_iterator_base.h

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1997
 * Moscow Center for SPARC Technology
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef _STLP_INTERNAL_ITERATOR_BASE_H
#define _STLP_INTERNAL_ITERATOR_BASE_H

#ifndef _STLP_CSTDDEF
# include <cstddef>
#endif

#ifndef __TYPE_TRAITS_H
# include <stl/type_traits.h>
#endif

_STLP_BEGIN_NAMESPACE

struct input_iterator_tag {};
struct output_iterator_tag {};
struct forward_iterator_tag : public input_iterator_tag {};
struct bidirectional_iterator_tag : public forward_iterator_tag {};
struct random_access_iterator_tag : public bidirectional_iterator_tag {};


template <class _Category, class _Tp, __DFL_TMPL_PARAM(_Distance,ptrdiff_t),
          __DFL_TMPL_PARAM(_Pointer,_Tp*), __DFL_TMPL_PARAM(_Reference,_Tp&) >
struct iterator {
  typedef _Category  iterator_category;
  typedef _Tp        value_type;
  typedef _Distance  difference_type;
  typedef _Pointer   pointer;
  typedef _Reference reference;
};
_STLP_TEMPLATE_NULL
struct iterator<output_iterator_tag, void, void, void, void> {
  typedef output_iterator_tag  iterator_category;
#ifdef _STLP_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
#endif
};

# ifdef _STLP_USE_OLD_HP_ITERATOR_QUERIES
#  define _STLP_ITERATOR_CATEGORY(_It, _Tp) iterator_category(_It)
#  define _STLP_DISTANCE_TYPE(_It, _Tp)     distance_type(_It)
#  define _STLP_VALUE_TYPE(_It, _Tp)        value_type(_It)
# else
#  ifdef _STLP_CLASS_PARTIAL_SPECIALIZATION
#   define _STLP_VALUE_TYPE(_It, _Tp)        (typename iterator_traits< _Tp >::value_type*)0
#   define _STLP_DISTANCE_TYPE(_It, _Tp)     (typename iterator_traits< _Tp >::difference_type*)0
#   if defined (__BORLANDC__) || defined (__SUNPRO_CC) || ( defined (__MWERKS__) && (__MWERKS__ <= 0x2303)) || ( defined (__sgi) && defined (_COMPILER_VERSION)) 
#    define _STLP_ITERATOR_CATEGORY(_It, _Tp) iterator_traits< _Tp >::iterator_category()
#   else
#    define _STLP_ITERATOR_CATEGORY(_It, _Tp) typename iterator_traits< _Tp >::iterator_category()
#   endif
#  else
#   define _STLP_ITERATOR_CATEGORY(_It, _Tp) __iterator_category(_It, _IsPtrType<_Tp>::_Ret())
#   define _STLP_DISTANCE_TYPE(_It, _Tp)     (ptrdiff_t*)0
#   define _STLP_VALUE_TYPE(_It, _Tp)        __value_type(_It, _IsPtrType<_Tp>::_Ret() )
#  endif
# endif

template <class _Iterator>
struct iterator_traits {
  typedef typename _Iterator::iterator_category iterator_category;
  typedef typename _Iterator::value_type        value_type;
  typedef typename _Iterator::difference_type   difference_type;
  typedef typename _Iterator::pointer           pointer;
  typedef typename _Iterator::reference         reference;
};


# if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION) && ! defined (__SUNPRO_CC)
#  define _STLP_DIFFERENCE_TYPE(_Iterator) typename iterator_traits<_Iterator>::difference_type
# else
#  define _STLP_DIFFERENCE_TYPE(_Iterator) ptrdiff_t
# endif

