/*

 * Copyright (c) 1999

 * Silicon Graphics Computer Systems, Inc.

 *

 * 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.

 *

 */ 

// WARNING: This is an internal header file, included by other C++

// standard library headers.  You should not attempt to use this header

// file directly.

#ifndef _STLP_INTERNAL_ISTREAMBUF_ITERATOR_H

#define _STLP_INTERNAL_ISTREAMBUF_ITERATOR_H

#ifndef _STLP_INTERNAL_ITERATOR_BASE_H

# include <stl/_iterator_base.h>

#endif

#ifndef _STLP_INTERNAL_STREAMBUF

# include <stl/_streambuf.h>

#endif

_STLP_BEGIN_NAMESPACE

// defined in _istream.h

template <class _CharT, class _Traits>

extern basic_streambuf<_CharT, _Traits>* _STLP_CALL _M_get_istreambuf(basic_istream<_CharT, _Traits>& ) ;

// We do not read any characters until operator* is called. operator* calls sgetc 

// unless the iterator is unchanged from the last call in which case a cached value is

// used. Calls to operator++ use sbumpc.

template<class _CharT, class _Traits>

class istreambuf_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_istream<_CharT, _Traits>   istream_type;

  typedef input_iterator_tag               iterator_category;

  typedef _CharT                           value_type;

  typedef typename _Traits::off_type       difference_type;

  typedef const _CharT*                    pointer;

  typedef const _CharT&                    reference;

public:

  istreambuf_iterator(streambuf_type* __p = 0) { this->_M_init(__p); }

  //  istreambuf_iterator(basic_istream<_CharT, _Traits>& __is) { this->_M_init(_M_get_istreambuf(__is)); }

  inline istreambuf_iterator(basic_istream<_CharT, _Traits>& __is);

  char_type operator*() const { this->_M_getc(); return _M_c; }

  istreambuf_iterator<_CharT, _Traits>& operator++() { this->_M_bumpc(); return *this; }

  istreambuf_iterator<_CharT, _Traits>  operator++(int);

  bool equal(const istreambuf_iterator<_CharT, _Traits>& __i) const {

    if (this->_M_buf)

      this->_M_getc();

    if (__i._M_buf)

      __i._M_getc(); 

    return this->_M_eof == __i._M_eof;

  }

private:

  void _M_init(streambuf_type* __p) {

    _M_buf = __p;

    _M_eof = !__p;

    //    _M_is_initialized = _M_eof;

    _M_have_c = false;

  }

  void _M_getc() const {

    if (_M_have_c)

      return;

    int_type __c = _M_buf->sgetc();

# if !defined (_STLP_NEED_MUTABLE) /* && ! defined (__SUNPRO_CC) */

    _M_c = traits_type::to_char_type(__c);

    _M_eof = traits_type::eq_int_type(__c, traits_type::eof());

    _M_have_c = true;

# else

    typedef istreambuf_iterator<_CharT,_Traits> _Self;

    _Self* __that = __CONST_CAST(_Self*, this);

    __that->_M_c = __STATIC_CAST(_CharT, traits_type::to_char_type(__c));

    __that->_M_eof = traits_type::eq_int_type(__c, traits_type::eof());

    __that->_M_have_c = true;

# endif

  }

  int_type _M_bumpc() {

  	int_type ch = _M_buf->sbumpc();

     _M_have_c = false;

	 return ch;

  }

private:

  streambuf_type* _M_buf;

  mutable _CharT _M_c;

  mutable unsigned char _M_eof;

  mutable unsigned char _M_have_c;

};

template<class _CharT, class _Traits>

inline istreambuf_iterator<_CharT, _Traits>::istreambuf_iterator(basic_istream<_CharT, _Traits>& __is) 

{ this->_M_init(_M_get_istreambuf(__is)); }

template<class _CharT, class _Traits>

inline bool _STLP_CALL operator==(const istreambuf_iterator<_CharT, _Traits>& __x,

                                  const istreambuf_iterator<_CharT, _Traits>& __y) {

  return __x.equal(__y);

}

#ifdef _STLP_USE_SEPARATE_RELOPS_NAMESPACE

template<class _CharT, class _Traits>

inline bool _STLP_CALL operator!=(const istreambuf_iterator<_CharT, _Traits>& __x,

                                  const istreambuf_iterator<_CharT, _Traits>& __y) {

  return !__x.equal(__y);

}

#endif /* _STLP_USE_SEPARATE_RELOPS_NAMESPACE */

# if defined (_STLP_USE_TEMPLATE_EXPORT)

_STLP_EXPORT_TEMPLATE_CLASS istreambuf_iterator<char, char_traits<char> >;

#  if defined (INSTANTIATE_WIDE_STREAMS)

_STLP_EXPORT_TEMPLATE_CLASS istreambuf_iterator<wchar_t, char_traits<wchar_t> >;

#  endif

# endif /* _STLP_USE_TEMPLATE_EXPORT */

# ifdef _STLP_USE_OLD_HP_ITERATOR_QUERIES

template <class _CharT, class _Traits>

inline input_iterator_tag _STLP_CALL iterator_category(const istreambuf_iterator<_CharT, _Traits>&) { return input_iterator_tag(); }

template <class _CharT, class _Traits>

inline streamoff* _STLP_CALL 

distance_type(const istreambuf_iterator<_CharT, _Traits>&) { return (streamoff*)0; }

template <class _CharT, class _Traits>

inline _CharT* _STLP_CALL value_type(const istreambuf_iterator<_CharT, _Traits>&) { return (_CharT*)0; }

# endif

template <class _CharT, class _Traits>

istreambuf_iterator<_CharT, _Traits>

istreambuf_iterator<_CharT, _Traits>::operator++(int) {

  istreambuf_iterator<_CharT, _Traits> __tmp = *this;

  __tmp._M_c = this->_M_bumpc();

  __tmp._M_have_c = true;

  this->_M_have_c = false;

  return __tmp;

}

_STLP_END_NAMESPACE

#endif /* _STLP_INTERNAL_ISTREAMBUF_ITERATOR_H */

// Local Variables:

// mode:C++

// End: