __catch(...)
601 {
602 std::_Destroy(__first, __cur);
603 __throw_exception_again;
604 }
605 }
606 };
607
608 template<>
609 struct __uninitialized_default_1<true>
610 {
611 template<typename _ForwardIterator>
612 static void
613 __uninit_default(_ForwardIterator __first, _ForwardIterator __last)
614 {
615 if (__first == __last)
616 return;
617
618 typename iterator_traits<_ForwardIterator>::value_type* __val
619 = std::__addressof(*__first);
620 std::_Construct(__val);
621 if (++__first != __last)
622 std::fill(__first, __last, *__val);
623 }
624 };
625
626 template<bool _TrivialValueType>
627 struct __uninitialized_default_n_1
628 {
629 template<typename _ForwardIterator, typename _Size>
630 _GLIBCXX20_CONSTEXPR
631 static _ForwardIterator
632 __uninit_default_n(_ForwardIterator __first, _Size __n)
633 {
634 _ForwardIterator __cur = __first;
635 __try
636 {
637 for (; __n > 0; --__n, (void) ++__cur)
639 return __cur;
640 }
641 __catch(...)
642 {
643 std::_Destroy(__first, __cur);
644 __throw_exception_again;
645 }
646 }
647 };
648
649 template<>
650 struct __uninitialized_default_n_1<true>
651 {
652 template<typename _ForwardIterator, typename _Size>
653 _GLIBCXX20_CONSTEXPR
654 static _ForwardIterator
655 __uninit_default_n(_ForwardIterator __first, _Size __n)
656 {
657 if (__n > 0)
658 {
659 typename iterator_traits<_ForwardIterator>::value_type* __val
660 = std::__addressof(*__first);
661 std::_Construct(__val);
662 ++__first;
663 __first = std::fill_n(__first, __n - 1, *__val);
664 }
665 return __first;
666 }
667 };
668
669 // __uninitialized_default
670 // Fills [first, last) with value-initialized value_types.
671 template<typename _ForwardIterator>
672 inline void
673 __uninitialized_default(_ForwardIterator __first,
674 _ForwardIterator __last)
675 {
676 typedef typename iterator_traits<_ForwardIterator>::value_type
677 _ValueType;
678 // trivial types can have deleted assignment
679 const bool __assignable = is_copy_assignable<_ValueType>::value;
680
681 std::__uninitialized_default_1<__is_trivial(_ValueType)
682 && __assignable>::
683 __uninit_default(__first, __last);
684 }
685
686 // __uninitialized_default_n
687 // Fills [first, first + n) with value-initialized value_types.
688 template<typename _ForwardIterator, typename _Size>
689 _GLIBCXX20_CONSTEXPR
690 inline _ForwardIterator
691 __uninitialized_default_n(_ForwardIterator __first, _Size __n)
692 {
693 typedef typename iterator_traits<_ForwardIterator>::value_type
694 _ValueType;
695 // See uninitialized_fill_n for the conditions for using std::fill_n.
696 constexpr bool __can_fill
697 = __and_<is_integral<_Size>, is_copy_assignable<_ValueType>>::value;
698
699 return __uninitialized_default_n_1<__is_trivial(_ValueType)
700 && __can_fill>::
701 __uninit_default_n(__first, __n);
702 }
703
704
705 // __uninitialized_default_a
706 // Fills [first, last) with value_types constructed by the allocator
707 // alloc, with no arguments passed to the construct call.
708 template<typename _ForwardIterator, typename _Allocator>
709 void
710 __uninitialized_default_a(_ForwardIterator __first,
711 _ForwardIterator __last,
712 _Allocator& __alloc)
713 {
714 _ForwardIterator __cur = __first;
715 __try
716 {
718 for (; __cur != __last; ++__cur)
719 __traits::construct(__alloc, std::__addressof(*__cur));
720 }
721 __catch(...)
722 {
723 std::_Destroy(__first, __cur, __alloc);
724 __throw_exception_again;
725 }
726 }
727
728 template<typename _ForwardIterator, typename _Tp>
729 inline void
730 __uninitialized_default_a(_ForwardIterator __first,
731 _ForwardIterator __last,
732 allocator<_Tp>&)
733 { std::__uninitialized_default(__first, __last); }
734
735
736 // __uninitialized_default_n_a
737 // Fills [first, first + n) with value_types constructed by the allocator
738 // alloc, with no arguments passed to the construct call.
