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);    // constexpr in C++20
81template <class T, size_t N>
82  bool operator<(const array<T,N>& x, const array<T,N>& y);     // constexpr in C++20
83template <class T, size_t N>
84  bool operator>(const array<T,N>& x, const array<T,N>& y);     // constexpr in C++20
85template <class T, size_t N>
86  bool operator<=(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
87template <class T, size_t N>
88  bool operator>=(const array<T,N>& x, const array<T,N>& y);    // constexpr in C++20
89
90template <class T, size_t N >
91  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // constexpr in C++20
92
93template <class T, size_t N>
94  constexpr array<remove_cv_t<T>, N> to_array(T (&a)[N]);  // C++20
95template <class T, size_t N>
96  constexpr array<remove_cv_t<T>, N> to_array(T (&&a)[N]); // C++20
97
98template <class T> struct tuple_size;
99template <size_t I, class T> struct tuple_element;
100template <class T, size_t N> struct tuple_size<array<T, N>>;
101template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
102template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept;               // constexpr in C++14
103template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept;   // constexpr in C++14
104template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept;             // constexpr in C++14
105template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
106
107}  // std
108
109*/
110
111#include <__algorithm/equal.h>
112#include <__algorithm/fill_n.h>
113#include <__algorithm/lexicographical_compare.h>
114#include <__algorithm/swap_ranges.h>
115#include <__assert> // all public C++ headers provide the assertion handler
116#include <__config>
117#include <__iterator/reverse_iterator.h>
118#include <__tuple>
119#include <__utility/integer_sequence.h>
120#include <__utility/move.h>
121#include <__utility/unreachable.h>
122#include <stdexcept>
123#include <type_traits>
124#include <version>
125
126#ifndef _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
127#  include <algorithm>
128#  include <iterator>
129#  include <utility>
130#endif
131
132// standard-mandated includes
133
134// [iterator.range]
135#include <__iterator/access.h>
136#include <__iterator/data.h>
137#include <__iterator/empty.h>
138#include <__iterator/reverse_access.h>
139#include <__iterator/size.h>
140
141// [array.syn]
142#include <compare>
143#include <initializer_list>
144
145#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
146#  pragma GCC system_header
147#endif
148
149_LIBCPP_BEGIN_NAMESPACE_STD
150
151template <class _Tp, size_t _Size>
152struct _LIBCPP_TEMPLATE_VIS array
153{
154    // types:
155    typedef array __self;
156    typedef _Tp                                   value_type;
157    typedef value_type&                           reference;
158    typedef const value_type&                     const_reference;
159    typedef value_type*                           iterator;
160    typedef const value_type*                     const_iterator;
161    typedef value_type*                           pointer;
162    typedef const value_type*                     const_pointer;
163    typedef size_t                                size_type;
164    typedef ptrdiff_t                             difference_type;
165    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
166    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
167
168    _Tp __elems_[_Size];
169
170    // No explicit construct/copy/destroy for aggregate type
171    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
172    void fill(const value_type& __u) {
173        _VSTD::fill_n(data(), _Size, __u);
174    }
175
176    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
177    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
178        _VSTD::swap_ranges(data(), data() + _Size, __a.data());
179    }
180
181    // iterators:
182    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
183    iterator begin() _NOEXCEPT {return iterator(data());}
184    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
185    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
186    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
187    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
188    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
189    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
190
191    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
192    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
193    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
194    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
195    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
196    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
197    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
198    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
199
200    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
201    const_iterator cbegin() const _NOEXCEPT {return begin();}
202    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
203    const_iterator cend() const _NOEXCEPT {return end();}
204    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
205    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
206    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
207    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
208
209    // capacity:
210    _LIBCPP_INLINE_VISIBILITY
211    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
212    _LIBCPP_INLINE_VISIBILITY
213    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
214    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
215    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
216
217    // element access:
218    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
219    reference operator[](size_type __n) _NOEXCEPT {
220        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
221        return __elems_[__n];
222    }
223    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
224    const_reference operator[](size_type __n) const _NOEXCEPT {
225        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
226        return __elems_[__n];
227    }
228
229    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
230    {
231        if (__n >= _Size)
232            __throw_out_of_range("array::at");
