/*

  * 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: