xref: /freebsd/contrib/llvm-project/libcxx/include/array (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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_ARRAY
11#define _LIBCPP_ARRAY
12
13/*
14    array synopsis
15
16namespace std
17{
18template <class T, size_t N >
19struct array
20{
21    // types:
22    typedef T & reference;
23    typedef const T & const_reference;
24    typedef implementation defined iterator;
25    typedef implementation defined const_iterator;
26    typedef size_t size_type;
27    typedef ptrdiff_t difference_type;
28    typedef T value_type;
29    typedef T* pointer;
30    typedef const T* const_pointer;
31    typedef std::reverse_iterator<iterator> reverse_iterator;
32    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
33
34    // No explicit construct/copy/destroy for aggregate type
35    void fill(const T& u);                                      // constexpr in C++20
36    void swap(array& a) noexcept(is_nothrow_swappable_v<T>);    // constexpr in C++20
37
38    // iterators:
39    iterator begin() noexcept;                                  // constexpr in C++17
40    const_iterator begin() const noexcept;                      // constexpr in C++17
41    iterator end() noexcept;                                    // constexpr in C++17
42    const_iterator end() const noexcept;                        // constexpr in C++17
43
44    reverse_iterator rbegin() noexcept;                         // constexpr in C++17
45    const_reverse_iterator rbegin() const noexcept;             // constexpr in C++17
46    reverse_iterator rend() noexcept;                           // constexpr in C++17
47    const_reverse_iterator rend() const noexcept;               // constexpr in C++17
48
49    const_iterator cbegin() const noexcept;                     // constexpr in C++17
50    const_iterator cend() const noexcept;                       // constexpr in C++17
51    const_reverse_iterator crbegin() const noexcept;            // constexpr in C++17
52    const_reverse_iterator crend() const noexcept;              // constexpr in C++17
53
54    // capacity:
55    constexpr size_type size() const noexcept;
56    constexpr size_type max_size() const noexcept;
57    constexpr bool empty() const noexcept;
58
59    // element access:
60    reference operator[](size_type n);                          // constexpr in C++17
61    const_reference operator[](size_type n) const;              // constexpr in C++14
62    reference at(size_type n);                                  // constexpr in C++17
63    const_reference at(size_type n) const;                      // constexpr in C++14
64
65    reference front();                                          // constexpr in C++17
66    const_reference front() const;                              // constexpr in C++14
67    reference back();                                           // constexpr in C++17
68    const_reference back() const;                               // constexpr in C++14
69
70    T* data() noexcept;                                         // constexpr in C++17
71    const T* data() const noexcept;                             // constexpr in C++17
72};
73
74template <class T, class... U>
75  array(T, U...) -> array<T, 1 + sizeof...(U)>;                 // C++17
76
77template <class T, size_t N>
78  bool operator==(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
79template <class T, size_t N>
80  bool operator!=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
81template <class T, size_t N>
82  bool operator<(const array<T,N>& x, const array<T,N>& y);     // removed in C++20
83template <class T, size_t N>
84  bool operator>(const array<T,N>& x, const array<T,N>& y);     // removed in C++20
85template <class T, size_t N>
86  bool operator<=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
87template <class T, size_t N>
88  bool operator>=(const array<T,N>& x, const array<T,N>& y);    // removed in C++20
89template<class T, size_t N>
90  constexpr synth-three-way-result<T>
91    operator<=>(const array<T, N>& x, const array<T, N>& y);    // since C++20
92
93template <class T, size_t N >
94  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // constexpr in C++20
95
96template <class T, size_t N>
97  constexpr array<remove_cv_t<T>, N> to_array(T (&a)[N]);  // C++20
98template <class T, size_t N>
99  constexpr array<remove_cv_t<T>, N> to_array(T (&&a)[N]); // C++20
100
101template <class T> struct tuple_size;
102template <size_t I, class T> struct tuple_element;
103template <class T, size_t N> struct tuple_size<array<T, N>>;
104template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
105template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept;               // constexpr in C++14
106template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept;   // constexpr in C++14
107template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept;             // constexpr in C++14
108template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
109
110}  // std
111
112*/
113
114#include <__algorithm/equal.h>
115#include <__algorithm/fill_n.h>
116#include <__algorithm/lexicographical_compare.h>
117#include <__algorithm/lexicographical_compare_three_way.h>
118#include <__algorithm/swap_ranges.h>
119#include <__assert> // all public C++ headers provide the assertion handler
120#include <__config>
121#include <__fwd/array.h>
122#include <__iterator/reverse_iterator.h>
123#include <__tuple/sfinae_helpers.h>
124#include <__type_traits/conditional.h>
125#include <__type_traits/is_array.h>
126#include <__type_traits/is_const.h>
127#include <__type_traits/is_constructible.h>
128#include <__type_traits/is_move_constructible.h>
