libstdc++-v3/include/debug/array

   1 // Debugging array implementation -*- C++ -*-
   2
   3 // Copyright (C) 2012-2020 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 debug/array
  26  *  This is a Standard C++ Library header.
  27  */
  28
  29 #ifndef _GLIBCXX_DEBUG_ARRAY
  30 #define _GLIBCXX_DEBUG_ARRAY 1
  31
  32 #pragma GCC system_header
  33
  34 #include <array>
  35
  36 #include <debug/formatter.h>
  37 #include <debug/macros.h>
  38
  39 namespace std _GLIBCXX_VISIBILITY(default)
  40 {
  41 namespace __debug
  42 {
  43   template<typename _Tp, std::size_t _Nm>
  44     struct array
  45     {
  46       typedef _Tp                                     value_type;
  47       typedef value_type*                             pointer;
  48       typedef const value_type*                       const_pointer;
  49       typedef value_type&                             reference;
  50       typedef const value_type&                       const_reference;
  51       typedef value_type*                             iterator;
  52       typedef const value_type*                       const_iterator;
  53       typedef std::size_t                             size_type;
  54       typedef std::ptrdiff_t                          difference_type;
  55       typedef std::reverse_iterator<iterator>         reverse_iterator;
  56       typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
  57
  58       // Support for zero-sized arrays mandatory.
  59       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
  60       typename _AT_Type::_Type                         _M_elems;
  61
  62       template<std::size_t _Size>
  63         struct _Array_check_subscript
  64         {
  65           std::size_t size() { return _Size; }
  66
  67           _Array_check_subscript(std::size_t __index)
  68           { __glibcxx_check_subscript(__index); }
  69         };
  70
  71       template<std::size_t _Size>
  72         struct _Array_check_nonempty
  73         {
  74           _GLIBCXX_NODISCARD bool empty() { return _Size == 0; }
  75
  76           _Array_check_nonempty()
  77           { __glibcxx_check_nonempty(); }
  78         };
  79
  80       // No explicit construct/copy/destroy for aggregate type.
  81
  82       // DR 776.
  83       _GLIBCXX20_CONSTEXPR void
  84       fill(const value_type& __u)
  85       { std::fill_n(begin(), size(), __u); }
  86
  87       _GLIBCXX20_CONSTEXPR void
  88       swap(array& __other)
  89       noexcept(_AT_Type::_Is_nothrow_swappable::value)
  90       { std::swap_ranges(begin(), end(), __other.begin()); }
  91
  92       // Iterators.
  93       _GLIBCXX17_CONSTEXPR iterator
  94       begin() noexcept
  95       { return iterator(data()); }
  96
  97       _GLIBCXX17_CONSTEXPR const_iterator
  98       begin() const noexcept
  99       { return const_iterator(data()); }
 100
 101       _GLIBCXX17_CONSTEXPR iterator
 102       end() noexcept
 103       { return iterator(data() + _Nm); }
 104
 105       _GLIBCXX17_CONSTEXPR const_iterator
 106       end() const noexcept
 107       { return const_iterator(data() + _Nm); }
 108
 109       _GLIBCXX17_CONSTEXPR reverse_iterator
 110       rbegin() noexcept
 111       { return reverse_iterator(end()); }
 112
 113       _GLIBCXX17_CONSTEXPR const_reverse_iterator
 114       rbegin() const noexcept
 115       { return const_reverse_iterator(end()); }
 116
 117       _GLIBCXX17_CONSTEXPR reverse_iterator
 118       rend() noexcept
 119       { return reverse_iterator(begin()); }
 120
 121       _GLIBCXX17_CONSTEXPR const_reverse_iterator
 122       rend() const noexcept
 123       { return const_reverse_iterator(begin()); }
 124
 125       _GLIBCXX17_CONSTEXPR const_iterator
 126       cbegin() const noexcept
 127       { return const_iterator(data()); }
 128
 129       _GLIBCXX17_CONSTEXPR const_iterator
 130       cend() const noexcept
 131       { return const_iterator(data() + _Nm); }
 132
 133       _GLIBCXX17_CONSTEXPR const_reverse_iterator
 134       crbegin() const noexcept
 135       { return const_reverse_iterator(end()); }
 136
 137       _GLIBCXX17_CONSTEXPR const_reverse_iterator
 138       crend() const noexcept
 139       { return const_reverse_iterator(begin()); }
 140
 141       // Capacity.
 142       constexpr size_type
 143       size() const noexcept { return _Nm; }
 144
 145       constexpr size_type
 146       max_size() const noexcept { return _Nm; }
 147
 148       _GLIBCXX_NODISCARD constexpr bool
 149       empty() const noexcept { return size() == 0; }
 150
 151       // Element access.