739 template<typename _ForwardIterator, typename _Size, typename _Allocator>
740 _GLIBCXX20_CONSTEXPR _ForwardIterator
741 __uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
742 _Allocator& __alloc)
743 {
744 _ForwardIterator __cur = __first;
745 __try
746 {
748 for (; __n > 0; --__n, (void) ++__cur)
749 __traits::construct(__alloc, std::__addressof(*__cur));
750 return __cur;
751 }
752 __catch(...)
753 {
754 std::_Destroy(__first, __cur, __alloc);
755 __throw_exception_again;
756 }
757 }
758
759 // __uninitialized_default_n_a specialization for std::allocator,
760 // which ignores the allocator and value-initializes the elements.
761 template<typename _ForwardIterator, typename _Size, typename _Tp>
762 _GLIBCXX20_CONSTEXPR
763 inline _ForwardIterator
764 __uninitialized_default_n_a(_ForwardIterator __first, _Size __n,
765 allocator<_Tp>&)
766 { return std::__uninitialized_default_n(__first, __n); }
767
768 template<bool _TrivialValueType>
769 struct __uninitialized_default_novalue_1
770 {
771 template<typename _ForwardIterator>
772 static void
773 __uninit_default_novalue(_ForwardIterator __first,
774 _ForwardIterator __last)
775 {
776 _ForwardIterator __cur = __first;
777 __try
778 {
779 for (; __cur != __last; ++__cur)
780 std::_Construct_novalue(std::__addressof(*__cur));
781 }
782 __catch(...)
783 {
784 std::_Destroy(__first, __cur);
785 __throw_exception_again;
786 }
787 }
788 };
789
790 template<>
791 struct __uninitialized_default_novalue_1<true>
792 {
793 template<typename _ForwardIterator>
794 static void
795 __uninit_default_novalue(_ForwardIterator __first,
796 _ForwardIterator __last)
797 {
798 }
799 };
800
801 template<bool _TrivialValueType>
802 struct __uninitialized_default_novalue_n_1
803 {
804 template<typename _ForwardIterator, typename _Size>
805 static _ForwardIterator
806 __uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
807 {
808 _ForwardIterator __cur = __first;
809 __try
810 {
811 for (; __n > 0; --__n, (void) ++__cur)
812 std::_Construct_novalue(std::__addressof(*__cur));
813 return __cur;
814 }
815 __catch(...)
816 {
817 std::_Destroy(__first, __cur);
818 __throw_exception_again;
819 }
820 }
821 };
822
823 template<>
824 struct __uninitialized_default_novalue_n_1<true>
825 {
826 template<typename _ForwardIterator, typename _Size>
827 static _ForwardIterator
828 __uninit_default_novalue_n(_ForwardIterator __first, _Size __n)
829 { return std::next(__first, __n); }
830 };
831
832 // __uninitialized_default_novalue
833 // Fills [first, last) with default-initialized value_types.
834 template<typename _ForwardIterator>
835 inline void
836 __uninitialized_default_novalue(_ForwardIterator __first,
837 _ForwardIterator __last)
838 {
839 typedef typename iterator_traits<_ForwardIterator>::value_type
840 _ValueType;
841
842 std::__uninitialized_default_novalue_1<
843 is_trivially_default_constructible<_ValueType>::value>::
844 __uninit_default_novalue(__first, __last);
845 }
846
847 // __uninitialized_default_novalue_n
848 // Fills [first, first + n) with default-initialized value_types.
849 template<typename _ForwardIterator, typename _Size>
850 inline _ForwardIterator
851 __uninitialized_default_novalue_n(_ForwardIterator __first, _Size __n)
852 {
853 typedef typename iterator_traits<_ForwardIterator>::value_type
854 _ValueType;
855
856 return __uninitialized_default_novalue_n_1<
857 is_trivially_default_constructible<_ValueType>::value>::
858 __uninit_default_novalue_n(__first, __n);
859 }
860
861 template<typename _InputIterator, typename _Size,
862 typename _ForwardIterator>
863 _ForwardIterator
864 __uninitialized_copy_n(_InputIterator __first, _Size __n,
865 _ForwardIterator __result, input_iterator_tag)
866 {
867 _ForwardIterator __cur = __result;
868 __try
869 {
870 for (; __n > 0; --__n, (void) ++__first, ++__cur)
871 std::_Construct(std::__addressof(*__cur), *__first);
872 return __cur;
873 }
874 __catch(...)
