libstdc++-v3/include/bits/streambuf_iterator.h

   1 // Streambuf iterators
   2
   3 // Copyright (C) 1997-2001 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 // XXX Should specialize copy, find algorithms for streambuf iterators.
  31
  32 /** @file streambuf_iterator.h
  33  *  This is an internal header file, included by other library headers.
  34  *  You should not attempt to use it directly.
  35  */
  36
  37 #ifndef _CPP_BITS_STREAMBUF_ITERATOR_H
  38 #define _CPP_BITS_STREAMBUF_ITERATOR_H 1
  39
  40 #pragma GCC system_header
  41
  42 namespace std
  43 {
  44   template<typename _CharT, typename _Traits>
  45     class ostreambuf_iterator
  46     : public iterator<output_iterator_tag, void, void, void, void>
  47     {
  48     public:
  49       // Types:
  50       typedef _CharT                           char_type;
  51       typedef _Traits                          traits_type;
  52       typedef basic_streambuf<_CharT, _Traits> streambuf_type;
  53       typedef basic_ostream<_CharT, _Traits>   ostream_type;
  54
  55     private:
  56       streambuf_type*   _M_sbuf;
  57       bool              _M_failed;
  58
  59     public:
  60       inline
  61       ostreambuf_iterator(ostream_type& __s) throw ()
  62       : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
  63
  64       ostreambuf_iterator(streambuf_type* __s) throw ()
  65       : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
  66
  67       ostreambuf_iterator&
  68       operator=(_CharT __c);
  69
  70       ostreambuf_iterator&
  71       operator*() throw()
  72       { return *this; }
  73
  74       ostreambuf_iterator&
  75       operator++(int) throw()
  76       { return *this; }
  77
  78       ostreambuf_iterator&
  79       operator++() throw()
  80       { return *this; }
  81
  82       bool
  83       failed() const throw()
  84       { return _M_failed; }
  85     };
  86
  87   template<typename _CharT, typename _Traits>
  88     inline ostreambuf_iterator<_CharT, _Traits>&
  89     ostreambuf_iterator<_CharT, _Traits>::operator=(_CharT __c)
  90     {
  91       if (!_M_failed &&
  92           _Traits::eq_int_type(_M_sbuf->sputc(__c),_Traits::eof()))
  93       _M_failed = true;
  94       return *this;
  95     }
  96
  97
  98   // 24.5.3 Template class istreambuf_iterator
  99   template<typename _CharT, typename _Traits>
 100     class istreambuf_iterator
 101     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
 102                       _CharT*, _CharT&>
 103     {
 104     public:
 105       // Types:
 106       typedef _CharT                                    char_type;
 107       typedef _Traits                                   traits_type;
 108       typedef typename _Traits::int_type                int_type;
 109       typedef basic_streambuf<_CharT, _Traits>          streambuf_type;
 110       typedef basic_istream<_CharT, _Traits>            istream_type;
 111
 112     private:
 113       // 24.5.3 istreambuf_iterator
 114       // p 1
 115       // If the end of stream is reached (streambuf_type::sgetc()
 116       // returns traits_type::eof()), the iterator becomes equal to
 117       // the "end of stream" iterator value.
 118       // NB: This implementation assumes the "end of stream" value
 119       // is EOF, or -1.
 120       streambuf_type*           _M_sbuf;
 121       int_type                  _M_c;
 122
 123     public:
 124       istreambuf_iterator() throw()
 125       : _M_sbuf(NULL), _M_c(-2) { }
 126
 127       istreambuf_iterator(istream_type& __s) throw()
 128       : _M_sbuf(__s.rdbuf()), _M_c(-2) { }
 129
 130       istreambuf_iterator(streambuf_type* __s) throw()
 131       : _M_sbuf(__s), _M_c(-2) { }
 132
 133       // NB: This should really have an int_type return
 134       // value, so "end of stream" postion can be checked without
 135       // hacking.
 136       char_type
 137       operator*() const
 138       {
 139         // The result of operator*() on an end of stream is undefined.
 140         char_type __ret;
 141         if (_M_sbuf && _M_c != static_cast<int_type>(-2))
 142           __ret = _M_c;
 143         else if (_M_sbuf)
 144           __ret = traits_type::to_char_type(_M_sbuf->sgetc());
 145         else
 146           __ret = static_cast<char_type>(traits_type::eof());
 147         return __ret;
 148       }
 149
 150       istreambuf_iterator&
 151       operator++()
 152       {
 153         if (_M_sbuf)
 154           _M_sbuf->sbumpc();
 155         _M_c = -2;
 156         return *this;
 157       }
 158
 159       istreambuf_iterator
 160       operator++(int)
 161       {
 162         istreambuf_iterator __old = *this;
 163         if (_M_sbuf)
 164           __old._M_c = _M_sbuf->sbumpc();
 165         _M_c = -2;
 166         return __old;
 167       }
 168
 169       bool
 170       equal(const istreambuf_iterator& __b)
 171       {
 172         int_type __eof = traits_type::eof();
 173         bool __thiseof = !_M_sbuf || _M_sbuf->sgetc() == __eof;
 174         bool __beof = !__b._M_sbuf || __b._M_sbuf->sgetc() == __eof;
 175         return (__thiseof && __beof || (!__thiseof && !__beof));
 176       }
 177
 178 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 179       // 110 istreambuf_iterator::equal not const
 180       // NB: there is also number 111 (NAD, Future) pending on this function.
 181       bool
 182       equal(const istreambuf_iterator& __b) const
 183       {
 184         int_type __eof = traits_type::eof();
 185         bool __thiseof = !_M_sbuf || _M_sbuf->sgetc() == __eof;
 186         bool __beof = !__b._M_sbuf || __b._M_sbuf->sgetc() == __eof;
 187         return (__thiseof && __beof || (!__thiseof && !__beof));
 188       }
 189 #endif
 190     };
 191
 192   template<typename _CharT, typename _Traits>
 193     inline bool
 194     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
 195                const istreambuf_iterator<_CharT, _Traits>& __b)
 196     { return __a.equal(__b); }
 197
 198   template<typename _CharT, typename _Traits>
 199     inline bool
 200     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
 201                const istreambuf_iterator<_CharT, _Traits>& __b)
 202     { return !__a.equal(__b); }
 203 } // namespace std
 204 #endif