/*
 *
 * 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 __SGI_STL_INTERNAL_ITERATOR_H
#define __SGI_STL_INTERNAL_ITERATOR_H

#ifndef __SGI_STL_INTERNAL_ITERATOR_BASE_H
# include <stl_iterator_base.h>
#endif

__STL_BEGIN_NAMESPACE

# if defined (__STL_MSVC50_COMPATIBILITY)
# define __Reference _Reference, class _Pointer
# define Reference__ _Reference, _Pointer
template <class _BidirectionalIterator, class _Tp, 
    __DFL_TMPL_PARAM(_Reference, _Tp& ),
    __DFL_TMPL_PARAM(_Pointer, _Tp*),
    __DFL_TYPE_PARAM(_Distance, ptrdiff_t)> 
# else
# define __Reference _Reference
# define Reference__ _Reference
template <class _BidirectionalIterator, class _Tp, __DFL_TMPL_PARAM(_Reference, _Tp& ),
    __DFL_TYPE_PARAM(_Distance, ptrdiff_t)> 
# endif
class reverse_bidirectional_iterator {
  typedef reverse_bidirectional_iterator<_BidirectionalIterator, _Tp, 
                                         Reference__, _Distance> _Self;
  //  friend inline bool operator== __STL_NULL_TMPL_ARGS (const _Self& x, const _Self& y);
protected:
  _BidirectionalIterator current;
public:
  typedef bidirectional_iterator_tag iterator_category;
  typedef _Tp                        value_type;
  typedef _Distance                  difference_type;
# if defined (__STL_MSVC50_COMPATIBILITY)
  typedef _Pointer                   pointer;
# else
  typedef _Tp*                       pointer;
# endif
  typedef _Reference                 reference;

  reverse_bidirectional_iterator() {}
  explicit reverse_bidirectional_iterator(_BidirectionalIterator __x)
    : current(__x) {}
  _BidirectionalIterator base() const { return current; }
  _Reference operator*() const {
    _BidirectionalIterator __tmp = current;
    return *--__tmp;
  }
# if !(defined __SGI_STL_NO_ARROW_OPERATOR && ! defined (__STL_MSVC50_COMPATIBILITY))
  __STL_DEFINE_ARROW_OPERATOR
# endif
  _Self& operator++() {
    --current;
    return *this;
  }
  _Self operator++(int) {
    _Self __tmp = *this;
    --current;
    return __tmp;
  }
  _Self& operator--() {
    ++current;
    return *this;
  }
  _Self operator--(int) {
    _Self __tmp = *this;
    ++current;
    return __tmp;
  }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _BidirectionalIterator, class _Tp, class __Reference, 
          class _Distance>
inline bidirectional_iterator_tag
iterator_category(const reverse_bidirectional_iterator<_BidirectionalIterator,
                                                       _Tp, Reference__, 
                                                       _Distance>&) 
{
  return bidirectional_iterator_tag();
}

template <class _BidirectionalIterator, class _Tp, class __Reference, 
          class _Distance>
inline _Tp*
value_type(const reverse_bidirectional_iterator<_BidirectionalIterator, _Tp,
                                               Reference__, _Distance>&)
{
  return (_Tp*) 0;
}

template <class _BidirectionalIterator, class _Tp, class __Reference, 
          class _Distance>
inline _Distance*
distance_type(const reverse_bidirectional_iterator<_BidirectionalIterator, 
                                                   _Tp,
                                                   Reference__, _Distance>&)
{
  return (_Distance*) 0;
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _BidirectionalIterator, class _Tp, class __Reference, 
          class _Distance>
inline bool operator==(
    const reverse_bidirectional_iterator<_BidirectionalIterator, _Tp,
                                               Reference__, _Distance>& __x,
    const reverse_bidirectional_iterator<_BidirectionalIterator, _Tp,
                                               Reference__, _Distance>& __y)
{
  return __x.base() == __y.base();
}

#ifdef __STL_USE_SEPARATE_RELOPS_NAMESPACE

template <class _BiIter, class _Tp, class __Reference, class _Distance>
inline bool operator!=(
    const reverse_bidirectional_iterator<_BiIter, _Tp, Reference__, _Distance>& __x, 
    const reverse_bidirectional_iterator<_BiIter, _Tp, Reference__, _Distance>& __y)
{
  return !(__x == __y);
}

#endif /* __STL_USE_SEPARATE_RELOPS_NAMESPACE */

#if defined ( __STL_CLASS_PARTIAL_SPECIALIZATION ) && \
! defined (__STL_PARTIAL_SPECIALIZATION_BUG)

// This is the new version of reverse_iterator, as defined in the
//  draft C++ standard.  It relies on the iterator_traits template,
//  which in turn relies on partial specialization.  The class
//  reverse_bidirectional_iterator is no longer part of the draft
//  standard, but it is retained for backward compatibility.