875 {
876 std::_Destroy(__result, __cur);
877 __throw_exception_again;
878 }
879 }
880
881 template<typename _RandomAccessIterator, typename _Size,
882 typename _ForwardIterator>
883 inline _ForwardIterator
884 __uninitialized_copy_n(_RandomAccessIterator __first, _Size __n,
885 _ForwardIterator __result,
886 random_access_iterator_tag)
887 { return std::uninitialized_copy(__first, __first + __n, __result); }
888
889 template<typename _InputIterator, typename _Size,
890 typename _ForwardIterator>
891 pair<_InputIterator, _ForwardIterator>
892 __uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
893 _ForwardIterator __result, input_iterator_tag)
894 {
895 _ForwardIterator __cur = __result;
896 __try
897 {
898 for (; __n > 0; --__n, (void) ++__first, ++__cur)
899 std::_Construct(std::__addressof(*__cur), *__first);
900 return {__first, __cur};
901 }
902 __catch(...)
903 {
904 std::_Destroy(__result, __cur);
905 __throw_exception_again;
906 }
907 }
908
909 template<typename _RandomAccessIterator, typename _Size,
910 typename _ForwardIterator>
911 inline pair<_RandomAccessIterator, _ForwardIterator>
912 __uninitialized_copy_n_pair(_RandomAccessIterator __first, _Size __n,
913 _ForwardIterator __result,
914 random_access_iterator_tag)
915 {
916 auto __second_res = uninitialized_copy(__first, __first + __n, __result);
917 auto __first_res = std::next(__first, __n);
918 return {__first_res, __second_res};
919 }
920
921 /// @endcond
922
923 /**
924 * @brief Copies the range [first,first+n) into result.
925 * @param __first An input iterator.
926 * @param __n The number of elements to copy.
927 * @param __result An output iterator.
928 * @return __result + __n
929 * @since C++11
930 *
931 * Like copy_n(), but does not require an initialized output range.
932 */
933 template<typename _InputIterator, typename _Size, typename _ForwardIterator>
934 inline _ForwardIterator
935 uninitialized_copy_n(_InputIterator __first, _Size __n,
936 _ForwardIterator __result)
937 { return std::__uninitialized_copy_n(__first, __n, __result,
938 std::__iterator_category(__first)); }
939
940 /// @cond undocumented
941 template<typename _InputIterator, typename _Size, typename _ForwardIterator>
942 inline pair<_InputIterator, _ForwardIterator>
943 __uninitialized_copy_n_pair(_InputIterator __first, _Size __n,
944 _ForwardIterator __result)
945 {
946 return
947 std::__uninitialized_copy_n_pair(__first, __n, __result,
948 std::__iterator_category(__first));
949 }
950 /// @endcond
951#endif
952
953#if __cplusplus >= 201703L
954# define __cpp_lib_raw_memory_algorithms 201606L
955
956 /**
957 * @brief Default-initializes objects in the range [first,last).
958 * @param __first A forward iterator.
959 * @param __last A forward iterator.
960 * @since C++17
961 */
962 template <typename _ForwardIterator>
963 inline void
964 uninitialized_default_construct(_ForwardIterator __first,
965 _ForwardIterator __last)
966 {
967 __uninitialized_default_novalue(__first, __last);
968 }
969
970 /**
971 * @brief Default-initializes objects in the range [first,first+count).
972 * @param __first A forward iterator.
973 * @param __count The number of objects to construct.
974 * @return __first + __count
975 * @since C++17
976 */
977 template <typename _ForwardIterator, typename _Size>
978 inline _ForwardIterator
979 uninitialized_default_construct_n(_ForwardIterator __first, _Size __count)
980 {
981 return __uninitialized_default_novalue_n(__first, __count);
982 }
983
984 /**
985 * @brief Value-initializes objects in the range [first,last).
986 * @param __first A forward iterator.
987 * @param __last A forward iterator.
988 * @since C++17
989 */
990 template <typename _ForwardIterator>
991 inline void
992 uninitialized_value_construct(_ForwardIterator __first,
993 _ForwardIterator __last)
994 {
995 return __uninitialized_default(__first, __last);
996 }
997
998 /**
999 * @brief Value-initializes objects in the range [first,first+count).
1000 * @param __first A forward iterator.
1001 * @param __count The number of objects to construct.
1002 * @return __result + __count
1003 * @since C++17
1004 */
1005 template <typename _ForwardIterator, typename _Size>
1006 inline _ForwardIterator
1007 uninitialized_value_construct_n(_ForwardIterator __first, _Size __count)
1008 {
1009 return __uninitialized_default_n(__first, __count);
1010 }
1011
1012 /**
1013 * @brief Move-construct from the range [first,last) into result.
1014 * @param __first An input iterator.
1015 * @param __last An input iterator.
1016 * @param __result An output iterator.
1017 * @return __result + (__first - __last)
1018 * @since C++17
1019 */
1020 template <typename _InputIterator, typename _ForwardIterator>
1021 inline _ForwardIterator
1022 uninitialized_move(_InputIterator __first, _InputIterator __last,
1023 _ForwardIterator __result)
1024 {
1026 (_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
1027 _GLIBCXX_MAKE_MOVE_ITERATOR(__last), __result);
1028 }
1029
1030 /**
1031 * @brief Move-construct from the range [first,first+count) into result.
1032 * @param __first An input iterator.
1033 * @param __count The number of objects to initialize.
1034 * @param __result An output iterator.
1035 * @return __result + __count
1036 * @since C++17
1037 */
1038 template <typename _InputIterator, typename _Size, typename _ForwardIterator>
1039 inline pair<_InputIterator, _ForwardIterator>
1040 uninitialized_move_n(_InputIterator __first, _Size __count,
1041 _ForwardIterator __result)
1042 {
1043 auto __res = std::__uninitialized_copy_n_pair
1044 (_GLIBCXX_MAKE_MOVE_ITERATOR(__first),
1045 __count, __result);
1046 return {__res.first.base(), __res.second};
1047 }
1048#endif // C++17
1049
1050#if __cplusplus >= 201103L
1051 /// @cond undocumented
1052
1053 template<typename _Tp, typename _Up, typename _Allocator>
1054 _GLIBCXX20_CONSTEXPR
1055 inline void
1056 __relocate_object_a(_Tp* __restrict __dest, _Up* __restrict __orig,
1057 _Allocator& __alloc)
1058 noexcept(noexcept(std::allocator_traits<_Allocator>::construct(__alloc,
1059 __dest, std::move(*__orig)))
1061 __alloc, std::__addressof(*__orig))))
1062 {
1063 typedef std::allocator_traits<_Allocator> __traits;
1064 __traits::construct(__alloc, __dest, std::move(*__orig));
1065 __traits::destroy(__alloc, std::__addressof(*__orig));
1066 }
1067
1068 // This class may be specialized for specific types.
1069 // Also known as is_trivially_relocatable.
1070 template<typename _Tp, typename = void>
1071 struct __is_bitwise_relocatable
1072 : is_trivial<_Tp> { };
1073
1074 template <typename _InputIterator, typename _ForwardIterator,
1075 typename _Allocator>
1076 _GLIBCXX20_CONSTEXPR
1077 inline _ForwardIterator
1078 __relocate_a_1(_InputIterator __first, _InputIterator __last,
1079 _ForwardIterator __result, _Allocator& __alloc)
1080 noexcept(noexcept(std::__relocate_object_a(std::addressof(*__result),
1081 std::addressof(*__first),
1082 __alloc)))
1083 {
1084 typedef typename iterator_traits<_InputIterator>::value_type
1085 _ValueType;
1086 typedef typename iterator_traits<_ForwardIterator>::value_type
1087 _ValueType2;
1089 "relocation is only possible for values of the same type");
1090 _ForwardIterator __cur = __result;
1091 for (; __first != __last; ++__first, (void)++__cur)
1092 std::__relocate_object_a(std::__addressof(*__cur),
1093 std::__addressof(*__first), __alloc);
1094 return __cur;
1095 }
1096
1097 template <typename _Tp, typename _Up>
1098 _GLIBCXX20_CONSTEXPR
1099 inline __enable_if_t<std::__is_bitwise_relocatable<_Tp>::value, _Tp*>
1100 __relocate_a_1(_Tp* __first, _Tp* __last,
1101 _Tp* __result,
1102 [[__maybe_unused__]] allocator<_Up>& __alloc) noexcept
1103 {
1104 ptrdiff_t __count = __last - __first;
1105 if (__count > 0)
1106 {
1107#ifdef __cpp_lib_is_constant_evaluated
1109 {
1110 // Can't use memmove. Wrap the pointer so that __relocate_a_1
1111 // resolves to the non-trivial overload above.
