libstdc++-v3/include/std/array

   1 // <array> -*- C++ -*-
   2
   3 // Copyright (C) 2007-2015 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 <stdexcept>
  39 #include <bits/stl_algobase.h>
  40 #include <bits/range_access.h>
  41
  42 namespace std _GLIBCXX_VISIBILITY(default)
  43 {
  44 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
  45
  46   template<typename _Tp, std::size_t _Nm>
  47     struct __array_traits
  48     {
  49       typedef _Tp _Type[_Nm];
  50
  51       static constexpr _Tp&
  52       _S_ref(const _Type& __t, std::size_t __n) noexcept
  53       { return const_cast<_Tp&>(__t[__n]); }
  54
  55       static constexpr _Tp*
  56       _S_ptr(const _Type& __t) noexcept
  57       { return const_cast<_Tp*>(__t); }
  58     };
  59
  60  template<typename _Tp>
  61    struct __array_traits<_Tp, 0>
  62    {
  63      struct _Type { };
  64
  65      static constexpr _Tp&
  66      _S_ref(const _Type&, std::size_t) noexcept
  67      { return *static_cast<_Tp*>(nullptr); }
  68
  69      static constexpr _Tp*
  70      _S_ptr(const _Type&) noexcept
  71      { return nullptr; }
  72    };
  73
  74   /**
  75    *  @brief A standard container for storing a fixed size sequence of elements.
  76    *
  77    *  @ingroup sequences
  78    *
  79    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
  80    *  <a href="tables.html#66">reversible container</a>, and a
  81    *  <a href="tables.html#67">sequence</a>.
  82    *
  83    *  Sets support random access iterators.
  84    *
  85    *  @tparam  Tp  Type of element. Required to be a complete type.
  86    *  @tparam  N  Number of elements.
  87   */
  88   template<typename _Tp, std::size_t _Nm>
  89     struct array
  90     {
  91       typedef _Tp                                     value_type;
  92       typedef value_type*                             pointer;
  93       typedef const value_type*                       const_pointer;
  94       typedef value_type&                             reference;
  95       typedef const value_type&                       const_reference;
  96       typedef value_type*                             iterator;
  97       typedef const value_type*                       const_iterator;
  98       typedef std::size_t                             size_type;
  99       typedef std::ptrdiff_t                          difference_type;
 100       typedef std::reverse_iterator<iterator>         reverse_iterator;
 101       typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
 102
 103       // Support for zero-sized arrays mandatory.
 104       typedef _GLIBCXX_STD_C::__array_traits<_Tp, _Nm> _AT_Type;
 105       typename _AT_Type::_Type                         _M_elems;
 106
 107       // No explicit construct/copy/destroy for aggregate type.
 108
 109       // DR 776.
 110       void
 111       fill(const value_type& __u)
 112       { std::fill_n(begin(), size(), __u); }
 113
 114       void
 115       swap(array& __other)
 116       noexcept(noexcept(swap(std::declval<_Tp&>(), std::declval<_Tp&>())))
 117       { std::swap_ranges(begin(), end(), __other.begin()); }
 118
 119       // Iterators.
 120       iterator
 121       begin() noexcept
 122       { return iterator(data()); }
 123
 124       const_iterator
 125       begin() const noexcept
 126       { return const_iterator(data()); }
 127
 128       iterator
 129       end() noexcept
 130       { return iterator(data() + _Nm); }
 131
 132       const_iterator
 133       end() const noexcept
 134       { return const_iterator(data() + _Nm); }
 135
 136       reverse_iterator
 137       rbegin() noexcept
 138       { return reverse_iterator(end()); }
 139
 140       const_reverse_iterator
 141       rbegin() const noexcept
 142       { return const_reverse_iterator(end()); }
 143
 144       reverse_iterator
 145       rend() noexcept
 146       { return reverse_iterator(begin()); }
 147
 148       const_reverse_iterator
 149       rend() const noexcept
 150       { return const_reverse_iterator(begin()); }
 151
 152       const_iterator
 153       cbegin() const noexcept
 154       { return const_iterator(data()); }
 155
 156       const_iterator
 157       cend() const noexcept
 158       { return const_iterator(data() + _Nm); }
 159
 160       const_reverse_iterator
 161       crbegin() const noexcept
 162       { return const_reverse_iterator(end()); }
 163
 164       const_reverse_iterator
 165       crend() const noexcept
 166       { return const_reverse_iterator(begin()); }
 167
 168       // Capacity.
 169       constexpr size_type
 170       size() const noexcept { return _Nm; }
 171
 172       constexpr size_type
 173       max_size() const noexcept { return _Nm; }
 174
 175       constexpr bool
 176       empty() const noexcept { return size() == 0; }
 177
 178       // Element access.
