libstdc++-v3/include/bits/range_access.h

   1 // <range_access.h> -*- C++ -*-
   2
   3 // Copyright (C) 2010-2018 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 bits/range_access.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{iterator}
  28  */
  29
  30 #ifndef _GLIBCXX_RANGE_ACCESS_H
  31 #define _GLIBCXX_RANGE_ACCESS_H 1
  32
  33 #pragma GCC system_header
  34
  35 #if __cplusplus >= 201103L
  36 #include <initializer_list>
  37 namespace std _GLIBCXX_VISIBILITY(default)
  38 {
  39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  40
  41   /**
  42    *  @brief  Return an iterator pointing to the first element of
  43    *          the container.
  44    *  @param  __cont  Container.
  45    */
  46   template<typename _Container>
  47     inline _GLIBCXX17_CONSTEXPR auto
  48     begin(_Container& __cont) -> decltype(__cont.begin())
  49     { return __cont.begin(); }
  50
  51   /**
  52    *  @brief  Return an iterator pointing to the first element of
  53    *          the const container.
  54    *  @param  __cont  Container.
  55    */
  56   template<typename _Container>
  57     inline _GLIBCXX17_CONSTEXPR auto
  58     begin(const _Container& __cont) -> decltype(__cont.begin())
  59     { return __cont.begin(); }
  60
  61   /**
  62    *  @brief  Return an iterator pointing to one past the last element of
  63    *          the container.
  64    *  @param  __cont  Container.
  65    */
  66   template<typename _Container>
  67     inline _GLIBCXX17_CONSTEXPR auto
  68     end(_Container& __cont) -> decltype(__cont.end())
  69     { return __cont.end(); }
  70
  71   /**
  72    *  @brief  Return an iterator pointing to one past the last element of
  73    *          the const container.
  74    *  @param  __cont  Container.
  75    */
  76   template<typename _Container>
  77     inline _GLIBCXX17_CONSTEXPR auto
  78     end(const _Container& __cont) -> decltype(__cont.end())
  79     { return __cont.end(); }
  80
  81   /**
  82    *  @brief  Return an iterator pointing to the first element of the array.
  83    *  @param  __arr  Array.
  84    */
  85   template<typename _Tp, size_t _Nm>
  86     inline _GLIBCXX14_CONSTEXPR _Tp*
  87     begin(_Tp (&__arr)[_Nm])
  88     { return __arr; }
  89
  90   /**
  91    *  @brief  Return an iterator pointing to one past the last element
  92    *          of the array.
  93    *  @param  __arr  Array.
  94    */
  95   template<typename _Tp, size_t _Nm>
  96     inline _GLIBCXX14_CONSTEXPR _Tp*
  97     end(_Tp (&__arr)[_Nm])
  98     { return __arr + _Nm; }
  99
 100 #if __cplusplus >= 201402L
 101
 102   template<typename _Tp> class valarray;
 103   // These overloads must be declared for cbegin and cend to use them.
 104   template<typename _Tp> _Tp* begin(valarray<_Tp>&);
 105   template<typename _Tp> const _Tp* begin(const valarray<_Tp>&);
 106   template<typename _Tp> _Tp* end(valarray<_Tp>&);
 107   template<typename _Tp> const _Tp* end(const valarray<_Tp>&);
 108
 109   /**
 110    *  @brief  Return an iterator pointing to the first element of
 111    *          the const container.
 112    *  @param  __cont  Container.
 113    */
 114   template<typename _Container>
 115     inline constexpr auto
 116     cbegin(const _Container& __cont) noexcept(noexcept(std::begin(__cont)))
 117       -> decltype(std::begin(__cont))
 118     { return std::begin(__cont); }
 119
 120   /**
 121    *  @brief  Return an iterator pointing to one past the last element of
 122    *          the const container.
 123    *  @param  __cont  Container.
 124    */
 125   template<typename _Container>
 126     inline constexpr auto
 127     cend(const _Container& __cont) noexcept(noexcept(std::end(__cont)))
 128       -> decltype(std::end(__cont))
 129     { return std::end(__cont); }
 130
 131   /**
 132    *  @brief  Return a reverse iterator pointing to the last element of
 133    *          the container.
 134    *  @param  __cont  Container.
 135    */
 136   template<typename _Container>
 137     inline _GLIBCXX17_CONSTEXPR auto
 138     rbegin(_Container& __cont) -> decltype(__cont.rbegin())
 139     { return __cont.rbegin(); }
 140
 141   /**
 142    *  @brief  Return a reverse iterator pointing to the last element of
 143    *          the const container.
 144    *  @param  __cont  Container.
 145    */
 146   template<typename _Container>
 147     inline _GLIBCXX17_CONSTEXPR auto
 148     rbegin(const _Container& __cont) -> decltype(__cont.rbegin())
 149     { return __cont.rbegin(); }
 150
 151   /**
 152    *  @brief  Return a reverse iterator pointing one past the first element of
 153    *          the container.
 154    *  @param  __cont  Container.
 155    */
 156   template<typename _Container>
 157     inline _GLIBCXX17_CONSTEXPR auto
 158     rend(_Container& __cont) -> decltype(__cont.rend())
 159     { return __cont.rend(); }
 160
 161   /**
 162    *  @brief  Return a reverse iterator pointing one past the first element of
 163    *          the const container.
 164    *  @param  __cont  Container.
 165    */
 166   template<typename _Container>
 167     inline _GLIBCXX17_CONSTEXPR auto
 168     rend(const _Container& __cont) -> decltype(__cont.rend())
 169     { return __cont.rend(); }
 170
 171   /**
 172    *  @brief  Return a reverse iterator pointing to the last element of
 173    *          the array.
