libstdc++-v3/include/ext/iterator

   1 // HP/SGI iterator extensions -*- C++ -*-
   2
   3 // Copyright (C) 2001-2022 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 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996-1998
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 /** @file ext/iterator
  52  *  This file is a GNU extension to the Standard C++ Library (possibly
  53  *  containing extensions from the HP/SGI STL subset).
  54  */
  55
  56 #ifndef _EXT_ITERATOR
  57 #define _EXT_ITERATOR 1
  58
  59 #pragma GCC system_header
  60
  61 #include <bits/concept_check.h>
  62 #include <iterator>
  63
  64 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  65 {
  66 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  67
  68   // There are two signatures for distance.  In addition to the one
  69   // taking two iterators and returning a result, there is another
  70   // taking two iterators and a reference-to-result variable, and
  71   // returning nothing.  The latter seems to be an SGI extension.
  72   // -- pedwards
  73   template<typename _InputIterator, typename _Distance>
  74     inline void
  75     __distance(_InputIterator __first, _InputIterator __last,
  76                _Distance& __n, std::input_iterator_tag)
  77     {
  78       // concept requirements
  79       __glibcxx_function_requires(_InputIteratorConcept<_InputIterator>)
  80       while (__first != __last)
  81         {
  82           ++__first;
  83           ++__n;
  84         }
  85     }
  86
  87   template<typename _RandomAccessIterator, typename _Distance>
  88     inline void
  89     __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
  90                _Distance& __n, std::random_access_iterator_tag)
  91     {
  92       // concept requirements
  93       __glibcxx_function_requires(_RandomAccessIteratorConcept<
  94                                   _RandomAccessIterator>)
  95       __n += __last - __first;
  96     }
  97
  98   /**
  99    *  This is an SGI extension.
 100    *  @ingroup SGIextensions
 101    *  @doctodo
 102   */
 103   template<typename _InputIterator, typename _Distance>
 104     inline void
 105     distance(_InputIterator __first, _InputIterator __last,
 106              _Distance& __n)
 107     {
 108       // concept requirements -- taken care of in __distance
 109       __distance(__first, __last, __n, std::__iterator_category(__first));
 110     }
 111
 112 _GLIBCXX_END_NAMESPACE_VERSION
 113 } // namespace
 114
 115 #endif
 116