xref: /llvm-project-15.0.7/libcxx/include/array (revision 83bd2c4a) 
1// -*- C++ -*-
2//===---------------------------- array -----------------------------------===//
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);
36    void swap(array& a) noexcept(is_nothrow_swappable_v<T>);
37
38    // iterators:
39    iterator begin() noexcept;
40    const_iterator begin() const noexcept;
41    iterator end() noexcept;
42    const_iterator end() const noexcept;
43
44    reverse_iterator rbegin() noexcept;
45    const_reverse_iterator rbegin() const noexcept;
46    reverse_iterator rend() noexcept;
47    const_reverse_iterator rend() const noexcept;
48
49    const_iterator cbegin() const noexcept;
50    const_iterator cend() const noexcept;
51    const_reverse_iterator crbegin() const noexcept;
52    const_reverse_iterator crend() const noexcept;
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);
61    const_reference operator[](size_type n) const; // constexpr in C++14
62    const_reference at(size_type n) const; // constexpr in C++14
63    reference at(size_type n);
64
65    reference front();
66    const_reference front() const; // constexpr in C++14
67    reference back();
68    const_reference back() const; // constexpr in C++14
69
70    T* data() noexcept;
71    const T* data() const noexcept;
72};
73
74  template <class T, class... U>
75    array(T, U...) -> array<T, 1 + sizeof...(U)>;
76
77template <class T, size_t N>
78  bool operator==(const array<T,N>& x, const array<T,N>& y);
79template <class T, size_t N>
80  bool operator!=(const array<T,N>& x, const array<T,N>& y);
81template <class T, size_t N>
82  bool operator<(const array<T,N>& x, const array<T,N>& y);
83template <class T, size_t N>
84  bool operator>(const array<T,N>& x, const array<T,N>& y);
85template <class T, size_t N>
86  bool operator<=(const array<T,N>& x, const array<T,N>& y);
87template <class T, size_t N>
88  bool operator>=(const array<T,N>& x, const array<T,N>& y);
89
90template <class T, size_t N >
91  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // C++17
92
93template <class T> struct tuple_size;
94template <size_t I, class T> struct tuple_element;
95template <class T, size_t N> struct tuple_size<array<T, N>>;
96template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
97template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
98template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept; // constexpr in C++14
99template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept; // constexpr in C++14
100template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
101
102}  // std
103
104*/
105
106#include <__config>
107#include <__tuple>
108#include <type_traits>
109#include <utility>
110#include <iterator>
111#include <algorithm>
112#include <stdexcept>
113#include <cstdlib> // for _LIBCPP_UNREACHABLE
114#include <version>
115#include <__debug>
116
117#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
118#pragma GCC system_header
119#endif
120
121
122
123_LIBCPP_BEGIN_NAMESPACE_STD
124
125
126template <class _Tp, size_t _Size>
127struct _LIBCPP_TEMPLATE_VIS array
128{
129    // types:
130    typedef array __self;
131    typedef _Tp                                   value_type;
132    typedef value_type&                           reference;
133    typedef const value_type&                     const_reference;
134    typedef value_type*                           iterator;
135    typedef const value_type*                     const_iterator;
136    typedef value_type*                           pointer;
137    typedef const value_type*                     const_pointer;
138    typedef size_t                                size_type;
139    typedef ptrdiff_t                             difference_type;
140    typedef std::reverse_iterator<iterator>       reverse_iterator;
141    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
142
143    _Tp __elems_[_Size];
144
145    // No explicit construct/copy/destroy for aggregate type
146    _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __u) {
147      _VSTD::fill_n(__elems_, _Size, __u);
148    }
149
150    _LIBCPP_INLINE_VISIBILITY
151    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
152      std::swap_ranges(__elems_, __elems_ + _Size, __a.__elems_);
153    }
154
155    // iterators:
156    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
157    iterator begin() _NOEXCEPT {return iterator(data());}
158    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
159    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
160    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
161    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
162    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
163    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
164
165    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
166    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
167    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
168    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
169    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
170    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
171    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
172    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
173
174    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
175    const_iterator cbegin() const _NOEXCEPT {return begin();}
176    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
177    const_iterator cend() const _NOEXCEPT {return end();}
178    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
179    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
180    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
181    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
182
183    // capacity:
184    _LIBCPP_INLINE_VISIBILITY
185    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
186    _LIBCPP_INLINE_VISIBILITY
187    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
188    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
189    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return false; }
190
191    // element access:
192    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
