# streambuf_iterator.h

Go to the documentation of this file.

    00001 // Streambuf iterators
    00002
    00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 // XXX Should specialize copy, find algorithms for streambuf iterators.
    00032
    00038 #ifndef _CPP_BITS_STREAMBUF_ITERATOR_H
    00039 #define _CPP_BITS_STREAMBUF_ITERATOR_H 1
    00040
    00041 #pragma GCC system_header
    00042
    00043 namespace std
    00044 {
    00045   // 24.5.3 Template class istreambuf_iterator
    00046   template<typename _CharT, typename _Traits>
    00047     class istreambuf_iterator
    00048     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
    00049                   _CharT*, _CharT&>
    00050     {
    00051     public:
    00052       // Types:
    00053       typedef _CharT                                char_type;
    00054       typedef _Traits                               traits_type;
    00055       typedef typename _Traits::int_type            int_type;
    00056       typedef basic_streambuf<_CharT, _Traits>      streambuf_type;
    00057       typedef basic_istream<_CharT, _Traits>            istream_type;
    00058
    00059     private:
    00060       // 24.5.3 istreambuf_iterator
    00061       // p 1
    00062       // If the end of stream is reached (streambuf_type::sgetc()
    00063       // returns traits_type::eof()), the iterator becomes equal to
    00064       // the "end of stream" iterator value.
    00065       // NB: This implementation assumes the "end of stream" value
    00066       // is EOF, or -1.
    00067       mutable streambuf_type*   _M_sbuf;
    00068       int_type          _M_c;
    00069
    00070     public:
    00071       istreambuf_iterator() throw()
    00072       : _M_sbuf(0), _M_c(-2) { }
    00073
    00074       istreambuf_iterator(istream_type& __s) throw()
    00075       : _M_sbuf(__s.rdbuf()), _M_c(-2) { }
    00076
    00077       istreambuf_iterator(streambuf_type* __s) throw()
    00078       : _M_sbuf(__s), _M_c(-2) { }
    00079
    00080       // NB: This should really have an int_type return
    00081       // value, so "end of stream" postion can be checked without
    00082       // hacking.
    00083       char_type
    00084       operator*() const
    00085       {
    00086     // The result of operator*() on an end of stream is undefined.
    00087     int_type __ret = traits_type::eof();
    00088     if (_M_sbuf)
    00089       {
    00090         if (_M_c != static_cast<int_type>(-2))
    00091           __ret = _M_c;
    00092         else
    00093           if ((__ret = _M_sbuf->sgetc()) == traits_type::eof())
    00094         _M_sbuf = 0;
    00095       }
    00096     return traits_type::to_char_type(__ret);
    00097       }
    00098
    00099       istreambuf_iterator&
    00100       operator++()
    00101       {
    00102     if (_M_sbuf && _M_sbuf->sbumpc() == traits_type::eof())
    00103       _M_sbuf = 0;
    00104     else
    00105       _M_c = -2;
    00106     return *this;
    00107       }
    00108
    00109       istreambuf_iterator
    00110       operator++(int)
    00111       {
    00112     istreambuf_iterator __old = *this;
    00113     if (_M_sbuf && (__old._M_c = _M_sbuf->sbumpc()) == traits_type::eof())
    00114       _M_sbuf = 0;
    00115     else
    00116       _M_c = -2;
    00117     return __old;
    00118       }
    00119
    00120 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
    00121       // 110 istreambuf_iterator::equal not const
    00122       // NB: there is also number 111 (NAD, Future) pending on this function.
    00123       bool
    00124       equal(const istreambuf_iterator& __b) const
    00125       {
    00126     const int_type __eof = traits_type::eof();
    00127     bool __thiseof = traits_type::eq_int_type(this->operator*(), __eof);
    00128     bool __beof = traits_type::eq_int_type(__b.operator*(), __eof);
    00129     return (__thiseof && __beof || (!__thiseof && !__beof));
    00130       }
    00131 #endif
    00132     };
    00133
    00134   template<typename _CharT, typename _Traits>
    00135     inline bool
    00136     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
    00137            const istreambuf_iterator<_CharT, _Traits>& __b)
    00138     { return __a.equal(__b); }
    00139
    00140   template<typename _CharT, typename _Traits>
    00141     inline bool
    00142     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
    00143            const istreambuf_iterator<_CharT, _Traits>& __b)
    00144     { return !__a.equal(__b); }
    00145
    00146   template<typename _CharT, typename _Traits>
    00147     class ostreambuf_iterator
    00148     : public iterator<output_iterator_tag, void, void, void, void>
    00149     {
    00150     public:
    00151       // Types:
    00152       typedef _CharT                           char_type;
    00153       typedef _Traits                          traits_type;
    00154       typedef basic_streambuf<_CharT, _Traits> streambuf_type;
    00155       typedef basic_ostream<_CharT, _Traits>   ostream_type;
    00156
    00157     private:
    00158       streambuf_type*   _M_sbuf;
    00159       bool      _M_failed;
    00160
    00161     public:
    00162       inline
    00163       ostreambuf_iterator(ostream_type& __s) throw ()
    00164       : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
    00165
    00166       ostreambuf_iterator(streambuf_type* __s) throw ()
    00167       : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
    00168
    00169       ostreambuf_iterator&
    00170       operator=(_CharT __c);
    00171
    00172       ostreambuf_iterator&
    00173       operator*() throw()
    00174       { return *this; }
    00175
    00176       ostreambuf_iterator&
    00177       operator++(int) throw()
    00178       { return *this; }
    00179
    00180       ostreambuf_iterator&
    00181       operator++() throw()
    00182       { return *this; }
    00183
    00184       bool
    00185       failed() const throw()
    00186       { return _M_failed; }
    00187     };
    00188
    00189   template<typename _CharT, typename _Traits>
    00190     inline ostreambuf_iterator<_CharT, _Traits>&
    00191     ostreambuf_iterator<_CharT, _Traits>::operator=(_CharT __c)
    00192     {
    00193       if (!_M_failed &&
    00194           _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
    00195     _M_failed = true;
    00196       return *this;
    00197     }
    00198 } // namespace std
    00199 #endif