1// <array> -*- C++ -*-
2
3// Copyright (C) 2007-2018 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/array
26 *  This is a Standard C++ Library header.
27 */
28
29#ifndef _GLIBCXX_ARRAY
30#define _GLIBCXX_ARRAY 1
31
32#pragma GCC system_header
33
34#if __cplusplus < 201103L
35# include <bits/c++0x_warning.h>
36#else
37
38#include <utility>
39#include <stdexcept>
40#include <bits/stl_algobase.h>
41#include <bits/range_access.h>
42
43namespace std _GLIBCXX_VISIBILITY(default)
44{
45_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
46
47  template<typename _Tp, std::size_t _Nm>
48    struct __array_traits
49    {
50      typedef _Tp _Type[_Nm];
51      typedef __is_swappable<_Tp> _Is_swappable;
52      typedef __is_nothrow_swappable<_Tp> _Is_nothrow_swappable;
53
54      static constexpr _Tp&
55      _S_ref(const _Type& __t, std::size_t __n) noexcept
56      { return const_cast<_Tp&>(__t[__n]); }
57
58      static constexpr _Tp*
59      _S_ptr(const _Type& __t) noexcept
60      { return const_cast<_Tp*>(__t); }
61    };
62
63 template<typename _Tp>
64   struct __array_traits<_Tp, 0>
65   {
66     struct _Type { };
67     typedef true_type _Is_swappable;
68     typedef true_type _Is_nothrow_swappable;
69
70     static constexpr _Tp&
71     _S_ref(const _Type&, std::size_t) noexcept
72     { return *static_cast<_Tp*>(nullptr); }
73
74     static constexpr _Tp*
75     _S_ptr(const _Type&) noexcept
76     { return nullptr; }
77   };
78
79  /**
80   *  @brief A standard container for storing a fixed size sequence of elements.
81   *
82   *  @ingroup sequences
83   *
84   *  Meets the requirements of a <a href="tables.html#65">container</a>, a
85   *  <a href="tables.html#66">reversible container</a>, and a
86   *  <a href="tables.html#67">sequence</a>.
87   *
88   *  Sets support random access iterators.
89   *
90   *  @tparam  Tp  Type of element. Required to be a complete type.
91   *  @tparam  N  Number of elements.
92  */
93  template<typename _Tp, std::size_t _Nm>
94    struct array
95    {
96      typedef _Tp 	    			      value_type;
97      typedef value_type*			      pointer;
98      typedef const value_type*                       const_pointer;
99      typedef value_type&                   	      reference;
100      typedef const value_type&             	      const_reference;
101      typedef value_type*          		      iterator;
102      typedef const value_type*			      const_iterator;
103      typedef std::size_t                    	      size_type;
104      typedef std::ptrdiff_t                   	      difference_type;
105      typedef std::reverse_iterator<iterator>	      reverse_iterator;
106      typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
107
108      // Support for zero-sized arrays mandatory.
109      typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
110      typename _AT_Type::_Type                         _M_elems;
111
112      // No explicit construct/copy/destroy for aggregate type.
113
114      // DR 776.
115      void
116      fill(const value_type& __u)
117      { std::fill_n(begin(), size(), __u); }
118
119      void
120      swap(array& __other)
121      noexcept(_AT_Type::_Is_nothrow_swappable::value)
122      { std::swap_ranges(begin(), end(), __other.begin()); }
123
124      // Iterators.
125      _GLIBCXX17_CONSTEXPR iterator
126      begin() noexcept
127      { return iterator(data()); }
128
129      _GLIBCXX17_CONSTEXPR const_iterator
130      begin() const noexcept
131      { return const_iterator(data()); }
132
133      _GLIBCXX17_CONSTEXPR iterator
134      end() noexcept
135      { return iterator(data() + _Nm); }
136
137      _GLIBCXX17_CONSTEXPR const_iterator
138      end() const noexcept
139      { return const_iterator(data() + _Nm); }
140
141      _GLIBCXX17_CONSTEXPR reverse_iterator
142      rbegin() noexcept
143      { return reverse_iterator(end()); }
144
145      _GLIBCXX17_CONSTEXPR const_reverse_iterator
146      rbegin() const noexcept
147      { return const_reverse_iterator(end()); }
148
149      _GLIBCXX17_CONSTEXPR reverse_iterator
150      rend() noexcept
151      { return reverse_iterator(begin()); }
152
153      _GLIBCXX17_CONSTEXPR const_reverse_iterator
154      rend() const noexcept
155      { return const_reverse_iterator(begin()); }
156
157      _GLIBCXX17_CONSTEXPR const_iterator
158      cbegin() const noexcept
159      { return const_iterator(data()); }
160
161      _GLIBCXX17_CONSTEXPR const_iterator
162      cend() const noexcept
163      { return const_iterator(data() + _Nm); }
164
165      _GLIBCXX17_CONSTEXPR const_reverse_iterator
166      crbegin() const noexcept
167      { return const_reverse_iterator(end()); }
168
169      _GLIBCXX17_CONSTEXPR const_reverse_iterator
170      crend() const noexcept
171      { return const_reverse_iterator(begin()); }
172
173      // Capacity.
174      constexpr size_type
175      size() const noexcept { return _Nm; }
176
177      constexpr size_type
178      max_size() const noexcept { return _Nm; }
179
180      constexpr bool
181      empty() const noexcept { return size() == 0; }
182
183      // Element access.