 179       reference
 180       operator[](size_type __n) noexcept
 181       { return _AT_Type::_S_ref(_M_elems, __n); }
 182
 183       constexpr const_reference
 184       operator[](size_type __n) const noexcept
 185       { return _AT_Type::_S_ref(_M_elems, __n); }
 186
 187       reference
 188       at(size_type __n)
 189       {
 190         if (__n >= _Nm)
 191           std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 192                                             ">= _Nm (which is %zu)"),
 193                                         __n, _Nm);
 194         return _AT_Type::_S_ref(_M_elems, __n);
 195       }
 196
 197       constexpr const_reference
 198       at(size_type __n) const
 199       {
 200         // Result of conditional expression must be an lvalue so use
 201         // boolean ? lvalue : (throw-expr, lvalue)
 202         return __n < _Nm ? _AT_Type::_S_ref(_M_elems, __n)
 203           : (std::__throw_out_of_range_fmt(__N("array::at: __n (which is %zu) "
 204                                                ">= _Nm (which is %zu)"),
 205                                            __n, _Nm),
 206              _AT_Type::_S_ref(_M_elems, 0));
 207       }
 208
 209       reference
 210       front() noexcept
 211       { return *begin(); }
 212
 213       constexpr const_reference
 214       front() const noexcept
 215       { return _AT_Type::_S_ref(_M_elems, 0); }
 216
 217       reference
 218       back() noexcept
 219       { return _Nm ? *(end() - 1) : *end(); }
 220
 221       constexpr const_reference
 222       back() const noexcept
 223       {
 224         return _Nm ? _AT_Type::_S_ref(_M_elems, _Nm - 1)
 225                    : _AT_Type::_S_ref(_M_elems, 0);
 226       }
 227
 228       pointer
 229       data() noexcept
 230       { return _AT_Type::_S_ptr(_M_elems); }
 231
 232       const_pointer
 233       data() const noexcept
 234       { return _AT_Type::_S_ptr(_M_elems); }
 235     };
 236
 237   // Array comparisons.
 238   template<typename _Tp, std::size_t _Nm>
 239     inline bool
 240     operator==(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 241     { return std::equal(__one.begin(), __one.end(), __two.begin()); }
 242
 243   template<typename _Tp, std::size_t _Nm>
 244     inline bool
 245     operator!=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 246     { return !(__one == __two); }
 247
 248   template<typename _Tp, std::size_t _Nm>
 249     inline bool
 250     operator<(const array<_Tp, _Nm>& __a, const array<_Tp, _Nm>& __b)
 251     {
 252       return std::lexicographical_compare(__a.begin(), __a.end(),
 253                                           __b.begin(), __b.end());
 254     }
 255
 256   template<typename _Tp, std::size_t _Nm>
 257     inline bool
 258     operator>(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 259     { return __two < __one; }
 260
 261   template<typename _Tp, std::size_t _Nm>
 262     inline bool
 263     operator<=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 264     { return !(__one > __two); }
 265
 266   template<typename _Tp, std::size_t _Nm>
 267     inline bool
 268     operator>=(const array<_Tp, _Nm>& __one, const array<_Tp, _Nm>& __two)
 269     { return !(__one < __two); }
 270
 271   // Specialized algorithms.
 272   template<typename _Tp, std::size_t _Nm>
 273     inline void
 274     swap(array<_Tp, _Nm>& __one, array<_Tp, _Nm>& __two)
 275     noexcept(noexcept(__one.swap(__two)))
 276     { __one.swap(__two); }
 277
 278   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 279     constexpr _Tp&
 280     get(array<_Tp, _Nm>& __arr) noexcept
 281     {
 282       static_assert(_Int < _Nm, "index is out of bounds");
 283       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 284         _S_ref(__arr._M_elems, _Int);
 285     }
 286
 287   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 288     constexpr _Tp&&
 289     get(array<_Tp, _Nm>&& __arr) noexcept
 290     {
 291       static_assert(_Int < _Nm, "index is out of bounds");
 292       return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
 293     }
 294
 295   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 296     constexpr const _Tp&
 297     get(const array<_Tp, _Nm>& __arr) noexcept
 298     {
 299       static_assert(_Int < _Nm, "index is out of bounds");
 300       return _GLIBCXX_STD_C::__array_traits<_Tp, _Nm>::
 301         _S_ref(__arr._M_elems, _Int);
 302     }
 303
 304 _GLIBCXX_END_NAMESPACE_CONTAINER
 305 } // namespace std
 306
 307 namespace std _GLIBCXX_VISIBILITY(default)
 308 {
 309 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 310
 311   // Tuple interface to class template array.
 312
 313   /// tuple_size
 314   template<typename _Tp>
 315     class tuple_size;
 316
 317   /// Partial specialization for std::array
 318   template<typename _Tp, std::size_t _Nm>
 319     struct tuple_size<_GLIBCXX_STD_C::array<_Tp, _Nm>>
 320     : public integral_constant<std::size_t, _Nm> { };
 321
 322   /// tuple_element
 323   template<std::size_t _Int, typename _Tp>
 324     class tuple_element;
 325
 326   /// Partial specialization for std::array
 327   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
 328     struct tuple_element<_Int, _GLIBCXX_STD_C::array<_Tp, _Nm>>
 329     {
 330       static_assert(_Int < _Nm, "index is out of bounds");
 331       typedef _Tp type;
 332     };
 333
 334 _GLIBCXX_END_NAMESPACE_VERSION
 335 } // namespace std
 336
 337 #ifdef _GLIBCXX_DEBUG
 338 # include <debug/array>
 339 #endif
 340
 341 #ifdef _GLIBCXX_PROFILE
 342 # include <profile/array>
 343 #endif
 344
 345 #endif // C++11
 346
 347 #endif // _GLIBCXX_ARRAY