xref: /llvm-project-15.0.7/libcxx/include/array (revision de2ddc8f) 
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 <__tuple>
118#include <__utility/integer_sequence.h>
119#include <__utility/move.h>
120#include <__utility/unreachable.h>
121#include <iterator>
122#include <stdexcept>
123#include <type_traits>
124#include <version>
125
126#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
127#  pragma GCC system_header
128#endif
129
130_LIBCPP_BEGIN_NAMESPACE_STD
131
132template <class _Tp, size_t _Size>
133struct _LIBCPP_TEMPLATE_VIS array
134{
135    // types:
136    typedef array __self;
137    typedef _Tp                                   value_type;
138    typedef value_type&                           reference;
139    typedef const value_type&                     const_reference;
140    typedef value_type*                           iterator;
141    typedef const value_type*                     const_iterator;
142    typedef value_type*                           pointer;
143    typedef const value_type*                     const_pointer;
144    typedef size_t                                size_type;
145    typedef ptrdiff_t                             difference_type;
146    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
147    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
148
149    _Tp __elems_[_Size];
150
151    // No explicit construct/copy/destroy for aggregate type
152    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
153    void fill(const value_type& __u) {
154        _VSTD::fill_n(data(), _Size, __u);
155    }
156
157    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
158    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
159        _VSTD::swap_ranges(data(), data() + _Size, __a.data());
160    }
161
162    // iterators:
163    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
164    iterator begin() _NOEXCEPT {return iterator(data());}
165    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
166    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
167    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
168    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
169    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
170    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
171
172    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
173    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
174    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
175    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
176    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
177    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
178    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
179    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
180
181    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
182    const_iterator cbegin() const _NOEXCEPT {return begin();}
183    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
184    const_iterator cend() const _NOEXCEPT {return end();}
185    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
186    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
187    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
188    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
189
190    // capacity:
191    _LIBCPP_INLINE_VISIBILITY
192    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
193    _LIBCPP_INLINE_VISIBILITY
194    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
195    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
196    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
197
198    // element access:
199    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
200    reference operator[](size_type __n) _NOEXCEPT {
201        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
202        return __elems_[__n];
203    }
204    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
205    const_reference operator[](size_type __n) const _NOEXCEPT {
206        _LIBCPP_ASSERT(__n < _Size, "out-of-bounds access in std::array<T, N>");
207        return __elems_[__n];
208    }
209
210    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
211    {
212        if (__n >= _Size)
213            __throw_out_of_range("array::at");
214        return __elems_[__n];
215    }
216
217    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
218    {
219        if (__n >= _Size)
220            __throw_out_of_range("array::at");
221        return __elems_[__n];
222    }
223
224    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return (*this)[0];}
225    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return (*this)[0];}
226    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return (*this)[_Size - 1];}
227    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return (*this)[_Size - 1];}
228
229    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
230    value_type* data() _NOEXCEPT {return __elems_;}
231    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
232    const value_type* data() const _NOEXCEPT {return __elems_;}
233};
234
235template <class _Tp>
236struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
237{
238    // types:
239    typedef array __self;
240    typedef _Tp                                   value_type;
241    typedef value_type&                           reference;
242    typedef const value_type&                     const_reference;
243    typedef value_type*                           iterator;
244    typedef const value_type*                     const_iterator;
245    typedef value_type*                           pointer;
246    typedef const value_type*                     const_pointer;
247    typedef size_t                                size_type;
248    typedef ptrdiff_t                             difference_type;
249    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
250    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
251
252    typedef typename conditional<is_const<_Tp>::value, const char,
253                                char>::type _CharType;
254
255    struct  _ArrayInStructT { _Tp __data_[1]; };
256    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
257
258    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
259    value_type* data() _NOEXCEPT {return nullptr;}
260    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
261    const value_type* data() const _NOEXCEPT {return nullptr;}
262
263    // No explicit construct/copy/destroy for aggregate type
264    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
265    void fill(const value_type&) {
266      static_assert(!is_const<_Tp>::value,
267                    "cannot fill zero-sized array of type 'const T'");
268    }
269
270    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
271    void swap(array&) _NOEXCEPT {
272      static_assert(!is_const<_Tp>::value,
273                    "cannot swap zero-sized array of type 'const T'");
274    }
275
276    // iterators:
277    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
278    iterator begin() _NOEXCEPT {return iterator(data());}
279    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
280    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
281    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
282    iterator end() _NOEXCEPT {return iterator(data());}
283    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
284    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
285
286    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
287    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
288    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
289    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
290    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
291    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
292    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
293    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
294
295    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
296    const_iterator cbegin() const _NOEXCEPT {return begin();}
297    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
298    const_iterator cend() const _NOEXCEPT {return end();}
299    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
300    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
301    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
302    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
303
304    // capacity:
305    _LIBCPP_INLINE_VISIBILITY
306    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
307    _LIBCPP_INLINE_VISIBILITY
308    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
309    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
310    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
311
312    // element access:
313    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
314    reference operator[](size_type) _NOEXCEPT {
315      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
316      __libcpp_unreachable();
317    }
318
319    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
320    const_reference operator[](size_type) const _NOEXCEPT {
321      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
322      __libcpp_unreachable();
323    }
324
325    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
326    reference at(size_type) {
327      __throw_out_of_range("array<T, 0>::at");
328      __libcpp_unreachable();
329    }
330
331    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
332    const_reference at(size_type) const {
333      __throw_out_of_range("array<T, 0>::at");
334      __libcpp_unreachable();
335    }
336
337    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
338    reference front() _NOEXCEPT {
339      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
340      __libcpp_unreachable();
341    }
342
343    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
344    const_reference front() const _NOEXCEPT {
345      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
346      __libcpp_unreachable();
347    }
348
349    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
350    reference back() _NOEXCEPT {
351      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
352      __libcpp_unreachable();
353    }
354
355    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
356    const_reference back() const _NOEXCEPT {
357      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
358      __libcpp_unreachable();
359    }
360};
361
362
363#if _LIBCPP_STD_VER > 14
364template<class _Tp, class... _Args,
365         class = enable_if_t<__all<_IsSame<_Tp, _Args>::value...>::value>
366         >
367array(_Tp, _Args...)