184      _GLIBCXX17_CONSTEXPR reference
185      operator[](size_type __n) noexcept
186      { return _AT_Type::_S_ref(_M_elems, __n); }
187
188      constexpr const_reference
189      operator[](size_type __n) const noexcept
190      { return _AT_Type::_S_ref(_M_elems, __n); }
191
192      _GLIBCXX17_CONSTEXPR reference
193      at(size_type __n)
194      {
195	if (__n >= _Nm)
196	  std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
197					    ">= _Nm (which is %zu)"),
198					__n, _Nm);
199	return _AT_Type::_S_ref(_M_elems, __n);
200      }
201
202      constexpr const_reference
203      at(size_type __n) const
204      {
205	// Result of conditional expression must be an lvalue so use
206	// boolean ? lvalue : (throw-expr, lvalue)
207	return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
208	  : (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
209					       ">= _Nm (which is %zu)"),
210					   __n, _Nm),
211	     _AT_Type::_S_ref(_M_elems, 0));
212      }
213
214      _GLIBCXX17_CONSTEXPR reference
215      front() noexcept
216      { return *begin(); }
217
218      constexpr const_reference
219      front() const noexcept
220      { return _AT_Type::_S_ref(_M_elems, 0); }
221
222      _GLIBCXX17_CONSTEXPR reference
223      back() noexcept
224      { return _Nm ? *(end() - 1) : *end(); }
225
226      constexpr const_reference
227      back() const noexcept
228      {
229	return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
230 	           : _AT_Type::_S_ref(_M_elems, 0);
231      }
232
233      _GLIBCXX17_CONSTEXPR pointer
234      data() noexcept
235      { return _AT_Type::_S_ptr(_M_elems); }
236
237      _GLIBCXX17_CONSTEXPR const_pointer
238      data() const noexcept
239      { return _AT_Type::_S_ptr(_M_elems); }
240    };
241
242#if __cpp_deduction_guides >= 201606
243  template<typename _Tp, typename... _Up>
244    array(_Tp, _Up...)
245      -> array<enable_if_t<(is_same_v<_Tp, _Up> && ...), _Tp>,
246	       1 + sizeof...(_Up)>;
247#endif
248
249  // Array comparisons.
250  template<typename _Tp, std::size_t _Nm>
251    inline bool
252    operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
253    { return std::equal(__one.begin(), __one.end(), __two.begin()); }
254
255  template<typename _Tp, std::size_t _Nm>
256    inline bool
257    operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
258    { return !(__one == __two); }
259
260  template<typename _Tp, std::size_t _Nm>
261    inline bool
262    operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
263    {
264      return std::lexicographical_compare(__a.begin(), __a.end(),
265					  __b.begin(), __b.end());
266    }
267
268  template<typename _Tp, std::size_t _Nm>
269    inline bool
270    operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
271    { return __two < __one; }
272
273  template<typename _Tp, std::size_t _Nm>
274    inline bool
275    operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
276    { return !(__one > __two); }
277
278  template<typename _Tp, std::size_t _Nm>
279    inline bool
280    operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
281    { return !(__one < __two); }
282
283  // Specialized algorithms.
284  template<typename _Tp, std::size_t _Nm>
285    inline
286#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
287    // Constrained free swap overload, see p0185r1
288    typename enable_if<
289      _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value
290    >::type
291#else
292    void
293#endif
294    swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
295    noexcept(noexcept(__one.swap(__two)))
296    { __one.swap(__two); }
297
298#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
299  template<typename _Tp, std::size_t _Nm>
300    typename enable_if<
301      !_GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value>::type
302    swap(array<_Tp, _Nm>&, array<_Tp, _Nm>&) = delete;
303#endif
304
305  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
306    constexpr _Tp&
307    get(array<_Tp, _Nm>& __arr) noexcept
308    {
309      static_assert(_Int < _Nm, "array index is within bounds");
310      return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
311	_S_ref(__arr._M_elems, _Int);
312    }
313
314  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
315    constexpr _Tp&&
316    get(array<_Tp, _Nm>&& __arr) noexcept
317    {
318      static_assert(_Int < _Nm, "array index is within bounds");
319      return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
320    }
321
322  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
323    constexpr const _Tp&
324    get(const array<_Tp, _Nm>& __arr) noexcept
325    {
326      static_assert(_Int < _Nm, "array index is within bounds");
327      return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
328	_S_ref(__arr._M_elems, _Int);
329    }
330
331  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
332    constexpr const _Tp&&
333    get(const array<_Tp, _Nm>&& __arr) noexcept
334    {
335      static_assert(_Int < _Nm, "array index is within bounds");
336      return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
337    }
338
339_GLIBCXX_END_NAMESPACE_CONTAINER
340} // namespace std
341
342namespace std _GLIBCXX_VISIBILITY(default)
343{
344_GLIBCXX_BEGIN_NAMESPACE_VERSION
345
346  // Tuple interface to class template array.
347
348  /// tuple_size
349  template<typename _Tp>
350    struct tuple_size;
351
352  /// Partial specialization for std::array
353  template<typename _Tp, std::size_t _Nm>
354    struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
355    : public integral_constant<std::size_t, _Nm> { };
356
357  /// tuple_element
358  template<std::size_t _Int, typename _Tp>
359    struct tuple_element;
360
361  /// Partial specialization for std::array
362  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
363    struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
364    {
365      static_assert(_Int < _Nm, "index is out of bounds");
366      typedef _Tp type;
367    };
368
369  template<typename _Tp, std::size_t _Nm>
370    struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
371    { };
372
373_GLIBCXX_END_NAMESPACE_VERSION
374} // namespace std
375
376#ifdef _GLIBCXX_DEBUG
377# include <debug/array>
378#endif
379
380#ifdef _GLIBCXX_PROFILE
381# include <profile/array>
382#endif
383
384#endif // C++11
385
386#endif // _GLIBCXX_ARRAY
387