# streambuf_iterator.h

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    00001 // Streambuf iterators
    00002
    00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
    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
    00036 #ifndef _CPP_BITS_STREAMBUF_ITERATOR_H
    00037 #define _CPP_BITS_STREAMBUF_ITERATOR_H 1
    00038
    00039 #pragma GCC system_header
    00040
    00041 #include <streambuf>
    00042
    00043 // NB: Should specialize copy, find algorithms for streambuf iterators.
    00044
    00045 namespace std
    00046 {
    00047   // 24.5.3 Template class istreambuf_iterator
    00048   template<typename _CharT, typename _Traits>
    00049     class istreambuf_iterator
    00050     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
    00051                   _CharT*, _CharT&>
    00052     {
    00053     public:
    00054       // Types:
    00055       typedef _CharT                                char_type;
    00056       typedef _Traits                               traits_type;
    00057       typedef typename _Traits::int_type            int_type;
    00058       typedef basic_streambuf<_CharT, _Traits>      streambuf_type;
    00059       typedef basic_istream<_CharT, _Traits>            istream_type;
    00060
    00061     private:
    00062       // 24.5.3 istreambuf_iterator
    00063       // p 1
    00064       // If the end of stream is reached (streambuf_type::sgetc()
    00065       // returns traits_type::eof()), the iterator becomes equal to
    00066       // the "end of stream" iterator value.
    00067       // NB: This implementation assumes the "end of stream" value
    00068       // is EOF, or -1.
    00069       mutable streambuf_type*   _M_sbuf;
    00070       int_type          _M_c;
    00071
    00072     public:
    00073       istreambuf_iterator() throw()
    00074       : _M_sbuf(0), _M_c(traits_type::eof()) { }
    00075
    00076       istreambuf_iterator(istream_type& __s) throw()
    00077       : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
    00078
    00079       istreambuf_iterator(streambuf_type* __s) throw()
    00080       : _M_sbuf(__s), _M_c(traits_type::eof()) { }
    00081
    00082       // NB: The result of operator*() on an end of stream is undefined.
    00083       char_type
    00084       operator*() const
    00085       { return traits_type::to_char_type(_M_get()); }
    00086
    00087       istreambuf_iterator&
    00088       operator++()
    00089       {
    00090     const int_type __eof = traits_type::eof();
    00091     if (_M_sbuf && traits_type::eq_int_type(_M_sbuf->sbumpc(), __eof))
    00092       _M_sbuf = 0;
    00093     else
    00094       _M_c = __eof;
    00095     return *this;
    00096       }
    00097
    00098       istreambuf_iterator
    00099       operator++(int)
    00100       {
    00101     const int_type __eof = traits_type::eof();
    00102     istreambuf_iterator __old = *this;
    00103     if (_M_sbuf
    00104         && traits_type::eq_int_type((__old._M_c = _M_sbuf->sbumpc()),
    00105                     __eof))
    00106       _M_sbuf = 0;
    00107     else
    00108       _M_c = __eof;
    00109     return __old;
    00110       }
    00111
    00112 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
    00113       // 110 istreambuf_iterator::equal not const
    00114       // NB: there is also number 111 (NAD, Future) pending on this function.
    00115       bool
    00116       equal(const istreambuf_iterator& __b) const
    00117       {
    00118     const int_type __eof = traits_type::eof();
    00119     bool __thiseof = traits_type::eq_int_type(_M_get(), __eof);
    00120     bool __beof = traits_type::eq_int_type(__b._M_get(), __eof);
    00121     return (__thiseof && __beof || (!__thiseof && !__beof));
    00122       }
    00123 #endif
    00124
    00125     private:
    00126       int_type
    00127       _M_get() const
    00128       {
    00129     const int_type __eof = traits_type::eof();
    00130     int_type __ret = __eof;
    00131     if (_M_sbuf)
    00132       {
    00133         if (!traits_type::eq_int_type(_M_c, __eof))
    00134           __ret = _M_c;
    00135         else
    00136           if (traits_type::eq_int_type((__ret = _M_sbuf->sgetc()), __eof))
    00137         _M_sbuf = 0;
    00138       }
    00139     return __ret;
    00140       }
    00141     };
    00142
    00143   template<typename _CharT, typename _Traits>
    00144     inline bool
    00145     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
    00146            const istreambuf_iterator<_CharT, _Traits>& __b)
    00147     { return __a.equal(__b); }
    00148
    00149   template<typename _CharT, typename _Traits>
    00150     inline bool
    00151     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
    00152            const istreambuf_iterator<_CharT, _Traits>& __b)
    00153     { return !__a.equal(__b); }
    00154
    00155   template<typename _CharT, typename _Traits>
    00156     class ostreambuf_iterator
    00157     : public iterator<output_iterator_tag, void, void, void, void>
    00158     {
    00159     public:
    00160       // Types:
    00161       typedef _CharT                           char_type;
    00162       typedef _Traits                          traits_type;
    00163       typedef basic_streambuf<_CharT, _Traits> streambuf_type;
    00164       typedef basic_ostream<_CharT, _Traits>   ostream_type;
    00165
    00166     private:
    00167       streambuf_type*   _M_sbuf;
    00168       bool      _M_failed;
    00169
    00170     public:
    00171       ostreambuf_iterator(ostream_type& __s) throw ()
    00172       : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
    00173
    00174       ostreambuf_iterator(streambuf_type* __s) throw ()
    00175       : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
    00176
    00177       ostreambuf_iterator&
    00178       operator=(_CharT __c)
    00179       {
    00180     if (!_M_failed &&
    00181         _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
    00182       _M_failed = true;
    00183     return *this;
    00184       }
    00185
    00186       ostreambuf_iterator&
    00187       operator*() throw()
    00188       { return *this; }
    00189
    00190       ostreambuf_iterator&
    00191       operator++(int) throw()
    00192       { return *this; }
    00193
    00194       ostreambuf_iterator&
    00195       operator++() throw()
    00196       { return *this; }
    00197
    00198       bool
    00199       failed() const throw()
    00200       { return _M_failed; }
    00201
    00202       ostreambuf_iterator&
    00203       _M_put(const _CharT* __ws, streamsize __len)
    00204       {
    00205     if (__builtin_expect(!_M_failed, true) &&
    00206         __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len, false))
    00207       _M_failed = true;
    00208     return *this;
    00209       }
    00210     };
    00211 } // namespace std
    00212 #endif