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

   1 // Streambuf iterators
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /** @file streambuf_iterator.h
  32  *  This is an internal header file, included by other library headers.
  33  *  You should not attempt to use it directly.
  34  */
  35
  36 #ifndef _CPP_BITS_STREAMBUF_ITERATOR_H
  37 #define _CPP_BITS_STREAMBUF_ITERATOR_H 1
  38
  39 #pragma GCC system_header
  40
  41 #include <streambuf>
  42
  43 // NB: Should specialize copy, find algorithms for streambuf iterators.
  44
  45 namespace std
  46 {
  47   // 24.5.3 Template class istreambuf_iterator
  48   template<typename _CharT, typename _Traits>
  49     class istreambuf_iterator
  50     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
  51                       _CharT*, _CharT&>
  52     {
  53     public:
  54       // Types:
  55       typedef _CharT                                    char_type;
  56       typedef _Traits                                   traits_type;
  57       typedef typename _Traits::int_type                int_type;
  58       typedef basic_streambuf<_CharT, _Traits>          streambuf_type;
  59       typedef basic_istream<_CharT, _Traits>            istream_type;
  60
  61     private:
  62       // 24.5.3 istreambuf_iterator
  63       // p 1
  64       // If the end of stream is reached (streambuf_type::sgetc()
  65       // returns traits_type::eof()), the iterator becomes equal to
  66       // the "end of stream" iterator value.
  67       // NB: This implementation assumes the "end of stream" value
  68       // is EOF, or -1.
  69       mutable streambuf_type*   _M_sbuf;
  70       int_type                  _M_c;
  71
  72     public:
  73       istreambuf_iterator() throw()
  74       : _M_sbuf(0), _M_c(traits_type::eof()) { }
  75
  76       istreambuf_iterator(istream_type& __s) throw()
  77       : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
  78
  79       istreambuf_iterator(streambuf_type* __s) throw()
  80       : _M_sbuf(__s), _M_c(traits_type::eof()) { }
  81
  82       // NB: The result of operator*() on an end of stream is undefined.
  83       char_type
  84       operator*() const
  85       { return traits_type::to_char_type(_M_get()); }
  86
  87       istreambuf_iterator&
  88       operator++()
  89       {
  90         const int_type __eof = traits_type::eof();
  91         if (_M_sbuf && traits_type::eq_int_type(_M_sbuf->sbumpc(), __eof))
  92           _M_sbuf = 0;
  93         else
  94           _M_c = __eof;
  95         return *this;
  96       }
  97
  98       istreambuf_iterator
  99       operator++(int)
 100       {
 101         const int_type __eof = traits_type::eof();
 102         istreambuf_iterator __old = *this;
 103         if (_M_sbuf
 104             && traits_type::eq_int_type((__old._M_c = _M_sbuf->sbumpc()),
 105                                         __eof))
 106           _M_sbuf = 0;
 107         else
 108           _M_c = __eof;
 109         return __old;
 110       }
 111
 112 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 113       // 110 istreambuf_iterator::equal not const
 114       // NB: there is also number 111 (NAD, Future) pending on this function.
 115       bool
 116       equal(const istreambuf_iterator& __b) const
 117       {
 118         const int_type __eof = traits_type::eof();
 119         bool __thiseof = traits_type::eq_int_type(_M_get(), __eof);
 120         bool __beof = traits_type::eq_int_type(__b._M_get(), __eof);
 121         return (__thiseof && __beof || (!__thiseof && !__beof));
 122       }
 123 #endif
 124
 125     private:
 126       int_type
 127       _M_get() const
 128       {
 129         const int_type __eof = traits_type::eof();
 130         int_type __ret = __eof;
 131         if (_M_sbuf)
 132           {
 133             if (!traits_type::eq_int_type(_M_c, __eof))
 134               __ret = _M_c;
 135             else
 136               if (traits_type::eq_int_type((__ret = _M_sbuf->sgetc()), __eof))
 137                 _M_sbuf = 0;
 138           }
 139         return __ret;
 140       }
 141     };
 142
 143   template<typename _CharT, typename _Traits>
 144     inline bool
 145     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
 146                const istreambuf_iterator<_CharT, _Traits>& __b)
 147     { return __a.equal(__b); }
 148
 149   template<typename _CharT, typename _Traits>
 150     inline bool
 151     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
 152                const istreambuf_iterator<_CharT, _Traits>& __b)
 153     { return !__a.equal(__b); }
 154
 155   template<typename _CharT, typename _Traits>
 156     class ostreambuf_iterator
 157     : public iterator<output_iterator_tag, void, void, void, void>
 158     {
 159     public:
 160       // Types:
 161       typedef _CharT                           char_type;
 162       typedef _Traits                          traits_type;
 163       typedef basic_streambuf<_CharT, _Traits> streambuf_type;
 164       typedef basic_ostream<_CharT, _Traits>   ostream_type;
 165
 166     private:
 167       streambuf_type*   _M_sbuf;
 168       bool              _M_failed;
 169
 170     public:
 171       ostreambuf_iterator(ostream_type& __s) throw ()
 172       : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
 173
 174       ostreambuf_iterator(streambuf_type* __s) throw ()
 175       : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
 176
 177       ostreambuf_iterator&
 178       operator=(_CharT __c)
 179       {
 180         if (!_M_failed &&
 181             _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
 182           _M_failed = true;
 183         return *this;
 184       }
 185
 186       ostreambuf_iterator&
 187       operator*() throw()
 188       { return *this; }
 189
 190       ostreambuf_iterator&
 191       operator++(int) throw()
 192       { return *this; }
 193
 194       ostreambuf_iterator&
 195       operator++() throw()
 196       { return *this; }
 197
 198       bool
 199       failed() const throw()
 200       { return _M_failed; }
 201
 202       ostreambuf_iterator&
 203       _M_put(const _CharT* __ws, streamsize __len)
 204       {
 205         this->_M_sbuf->sputn(__ws, __len);
 206         return *this;
 207       }
 208     };
 209 } // namespace std
 210 #endif