368  -> array<_Tp, 1 + sizeof...(_Args)>;
369#endif
370
371template <class _Tp, size_t _Size>
372inline _LIBCPP_INLINE_VISIBILITY
373_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
374operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
375{
376    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
377}
378
379template <class _Tp, size_t _Size>
380inline _LIBCPP_INLINE_VISIBILITY
381_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
382operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
383{
384    return !(__x == __y);
385}
386
387template <class _Tp, size_t _Size>
388inline _LIBCPP_INLINE_VISIBILITY
389_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
390operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
391{
392    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
393                                          __y.begin(), __y.end());
394}
395
396template <class _Tp, size_t _Size>
397inline _LIBCPP_INLINE_VISIBILITY
398_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
399operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
400{
401    return __y < __x;
402}
403
404template <class _Tp, size_t _Size>
405inline _LIBCPP_INLINE_VISIBILITY
406_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
407operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
408{
409    return !(__y < __x);
410}
411
412template <class _Tp, size_t _Size>
413inline _LIBCPP_INLINE_VISIBILITY
414_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
415operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
416{
417    return !(__x < __y);
418}
419
420template <class _Tp, size_t _Size>
421inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
422typename enable_if
423<
424    _Size == 0 ||
425    __is_swappable<_Tp>::value,
426    void
427>::type
428swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
429                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
430{
431    __x.swap(__y);
432}
433
434template <class _Tp, size_t _Size>
435struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
436    : public integral_constant<size_t, _Size> {};
437
438template <size_t _Ip, class _Tp, size_t _Size>
439struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
440{
441    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
442    typedef _Tp type;
443};
444
445template <size_t _Ip, class _Tp, size_t _Size>
446inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
447_Tp&
448get(array<_Tp, _Size>& __a) _NOEXCEPT
449{
450    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
451    return __a.__elems_[_Ip];
452}
453
454template <size_t _Ip, class _Tp, size_t _Size>
455inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
456const _Tp&
457get(const array<_Tp, _Size>& __a) _NOEXCEPT
458{
459    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
460    return __a.__elems_[_Ip];
461}
462
463template <size_t _Ip, class _Tp, size_t _Size>
464inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
465_Tp&&
466get(array<_Tp, _Size>&& __a) _NOEXCEPT
467{
468    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
469    return _VSTD::move(__a.__elems_[_Ip]);
470}
471
472template <size_t _Ip, class _Tp, size_t _Size>
473inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
474const _Tp&&
475get(const array<_Tp, _Size>&& __a) _NOEXCEPT
476{
477    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
478    return _VSTD::move(__a.__elems_[_Ip]);
479}
480
481#if _LIBCPP_STD_VER > 17
482
483template <typename _Tp, size_t _Size, size_t... _Index>
484_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
485__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
486  return {{__arr[_Index]...}};
487}
488
489template <typename _Tp, size_t _Size, size_t... _Index>
490_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
491__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
492  return {{_VSTD::move(__arr[_Index])...}};
493}
494
495template <typename _Tp, size_t _Size>
496_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
497to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
498  static_assert(
499      !is_array_v<_Tp>,
500      "[array.creation]/1: to_array does not accept multidimensional arrays.");
501  static_assert(
502      is_constructible_v<_Tp, _Tp&>,
503      "[array.creation]/1: to_array requires copy constructible elements.");
504  return _VSTD::__to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
505}
506
507template <typename _Tp, size_t _Size>
508_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
509to_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
510  static_assert(
511      !is_array_v<_Tp>,
512      "[array.creation]/4: to_array does not accept multidimensional arrays.");
513  static_assert(
514      is_move_constructible_v<_Tp>,
515      "[array.creation]/4: to_array requires move constructible elements.");
516  return _VSTD::__to_array_rvalue_impl(_VSTD::move(__arr),
517                                       make_index_sequence<_Size>());
518}
519
520#endif // _LIBCPP_STD_VER > 17
521
522_LIBCPP_END_NAMESPACE_STD
523
524#endif // _LIBCPP_ARRAY
525