 152       _GLIBCXX17_CONSTEXPR reference
 153       operator[](size_type __n) noexcept
 154       {
 155         __glibcxx_check_subscript(__n);
 156         return _AT_Type::_S_ref(_M_elems, __n);
 157       }
 158
 159       constexpr const_reference
 160       operator[](size_type __n) const noexcept
 161       {
 162         return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
 163          : (_GLIBCXX_THROW_OR_ABORT(_Array_check_subscript<_Nm>(__n)),
 164             _AT_Type::_S_ref(_M_elems, 0));
 165       }
 166
 167       _GLIBCXX17_CONSTEXPR reference
 168       at(size_type __n)
 169       {
 170         if (__n >= _Nm)
 171           std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 172                                             ">= _Nm (which is %zu)"),
 173                                         __n, _Nm);
 174         return _AT_Type::_S_ref(_M_elems, __n);
 175       }
 176
 177       constexpr const_reference
 178       at(size_type __n) const
 179       {
 180         // Result of conditional expression must be an lvalue so use
 181         // boolean ? lvalue : (throw-expr, lvalue)
 182         return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
 183           : (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 184                                                ">= _Nm (which is %zu)"),
 185                                            __n, _Nm),
 186              _AT_Type::_S_ref(_M_elems, 0));
 187       }
 188
 189       _GLIBCXX17_CONSTEXPR reference
 190       front() noexcept
 191       {
 192         __glibcxx_check_nonempty();
 193         return *begin();
 194       }
 195
 196       constexpr const_reference
 197       front() const noexcept
 198       {
 199         return _Nm ? _AT_Type::_S_ref(_M_elems, 0)
 200           : (_GLIBCXX_THROW_OR_ABORT(_Array_check_nonempty<_Nm>()),
 201              _AT_Type::_S_ref(_M_elems, 0));
 202       }
 203
 204       _GLIBCXX17_CONSTEXPR reference
 205       back() noexcept
 206       {
 207         __glibcxx_check_nonempty();
 208         return _Nm ? *(end() - 1) : *end();
 209       }
 210
 211       constexpr const_reference
 212       back() const noexcept
 213       {
 214         return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
 215           : (_GLIBCXX_THROW_OR_ABORT(_Array_check_nonempty<_Nm>()),
 216              _AT_Type::_S_ref(_M_elems, 0));
 217       }
 218
 219       _GLIBCXX17_CONSTEXPR pointer
 220       data() noexcept
 221       { return _AT_Type::_S_ptr(_M_elems); }
 222
 223       _GLIBCXX17_CONSTEXPR const_pointer
 224       data() const noexcept
 225       { return _AT_Type::_S_ptr(_M_elems); }
 226     };
 227
 228 #if __cpp_deduction_guides >= 201606
 229   template<typename _Tp, typename... _Up>
 230     array(_Tp, _Up...)
 231       -> array<std::enable_if_t<(std::is_same_v<_Tp, _Up> && ...), _Tp>,
 232                1 + sizeof...(_Up)>;
 233 #endif
 234
 235   // Array comparisons.
 236   template<typename _Tp, std::size_t _Nm>
 237     _GLIBCXX20_CONSTEXPR
 238     inline bool
 239     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 240     { return std::equal(__one.begin(), __one.end(), __two.begin()); }
 241
 242 #if __cpp_lib_three_way_comparison && __cpp_lib_concepts
 243   template<typename _Tp, size_t _Nm>
 244     constexpr __detail::__synth3way_t<_Tp>
 245     operator<=>(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
 246     {
 247       if constexpr (_Nm && __is_byte<_Tp>::__value)
 248         return __builtin_memcmp(__a.data(), __b.data(), _Nm) <=> 0;
 249       else
 250         {
 251           for (size_t __i = 0; __i < _Nm; ++__i)
 252             {
 253               auto __c = __detail::__synth3way(__a[__i], __b[__i]);
 254               if (__c != 0)
 255                 return __c;
 256             }
 257         }
 258       return strong_ordering::equal;
 259     }
 260 #else
 261   template<typename _Tp, std::size_t _Nm>
 262     _GLIBCXX20_CONSTEXPR
 263     inline bool
 264     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 265     { return !(__one == __two); }
 266
 267   template<typename _Tp, std::size_t _Nm>
 268     _GLIBCXX20_CONSTEXPR
 269     inline bool
 270     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
 271     {
 272       return std::lexicographical_compare(__a.begin(), __a.end(),
 273                                           __b.begin(), __b.end());
 274     }
 275
 276   template<typename _Tp, std::size_t _Nm>
 277     _GLIBCXX20_CONSTEXPR
 278     inline bool
 279     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 280     { return __two < __one; }
 281
 282   template<typename _Tp, std::size_t _Nm>
 283     _GLIBCXX20_CONSTEXPR
 284     inline bool
 285     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 286     { return !(__one > __two); }
 287
 288   template<typename _Tp, std::size_t _Nm>
 289     _GLIBCXX20_CONSTEXPR
 290     inline bool
 291     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 292     { return !(__one < __two); }
 293 #endif // three_way_comparison && concepts
 294
 295   // Specialized algorithms.