# ifdef _STLP_CLASS_PARTIAL_SPECIALIZATION

// fbp : this order keeps gcc happy
template <class _Tp>
struct iterator_traits<const _Tp*> {
  typedef random_access_iterator_tag iterator_category;
  typedef _Tp                         value_type;
  typedef ptrdiff_t                   difference_type;
  typedef const _Tp*                  pointer;
  typedef const _Tp&                  reference;
};

template <class _Tp>
struct iterator_traits<_Tp*> {
  typedef random_access_iterator_tag iterator_category;
  typedef _Tp                         value_type;
  typedef ptrdiff_t                   difference_type;
  typedef _Tp*                        pointer;
  typedef _Tp&                        reference;
};

#  if defined (__BORLANDC__)
template <class _Tp>
struct iterator_traits<_Tp* const> {
  typedef random_access_iterator_tag iterator_category;
  typedef _Tp                         value_type;
  typedef ptrdiff_t                   difference_type;
  typedef const _Tp*                  pointer;
  typedef const _Tp&                  reference;
};
#  endif

# endif /* _STLP_CLASS_PARTIAL_SPECIALIZATION */


# if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION) \
  || (defined (_STLP_SIMULATE_PARTIAL_SPEC_FOR_TYPE_TRAITS) && ! defined (_STLP_NO_ARROW_OPERATOR))
#  define _STLP_POINTERS_SPECIALIZE( _TpP )
#  define _STLP_DEFINE_ARROW_OPERATOR  pointer operator->() const { return &(operator*()); }
# else 
   _STLP_END_NAMESPACE
#  include <stl/_ptrs_specialize.h>
   _STLP_BEGIN_NAMESPACE
# endif

# ifndef _STLP_USE_OLD_HP_ITERATOR_QUERIES
// The overloaded functions iterator_category, distance_type, and
// value_type are not part of the C++ standard.  (They have been
// replaced by struct iterator_traits.)  They are included for
// backward compatibility with the HP STL.
// We introduce internal names for these functions.

#  ifdef  _STLP_CLASS_PARTIAL_SPECIALIZATION

template <class _Iter>
inline typename iterator_traits<_Iter>::iterator_category __iterator_category(const _Iter&) {
  typedef typename iterator_traits<_Iter>::iterator_category _Category;
  return _Category();
}

template <class _Iter>
inline typename iterator_traits<_Iter>::difference_type* __distance_type(const _Iter&) {
  typedef typename iterator_traits<_Iter>::difference_type _diff_type;
  return __STATIC_CAST(_diff_type*,0);
}

template <class _Iter>
inline typename iterator_traits<_Iter>::value_type* __value_type(const _Iter&) {
  typedef typename iterator_traits<_Iter>::value_type _value_type;
  return __STATIC_CAST(_value_type*,0);
}

# else

template <class _Iter>
inline random_access_iterator_tag 
__iterator_category(const _Iter&, const __true_type&) {
  return random_access_iterator_tag();
}

template <class _Iter>
inline _STLP_TYPENAME_ON_RETURN_TYPE iterator_traits<_Iter>::iterator_category
__iterator_category(const _Iter&, const __false_type&) {
  typedef typename iterator_traits<_Iter>::iterator_category _Category;
  return _Category();
}


template <class _Iter>
inline ptrdiff_t* _STLP_CALL __distance_type(const _Iter&) { return (ptrdiff_t*)(0); }

template <class _Iter>
inline _STLP_TYPENAME_ON_RETURN_TYPE iterator_traits<_Iter>::value_type* 
__value_type(const _Iter&, const __false_type&) {
  typedef typename iterator_traits<_Iter>::value_type _value_type;
  return __STATIC_CAST(_value_type*,0);
}

template <class _Tp>
inline _Tp*  
__value_type(const _Tp*, const __true_type&) {
  return __STATIC_CAST(_Tp*, 0);
}

