libstdc++-v3/include/std/array

   1 // <array> -*- C++ -*-
   2
   3 // Copyright (C) 2007-2016 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
  52       static constexpr _Tp&
  53       _S_ref(const _Type& __t, std::size_t __n) noexcept
  54       { return const_cast<_Tp&>(__t[__n]); }
  55
  56       static constexpr _Tp*
  57       _S_ptr(const _Type& __t) noexcept
  58       { return const_cast<_Tp*>(__t); }
  59     };
  60
  61  template<typename _Tp>
  62    struct __array_traits<_Tp, 0>
  63    {
  64      struct _Type { };
  65
  66      static constexpr _Tp&
  67      _S_ref(const _Type&, std::size_t) noexcept
  68      { return *static_cast<_Tp*>(nullptr); }
  69
  70      static constexpr _Tp*
  71      _S_ptr(const _Type&) noexcept
  72      { return nullptr; }
  73    };
  74
  75   /**
  76    *  @brief A standard container for storing a fixed size sequence of elements.
  77    *
  78    *  @ingroup sequences
  79    *
  80    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  81    *  <a href="tables.html#66">reversible container</a>, and a
  82    *  <a href="tables.html#67">sequence</a>.
  83    *
  84    *  Sets support random access iterators.
  85    *
  86    *  @tparam  Tp  Type of element. Required to be a complete type.
  87    *  @tparam  N  Number of elements.
  88   */
  89   template<typename _Tp, std::size_t _Nm>
  90     struct array
  91     {
  92       typedef _Tp                                     value_type;
  93       typedef value_type*                             pointer;
  94       typedef const value_type*                       const_pointer;
  95       typedef value_type&                             reference;
  96       typedef const value_type&                       const_reference;
  97       typedef value_type*                             iterator;
  98       typedef const value_type*                       const_iterator;
  99       typedef std::size_t                             size_type;
 100       typedef std::ptrdiff_t                          difference_type;
 101       typedef std::reverse_iterator<iterator>         reverse_iterator;
 102       typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
 103
 104       // Support for zero-sized arrays mandatory.
 105       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
 106       typename _AT_Type::_Type                         _M_elems;
 107
 108       // No explicit construct/copy/destroy for aggregate type.
 109
 110       // DR 776.
 111       void
 112       fill(const value_type& __u)
 113       { std::fill_n(begin(), size(), __u); }
 114
 115       void
 116       swap(array& __other)
 117       noexcept(__is_nothrow_swappable<_Tp>::value)
 118       { std::swap_ranges(begin(), end(), __other.begin()); }
 119
 120       // Iterators.
 121       iterator
 122       begin() noexcept
 123       { return iterator(data()); }
 124
 125       const_iterator
 126       begin() const noexcept
 127       { return const_iterator(data()); }
 128
 129       iterator
 130       end() noexcept
 131       { return iterator(data() + _Nm); }
 132
 133       const_iterator
 134       end() const noexcept
 135       { return const_iterator(data() + _Nm); }
 136
 137       reverse_iterator
 138       rbegin() noexcept
 139       { return reverse_iterator(end()); }
 140
 141       const_reverse_iterator
 142       rbegin() const noexcept
 143       { return const_reverse_iterator(end()); }
 144
 145       reverse_iterator
 146       rend() noexcept
 147       { return reverse_iterator(begin()); }
 148
 149       const_reverse_iterator
 150       rend() const noexcept
 151       { return const_reverse_iterator(begin()); }
 152
 153       const_iterator
 154       cbegin() const noexcept
 155       { return const_iterator(data()); }
 156
 157       const_iterator
 158       cend() const noexcept
 159       { return const_iterator(data() + _Nm); }
 160
 161       const_reverse_iterator
 162       crbegin() const noexcept
 163       { return const_reverse_iterator(end()); }
 164
 165       const_reverse_iterator
 166       crend() const noexcept
 167       { return const_reverse_iterator(begin()); }
 168
 169       // Capacity.
 170       constexpr size_type
 171       size() const noexcept { return _Nm; }
 172
 173       constexpr size_type
 174       max_size() const noexcept { return _Nm; }
 175
 176       constexpr bool
 177       empty() const noexcept { return size() == 0; }
 178
 179       // Element access.