193    reference operator[](size_type __n)             _NOEXCEPT {return __elems_[__n];}
194    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
195    const_reference operator[](size_type __n) const _NOEXCEPT {return __elems_[__n];}
196
197    _LIBCPP_CONSTEXPR_AFTER_CXX14 reference at(size_type __n)
198    {
199        if (__n >= _Size)
200            __throw_out_of_range("array::at");
201        return __elems_[__n];
202    }
203
204    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const
205    {
206        if (__n >= _Size)
207            __throw_out_of_range("array::at");
208        return __elems_[__n];
209    }
210
211    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return __elems_[0];}
212    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return __elems_[0];}
213    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return __elems_[_Size - 1];}
214    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return __elems_[_Size - 1];}
215
216    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
217    value_type* data() _NOEXCEPT {return __elems_;}
218    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
219    const value_type* data() const _NOEXCEPT {return __elems_;}
220};
221
222template <class _Tp>
223struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
224{
225    // types:
226    typedef array __self;
227    typedef _Tp                                   value_type;
228    typedef value_type&                           reference;
229    typedef const value_type&                     const_reference;
230    typedef value_type*                           iterator;
231    typedef const value_type*                     const_iterator;
232    typedef value_type*                           pointer;
233    typedef const value_type*                     const_pointer;
234    typedef size_t                                size_type;
235    typedef ptrdiff_t                             difference_type;
236    typedef std::reverse_iterator<iterator>       reverse_iterator;
237    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
238
239    typedef typename conditional<is_const<_Tp>::value, const char,
240                                char>::type _CharType;
241
242    struct  _ArrayInStructT { _Tp __data_[1]; };
243    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
244
245    // No explicit construct/copy/destroy for aggregate type
246    _LIBCPP_INLINE_VISIBILITY void fill(const value_type&) {
247      static_assert(!is_const<_Tp>::value,
248                    "cannot fill zero-sized array of type 'const T'");
249    }
250
251    _LIBCPP_INLINE_VISIBILITY
252    void swap(array&) _NOEXCEPT {
253      static_assert(!is_const<_Tp>::value,
254                    "cannot swap zero-sized array of type 'const T'");
255    }
256
257    // iterators:
258    _LIBCPP_INLINE_VISIBILITY
259    iterator begin() _NOEXCEPT {return iterator(data());}
260    _LIBCPP_INLINE_VISIBILITY
261    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
262    _LIBCPP_INLINE_VISIBILITY
263    iterator end() _NOEXCEPT {return iterator(data());}
264    _LIBCPP_INLINE_VISIBILITY
265    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
266
267    _LIBCPP_INLINE_VISIBILITY
268    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
269    _LIBCPP_INLINE_VISIBILITY
270    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
271    _LIBCPP_INLINE_VISIBILITY
272    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
273    _LIBCPP_INLINE_VISIBILITY
274    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
275
276    _LIBCPP_INLINE_VISIBILITY
277    const_iterator cbegin() const _NOEXCEPT {return begin();}
278    _LIBCPP_INLINE_VISIBILITY
279    const_iterator cend() const _NOEXCEPT {return end();}
280    _LIBCPP_INLINE_VISIBILITY
281    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
282    _LIBCPP_INLINE_VISIBILITY
283    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
284
285    // capacity:
286    _LIBCPP_INLINE_VISIBILITY
287    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
288    _LIBCPP_INLINE_VISIBILITY
289    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
290    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
291    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
292
293    // element access:
294    _LIBCPP_INLINE_VISIBILITY
295    reference operator[](size_type) _NOEXCEPT {
296      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
297      _LIBCPP_UNREACHABLE();
298    }
299
300    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
301    const_reference operator[](size_type) const _NOEXCEPT {
302      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
303      _LIBCPP_UNREACHABLE();
304    }
305
306    _LIBCPP_INLINE_VISIBILITY
307    reference at(size_type) {
308      __throw_out_of_range("array<T, 0>::at");
309      _LIBCPP_UNREACHABLE();
310    }
311
312    _LIBCPP_INLINE_VISIBILITY
313    const_reference at(size_type) const {
314      __throw_out_of_range("array<T, 0>::at");
315      _LIBCPP_UNREACHABLE();
316    }
317
318    _LIBCPP_INLINE_VISIBILITY
319    reference front() _NOEXCEPT {
320      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
321      _LIBCPP_UNREACHABLE();
322    }
323
324    _LIBCPP_INLINE_VISIBILITY
325    const_reference front() const _NOEXCEPT {
326      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
327      _LIBCPP_UNREACHABLE();
328    }
329
330    _LIBCPP_INLINE_VISIBILITY
331    reference back() _NOEXCEPT {
332      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
333      _LIBCPP_UNREACHABLE();
334    }
335
336    _LIBCPP_INLINE_VISIBILITY
337    const_reference back() const _NOEXCEPT {
338      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
339      _LIBCPP_UNREACHABLE();
340    }
341
342    _LIBCPP_INLINE_VISIBILITY
343    value_type* data() _NOEXCEPT {return reinterpret_cast<value_type*>(__elems_);}
344    _LIBCPP_INLINE_VISIBILITY
345    const value_type* data() const _NOEXCEPT {return reinterpret_cast<const value_type*>(__elems_);}
346};
347
348
349#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
350template<class _Tp, class... _Args,
351         class = _EnableIf<__all<_IsSame<_Tp, _Args>::value...>::value>
352         >
353array(_Tp, _Args...)