template <class _Iterator>
class reverse_iterator 
{
protected:
  _Iterator current;
public:
  typedef typename iterator_traits<_Iterator>::iterator_category
          iterator_category;
  typedef typename iterator_traits<_Iterator>::value_type
          value_type;
  typedef typename iterator_traits<_Iterator>::difference_type
          difference_type;
  typedef typename iterator_traits<_Iterator>::pointer
          pointer;
  typedef typename iterator_traits<_Iterator>::reference
          reference;

  typedef _Iterator iterator_type;
  typedef reverse_iterator<_Iterator> _Self;

public:
  reverse_iterator() {}
  explicit reverse_iterator(iterator_type __x) : current(__x) {}

  reverse_iterator(const _Self& __x) : current(__x.current) {}
#ifdef __STL_MEMBER_TEMPLATES
  template <class _Iter>
  reverse_iterator(const reverse_iterator<_Iter>& __x)
    : current(__x.base()) {}
#endif /* __STL_MEMBER_TEMPLATES */
    
  iterator_type base() const { return current; }
  reference operator*() const {
    _Iterator __tmp = current;
    return *--__tmp;
  }
  __STL_DEFINE_ARROW_OPERATOR
  _Self& operator++() {
    --current;
    return *this;
  }
  _Self operator++(int) {
    _Self __tmp = *this;
    --current;
    return __tmp;
  }
  _Self& operator--() {
    ++current;
    return *this;
  }
  _Self operator--(int) {
    _Self __tmp = *this;
    ++current;
    return __tmp;
  }

  _Self operator+(difference_type __n) const {
    return _Self(current - __n);
  }
  _Self& operator+=(difference_type __n) {
    current -= __n;
    return *this;
  }
  _Self operator-(difference_type __n) const {
    return _Self(current + __n);
  }
  _Self& operator-=(difference_type __n) {
    current += __n;
    return *this;
  }
  reference operator[](difference_type __n) const { return *(*this + __n); }  
}; 
 
template <class _Iterator>
inline bool operator==(const reverse_iterator<_Iterator>& __x, 
                       const reverse_iterator<_Iterator>& __y) {
  return __x.base() == __y.base();
}

template <class _Iterator>
inline bool operator<(const reverse_iterator<_Iterator>& __x, 
                      const reverse_iterator<_Iterator>& __y) {
  return __y.base() < __x.base();
}

#ifdef __STL_USE_SEPARATE_RELOPS_NAMESPACE

template <class _Iterator>
inline bool operator!=(const reverse_iterator<_Iterator>& __x, 
                       const reverse_iterator<_Iterator>& __y) {
  return !(__x == __y);
}

template <class _Iterator>
inline bool operator>(const reverse_iterator<_Iterator>& __x, 
                      const reverse_iterator<_Iterator>& __y) {
  return __y < __x;
}

template <class _Iterator>
inline bool operator<=(const reverse_iterator<_Iterator>& __x, 
                       const reverse_iterator<_Iterator>& __y) {
  return !(__y < __x);
}

template <class _Iterator>
inline bool operator>=(const reverse_iterator<_Iterator>& __x, 
                      const reverse_iterator<_Iterator>& __y) {
  return !(__x < __y);
}

#endif /* __STL_USE_SEPARATE_RELOPS_NAMESPACE */

template <class _Iterator>
inline typename reverse_iterator<_Iterator>::difference_type
operator-(const reverse_iterator<_Iterator>& __x, 
          const reverse_iterator<_Iterator>& __y) {
  return __y.base() - __x.base();
}

template <class _Iterator>
inline reverse_iterator<_Iterator> 
operator+(typename reverse_iterator<_Iterator>::difference_type __n,
          const reverse_iterator<_Iterator>& __x) {
  return reverse_iterator<_Iterator>(__x.base() - __n);
}

#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */

// This is the old version of reverse_iterator, as found in the original
//  HP STL.  It does not use partial specialization.

template <class _RandomAccessIterator, 
# if defined (__MSL__) && (__MSL__ >= 0x2405)
	__DFL_TMPL_PARAM(_Tp,iterator_traits<_RandomAccessIterator>::value_type),
# else
	class _Tp,
#endif
 __DFL_TMPL_PARAM(_Reference,_Tp&),
# if defined (__STL_MSVC50_COMPATIBILITY)
        __DFL_TMPL_PARAM(_Pointer, _Tp*),
# endif
        __DFL_TYPE_PARAM(_Distance,ptrdiff_t)> 
class reverse_iterator {
  typedef reverse_iterator<_RandomAccessIterator, _Tp, Reference__, _Distance>
          _Self;
protected:
  _RandomAccessIterator __current;
public:
  typedef random_access_iterator_tag iterator_category;
  typedef _Tp                        value_type;
  typedef _Distance                  difference_type;
# if defined (__STL_MSVC50_COMPATIBILITY)
  typedef _Pointer                   pointer;
# else
  typedef _Tp*                       pointer;
# endif
  typedef _Reference                 reference;

  reverse_iterator() {}
  reverse_iterator(const _Self& __x) : __current(__x.base()) {}
  explicit reverse_iterator(_RandomAccessIterator __x) : __current(__x) {}
  _Self& operator=(const _Self& __x) {__current = __x.base(); return *this; }  
       
  _RandomAccessIterator base() const { return __current; }
  _Reference operator*() const { return *(__current - (difference_type)1); }

