stream_iterator.h

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00001 // Stream iterators
00002 
00003 // Copyright (C) 2001 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 /** @file stream_iterator.h
00031  *  This is an internal header file, included by other library headers.
00032  *  You should not attempt to use it directly.
00033  */
00034 
00035 #ifndef _CPP_BITS_STREAM_ITERATOR_H
00036 #define _CPP_BITS_STREAM_ITERATOR_H 1
00037 
00038 #pragma GCC system_header
00039 
00040 namespace std
00041 {
00042   template<typename _Tp, typename _CharT = char, 
00043            typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t> 
00044     class istream_iterator 
00045       : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
00046     {
00047     public:
00048       typedef _CharT                         char_type;
00049       typedef _Traits                        traits_type;
00050       typedef basic_istream<_CharT, _Traits> istream_type;
00051 
00052     private:
00053       istream_type*     _M_stream;
00054       _Tp       _M_value;
00055       bool      _M_ok;
00056 
00057     public:      
00058       istream_iterator() : _M_stream(0), _M_ok(false) {}
00059 
00060       istream_iterator(istream_type& __s) : _M_stream(&__s) { _M_read(); }
00061 
00062       istream_iterator(const istream_iterator& __obj) 
00063       : _M_stream(__obj._M_stream), _M_value(__obj._M_value), 
00064         _M_ok(__obj._M_ok) 
00065       { }
00066 
00067       const _Tp&
00068       operator*() const { return _M_value; }
00069 
00070       const _Tp*
00071       operator->() const { return &(operator*()); }
00072 
00073       istream_iterator& 
00074       operator++() 
00075       { _M_read(); return *this; }
00076 
00077       istream_iterator 
00078       operator++(int)  
00079       {
00080     istream_iterator __tmp = *this;
00081     _M_read();
00082     return __tmp;
00083       }
00084 
00085       bool 
00086       _M_equal(const istream_iterator& __x) const
00087       { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream);}
00088 
00089     private:      
00090       void 
00091       _M_read() 
00092       {
00093     _M_ok = (_M_stream && *_M_stream) ? true : false;
00094     if (_M_ok) 
00095       {
00096         *_M_stream >> _M_value;
00097         _M_ok = *_M_stream ? true : false;
00098       }
00099       }
00100     };
00101   
00102   template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
00103     inline bool 
00104     operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
00105            const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 
00106     { return __x._M_equal(__y); }
00107 
00108   template <class _Tp, class _CharT, class _Traits, class _Dist>
00109     inline bool 
00110     operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
00111            const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y) 
00112     { return !__x._M_equal(__y); }
00113 
00114 
00115   template<typename _Tp, typename _CharT = char, 
00116            typename _Traits = char_traits<_CharT> >
00117     class ostream_iterator 
00118       : public iterator<output_iterator_tag, void, void, void, void>
00119     {
00120     public:
00121       typedef _CharT                         char_type;
00122       typedef _Traits                        traits_type;
00123       typedef basic_ostream<_CharT, _Traits> ostream_type;
00124 
00125     private:
00126       ostream_type*     _M_stream;
00127       const _CharT*     _M_string;
00128 
00129     public:
00130       ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
00131 
00132       ostream_iterator(ostream_type& __s, const _CharT* __c) 
00133       : _M_stream(&__s), _M_string(__c)  { }
00134 
00135       ostream_iterator(const ostream_iterator& __obj)
00136       : _M_stream(__obj._M_stream), _M_string(__obj._M_string)  { }
00137 
00138       ostream_iterator& 
00139       operator=(const _Tp& __value) 
00140       { 
00141     *_M_stream << __value;
00142     if (_M_string) *_M_stream << _M_string;
00143     return *this;
00144       }
00145       
00146       ostream_iterator& 
00147       operator*() { return *this; }
00148       
00149       ostream_iterator& 
00150       operator++() { return *this; } 
00151       
00152       ostream_iterator& 
00153       operator++(int) { return *this; } 
00154     };
00155 } // namespace std
00156 #endif

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