129#include <__type_traits/is_nothrow_constructible.h>
130#include <__type_traits/is_nothrow_move_constructible.h>
131#include <__type_traits/is_same.h>
132#include <__type_traits/is_swappable.h>
133#include <__type_traits/remove_cv.h>
134#include <__utility/integer_sequence.h>
135#include <__utility/move.h>
136#include <__utility/unreachable.h>
137#include <stdexcept>
138#include <version>
139
140// standard-mandated includes
141
142// [iterator.range]
143#include <__iterator/access.h>
144#include <__iterator/data.h>
145#include <__iterator/empty.h>
146#include <__iterator/reverse_access.h>
147#include <__iterator/size.h>
148
149// [array.syn]
150#include <compare>
151#include <initializer_list>
152
153// [tuple.helper]
154#include <__tuple/tuple_element.h>
155#include <__tuple/tuple_size.h>
156
157#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
158#  pragma GCC system_header
159#endif
160
161_LIBCPP_BEGIN_NAMESPACE_STD
162
163template <class _Tp, size_t _Size>
164struct _LIBCPP_TEMPLATE_VIS array
165{
166    // types:
167    typedef array __self;
168    typedef _Tp                                   value_type;
169    typedef value_type&                           reference;
170    typedef const value_type&                     const_reference;
171    typedef value_type*                           iterator;
172    typedef const value_type*                     const_iterator;
173    typedef value_type*                           pointer;
174    typedef const value_type*                     const_pointer;
175    typedef size_t                                size_type;
176    typedef ptrdiff_t                             difference_type;
177    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
178    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
179
180    _Tp __elems_[_Size];
181
182    // No explicit construct/copy/destroy for aggregate type
183    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
184    void fill(const value_type& __u) {
185        _VSTD::fill_n(data(), _Size, __u);
186    }
187
188    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
189    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
190        _VSTD::swap_ranges(data(), data() + _Size, __a.data());
191    }
192
193    // iterators:
194    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
195    iterator begin() _NOEXCEPT {return iterator(data());}
196    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
197    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
198    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
199    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
200    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
201    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
202
203    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
204    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
205    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
206    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
207    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
208    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
209    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
210    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
211
212    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
213    const_iterator cbegin() const _NOEXCEPT {return begin();}
214    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
215    const_iterator cend() const _NOEXCEPT {return end();}
216    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
217    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
218    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
219    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
220
221    // capacity:
222    _LIBCPP_INLINE_VISIBILITY
223    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
224    _LIBCPP_INLINE_VISIBILITY
225    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
226    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
227    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
228
229    // element access:
230    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
231    reference operator[](size_type __n) _NOEXCEPT {
232        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < _Size, "out-of-bounds access in std::array<T, N>");
233        return __elems_[__n];
234    }
235    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
236    const_reference operator[](size_type __n) const _NOEXCEPT {
237        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < _Size, "out-of-bounds access in std::array<T, N>");
238        return __elems_[__n];
239    }
240
241    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 reference at(size_type __n)
242    {
243        if (__n >= _Size)
244            __throw_out_of_range("array::at");
245        return __elems_[__n];
246    }
247
248    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference at(size_type __n) const
249    {
250        if (__n >= _Size)
251            __throw_out_of_range("array::at");
252        return __elems_[__n];
253    }
254
255    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17 reference front()             _NOEXCEPT {return (*this)[0];}
256    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference front() const _NOEXCEPT {return (*this)[0];}
257    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
258    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
259
260    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
261    value_type* data() _NOEXCEPT {return __elems_;}
262    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
263    const value_type* data() const _NOEXCEPT {return __elems_;}
264};
265
266template <class _Tp>
267struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
268{
269    // types:
270    typedef array __self;
271    typedef _Tp                                   value_type;
272    typedef value_type&                           reference;
273    typedef const value_type&                     const_reference;
274    typedef value_type*                           iterator;
275    typedef const value_type*                     const_iterator;
276    typedef value_type*                           pointer;
277    typedef const value_type*                     const_pointer;
278    typedef size_t                                size_type;
279    typedef ptrdiff_t                             difference_type;
280    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
281    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
282
283    typedef __conditional_t<is_const<_Tp>::value, const char, char> _CharType;
284
285    struct  _ArrayInStructT { _Tp __data_[1]; };
286    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
287
288    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
289    value_type* data() _NOEXCEPT {return nullptr;}
290    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
291    const value_type* data() const _NOEXCEPT {return nullptr;}
292
293    // No explicit construct/copy/destroy for aggregate type
294    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
295    void fill(const value_type&) {
296      static_assert(!is_const<_Tp>::value,
297                    "cannot fill zero-sized array of type 'const T'");
298    }
299
300    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
301    void swap(array&) _NOEXCEPT {
302      static_assert(!is_const<_Tp>::value,
303                    "cannot swap zero-sized array of type 'const T'");
304    }
305
306    // iterators:
307    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
308    iterator begin() _NOEXCEPT {return iterator(data());}
309    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
310    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
311    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
312    iterator end() _NOEXCEPT {return iterator(data());}
313    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
314    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
315
316    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
317    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
318    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
319    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
320    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
321    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
322    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
323    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
324
325    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
326    const_iterator cbegin() const _NOEXCEPT {return begin();}
327    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
328    const_iterator cend() const _NOEXCEPT {return end();}
329    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
330    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
331    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
332    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
333
334    // capacity:
335    _LIBCPP_INLINE_VISIBILITY
336    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
337    _LIBCPP_INLINE_VISIBILITY
338    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
339    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
340    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
341
342    // element access:
343    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
344    reference operator[](size_type) _NOEXCEPT {
345      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
346      __libcpp_unreachable();
347    }
348
349    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
350    const_reference operator[](size_type) const _NOEXCEPT {
351      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
352      __libcpp_unreachable();
353    }
354
355    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
356    reference at(size_type) {
357      __throw_out_of_range("array<T, 0>::at");
358      __libcpp_unreachable();
359    }
360
361    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
362    const_reference at(size_type) const {
363      __throw_out_of_range("array<T, 0>::at");
364      __libcpp_unreachable();
365    }
366
367    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
368    reference front() _NOEXCEPT {
369      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::front() on a zero-sized array");
370      __libcpp_unreachable();
371    }
372
373    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
374    const_reference front() const _NOEXCEPT {
375      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::front() on a zero-sized array");
376      __libcpp_unreachable();
377    }
378
379    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX17
380    reference back() _NOEXCEPT {
381      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::back() on a zero-sized array");
382      __libcpp_unreachable();
383    }
384
385    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
386    const_reference back() const _NOEXCEPT {
387      _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(false, "cannot call array<T, 0>::back() on a zero-sized array");
388      __libcpp_unreachable();
389    }
390};
391
392
393#if _LIBCPP_STD_VER >= 17
394template<class _Tp, class... _Args,
395         class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value>
396         >
397array(_Tp, _Args...)