# if !(defined __SGI_STL_NO_ARROW_OPERATOR && ! defined (__STL_MSVC50_COMPATIBILITY))
  __STL_DEFINE_ARROW_OPERATOR
# endif

  _Self& operator++() {
    --__current;
    return *this;
  }
  _Self operator++(int) {
    _Self __tmp = *this;
    --__current;
    return __tmp;
  }
  _Self& operator--() {
    ++__current;
    return *this;
  }
  _Self operator--(int) {
    _Self __tmp = *this;
    ++__current;
    return __tmp;
  }
  _Self operator+(_Distance __n) const {
    return _Self(__current - __n);
  }
  _Self& operator+=(_Distance __n) {
    __current -= __n;
    return *this;
  }
  _Self operator-(_Distance __n) const {
    return _Self(__current + __n);
  }
  _Self& operator-=(_Distance __n) {
    __current += __n;
    return *this;
  }
  _Reference operator[](_Distance __n) const { return *(*this + __n); }
};

template <class _RandomAccessIterator, class _Tp, 
          class __Reference, class _Distance>
inline random_access_iterator_tag
iterator_category(const reverse_iterator<_RandomAccessIterator, _Tp,
                                         Reference__, _Distance>&)
{
  return random_access_iterator_tag();
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline _Tp* value_type(const reverse_iterator<_RandomAccessIterator, _Tp,
                                              Reference__, _Distance>&)
{
  return (_Tp*) 0;
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline _Distance* 
distance_type(const reverse_iterator<_RandomAccessIterator, 
                                     _Tp, Reference__, _Distance>&)
{
  return (_Distance*) 0;
}


template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator==(const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __x, 
           const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __y)
{
  return __x.base() == __y.base();
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator<(const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __x, 
          const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __y)
{
  return __y.base() < __x.base();
}

#ifdef __STL_USE_SEPARATE_RELOPS_NAMESPACE

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator!=(const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __x, 
           const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __y) {
  return !(__x == __y);
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator>(const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __x, 
          const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __y) {
  return __y < __x;
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator<=(const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __x, 
           const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __y) {
  return !(__y < __x);
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline bool 
operator>=(const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __x, 
           const reverse_iterator<_RandomAccessIterator, _Tp,
                                  Reference__, _Distance>& __y) {
  return !(__x < __y);
}

#endif /* __STL_USE_SEPARATE_RELOPS_NAMESPACE */

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline _Distance 
operator-(const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __x, 
          const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __y)
{
  return __y.base() - __x.base();
}

template <class _RandomAccessIterator, class _Tp,
          class __Reference, class _Distance>
inline reverse_iterator<_RandomAccessIterator, _Tp,
                        Reference__, _Distance> 
operator+(_Distance __n,
          const reverse_iterator<_RandomAccessIterator, _Tp,
                                 Reference__, _Distance>& __x)
{
  return reverse_iterator<_RandomAccessIterator, _Tp,
                          Reference__, _Distance>(__x.base() - __n);
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Container>
class back_insert_iterator {
protected:
  _Container* container;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
#endif
  explicit back_insert_iterator(_Container& __x) : container(&__x) {}
  back_insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    container->push_back(__value);
    return *this;
  }
  back_insert_iterator<_Container>& operator*() { return *this; }
  back_insert_iterator<_Container>& operator++() { return *this; }
  back_insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const back_insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Container>
inline back_insert_iterator<_Container> back_inserter(_Container& __x) {
  return back_insert_iterator<_Container>(__x);
}

template <class _Container>
class front_insert_iterator {
protected:
  _Container* container;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
# ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
# endif
  explicit front_insert_iterator(_Container& __x) : container(&__x) {}
  front_insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    container->push_front(__value);
    return *this;
  }
  front_insert_iterator<_Container>& operator*() { return *this; }
  front_insert_iterator<_Container>& operator++() { return *this; }
  front_insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const front_insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Container>
inline front_insert_iterator<_Container> front_inserter(_Container& __x) {
  return front_insert_iterator<_Container>(__x);
}

template <class _Container>
class insert_iterator {
protected:
  _Container* container;
  typename _Container::iterator iter;
public:
  typedef _Container          container_type;
  typedef output_iterator_tag iterator_category;
# ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;
# endif
  insert_iterator(_Container& __x, typename _Container::iterator __i) 
    : container(&__x), iter(__i) {}
  insert_iterator<_Container>&
  operator=(const typename _Container::value_type& __value) { 
    iter = container->insert(iter, __value);
    ++iter;
    return *this;
  }
  insert_iterator<_Container>& operator*() { return *this; }
  insert_iterator<_Container>& operator++() { return *this; }
  insert_iterator<_Container>& operator++(int) { return *this; }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Container>
inline output_iterator_tag
iterator_category(const insert_iterator<_Container>&)
{
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Container, class _Iterator>
inline 
insert_iterator<_Container> inserter(_Container& __x, _Iterator __i)
{
  typedef typename _Container::iterator __iter;
  return insert_iterator<_Container>(__x, __iter(__i));
}

__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_ITERATOR_H */

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