# endif

#else /* old queries */
template <class _Category, class _Tp, class _Distance, class _Pointer, class _Reference>
inline _Category _STLP_CALL iterator_category(const iterator<_Category,_Tp,_Distance,_Pointer,_Reference>&) { return _Category(); }
template <class _Category, class _Tp, class _Distance, class _Pointer, class _Reference>
inline _Tp* _STLP_CALL value_type(const iterator<_Category,_Tp,_Distance,_Pointer,_Reference>&) { return (_Tp*)(0); }
template <class _Category, class _Tp, class _Distance, class _Pointer, class _Reference>
inline _Distance* _STLP_CALL distance_type(const iterator<_Category,_Tp,_Distance,_Pointer,_Reference>&) { return (_Distance*)(0); }
template <class _Tp>
inline random_access_iterator_tag _STLP_CALL iterator_category(const _Tp*) { return random_access_iterator_tag(); }
template <class _Tp>
inline _Tp* _STLP_CALL value_type(const _Tp*) { return (_Tp*)(0); }
template <class _Tp>
inline ptrdiff_t* _STLP_CALL distance_type(const _Tp*) { return (ptrdiff_t*)(0); }
#endif /* _STLP_USE_OLD_HP_ITERATOR_QUERIES */

# if ! defined (_STLP_NO_ANACHRONISMS)
// The base classes input_iterator, output_iterator, forward_iterator,
// bidirectional_iterator, and random_access_iterator are not part of
// the C++ standard.  (They have been replaced by struct iterator.)
// They are included for backward compatibility with the HP STL.
template <class _Tp, class _Distance> struct input_iterator : 
  public iterator <input_iterator_tag, _Tp, _Distance, _Tp*, _Tp&> {};
struct output_iterator : public iterator <output_iterator_tag, void, void, void, void> {};
template <class _Tp, class _Distance> struct forward_iterator :
  public iterator<forward_iterator_tag, _Tp, _Distance, _Tp*, _Tp&> {};
template <class _Tp, class _Distance> struct bidirectional_iterator :
  public iterator<bidirectional_iterator_tag, _Tp, _Distance, _Tp*, _Tp&> {};
template <class _Tp, class _Distance> struct random_access_iterator :
  public iterator<random_access_iterator_tag, _Tp, _Distance, _Tp*, _Tp&> {};

# if defined (_STLP_BASE_MATCH_BUG) && defined (_STLP_USE_OLD_HP_ITERATOR_QUERIES)
template <class _Tp, class _Distance> 
inline input_iterator_tag _STLP_CALL 
iterator_category(const input_iterator<_Tp, _Distance>&) { return input_iterator_tag(); }
inline output_iterator_tag _STLP_CALL
iterator_category(const output_iterator&) { return output_iterator_tag(); }
template <class _Tp, class _Distance> 
inline forward_iterator_tag _STLP_CALL
iterator_category(const forward_iterator<_Tp, _Distance>&) { return forward_iterator_tag(); }
template <class _Tp, class _Distance> 
inline bidirectional_iterator_tag _STLP_CALL 
iterator_category(const bidirectional_iterator<_Tp, _Distance>&) { return bidirectional_iterator_tag(); }
template <class _Tp, class _Distance> 
inline random_access_iterator_tag _STLP_CALL
iterator_category(const random_access_iterator<_Tp, _Distance>&) { return random_access_iterator_tag(); }
template <class _Tp, class _Distance> 
inline _Tp*  _STLP_CALL value_type(const input_iterator<_Tp, _Distance>&) { return (_Tp*)(0); }
template <class _Tp, class _Distance> 
inline _Tp* _STLP_CALL value_type(const forward_iterator<_Tp, _Distance>&) { return (_Tp*)(0); }
template <class _Tp, class _Distance> 
inline _Tp* _STLP_CALL value_type(const bidirectional_iterator<_Tp, _Distance>&) { return (_Tp*)(0); }
template <class _Tp, class _Distance> 
inline _Tp* _STLP_CALL value_type(const random_access_iterator<_Tp, _Distance>&) { return (_Tp*)(0); }
template <class _Tp, class _Distance> 
inline _Distance* _STLP_CALL distance_type(const input_iterator<_Tp, _Distance>&) { return (_Distance*)(0); }
template <class _Tp, class _Distance> 
inline _Distance* _STLP_CALL distance_type(const forward_iterator<_Tp, _Distance>&) { return (_Distance*)(0); }
template <class _Tp, class _Distance> 
inline _Distance* _STLP_CALL distance_type(const bidirectional_iterator<_Tp, _Distance>&) { return (_Distance*)(0);}
template <class _Tp, class _Distance> 
inline _Distance* _STLP_CALL distance_type(const random_access_iterator<_Tp, _Distance>&) { return (_Distance*)(0); }
# endif /* BASE_MATCH */