398  -> array<_Tp, 1 + sizeof...(_Args)>;
399#endif
400
401template <class _Tp, size_t _Size>
402inline _LIBCPP_INLINE_VISIBILITY
403_LIBCPP_CONSTEXPR_SINCE_CXX20 bool
404operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
405{
406    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
407}
408
409#if _LIBCPP_STD_VER <= 17
410
411template <class _Tp, size_t _Size>
412inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
413    return !(__x == __y);
414}
415
416template <class _Tp, size_t _Size>
417inline _LIBCPP_HIDE_FROM_ABI bool operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
418    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
419}
420
421template <class _Tp, size_t _Size>
422inline _LIBCPP_HIDE_FROM_ABI bool operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
423    return __y < __x;
424}
425
426template <class _Tp, size_t _Size>
427inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
428    return !(__y < __x);
429}
430
431template <class _Tp, size_t _Size>
432inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
433    return !(__x < __y);
434}
435
436#else // _LIBCPP_STD_VER <= 17
437
438template <class _Tp, size_t _Size>
439_LIBCPP_HIDE_FROM_ABI constexpr __synth_three_way_result<_Tp>
440operator<=>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y) {
441    return std::lexicographical_compare_three_way(
442        __x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way<_Tp, _Tp>);
443}
444
445#endif // _LIBCPP_STD_VER <= 17
446
447template <class _Tp, size_t _Size>
448inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20
449__enable_if_t<_Size == 0 || __is_swappable<_Tp>::value, void>
450swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
451                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
452{
453    __x.swap(__y);
454}
455
456template <class _Tp, size_t _Size>
457struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
458    : public integral_constant<size_t, _Size> {};
459
460template <size_t _Ip, class _Tp, size_t _Size>
461struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
462{
463    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
464    typedef _Tp type;
465};
466
467template <size_t _Ip, class _Tp, size_t _Size>
468inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
469_Tp&
470get(array<_Tp, _Size>& __a) _NOEXCEPT
471{
472    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
473    return __a.__elems_[_Ip];
474}
475
476template <size_t _Ip, class _Tp, size_t _Size>
477inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
478const _Tp&
479get(const array<_Tp, _Size>& __a) _NOEXCEPT
480{
481    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
482    return __a.__elems_[_Ip];
483}
484
485template <size_t _Ip, class _Tp, size_t _Size>
486inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
487_Tp&&
488get(array<_Tp, _Size>&& __a) _NOEXCEPT
489{
490    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
491    return _VSTD::move(__a.__elems_[_Ip]);
492}
493
494template <size_t _Ip, class _Tp, size_t _Size>
495inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX14
496const _Tp&&
497get(const array<_Tp, _Size>&& __a) _NOEXCEPT
498{
499    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
500    return _VSTD::move(__a.__elems_[_Ip]);
501}
502
503#if _LIBCPP_STD_VER >= 20
504
505template <typename _Tp, size_t _Size, size_t... _Index>
506_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
507__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
508  return {{__arr[_Index]...}};
509}
510
511template <typename _Tp, size_t _Size, size_t... _Index>
512_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
513__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
514  return {{_VSTD::move(__arr[_Index])...}};
515}
516
517template <typename _Tp, size_t _Size>
518_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
519to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
520  static_assert(
521      !is_array_v<_Tp>,
522      "[array.creation]/1: to_array does not accept multidimensional arrays.");
523  static_assert(
524      is_constructible_v<_Tp, _Tp&>,
525      "[array.creation]/1: to_array requires copy constructible elements.");
526  return _VSTD::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
527}
528
529template <typename _Tp, size_t _Size>
530_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
531to_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
532  static_assert(
533      !is_array_v<_Tp>,
534      "[array.creation]/4: to_array does not accept multidimensional arrays.");
535  static_assert(
536      is_move_constructible_v<_Tp>,
537      "[array.creation]/4: to_array requires move constructible elements.");
538  return _VSTD::__to_array_rvalue_impl(_VSTD::move(__arr),
539                                       make_index_sequence<_Size>());
540}
541
542#endif // _LIBCPP_STD_VER >= 20
543
544_LIBCPP_END_NAMESPACE_STD
545
546#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
547#  include <algorithm>
548#  include <concepts>
549#  include <cstdlib>
550#  include <iterator>
551#  include <type_traits>
552#  include <utility>
553#endif
554
555#endif // _LIBCPP_ARRAY
556