 296
 297 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
 298   template<typename _Tp, size_t _Nm>
 299     typename enable_if<
 300       !_GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::_Is_swappable::value>::type
 301     swap(array<_Tp, _Nm>&, array<_Tp, _Nm>&) = delete;
 302 #endif
 303
 304   template<typename _Tp, std::size_t _Nm>
 305     _GLIBCXX20_CONSTEXPR
 306     inline void
 307     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
 308     noexcept(noexcept(__one.swap(__two)))
 309     { __one.swap(__two); }
 310
 311   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 312     constexpr _Tp&
 313     get(array<_Tp, _Nm>& __arr) noexcept
 314     {
 315       static_assert(_Int < _Nm, "index is out of bounds");
 316       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 317         _S_ref(__arr._M_elems, _Int);
 318     }
 319
 320   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 321     constexpr _Tp&&
 322     get(array<_Tp, _Nm>&& __arr) noexcept
 323     {
 324       static_assert(_Int < _Nm, "index is out of bounds");
 325       return std::move(__debug::get<_Int>(__arr));
 326     }
 327
 328   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 329     constexpr const _Tp&
 330     get(const array<_Tp, _Nm>& __arr) noexcept
 331     {
 332       static_assert(_Int < _Nm, "index is out of bounds");
 333       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 334         _S_ref(__arr._M_elems, _Int);
 335     }
 336
 337   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 338     constexpr const _Tp&&
 339     get(const array<_Tp, _Nm>&& __arr) noexcept
 340     {
 341       static_assert(_Int < _Nm, "index is out of bounds");
 342       return std::move(__debug::get<_Int>(__arr));
 343     }
 344
 345 #if __cplusplus > 201703L
 346 #define __cpp_lib_to_array 201907L
 347
 348   template<bool _Move = false, typename _Tp, size_t... _Idx>
 349     constexpr array<remove_cv_t<_Tp>, sizeof...(_Idx)>
 350     __to_array(_Tp (&__a)[sizeof...(_Idx)], index_sequence<_Idx...>)
 351     {
 352       if constexpr (_Move)
 353         return {{std::move(__a[_Idx])...}};
 354       else
 355         return {{__a[_Idx]...}};
 356     }
 357
 358   template<typename _Tp, size_t _Nm>
 359     constexpr array<remove_cv_t<_Tp>, _Nm>
 360     to_array(_Tp (&__a)[_Nm])
 361     noexcept(is_nothrow_constructible_v<_Tp, _Tp&>)
 362     {
 363       static_assert(!is_array_v<_Tp>);
 364       static_assert(is_constructible_v<_Tp, _Tp&>);
 365       if constexpr (is_constructible_v<_Tp, _Tp&>)
 366         return __debug::__to_array(__a, make_index_sequence<_Nm>{});
 367       __builtin_unreachable(); // FIXME: see PR c++/91388
 368     }
 369
 370   template<typename _Tp, size_t _Nm>
 371     constexpr array<remove_cv_t<_Tp>, _Nm>
 372     to_array(_Tp (&&__a)[_Nm])
 373     noexcept(is_nothrow_move_constructible_v<_Tp>)
 374     {
 375       static_assert(!is_array_v<_Tp>);
 376       static_assert(is_move_constructible_v<_Tp>);
 377       if constexpr (is_move_constructible_v<_Tp>)
 378         return __debug::__to_array<1>(__a, make_index_sequence<_Nm>{});
 379       __builtin_unreachable(); // FIXME: see PR c++/91388
 380     }
 381 #endif // C++20
 382
 383 } // namespace __debug
 384
 385 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 386   // Tuple interface to class template array.
 387
 388   /// tuple_size
 389   template<typename _Tp, std::size_t _Nm>
 390     struct tuple_size<std::__debug::array<_Tp, _Nm>>
 391     : public integral_constant<std::size_t, _Nm> { };
 392
 393   /// tuple_element
 394   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 395     struct tuple_element<_Int, std::__debug::array<_Tp, _Nm>>
 396     {
 397       static_assert(_Int < _Nm, "index is out of bounds");
 398       typedef _Tp type;
 399     };
 400
 401   template<typename _Tp, std::size_t _Nm>
 402     struct __is_tuple_like_impl<std::__debug::array<_Tp, _Nm>> : true_type
 403     { };
 404
 405 _GLIBCXX_END_NAMESPACE_VERSION
 406 } // namespace std
 407
 408 #endif // _GLIBCXX_DEBUG_ARRAY