stl_iterator.h

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  void _M_postincr_aux();

  void _M_nextc() {
    int_type __c = _M_buf->snextc();
    _M_c = traits_type::to_char_type(__c);    
    _M_eof = traits_type::eq_int_type(__c, traits_type::eof());
    _M_is_initialized = true;
  }

  void _M_getc() const {
    int_type __c = _M_buf->sgetc();
    _M_c = traits_type::to_char_type(__c);
    _M_eof = traits_type::eq_int_type(__c, traits_type::eof());
    _M_is_initialized = true;
  }

private:
  streambuf_type* _M_buf;
  mutable _CharT _M_c;
  mutable bool _M_eof : 1;
  mutable bool _M_is_initialized : 1;
};

template<class _CharT, class _Traits>
_CharT istreambuf_iterator<_CharT, _Traits>::_M_dereference_aux() const
{
  this->_M_getc();
  return _M_c;
}

template<class _CharT, class _Traits>
bool istreambuf_iterator<_CharT, _Traits>
  ::_M_equal_aux(const istreambuf_iterator& __i) const
{
  if (!this->_M_is_initialized)
    this->_M_getc();
  if (!__i._M_is_initialized)
    __i._M_getc();

  return this->_M_eof == __i._M_eof;
}

template<class _CharT, class _Traits>
void istreambuf_iterator<_CharT, _Traits>::_M_postincr_aux()
{
  this->_M_getc();
}

template<class _CharT, class _Traits>
inline bool operator==(const istreambuf_iterator<_CharT, _Traits>& __x,
                       const istreambuf_iterator<_CharT, _Traits>& __y) {
  return __x.equal(__y);
}

#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER

template<class _CharT, class _Traits>
inline bool operator!=(const istreambuf_iterator<_CharT, _Traits>& __x,
                       const istreambuf_iterator<_CharT, _Traits>& __y) {
  return !__x.equal(__y);
}

#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */

// The default template argument is declared in iosfwd
template<class _CharT, class _Traits>
class ostreambuf_iterator
{
public:
  typedef _CharT                           char_type;
  typedef _Traits                          traits_type;
  typedef typename _Traits::int_type       int_type;
  typedef basic_streambuf<_CharT, _Traits> streambuf_type;
  typedef basic_ostream<_CharT, _Traits>   ostream_type;

  typedef output_iterator_tag              iterator_category;
  typedef void                             value_type;
  typedef void                             difference_type;
  typedef void                             pointer;
  typedef void                             reference;

public:
  ostreambuf_iterator(streambuf_type* __buf) : _M_buf(__buf), _M_ok(__buf) {}
  ostreambuf_iterator(ostream_type& __o)
    : _M_buf(__o.rdbuf()), _M_ok(__o.rdbuf()) {}

  ostreambuf_iterator& operator=(char_type __c) {
    _M_ok = _M_ok && !traits_type::eq_int_type(_M_buf->sputc(__c),
                                               traits_type::eof());
    return *this;
  }    
  
  ostreambuf_iterator& operator*()     { return *this; }
  ostreambuf_iterator& operator++()    { return *this; }
  ostreambuf_iterator& operator++(int) { return *this; }

  bool failed() const { return !_M_ok; }

private:
  streambuf_type* _M_buf;
  bool _M_ok;
};

#else /* __STL_USE_NEW_IOSTREAMS */

template <class _Tp, class _Dist = ptrdiff_t> class istream_iterator;

template <class _Tp, class _Dist>
inline bool operator==(const istream_iterator<_Tp, _Dist>&,
                       const istream_iterator<_Tp, _Dist>&);

template <class _Tp, class _Dist>
class istream_iterator {
#ifdef __STL_MEMBER_TEMPLATES
  template <class _T1, class _D1>
  friend bool operator==(const istream_iterator<_T1, _D1>&,
                         const istream_iterator<_T1, _D1>&);
#else /* __STL_MEMBER_TEMPLATES */
  friend bool __STD_QUALIFIER
  operator== __STL_NULL_TMPL_ARGS (const istream_iterator&,
                                   const istream_iterator&);
#endif /* __STL_MEMBER_TEMPLATES */

protected:
  istream* _M_stream;
  _Tp _M_value;
  bool _M_end_marker;
  void _M_read() {
    _M_end_marker = (*_M_stream) ? true : false;
    if (_M_end_marker) *_M_stream >> _M_value;
    _M_end_marker = (*_M_stream) ? true : false;
  }
public:
  typedef input_iterator_tag  iterator_category;
  typedef _Tp                 value_type;
  typedef _Dist               difference_type;
  typedef const _Tp*          pointer;
  typedef const _Tp&          reference;

  istream_iterator() : _M_stream(&cin), _M_end_marker(false) {}
  istream_iterator(istream& __s) : _M_stream(&__s) { _M_read(); }
  reference operator*() const { return _M_value; }
#ifndef __SGI_STL_NO_ARROW_OPERATOR
  pointer operator->() const { return &(operator*()); }
#endif /* __SGI_STL_NO_ARROW_OPERATOR */
  istream_iterator<_Tp, _Dist>& operator++() { 
    _M_read(); 
    return *this;
  }
  istream_iterator<_Tp, _Dist> operator++(int)  {
    istream_iterator<_Tp, _Dist> __tmp = *this;
    _M_read();
    return __tmp;
  }
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Tp, class _Dist>
inline input_iterator_tag 
iterator_category(const istream_iterator<_Tp, _Dist>&)
{
  return input_iterator_tag();
}

template <class _Tp, class _Dist>
inline _Tp* 
value_type(const istream_iterator<_Tp, _Dist>&) { return (_Tp*) 0; }

template <class _Tp, class _Dist>
inline _Dist* 
distance_type(const istream_iterator<_Tp, _Dist>&) { return (_Dist*)0; }

