mingw/lib/gcc/mingw32/4.3.3/include/c++/bits/stl_iterator_base_types.h

   1 // Types used in iterator implementation -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /*
  32  *
  33  * Copyright (c) 1994
  34  * Hewlett-Packard Company
  35  *
  36  * Permission to use, copy, modify, distribute and sell this software
  37  * and its documentation for any purpose is hereby granted without fee,
  38  * provided that the above copyright notice appear in all copies and
  39  * that both that copyright notice and this permission notice appear
  40  * in supporting documentation.  Hewlett-Packard Company makes no
  41  * representations about the suitability of this software for any
  42  * purpose.  It is provided "as is" without express or implied warranty.
  43  *
  44  *
  45  * Copyright (c) 1996-1998
  46  * Silicon Graphics Computer Systems, Inc.
  47  *
  48  * Permission to use, copy, modify, distribute and sell this software
  49  * and its documentation for any purpose is hereby granted without fee,
  50  * provided that the above copyright notice appear in all copies and
  51  * that both that copyright notice and this permission notice appear
  52  * in supporting documentation.  Silicon Graphics makes no
  53  * representations about the suitability of this software for any
  54  * purpose.  It is provided "as is" without express or implied warranty.
  55  */
  56
  57 /** @file stl_iterator_base_types.h
  58  *  This is an internal header file, included by other library headers.
  59  *  You should not attempt to use it directly.
  60  *
  61  *  This file contains all of the general iterator-related utility types,
  62  *  such as iterator_traits and struct iterator.
  63  */
  64
  65 #ifndef _STL_ITERATOR_BASE_TYPES_H
  66 #define _STL_ITERATOR_BASE_TYPES_H 1
  67
  68 #pragma GCC system_header
  69
  70 #include <bits/c++config.h>
  71 #include <cstddef>
  72
  73 _GLIBCXX_BEGIN_NAMESPACE(std)
  74
  75   //@{
  76   /**
  77    *  @defgroup iterator_tags Iterator Tags
  78    *  These are empty types, used to distinguish different iterators.  The
  79    *  distinction is not made by what they contain, but simply by what they
  80    *  are.  Different underlying algorithms can then be used based on the
  81    *  different operations supported by different iterator types.
  82   */
  83   ///  Marking input iterators.
  84   struct input_iterator_tag {};
  85   ///  Marking output iterators.
  86   struct output_iterator_tag {};
  87   /// Forward iterators support a superset of input iterator operations.
  88   struct forward_iterator_tag : public input_iterator_tag {};
  89   /// Bidirectional iterators support a superset of forward iterator
  90   /// operations.
  91   struct bidirectional_iterator_tag : public forward_iterator_tag {};
  92   /// Random-access iterators support a superset of bidirectional iterator
  93   /// operations.
  94   struct random_access_iterator_tag : public bidirectional_iterator_tag {};
  95   //@}
  96
  97
  98   /**
  99    *  @brief  Common %iterator class.
 100    *
 101    *  This class does nothing but define nested typedefs.  %Iterator classes
 102    *  can inherit from this class to save some work.  The typedefs are then
 103    *  used in specializations and overloading.
 104    *
 105    *  In particular, there are no default implementations of requirements
 106    *  such as @c operator++ and the like.  (How could there be?)
 107   */
 108   template<typename _Category, typename _Tp, typename _Distance = ptrdiff_t,
 109            typename _Pointer = _Tp*, typename _Reference = _Tp&>
 110     struct iterator
 111     {
 112       /// One of the @link iterator_tags tag types@endlink.
 113       typedef _Category  iterator_category;
 114       /// The type "pointed to" by the iterator.
 115       typedef _Tp        value_type;
 116       /// Distance between iterators is represented as this type.
 117       typedef _Distance  difference_type;
 118       /// This type represents a pointer-to-value_type.
 119       typedef _Pointer   pointer;
 120       /// This type represents a reference-to-value_type.
 121       typedef _Reference reference;
 122     };
 123
 124   /**
 125    *  This class does nothing but define nested typedefs.  The general
 126    *  version simply "forwards" the nested typedefs from the Iterator
 127    *  argument.  Specialized versions for pointers and pointers-to-const
 128    *  provide tighter, more correct semantics.
 129   */
 130   template<typename _Iterator>
 131     struct iterator_traits
 132     {
 133       typedef typename _Iterator::iterator_category iterator_category;
 134       typedef typename _Iterator::value_type        value_type;
 135       typedef typename _Iterator::difference_type   difference_type;
 136       typedef typename _Iterator::pointer           pointer;
 137       typedef typename _Iterator::reference         reference;
 138     };
 139
 140   template<typename _Tp>
 141     struct iterator_traits<_Tp*>
 142     {
 143       typedef random_access_iterator_tag iterator_category;
 144       typedef _Tp                         value_type;
 145       typedef ptrdiff_t                   difference_type;
 146       typedef _Tp*                        pointer;
 147       typedef _Tp&                        reference;
 148     };
 149
 150   template<typename _Tp>
 151     struct iterator_traits<const _Tp*>
 152     {
 153       typedef random_access_iterator_tag iterator_category;
 154       typedef _Tp                         value_type;
 155       typedef ptrdiff_t                   difference_type;
 156       typedef const _Tp*                  pointer;
 157       typedef const _Tp&                  reference;
 158     };
 159
 160   /**
 161    *  This function is not a part of the C++ standard but is syntactic
 162    *  sugar for internal library use only.
 163   */
 164   template<typename _Iter>
 165     inline typename iterator_traits<_Iter>::iterator_category
 166     __iterator_category(const _Iter&)
 167     { return typename iterator_traits<_Iter>::iterator_category(); }
 168
 169 _GLIBCXX_END_NAMESPACE
 170
 171 #endif /* _STL_ITERATOR_BASE_TYPES_H */
 172