#endif /* _STLP_NO_ANACHRONISMS */

template <class _InputIterator, class _Distance>
inline void _STLP_CALL __distance(const _InputIterator& __first, const _InputIterator& __last,
                                  _Distance& __n, const input_iterator_tag &) {
  _InputIterator __it(__first);
  while (__it != __last) { ++__it; ++__n; }
}

# if defined (_STLP_NONTEMPL_BASE_MATCH_BUG) 
template <class _ForwardIterator, class _Distance>
inline void _STLP_CALL __distance(const _ForwardIterator& __first, const _ForwardIterator& __last,
                                  _Distance& __n, const forward_iterator_tag &) {
  _ForwardIterator __it(__first);
  while (__it != __last) { ++__first; ++__n; }
}

template <class _BidirectionalIterator, class _Distance>
_STLP_INLINE_LOOP void _STLP_CALL __distance(const _BidirectionalIterator& __first, 
                                             const _BidirectionalIterator& __last,
                                             _Distance& __n, const bidirectional_iterator_tag &) {
  _BidirectionalIterator __it(__first);
  while (__it != __last) { ++__it; ++__n; }
}
# endif

template <class _RandomAccessIterator, class _Distance>
inline void _STLP_CALL __distance(const _RandomAccessIterator& __first, 
                                  const _RandomAccessIterator& __last, 
                                  _Distance& __n, const random_access_iterator_tag &) {
  __n += __last - __first;
}

#ifndef _STLP_NO_ANACHRONISMS 
template <class _InputIterator, class _Distance>
inline void _STLP_CALL distance(const _InputIterator& __first, 
                                const _InputIterator& __last, _Distance& __n) {
  __distance(__first, __last, __n, _STLP_ITERATOR_CATEGORY(__first, _InputIterator));
}
#endif

template <class _InputIterator>
inline _STLP_DIFFERENCE_TYPE(_InputIterator) _STLP_CALL
__distance(const _InputIterator& __first, const _InputIterator& __last, const input_iterator_tag &) {
  _STLP_DIFFERENCE_TYPE(_InputIterator) __n = 0;
  _InputIterator __it(__first);  
  while (__it != __last) {
    ++__it; ++__n;
  }
  return __n;
}

# if defined (_STLP_NONTEMPL_BASE_MATCH_BUG) 
template <class _ForwardIterator>
inline _STLP_DIFFERENCE_TYPE(_ForwardIterator) _STLP_CALL 
__distance(const _ForwardIterator& __first, const _ForwardIterator& __last,
           const forward_iterator_tag &)
{
  _STLP_DIFFERENCE_TYPE(_ForwardIterator) __n = 0;
  _ForwardIterator __it(__first);
  while (__it != __last) {
    ++__it; ++__n;
  }
  return __n;
}

template <class _BidirectionalIterator>
_STLP_INLINE_LOOP _STLP_DIFFERENCE_TYPE(_BidirectionalIterator) _STLP_CALL 
__distance(const _BidirectionalIterator& __first, 
           const _BidirectionalIterator& __last,
           const bidirectional_iterator_tag &) {
  _STLP_DIFFERENCE_TYPE(_BidirectionalIterator) __n = 0;
  _BidirectionalIterator __it(__first);
  while (__it != __last) {
    ++__it; ++__n;
  }
  return __n;
}
# endif

