xref: /llvm-project-15.0.7/libcxx/include/array (revision 8b68da2c) 
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// standard-mandated includes
127
128// [iterator.range]
129#include <__iterator/access.h>
130#include <__iterator/data.h>
131#include <__iterator/empty.h>
132#include <__iterator/reverse_access.h>
133#include <__iterator/size.h>
134
135// [array.syn]
136#include <compare>
137#include <initializer_list>
138
139#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
140#  pragma GCC system_header
141#endif
142
143_LIBCPP_BEGIN_NAMESPACE_STD
144
145template <class _Tp, size_t _Size>
146struct _LIBCPP_TEMPLATE_VIS array
147{
148    // types:
149    typedef array __self;
150    typedef _Tp                                   value_type;
151    typedef value_type&                           reference;
152    typedef const value_type&                     const_reference;
153    typedef value_type*                           iterator;
154    typedef const value_type*                     const_iterator;
155    typedef value_type*                           pointer;
156    typedef const value_type*                     const_pointer;
157    typedef size_t                                size_type;
158    typedef ptrdiff_t                             difference_type;
159    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
160    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
161
162    _Tp __elems_[_Size];
163
164    // No explicit construct/copy/destroy for aggregate type
165    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
166    void fill(const value_type& __u) {
167        _VSTD::fill_n(data(), _Size, __u);
168    }
169
170    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
171    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
172        _VSTD::swap_ranges(data(), data() + _Size, __a.data());
173    }
174
175    // iterators:
176    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
177    iterator begin() _NOEXCEPT {return iterator(data());}
178    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
179    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
180    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
181    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
182    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
183    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
184
185    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
186    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
187    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
188    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
189    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
190    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
191    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
192    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
193
194    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
195    const_iterator cbegin() const _NOEXCEPT {return begin();}
196    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
197    const_iterator cend() const _NOEXCEPT {return end();}
198    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
199    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
200    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
201    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
202
203    // capacity:
204    _LIBCPP_INLINE_VISIBILITY
205    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
206    _LIBCPP_INLINE_VISIBILITY
207    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
208    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
209    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
210
211    // element access:
212    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
213    reference operator[](size_type __n) _NOEXCEPT {
214        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
215        return __elems_[__n];
216    }
217    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
218    const_reference operator[](size_type __n) const _NOEXCEPT {
219        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
220        return __elems_[__n];
221    }
222
223    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
224    {
225        if (__n >= _Size)
226            __throw_out_of_range("array::at");
227        return __elems_[__n];
228    }
229
230    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
231    {
232        if (__n >= _Size)
233            __throw_out_of_range("array::at");
234        return __elems_[__n];
235    }
236
237    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return (*this)[0];}
238    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return (*this)[0];}
239    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
240    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
241
242    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
243    value_type* data() _NOEXCEPT {return __elems_;}
244    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
245    const value_type* data() const _NOEXCEPT {return __elems_;}
246};
247
248template <class _Tp>
249struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
250{
251    // types:
252    typedef array __self;
253    typedef _Tp                                   value_type;
254    typedef value_type&                           reference;
255    typedef const value_type&                     const_reference;
256    typedef value_type*                           iterator;
257    typedef const value_type*                     const_iterator;
258    typedef value_type*                           pointer;
259    typedef const value_type*                     const_pointer;
260    typedef size_t                                size_type;
261    typedef ptrdiff_t                             difference_type;
262    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
263    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
264
265    typedef typename conditional<is_const<_Tp>::value, const char,
266                                char>::type _CharType;
267
268    struct  _ArrayInStructT { _Tp __data_[1]; };
269    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
270
271    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
272    value_type* data() _NOEXCEPT {return nullptr;}
273    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
274    const value_type* data() const _NOEXCEPT {return nullptr;}
275
276    // No explicit construct/copy/destroy for aggregate type
277    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
278    void fill(const value_type&) {
279      static_assert(!is_const<_Tp>::value,
280                    "cannot fill zero-sized array of type 'const T'");
281    }
282
283    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
284    void swap(array&) _NOEXCEPT {
285      static_assert(!is_const<_Tp>::value,
286                    "cannot swap zero-sized array of type 'const T'");
287    }
288
289    // iterators:
290    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
291    iterator begin() _NOEXCEPT {return iterator(data());}
292    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
293    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
294    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
295    iterator end() _NOEXCEPT {return iterator(data());}
296    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
297    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
298
299    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
300    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
301    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
302    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
303    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
304    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
305    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
306    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
307
308    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
309    const_iterator cbegin() const _NOEXCEPT {return begin();}
310    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
311    const_iterator cend() const _NOEXCEPT {return end();}
312    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
313    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
314    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
315    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
316
317    // capacity:
318    _LIBCPP_INLINE_VISIBILITY
319    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
320    _LIBCPP_INLINE_VISIBILITY
321    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
322    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
323    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
324
325    // element access:
326    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
327    reference operator[](size_type) _NOEXCEPT {
328      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
329      __libcpp_unreachable();
330    }
331
332    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
333    const_reference operator[](size_type) const _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_CXX14
339    reference at(size_type) {
340      __throw_out_of_range("array<T, 0>::at");
341      __libcpp_unreachable();
342    }
343
344    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
345    const_reference at(size_type) const {
346      __throw_out_of_range("array<T, 0>::at");
347      __libcpp_unreachable();
348    }
349
350    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
351    reference front() _NOEXCEPT {
352      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
353      __libcpp_unreachable();
354    }
355
356    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
357    const_reference front() const _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_CXX14
363    reference back() _NOEXCEPT {
364      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
365      __libcpp_unreachable();
366    }
367
368    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
369    const_reference back() const _NOEXCEPT {
370      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
371      __libcpp_unreachable();
372    }
373};
374
375
376#if _LIBCPP_STD_VER > 14
377template<class _Tp, class... _Args,
378         class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value>
379         >
380array(_Tp, _Args...)
