# stl_iterator_base_funcs.h

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    00001 // Functions used by iterators -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002 Free Software Foundation, Inc.
    00004 //
    00005 // This file is part of the GNU ISO C++ Library.  This library is free
    00006 // software; you can redistribute it and/or modify it under the
    00007 // terms of the GNU General Public License as published by the
    00008 // Free Software Foundation; either version 2, or (at your option)
    00009 // any later version.
    00010
    00011 // This library is distributed in the hope that it will be useful,
    00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00014 // GNU General Public License for more details.
    00015
    00016 // You should have received a copy of the GNU General Public License along
    00017 // with this library; see the file COPYING.  If not, write to the Free
    00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00019 // USA.
    00020
    00021 // As a special exception, you may use this file as part of a free software
    00022 // library without restriction.  Specifically, if other files instantiate
    00023 // templates or use macros or inline functions from this file, or you compile
    00024 // this file and link it with other files to produce an executable, this
    00025 // file does not by itself cause the resulting executable to be covered by
    00026 // the GNU General Public License.  This exception does not however
    00027 // invalidate any other reasons why the executable file might be covered by
    00028 // the GNU General Public License.
    00029
    00030 /*
    00031  *
    00032  * Copyright (c) 1994
    00033  * Hewlett-Packard Company
    00034  *
    00035  * Permission to use, copy, modify, distribute and sell this software
    00036  * and its documentation for any purpose is hereby granted without fee,
    00037  * provided that the above copyright notice appear in all copies and
    00038  * that both that copyright notice and this permission notice appear
    00039  * in supporting documentation.  Hewlett-Packard Company makes no
    00040  * representations about the suitability of this software for any
    00041  * purpose.  It is provided "as is" without express or implied warranty.
    00042  *
    00043  *
    00044  * Copyright (c) 1996-1998
    00045  * Silicon Graphics Computer Systems, Inc.
    00046  *
    00047  * Permission to use, copy, modify, distribute and sell this software
    00048  * and its documentation for any purpose is hereby granted without fee,
    00049  * provided that the above copyright notice appear in all copies and
    00050  * that both that copyright notice and this permission notice appear
    00051  * in supporting documentation.  Silicon Graphics makes no
    00052  * representations about the suitability of this software for any
    00053  * purpose.  It is provided "as is" without express or implied warranty.
    00054  */
    00055
    00064 #ifndef __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H
    00065 #define __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H
    00066
    00067 #pragma GCC system_header
    00068 #include <bits/concept_check.h>
    00069
    00070 namespace std
    00071 {
    00072   template<typename _InputIterator>
    00073     inline typename iterator_traits<_InputIterator>::difference_type
    00074     __distance(_InputIterator __first, _InputIterator __last,
    00075                input_iterator_tag)
    00076     {
    00077       // concept requirements
    00078       __glibcpp_function_requires(_InputIteratorConcept<_InputIterator>)
    00079
    00080       typename iterator_traits<_InputIterator>::difference_type __n = 0;
    00081       while (__first != __last) {
    00082         ++__first; ++__n;
    00083       }
    00084       return __n;
    00085     }
    00086
    00087   template<typename _RandomAccessIterator>
    00088     inline typename iterator_traits<_RandomAccessIterator>::difference_type
    00089     __distance(_RandomAccessIterator __first, _RandomAccessIterator __last,
    00090                random_access_iterator_tag)
    00091     {
    00092       // concept requirements
    00093       __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>)
    00094       return __last - __first;
    00095     }
    00096
    00109   template<typename _InputIterator>
    00110     inline typename iterator_traits<_InputIterator>::difference_type
    00111     distance(_InputIterator __first, _InputIterator __last)
    00112     {
    00113       // concept requirements -- taken care of in __distance
    00114       return __distance(__first, __last, __iterator_category(__first));
    00115     }
    00116
    00117   template<typename _InputIter, typename _Distance>
    00118     inline void
    00119     __advance(_InputIter& __i, _Distance __n, input_iterator_tag)
    00120     {
    00121       // concept requirements
    00122       __glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
    00123       while (__n--) ++__i;
    00124     }
    00125
    00126   template<typename _BidirectionalIterator, typename _Distance>
    00127     inline void
    00128     __advance(_BidirectionalIterator& __i, _Distance __n,
    00129               bidirectional_iterator_tag)
    00130     {
    00131       // concept requirements
    00132       __glibcpp_function_requires(_BidirectionalIteratorConcept<_BidirectionalIterator>)
    00133
    00134       if (__n > 0)
    00135         while (__n--) ++__i;
    00136       else
    00137         while (__n++) --__i;
    00138     }
    00139
    00140   template<typename _RandomAccessIterator, typename _Distance>
    00141     inline void
    00142     __advance(_RandomAccessIterator& __i, _Distance __n,
    00143               random_access_iterator_tag)
    00144     {
    00145       // concept requirements
    00146       __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIterator>)
    00147       __i += __n;
    00148     }
    00149
    00162   template<typename _InputIterator, typename _Distance>
    00163     inline void
    00164     advance(_InputIterator& __i, _Distance __n)
    00165     {
    00166       // concept requirements -- taken care of in __advance
    00167       __advance(__i, __n, __iterator_category(__i));
    00168     }
    00169 } // namespace std
    00170
    00171 #endif /* __GLIBCPP_INTERNAL_ITERATOR_BASE_FUNCS_H */