array revision 363496 
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    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const;
199
200    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             _NOEXCEPT {return __elems_[0];}
201    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const _NOEXCEPT {return __elems_[0];}
202    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              _NOEXCEPT {return __elems_[_Size - 1];}
203    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  _NOEXCEPT {return __elems_[_Size - 1];}
204
205    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
206    value_type* data() _NOEXCEPT {return __elems_;}
207    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
208    const value_type* data() const _NOEXCEPT {return __elems_;}
209};
210
211
212template <class _Tp, size_t _Size>
213_LIBCPP_CONSTEXPR_AFTER_CXX14
214typename array<_Tp, _Size>::reference
215array<_Tp, _Size>::at(size_type __n)
216{
217    if (__n >= _Size)
218        __throw_out_of_range("array::at");
219
220    return __elems_[__n];
221}
222
223template <class _Tp, size_t _Size>
224_LIBCPP_CONSTEXPR_AFTER_CXX11
225typename array<_Tp, _Size>::const_reference
226array<_Tp, _Size>::at(size_type __n) const
227{
228    if (__n >= _Size)
229        __throw_out_of_range("array::at");
230    return __elems_[__n];
231}
232
233template <class _Tp>
234struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
235{
236    // types:
237    typedef array __self;
238    typedef _Tp                                   value_type;
239    typedef value_type&                           reference;
240    typedef const value_type&                     const_reference;
241    typedef value_type*                           iterator;
242    typedef const value_type*                     const_iterator;
243    typedef value_type*                           pointer;
244    typedef const value_type*                     const_pointer;
245    typedef size_t                                size_type;
246    typedef ptrdiff_t                             difference_type;
247    typedef std::reverse_iterator<iterator>       reverse_iterator;
248    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
249
250    typedef typename conditional<is_const<_Tp>::value, const char,
251                                char>::type _CharType;
252
253    struct  _ArrayInStructT { _Tp __data_[1]; };
254    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
255
256    // No explicit construct/copy/destroy for aggregate type
257    _LIBCPP_INLINE_VISIBILITY void fill(const value_type&) {
258      static_assert(!is_const<_Tp>::value,
259                    "cannot fill zero-sized array of type 'const T'");
260    }
261
262    _LIBCPP_INLINE_VISIBILITY
263    void swap(array&) _NOEXCEPT {
264      static_assert(!is_const<_Tp>::value,
265                    "cannot swap zero-sized array of type 'const T'");
266    }
267
268    // iterators:
269    _LIBCPP_INLINE_VISIBILITY
270    iterator begin() _NOEXCEPT {return iterator(data());}
271    _LIBCPP_INLINE_VISIBILITY
272    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
273    _LIBCPP_INLINE_VISIBILITY
274    iterator end() _NOEXCEPT {return iterator(data());}
275    _LIBCPP_INLINE_VISIBILITY
276    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
277
278    _LIBCPP_INLINE_VISIBILITY
279    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
280    _LIBCPP_INLINE_VISIBILITY
281    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
282    _LIBCPP_INLINE_VISIBILITY
283    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
284    _LIBCPP_INLINE_VISIBILITY
285    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
286
287    _LIBCPP_INLINE_VISIBILITY
288    const_iterator cbegin() const _NOEXCEPT {return begin();}
289    _LIBCPP_INLINE_VISIBILITY
290    const_iterator cend() const _NOEXCEPT {return end();}
291    _LIBCPP_INLINE_VISIBILITY
292    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
293    _LIBCPP_INLINE_VISIBILITY
294    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
295
296    // capacity:
297    _LIBCPP_INLINE_VISIBILITY
298    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
299    _LIBCPP_INLINE_VISIBILITY
300    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
301    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
302    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
303
304    // element access:
305    _LIBCPP_INLINE_VISIBILITY
306    reference operator[](size_type) _NOEXCEPT {
307      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
308      _LIBCPP_UNREACHABLE();
309    }
310
311    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
312    const_reference operator[](size_type) const _NOEXCEPT {
313      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