381  -> array<_Tp, 1 + sizeof...(_Args)>;
382#endif
383
384template <class _Tp, size_t _Size>
385inline _LIBCPP_INLINE_VISIBILITY
386_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
387operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
388{
389    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
390}
391
392template <class _Tp, size_t _Size>
393inline _LIBCPP_INLINE_VISIBILITY
394_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
395operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
396{
397    return !(__x == __y);
398}
399
400template <class _Tp, size_t _Size>
401inline _LIBCPP_INLINE_VISIBILITY
402_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
403operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
404{
405    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
406                                          __y.begin(), __y.end());
407}
408
409template <class _Tp, size_t _Size>
410inline _LIBCPP_INLINE_VISIBILITY
411_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
412operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
413{
414    return __y < __x;
415}
416
417template <class _Tp, size_t _Size>
418inline _LIBCPP_INLINE_VISIBILITY
419_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
420operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
421{
422    return !(__y < __x);
423}
424
425template <class _Tp, size_t _Size>
426inline _LIBCPP_INLINE_VISIBILITY
427_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
428operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
429{
430    return !(__x < __y);
431}
432
433template <class _Tp, size_t _Size>
434inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
435typename enable_if
436<
437    _Size == 0 ||
438    __is_swappable<_Tp>::value,
439    void
440>::type
441swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
442                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
443{
444    __x.swap(__y);
445}
446
447template <class _Tp, size_t _Size>
448struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
449    : public integral_constant<size_t, _Size> {};
450
451template <size_t _Ip, class _Tp, size_t _Size>
452struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
453{
454    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
455    typedef _Tp type;
456};
457
458template <size_t _Ip, class _Tp, size_t _Size>
459inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
460_Tp&
461get(array<_Tp, _Size>& __a) _NOEXCEPT
462{
463    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
464    return __a.__elems_[_Ip];
465}
466
467template <size_t _Ip, class _Tp, size_t _Size>
468inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
469const _Tp&
470get(const array<_Tp, _Size>& __a) _NOEXCEPT
471{
472    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
473    return __a.__elems_[_Ip];
474}
475
476template <size_t _Ip, class _Tp, size_t _Size>
477inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
478_Tp&&
479get(array<_Tp, _Size>&& __a) _NOEXCEPT
480{
481    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
482    return _VSTD::move(__a.__elems_[_Ip]);
483}
484
485template <size_t _Ip, class _Tp, size_t _Size>
486inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
487const _Tp&&
488get(const array<_Tp, _Size>&& __a) _NOEXCEPT
489{
490    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
491    return _VSTD::move(__a.__elems_[_Ip]);
492}
493
494#if _LIBCPP_STD_VER > 17
495
496template <typename _Tp, size_t _Size, size_t... _Index>
497_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
498__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
499  return {{__arr[_Index]...}};
500}
501
502template <typename _Tp, size_t _Size, size_t... _Index>
503_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
504__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
505  return {{_VSTD::move(__arr[_Index])...}};
506}
507
508template <typename _Tp, size_t _Size>
509_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
510to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
511  static_assert(
512      !is_array_v<_Tp>,
513      "[array.creation]/1: to_array does not accept multidimensional arrays.");
514  static_assert(
515      is_constructible_v<_Tp, _Tp&>,
516      "[array.creation]/1: to_array requires copy constructible elements.");
517  return _VSTD::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
518}
519
520template <typename _Tp, size_t _Size>
521_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
522to_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
523  static_assert(
524      !is_array_v<_Tp>,
525      "[array.creation]/4: to_array does not accept multidimensional arrays.");
526  static_assert(
527      is_move_constructible_v<_Tp>,
528      "[array.creation]/4: to_array requires move constructible elements.");
529  return _VSTD::__to_array_rvalue_impl(_VSTD::move(__arr),
530                                       make_index_sequence<_Size>());
531}
532
533#endif // _LIBCPP_STD_VER > 17
534
535_LIBCPP_END_NAMESPACE_STD
536
537#endif // _LIBCPP_ARRAY
538