 180       reference
 181       operator[](size_type __n) noexcept
 182       { return _AT_Type::_S_ref(_M_elems, __n); }
 183
 184       constexpr const_reference
 185       operator[](size_type __n) const noexcept
 186       { return _AT_Type::_S_ref(_M_elems, __n); }
 187
 188       reference
 189       at(size_type __n)
 190       {
 191         if (__n >= _Nm)
 192           std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 193                                             ">= _Nm (which is %zu)"),
 194                                         __n, _Nm);
 195         return _AT_Type::_S_ref(_M_elems, __n);
 196       }
 197
 198       constexpr const_reference
 199       at(size_type __n) const
 200       {
 201         // Result of conditional expression must be an lvalue so use
 202         // boolean ? lvalue : (throw-expr, lvalue)
 203         return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
 204           : (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 205                                                ">= _Nm (which is %zu)"),
 206                                            __n, _Nm),
 207              _AT_Type::_S_ref(_M_elems, 0));
 208       }
 209
 210       reference
 211       front() noexcept
 212       { return *begin(); }
 213
 214       constexpr const_reference
 215       front() const noexcept
 216       { return _AT_Type::_S_ref(_M_elems, 0); }
 217
 218       reference
 219       back() noexcept
 220       { return _Nm ? *(end() - 1) : *end(); }
 221
 222       constexpr const_reference
 223       back() const noexcept
 224       {
 225         return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
 226                    : _AT_Type::_S_ref(_M_elems, 0);
 227       }
 228
 229       pointer
 230       data() noexcept
 231       { return _AT_Type::_S_ptr(_M_elems); }
 232
 233       const_pointer
 234       data() const noexcept
 235       { return _AT_Type::_S_ptr(_M_elems); }
 236     };
 237
 238   // Array comparisons.
 239   template<typename _Tp, std::size_t _Nm>
 240     inline bool
 241     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 242     { return std::equal(__one.begin(), __one.end(), __two.begin()); }
 243
 244   template<typename _Tp, std::size_t _Nm>
 245     inline bool
 246     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 247     { return !(__one == __two); }
 248
 249   template<typename _Tp, std::size_t _Nm>
 250     inline bool
 251     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
 252     {
 253       return std::lexicographical_compare(__a.begin(), __a.end(),
 254                                           __b.begin(), __b.end());
 255     }
 256
 257   template<typename _Tp, std::size_t _Nm>
 258     inline bool
 259     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 260     { return __two < __one; }
 261
 262   template<typename _Tp, std::size_t _Nm>
 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     inline bool
 269     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 270     { return !(__one < __two); }
 271
 272   // Specialized algorithms.
 273   template<typename _Tp, std::size_t _Nm>
 274     inline void
 275     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
 276     noexcept(noexcept(__one.swap(__two)))
 277     { __one.swap(__two); }
 278
 279   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 280     constexpr _Tp&
 281     get(array<_Tp, _Nm>& __arr) noexcept
 282     {
 283       static_assert(_Int < _Nm, "index is out of bounds");
 284       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 285         _S_ref(__arr._M_elems, _Int);
 286     }
 287
 288   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 289     constexpr _Tp&&
 290     get(array<_Tp, _Nm>&& __arr) noexcept
 291     {
 292       static_assert(_Int < _Nm, "index is out of bounds");
 293       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
 294     }
 295
 296   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 297     constexpr const _Tp&
 298     get(const array<_Tp, _Nm>& __arr) noexcept
 299     {
 300       static_assert(_Int < _Nm, "index is out of bounds");
 301       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 302         _S_ref(__arr._M_elems, _Int);
 303     }
 304
 305 _GLIBCXX_END_NAMESPACE_CONTAINER
 306 } // namespace std
 307
 308 namespace std _GLIBCXX_VISIBILITY(default)
 309 {
 310 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 311
 312   // Tuple interface to class template array.
 313
 314   /// tuple_size
 315   template<typename _Tp>
 316     class tuple_size;
 317
 318   /// Partial specialization for std::array
 319   template<typename _Tp, std::size_t _Nm>
 320     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
 321     : public integral_constant<std::size_t, _Nm> { };
 322
 323   /// tuple_element
 324   template<std::size_t _Int, typename _Tp>
 325     class tuple_element;
 326
 327   /// Partial specialization for std::array
 328   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 329     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
 330     {
 331       static_assert(_Int < _Nm, "index is out of bounds");
 332       typedef _Tp type;
 333     };
 334
 335   template<typename _Tp, std::size_t _Nm>
 336     struct __is_tuple_like_impl<_GLIBCXX_STD_C::array<_Tp, _Nm>> : true_type
 337     { };
 338
 339 _GLIBCXX_END_NAMESPACE_VERSION
 340 } // namespace std
 341
 342 #ifdef _GLIBCXX_DEBUG
 343 # include <debug/array>
 344 #endif
 345
 346 #ifdef _GLIBCXX_PROFILE
 347 # include <profile/array>
 348 #endif
 349
 350 #endif // C++11
 351
 352 #endif // _GLIBCXX_ARRAY