1    	// <array> -*- C++ -*-
2    	
3    	// Copyright (C) 2007-2017 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   	
43   	namespace 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  	_GLIBCXX_END_NAMESPACE_CONTAINER
332  	} // namespace std
333  	
334  	namespace std _GLIBCXX_VISIBILITY(default)
335  	{
336  	_GLIBCXX_BEGIN_NAMESPACE_VERSION
337  	
338  	  // Tuple interface to class template array.
339  	
340  	  /// tuple_size
341  	  template<typename _Tp>
342  	    class tuple_size;
343  	
344  	  /// Partial specialization for std::array
345  	  template<typename _Tp, std::size_t _Nm>
346  	    struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
347  	    : public integral_constant<std::size_t, _Nm> { };
348  	
349  	  /// tuple_element
350  	  template<std::size_t _Int, typename _Tp>
351  	    class tuple_element;
352  	
353  	  /// Partial specialization for std::array
354  	  template<std::size_t _Int, typename _Tp, std::size_t _Nm>
355  	    struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
356  	    {
357  	      static_assert(_Int < _Nm, "index is out of bounds");
358  	      typedef _Tp type;
359  	    };
360  	
361  	  template<typename _Tp, std::size_t _Nm>
362  	    struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
363  	    { };
364  	
365  	_GLIBCXX_END_NAMESPACE_VERSION
366  	} // namespace std
367  	
368  	#ifdef _GLIBCXX_DEBUG
369  	# include <debug/array>
370  	#endif
371  	
372  	#ifdef _GLIBCXX_PROFILE
373  	# include <profile/array>
374  	#endif
375  	
376  	#endif // C++11
377  	
378  	#endif // _GLIBCXX_ARRAY
379