template <class _RandomAccessIterator>
inline _STLP_DIFFERENCE_TYPE(_RandomAccessIterator) _STLP_CALL
__distance(const _RandomAccessIterator& __first, const _RandomAccessIterator& __last,
           const random_access_iterator_tag &) {
  return __last - __first;
}

template <class _InputIterator>
inline _STLP_DIFFERENCE_TYPE(_InputIterator) _STLP_CALL
distance(const _InputIterator& __first, const _InputIterator& __last) {
  return __distance(__first, __last, _STLP_ITERATOR_CATEGORY(__first, _InputIterator));  
}


// fbp: those are being used for iterator/const_iterator definitions everywhere
template <class _Tp>
struct _Nonconst_traits;

template <class _Tp>
struct _Const_traits {
  typedef _Tp value_type;
  typedef const _Tp&  reference;
  typedef const _Tp*  pointer;
  typedef _Nonconst_traits<_Tp> _Non_const_traits;
};

template <class _Tp>
struct _Nonconst_traits {
  typedef _Tp value_type;
  typedef _Tp& reference;
  typedef _Tp* pointer;
  typedef _Nonconst_traits<_Tp> _Non_const_traits;
};

#  if defined (_STLP_BASE_TYPEDEF_BUG)
// this workaround is needed for SunPro 4.0.1
template <class _Traits>
struct __cnst_traits_aux : private _Traits
{
  typedef typename _Traits::value_type value_type;
};
#  define __TRAITS_VALUE_TYPE(_Traits) __cnst_traits_aux<_Traits>::value_type
#  else
#  define __TRAITS_VALUE_TYPE(_Traits) _Traits::value_type
#  endif

# if defined (_STLP_MSVC)
// MSVC specific
template <class _InputIterator, class _Dist>
inline void  _STLP_CALL _Distance(_InputIterator __first, 
                      _InputIterator __last, _Dist& __n) {
  __distance(__first, __last, __n, _STLP_ITERATOR_CATEGORY(__first, _InputIterator));
}
# endif

template <class _InputIter, class _Distance>
_STLP_INLINE_LOOP void  _STLP_CALL __advance(_InputIter& __i, _Distance __n, const input_iterator_tag &) {
  while (__n--) ++__i;
}

// fbp : added output iterator tag variant
template <class _InputIter, class _Distance>
_STLP_INLINE_LOOP void  _STLP_CALL __advance(_InputIter& __i, _Distance __n, const output_iterator_tag &) {
  while (__n--) ++__i;
}

# if defined (_STLP_NONTEMPL_BASE_MATCH_BUG)
template <class _ForwardIterator, class _Distance>
_STLP_INLINE_LOOP void _STLP_CALL __advance(_ForwardIterator& i, _Distance n, const forward_iterator_tag &) {
    while (n--) ++i;
}
# endif

template <class _BidirectionalIterator, class _Distance>
_STLP_INLINE_LOOP void _STLP_CALL __advance(_BidirectionalIterator& __i, _Distance __n, 
                      const bidirectional_iterator_tag &) {
  if (__n > 0)
    while (__n--) ++__i;
  else
    while (__n++) --__i;
}

template <class _RandomAccessIterator, class _Distance>
inline void _STLP_CALL __advance(_RandomAccessIterator& __i, _Distance __n, 
                      const random_access_iterator_tag &) {
  __i += __n;
}

template <class _InputIterator, class _Distance>
inline void _STLP_CALL advance(_InputIterator& __i, _Distance __n) {
  __advance(__i, __n, _STLP_ITERATOR_CATEGORY(__i, _InputIterator));
}

_STLP_END_NAMESPACE

# if defined (_STLP_DEBUG) && ! defined (_STLP_DEBUG_H)
#  include <stl/debug/_debug.h>
# endif

#endif /* _STLP_INTERNAL_ITERATOR_BASE_H */


// Local Variables:
// mode:C++
// End:

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