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

template <class _Tp, class _Distance>
inline bool operator==(const istream_iterator<_Tp, _Distance>& __x,
                       const istream_iterator<_Tp, _Distance>& __y) {
  return (__x._M_stream == __y._M_stream &&
          __x._M_end_marker == __y._M_end_marker) ||
         __x._M_end_marker == false && __y._M_end_marker == false;
}

#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDER

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

#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */

template <class _Tp>
class ostream_iterator {
protected:
  ostream* _M_stream;
  const char* _M_string;
public:
  typedef output_iterator_tag iterator_category;
  typedef void                value_type;
  typedef void                difference_type;
  typedef void                pointer;
  typedef void                reference;

  ostream_iterator(ostream& __s) : _M_stream(&__s), _M_string(0) {}
  ostream_iterator(ostream& __s, const char* __c) 
    : _M_stream(&__s), _M_string(__c)  {}
  ostream_iterator<_Tp>& operator=(const _Tp& __value) { 
    *_M_stream << __value;
    if (_M_string) *_M_stream << _M_string;
    return *this;
  }
  ostream_iterator<_Tp>& operator*() { return *this; }
  ostream_iterator<_Tp>& operator++() { return *this; } 
  ostream_iterator<_Tp>& operator++(int) { return *this; } 
};

#ifndef __STL_CLASS_PARTIAL_SPECIALIZATION

template <class _Tp>
inline output_iterator_tag 
iterator_category(const ostream_iterator<_Tp>&) {
  return output_iterator_tag();
}

#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */

#endif /* __STL_USE_NEW_IOSTREAMS */

// This iterator adapter is 'normal' in the sense that it does not
// change the semantics of any of the operators of its itererator
// parameter.  Its primary purpose is to convert an iterator that is
// not a class, e.g. a pointer, into an iterator that is a class.
// The _Container parameter exists solely so that different containers
// using this template can instantiate different types, even if the
// _Iterator parameter is the same.
template<typename _Iterator, typename _Container>
class __normal_iterator
  : public iterator<iterator_traits<_Iterator>::iterator_category,
                    iterator_traits<_Iterator>::value_type,
                    iterator_traits<_Iterator>::difference_type,
                    iterator_traits<_Iterator>::pointer,
                    iterator_traits<_Iterator>::reference>
{
public:

  typedef __normal_iterator<_Iterator, _Container> normal_iterator_type;

  inline __normal_iterator() : _M_current() { }

  inline explicit __normal_iterator(const _Iterator& __i)
    : _M_current(__i) { }

  // Allow iterator to const_iterator conversion
  template<typename _Iter>
  inline __normal_iterator(const __normal_iterator<_Iter, _Container>& __i)
    : _M_current(__i.base()) { }

  // forward iterator requirements

  inline reference
  operator*() const
    { return *_M_current; }

  inline pointer
  operator->() const
    { return _M_current; }

  inline normal_iterator_type&
  operator++()
    { ++_M_current; return *this; }

  inline normal_iterator_type
  operator++(int)
    { return __normal_iterator(_M_current++); }

  // bidirectional iterator requirements

  inline normal_iterator_type&
  operator--()
    { --_M_current; return *this; }

  inline normal_iterator_type
  operator--(int)
    { return __normal_iterator(_M_current--); }

  // random access iterator requirements

  inline reference
  operator[](const difference_type& __n) const
    { return _M_current[__n]; }

  inline normal_iterator_type&
  operator+=(const difference_type& __n)
    { _M_current += __n; return *this; }

  inline normal_iterator_type
  operator+(const difference_type& __n) const
    { return __normal_iterator(_M_current + __n); }

  inline normal_iterator_type&
  operator-=(const difference_type& __n)
    { _M_current -= __n; return *this; }

  inline normal_iterator_type
  operator-(const difference_type& __n) const
    { return __normal_iterator(_M_current - __n); }

  inline difference_type
  operator-(const normal_iterator_type& __i) const
    { return _M_current - __i._M_current; }

  const _Iterator& base() const
    { return _M_current; }

protected:
  _Iterator _M_current;
};

// forward iterator requirements

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator==(const __normal_iterator<_IteratorL, _Container>& __lhs,
                const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() == __rhs.base(); }

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator!=(const __normal_iterator<_IteratorL, _Container>& __lhs,
                const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return !(__lhs == __rhs); }

// random access iterator requirements

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator<(const __normal_iterator<_IteratorL, _Container>& __lhs,
               const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __lhs.base() < __rhs.base(); }

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator>(const __normal_iterator<_IteratorL, _Container>& __lhs,
               const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return __rhs < __lhs; }

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator<=(const __normal_iterator<_IteratorL, _Container>& __lhs,
                const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return !(__rhs < __lhs); }

template<typename _IteratorL, typename _IteratorR, typename _Container>
bool operator>=(const __normal_iterator<_IteratorL, _Container>& __lhs,
                const __normal_iterator<_IteratorR, _Container>& __rhs)
{ return !(__lhs < __rhs); }

template<typename _Iterator, typename _Container>
inline __normal_iterator<_Iterator, _Container>
operator+(__normal_iterator<_Iterator, _Container>::difference_type __n,
          const __normal_iterator<_Iterator, _Container>& __i)
{ return __normal_iterator<_Iterator, _Container>(__i.base() + __n); }

__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_ITERATOR_H */

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// mode:C++
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