libstdc++-v3/include/ext/iterator

   1 // HP/SGI iterator extensions -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002 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 2, 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 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /*
  31  *
  32  * Copyright (c) 1994
  33  * Hewlett-Packard Company
  34  *
  35  * Permission to use, copy, modify, distribute and sell this software
  36  * and its documentation for any purpose is hereby granted without fee,
  37  * provided that the above copyright notice appear in all copies and
  38  * that both that copyright notice and this permission notice appear
  39  * in supporting documentation.  Hewlett-Packard Company makes no
  40  * representations about the suitability of this software for any
  41  * purpose.  It is provided "as is" without express or implied warranty.
  42  *
  43  *
  44  * Copyright (c) 1996-1998
  45  * Silicon Graphics Computer Systems, Inc.
  46  *
  47  * Permission to use, copy, modify, distribute and sell this software
  48  * and its documentation for any purpose is hereby granted without fee,
  49  * provided that the above copyright notice appear in all copies and
  50  * that both that copyright notice and this permission notice appear
  51  * in supporting documentation.  Silicon Graphics makes no
  52  * representations about the suitability of this software for any
  53  * purpose.  It is provided "as is" without express or implied warranty.
  54  */
  55
  56 /** @file ext/iterator
  57  *  This file is a GNU extension to the Standard C++ Library (possibly
  58  *  containing extensions from the HP/SGI STL subset).  You should only
  59  *  include this header if you are using GCC 3 or later.
  60  */
  61
  62 #ifndef _EXT_ITERATOR
  63 #define _EXT_ITERATOR 1
  64
  65 #pragma GCC system_header
  66
  67 #include <bits/concept_check.h>
  68 #include <iterator>
  69
  70 namespace __gnu_cxx
  71 {
  72   // There are two signatures for distance.  In addition to the one
  73   // taking two iterators and returning a result, there is another
  74   // taking two iterators and a reference-to-result variable, and
  75   // returning nothing.  The latter seems to be an SGI extension.
  76   // -- pedwards
  77   template<typename _InputIterator, typename _Distance>
  78     inline void
  79     __distance(_InputIterator __first, _InputIterator __last,
  80                _Distance& __n, std::input_iterator_tag)
  81     {
  82       // concept requirements
  83       __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>)
  84       while (__first != __last) { ++__first; ++__n; }
  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       __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>)
  94       __n += __last - __first;
  95     }
  96
  97   /**
  98    *  This is an SGI extension.
  99    *  @ingroup SGIextensions
 100    *  @doctodo
 101   */
 102   template<typename _InputIterator, typename _Distance>
 103     inline void
 104     distance(_InputIterator __first, _InputIterator __last,
 105              _Distance& __n)
 106     {
 107       // concept requirements -- taken care of in __distance
 108       __distance(__first, __last, __n, std::__iterator_category(__first));
 109     }
 110 } // namespace __gnu_cxx
 111
 112 #endif
 113