314      _LIBCPP_UNREACHABLE();
315    }
316
317    _LIBCPP_INLINE_VISIBILITY
318    reference at(size_type) {
319      __throw_out_of_range("array<T, 0>::at");
320      _LIBCPP_UNREACHABLE();
321    }
322
323    _LIBCPP_INLINE_VISIBILITY
324    const_reference at(size_type) const {
325      __throw_out_of_range("array<T, 0>::at");
326      _LIBCPP_UNREACHABLE();
327    }
328
329    _LIBCPP_INLINE_VISIBILITY
330    reference front() _NOEXCEPT {
331      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
332      _LIBCPP_UNREACHABLE();
333    }
334
335    _LIBCPP_INLINE_VISIBILITY
336    const_reference front() const _NOEXCEPT {
337      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
338      _LIBCPP_UNREACHABLE();
339    }
340
341    _LIBCPP_INLINE_VISIBILITY
342    reference back() _NOEXCEPT {
343      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
344      _LIBCPP_UNREACHABLE();
345    }
346
347    _LIBCPP_INLINE_VISIBILITY
348    const_reference back() const _NOEXCEPT {
349      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
350      _LIBCPP_UNREACHABLE();
351    }
352
353    _LIBCPP_INLINE_VISIBILITY
354    value_type* data() _NOEXCEPT {return reinterpret_cast<value_type*>(__elems_);}
355    _LIBCPP_INLINE_VISIBILITY
356    const value_type* data() const _NOEXCEPT {return reinterpret_cast<const value_type*>(__elems_);}
357};
358
359
360#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
361template<class _Tp, class... _Args,
362         class = _EnableIf<__all<_IsSame<_Tp, _Args>::value...>::value>
363         >
364array(_Tp, _Args...)
365  -> array<_Tp, 1 + sizeof...(_Args)>;
366#endif
367
368template <class _Tp, size_t _Size>
369inline _LIBCPP_INLINE_VISIBILITY
370_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
371operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
372{
373    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
374}
375
376template <class _Tp, size_t _Size>
377inline _LIBCPP_INLINE_VISIBILITY
378_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
379operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
380{
381    return !(__x == __y);
382}
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::lexicographical_compare(__x.begin(), __x.end(),
390                                          __y.begin(), __y.end());
391}
392
393template <class _Tp, size_t _Size>
394inline _LIBCPP_INLINE_VISIBILITY
395_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
396operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
397{
398    return __y < __x;
399}
400
401template <class _Tp, size_t _Size>
402inline _LIBCPP_INLINE_VISIBILITY
403_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
404operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
405{
406    return !(__y < __x);
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 !(__x < __y);
415}
416
417template <class _Tp, size_t _Size>
418inline _LIBCPP_INLINE_VISIBILITY
419typename enable_if
420<
421    _Size == 0 ||
422    __is_swappable<_Tp>::value,
423    void
424>::type
425swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
426                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
427{
428    __x.swap(__y);
429}
430
431template <class _Tp, size_t _Size>
432struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
433    : public integral_constant<size_t, _Size> {};
434
435template <size_t _Ip, class _Tp, size_t _Size>
436struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
437{
438    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
439    typedef _Tp type;
440};
441
442template <size_t _Ip, class _Tp, size_t _Size>
443inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
444_Tp&
445get(array<_Tp, _Size>& __a) _NOEXCEPT
446{
447    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
448    return __a.__elems_[_Ip];
449}
450
451template <size_t _Ip, class _Tp, size_t _Size>
452inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
453const _Tp&
454get(const array<_Tp, _Size>& __a) _NOEXCEPT
455{
456    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
457    return __a.__elems_[_Ip];
458}
459
460#ifndef _LIBCPP_CXX03_LANG
461
462template <size_t _Ip, class _Tp, size_t _Size>
463inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
464_Tp&&
465get(array<_Tp, _Size>&& __a) _NOEXCEPT
466{
467    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
468    return _VSTD::move(__a.__elems_[_Ip]);
469}
470
471template <size_t _Ip, class _Tp, size_t _Size>
472inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
473const _Tp&&
474get(const array<_Tp, _Size>&& __a) _NOEXCEPT
475{
476    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
477    return _VSTD::move(__a.__elems_[_Ip]);
478}
479
480#endif  // !_LIBCPP_CXX03_LANG
481
482_LIBCPP_END_NAMESPACE_STD
483
484#endif  // _LIBCPP_ARRAY
485