233        return __elems_[__n];
234    }
235
236    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
237    {
238        if (__n >= _Size)
239            __throw_out_of_range("array::at");
240        return __elems_[__n];
241    }
242
243    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return (*this)[0];}
244    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return (*this)[0];}
245    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
246    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
247
248    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
249    value_type* data() _NOEXCEPT {return __elems_;}
250    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
251    const value_type* data() const _NOEXCEPT {return __elems_;}
252};
253
254template <class _Tp>
255struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
256{
257    // types:
258    typedef array __self;
259    typedef _Tp                                   value_type;
260    typedef value_type&                           reference;
261    typedef const value_type&                     const_reference;
262    typedef value_type*                           iterator;
263    typedef const value_type*                     const_iterator;
264    typedef value_type*                           pointer;
265    typedef const value_type*                     const_pointer;
266    typedef size_t                                size_type;
267    typedef ptrdiff_t                             difference_type;
268    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
269    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
270
271    typedef typename conditional<is_const<_Tp>::value, const char,
272                                char>::type _CharType;
273
274    struct  _ArrayInStructT { _Tp __data_[1]; };
275    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
276
277    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
278    value_type* data() _NOEXCEPT {return nullptr;}
279    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
280    const value_type* data() const _NOEXCEPT {return nullptr;}
281
282    // No explicit construct/copy/destroy for aggregate type
283    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
284    void fill(const value_type&) {
285      static_assert(!is_const<_Tp>::value,
286                    "cannot fill zero-sized array of type 'const T'");
287    }
288
289    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
290    void swap(array&) _NOEXCEPT {
291      static_assert(!is_const<_Tp>::value,
292                    "cannot swap zero-sized array of type 'const T'");
293    }
294
295    // iterators:
296    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
297    iterator begin() _NOEXCEPT {return iterator(data());}
298    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
299    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
300    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
301    iterator end() _NOEXCEPT {return iterator(data());}
302    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
303    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
304
305    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
306    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
307    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
308    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
309    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
310    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
311    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
312    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
313
314    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
315    const_iterator cbegin() const _NOEXCEPT {return begin();}
316    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
317    const_iterator cend() const _NOEXCEPT {return end();}
318    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
319    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
320    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
321    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
322
323    // capacity:
324    _LIBCPP_INLINE_VISIBILITY
325    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
326    _LIBCPP_INLINE_VISIBILITY
327    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
328    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
329    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
330
331    // element access:
332    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
333    reference operator[](size_type) _NOEXCEPT {
334      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
335      __libcpp_unreachable();
336    }
337
338    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
339    const_reference operator[](size_type) const _NOEXCEPT {
340      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
341      __libcpp_unreachable();
342    }
343
344    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
345    reference at(size_type) {
346      __throw_out_of_range("array<T, 0>::at");
347      __libcpp_unreachable();
348    }
349
350    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
351    const_reference at(size_type) const {
352      __throw_out_of_range("array<T, 0>::at");
353      __libcpp_unreachable();
354    }
355
356    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
357    reference front() _NOEXCEPT {
358      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
359      __libcpp_unreachable();
360    }
361
362    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
363    const_reference front() const _NOEXCEPT {
364      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
365      __libcpp_unreachable();
366    }
367
368    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
369    reference back() _NOEXCEPT {
370      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
371      __libcpp_unreachable();
372    }
373
374    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
375    const_reference back() const _NOEXCEPT {
376      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
377      __libcpp_unreachable();
378    }
379};
380
381
382#if _LIBCPP_STD_VER > 14
383template<class _Tp, class... _Args,
384         class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value>
385         >
386array(_Tp, _Args...)