1112 __gnu_cxx::__normal_iterator<_Tp*, void> __out(__result);
1113 __out = std::__relocate_a_1(__first, __last, __out, __alloc);
1114 return __out.base();
1115 }
1116#endif
1117 __builtin_memmove(__result, __first, __count * sizeof(_Tp));
1118 }
1119 return __result + __count;
1120 }
1121
1122
1123 template <typename _InputIterator, typename _ForwardIterator,
1124 typename _Allocator>
1125 _GLIBCXX20_CONSTEXPR
1126 inline _ForwardIterator
1127 __relocate_a(_InputIterator __first, _InputIterator __last,
1128 _ForwardIterator __result, _Allocator& __alloc)
1129 noexcept(noexcept(__relocate_a_1(std::__niter_base(__first),
1130 std::__niter_base(__last),
1131 std::__niter_base(__result), __alloc)))
1132 {
1133 return std::__relocate_a_1(std::__niter_base(__first),
1134 std::__niter_base(__last),
1135 std::__niter_base(__result), __alloc);
1136 }
1137
1138 /// @endcond
1139#endif
1140
1141 /// @} group memory
1142
1143_GLIBCXX_END_NAMESPACE_VERSION
1144} // namespace
1145
1146#endif /* _STL_UNINITIALIZED_H */
_ForwardIterator uninitialized_copy_n(_InputIterator __first, _Size __n, _ForwardIterator __result)
Copies the range [first,first+n) into result.
void uninitialized_fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp &__x)
Copies the value x into the range [first,last).
_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __count)
Value-initializes objects in the range [first,first+count).
_ForwardIterator uninitialized_move(_InputIterator __first, _InputIterator __last, _ForwardIterator __result)
Move-construct from the range [first,last) into result.
_ForwardIterator uninitialized_fill_n(_ForwardIterator __first, _Size __n, const _Tp &__x)
Copies the value x into the range [first,first+n).
_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __count)
Default-initializes objects in the range [first,first+count).
void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last)
Default-initializes objects in the range [first,last).
_ForwardIterator uninitialized_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result)
Copies the range [first,last) into result.
void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last)
Value-initializes objects in the range [first,last).
pair< _InputIterator, _ForwardIterator > uninitialized_move_n(_InputIterator __first, _Size __count, _ForwardIterator __result)
Move-construct from the range [first,first+count) into result.
constexpr bool is_constant_evaluated() noexcept
Returns true only when called during constant evaluation.
Definition: type_traits:3520
constexpr _Tp * addressof(_Tp &__r) noexcept
Returns the actual address of the object or function referenced by r, even in the presence of an over...
Definition: move.h:145
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:104
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:49
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
ISO C++ entities toplevel namespace is std.
constexpr void _Construct(_Tp *__p, _Args &&... __args)
constexpr void _Destroy(_ForwardIterator __first, _ForwardIterator __last, _Allocator &__alloc)
is_same
Definition: type_traits:1435
Uniform interface to all allocator types.
static constexpr auto construct(_Alloc &__a, _Tp *__p, _Args &&... __args) noexcept(noexcept(_S_construct(__a, __p, std::forward< _Args >(__args)...))) -> decltype(_S_construct(__a, __p, std::forward< _Args >(__args)...))
Construct an object of type _Tp
Traits class for iterators.
Uniform interface to C++98 and C++11 allocators.