 174    *  @param  __arr  Array.
 175    */
 176   template<typename _Tp, size_t _Nm>
 177     inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
 178     rbegin(_Tp (&__arr)[_Nm])
 179     { return reverse_iterator<_Tp*>(__arr + _Nm); }
 180
 181   /**
 182    *  @brief  Return a reverse iterator pointing one past the first element of
 183    *          the array.
 184    *  @param  __arr  Array.
 185    */
 186   template<typename _Tp, size_t _Nm>
 187     inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
 188     rend(_Tp (&__arr)[_Nm])
 189     { return reverse_iterator<_Tp*>(__arr); }
 190
 191   /**
 192    *  @brief  Return a reverse iterator pointing to the last element of
 193    *          the initializer_list.
 194    *  @param  __il  initializer_list.
 195    */
 196   template<typename _Tp>
 197     inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
 198     rbegin(initializer_list<_Tp> __il)
 199     { return reverse_iterator<const _Tp*>(__il.end()); }
 200
 201   /**
 202    *  @brief  Return a reverse iterator pointing one past the first element of
 203    *          the initializer_list.
 204    *  @param  __il  initializer_list.
 205    */
 206   template<typename _Tp>
 207     inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
 208     rend(initializer_list<_Tp> __il)
 209     { return reverse_iterator<const _Tp*>(__il.begin()); }
 210
 211   /**
 212    *  @brief  Return a reverse iterator pointing to the last element of
 213    *          the const container.
 214    *  @param  __cont  Container.
 215    */
 216   template<typename _Container>
 217     inline _GLIBCXX17_CONSTEXPR auto
 218     crbegin(const _Container& __cont) -> decltype(std::rbegin(__cont))
 219     { return std::rbegin(__cont); }
 220
 221   /**
 222    *  @brief  Return a reverse iterator pointing one past the first element of
 223    *          the const container.
 224    *  @param  __cont  Container.
 225    */
 226   template<typename _Container>
 227     inline _GLIBCXX17_CONSTEXPR auto
 228     crend(const _Container& __cont) -> decltype(std::rend(__cont))
 229     { return std::rend(__cont); }
 230
 231 #endif // C++14
 232
 233 #if __cplusplus >= 201703L
 234 #define __cpp_lib_nonmember_container_access 201411
 235
 236   /**
 237    *  @brief  Return the size of a container.
 238    *  @param  __cont  Container.
 239    */
 240   template <typename _Container>
 241     constexpr auto
 242     size(const _Container& __cont) noexcept(noexcept(__cont.size()))
 243     -> decltype(__cont.size())
 244     { return __cont.size(); }
 245
 246   /**
 247    *  @brief  Return the size of an array.
 248    *  @param  __array  Array.
 249    */
 250   template <typename _Tp, size_t _Nm>
 251     constexpr size_t
 252     size(const _Tp (&/*__array*/)[_Nm]) noexcept
 253     { return _Nm; }
 254
 255   /**
 256    *  @brief  Return whether a container is empty.
 257    *  @param  __cont  Container.
 258    */
 259   template <typename _Container>
 260     [[nodiscard]] constexpr auto
 261     empty(const _Container& __cont) noexcept(noexcept(__cont.empty()))
 262     -> decltype(__cont.empty())
 263     { return __cont.empty(); }
 264
 265   /**
 266    *  @brief  Return whether an array is empty (always false).
 267    *  @param  __array  Container.
 268    */
 269   template <typename _Tp, size_t _Nm>
 270     [[nodiscard]] constexpr bool
 271     empty(const _Tp (&/*__array*/)[_Nm]) noexcept
 272     { return false; }
 273
 274   /**
 275    *  @brief  Return whether an initializer_list is empty.
 276    *  @param  __il  Initializer list.
 277    */
 278   template <typename _Tp>
 279     [[nodiscard]] constexpr bool
 280     empty(initializer_list<_Tp> __il) noexcept
 281     { return __il.size() == 0;}
 282
 283   /**
 284    *  @brief  Return the data pointer of a container.
 285    *  @param  __cont  Container.
 286    */
 287   template <typename _Container>
 288     constexpr auto
 289     data(_Container& __cont) noexcept(noexcept(__cont.data()))
 290     -> decltype(__cont.data())
 291     { return __cont.data(); }
 292
 293   /**
 294    *  @brief  Return the data pointer of a const container.
 295    *  @param  __cont  Container.
 296    */
 297   template <typename _Container>
 298     constexpr auto
 299     data(const _Container& __cont) noexcept(noexcept(__cont.data()))
 300     -> decltype(__cont.data())
 301     { return __cont.data(); }
 302
 303   /**
 304    *  @brief  Return the data pointer of an array.
 305    *  @param  __array  Array.
 306    */
 307   template <typename _Tp, size_t _Nm>
 308     constexpr _Tp*
 309     data(_Tp (&__array)[_Nm]) noexcept
 310     { return __array; }
 311
 312   /**
 313    *  @brief  Return the data pointer of an initializer list.
 314    *  @param  __il  Initializer list.
 315    */
 316   template <typename _Tp>
 317     constexpr const _Tp*
 318     data(initializer_list<_Tp> __il) noexcept
 319     { return __il.begin(); }
 320
 321 #endif // C++17
 322
 323 _GLIBCXX_END_NAMESPACE_VERSION
 324 } // namespace
 325
 326 #endif // C++11
 327
 328 #endif // _GLIBCXX_RANGE_ACCESS_H