387  -> array<_Tp, 1 + sizeof...(_Args)>;
388#endif
389
390template <class _Tp, size_t _Size>
391inline _LIBCPP_INLINE_VISIBILITY
392_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
393operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
394{
395    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
396}
397
398template <class _Tp, size_t _Size>
399inline _LIBCPP_INLINE_VISIBILITY
400_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
401operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
402{
403    return !(__x == __y);
404}
405
406template <class _Tp, size_t _Size>
407inline _LIBCPP_INLINE_VISIBILITY
408_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
409operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
410{
411    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
412                                          __y.begin(), __y.end());
413}
414
415template <class _Tp, size_t _Size>
416inline _LIBCPP_INLINE_VISIBILITY
417_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
418operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
419{
420    return __y < __x;
421}
422
423template <class _Tp, size_t _Size>
424inline _LIBCPP_INLINE_VISIBILITY
425_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
426operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
427{
428    return !(__y < __x);
429}
430
431template <class _Tp, size_t _Size>
432inline _LIBCPP_INLINE_VISIBILITY
433_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
434operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
435{
436    return !(__x < __y);
437}
438
439template <class _Tp, size_t _Size>
440inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
441__enable_if_t<_Size == 0 || __is_swappable<_Tp>::value, void>
442swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
443                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
444{
445    __x.swap(__y);
446}
447
448template <class _Tp, size_t _Size>
449struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
450    : public integral_constant<size_t, _Size> {};
451
452template <size_t _Ip, class _Tp, size_t _Size>
453struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
454{
455    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
456    typedef _Tp type;
457};
458
459template <size_t _Ip, class _Tp, size_t _Size>
460inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
461_Tp&
462get(array<_Tp, _Size>& __a) _NOEXCEPT
463{
464    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
465    return __a.__elems_[_Ip];
466}
467
468template <size_t _Ip, class _Tp, size_t _Size>
469inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
470const _Tp&
471get(const array<_Tp, _Size>& __a) _NOEXCEPT
472{
473    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
474    return __a.__elems_[_Ip];
475}
476
477template <size_t _Ip, class _Tp, size_t _Size>
478inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
479_Tp&&
480get(array<_Tp, _Size>&& __a) _NOEXCEPT
481{
482    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
483    return _VSTD::move(__a.__elems_[_Ip]);
484}
485
486template <size_t _Ip, class _Tp, size_t _Size>
487inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
488const _Tp&&
489get(const array<_Tp, _Size>&& __a) _NOEXCEPT
490{
491    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
492    return _VSTD::move(__a.__elems_[_Ip]);
493}
494
495#if _LIBCPP_STD_VER > 17
496
497template <typename _Tp, size_t _Size, size_t... _Index>
498_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
499__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
500  return {{__arr[_Index]...}};
501}
502
503template <typename _Tp, size_t _Size, size_t... _Index>
504_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
505__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
506  return {{_VSTD::move(__arr[_Index])...}};
507}
508
509template <typename _Tp, size_t _Size>
510_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
511to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
512  static_assert(
513      !is_array_v<_Tp>,
514      "[array.creation]/1: to_array does not accept multidimensional arrays.");
515  static_assert(
516      is_constructible_v<_Tp, _Tp&>,
517      "[array.creation]/1: to_array requires copy constructible elements.");
518  return _VSTD::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
519}
520
521template <typename _Tp, size_t _Size>
522_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
523to_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
524  static_assert(
525      !is_array_v<_Tp>,
526      "[array.creation]/4: to_array does not accept multidimensional arrays.");
527  static_assert(
528      is_move_constructible_v<_Tp>,
529      "[array.creation]/4: to_array requires move constructible elements.");
530  return _VSTD::__to_array_rvalue_impl(_VSTD::move(__arr),
531                                       make_index_sequence<_Size>());
532}
533
534#endif // _LIBCPP_STD_VER > 17
535
536_LIBCPP_END_NAMESPACE_STD
537
538#endif // _LIBCPP_ARRAY
539