354  -> array<_Tp, 1 + sizeof...(_Args)>;
355#endif
356
357template <class _Tp, size_t _Size>
358inline _LIBCPP_INLINE_VISIBILITY
359_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
360operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
361{
362    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
363}
364
365template <class _Tp, size_t _Size>
366inline _LIBCPP_INLINE_VISIBILITY
367_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
368operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
369{
370    return !(__x == __y);
371}
372
373template <class _Tp, size_t _Size>
374inline _LIBCPP_INLINE_VISIBILITY
375_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
376operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
377{
378    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
379                                          __y.begin(), __y.end());
380}
381
382template <class _Tp, size_t _Size>
383inline _LIBCPP_INLINE_VISIBILITY
384_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
385operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
386{
387    return __y < __x;
388}
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 !(__y < __x);
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
408typename enable_if
409<
410    _Size == 0 ||
411    __is_swappable<_Tp>::value,
412    void
413>::type
414swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
415                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
416{
417    __x.swap(__y);
418}
419
420template <class _Tp, size_t _Size>
421struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
422    : public integral_constant<size_t, _Size> {};
423
424template <size_t _Ip, class _Tp, size_t _Size>
425struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
426{
427    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
428    typedef _Tp type;
429};
430
431template <size_t _Ip, class _Tp, size_t _Size>
432inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
433_Tp&
434get(array<_Tp, _Size>& __a) _NOEXCEPT
435{
436    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
437    return __a.__elems_[_Ip];
438}
439
440template <size_t _Ip, class _Tp, size_t _Size>
441inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
442const _Tp&
443get(const array<_Tp, _Size>& __a) _NOEXCEPT
444{
445    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
446    return __a.__elems_[_Ip];
447}
448
449#ifndef _LIBCPP_CXX03_LANG
450
451template <size_t _Ip, class _Tp, size_t _Size>
452inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
453_Tp&&
454get(array<_Tp, _Size>&& __a) _NOEXCEPT
455{
456    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
457    return _VSTD::move(__a.__elems_[_Ip]);
458}
459
460template <size_t _Ip, class _Tp, size_t _Size>
461inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
462const _Tp&&
463get(const array<_Tp, _Size>&& __a) _NOEXCEPT
464{
465    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
466    return _VSTD::move(__a.__elems_[_Ip]);
467}
468
469#endif  // !_LIBCPP_CXX03_LANG
470
471#if _LIBCPP_STD_VER > 17
472
473template <typename _Tp, size_t _Size, size_t... _Index>
474_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
475__to_array_lvalue_impl(_Tp (&__arr)[_Size], index_sequence<_Index...>) {
476  return {{__arr[_Index]...}};
477}
478
479template <typename _Tp, size_t _Size, size_t... _Index>
480_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
481__to_array_rvalue_impl(_Tp(&&__arr)[_Size], index_sequence<_Index...>) {
482  return {{_VSTD::move(__arr[_Index])...}};
483}
484
485template <typename _Tp, size_t _Size>
486_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
487to_array(_Tp (&__arr)[_Size]) noexcept(is_nothrow_constructible_v<_Tp, _Tp&>) {
488  static_assert(
489      !is_array_v<_Tp>,
490      "[array.creation]/1: to_array does not accept multidimensional arrays.");
491  static_assert(
492      is_constructible_v<_Tp, _Tp&>,
493      "[array.creation]/1: to_array requires copy constructible elements.");
494  return __to_array_lvalue_impl(__arr, make_index_sequence<_Size>());
495}
496
497template <typename _Tp, size_t _Size>
498_LIBCPP_INLINE_VISIBILITY constexpr array<remove_cv_t<_Tp>, _Size>
499to_array(_Tp(&&__arr)[_Size]) noexcept(is_nothrow_move_constructible_v<_Tp>) {
500  static_assert(
501      !is_array_v<_Tp>,
502      "[array.creation]/4: to_array does not accept multidimensional arrays.");
503  static_assert(
504      is_move_constructible_v<_Tp>,
505      "[array.creation]/4: to_array requires move constructible elements.");
506  return __to_array_rvalue_impl(_VSTD::move(__arr),
507                                make_index_sequence<_Size>());
508}
509
510#endif // _LIBCPP_STD_VER > 17
511
512_LIBCPP_END_NAMESPACE_STD
513
514#endif  // _LIBCPP_ARRAY
515