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

   1 // Stream iterators
   2
   3 // Copyright (C) 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 /** @file stream_iterator.h
  31  *  This is an internal header file, included by other library headers.
  32  *  You should not attempt to use it directly.
  33  */
  34
  35 #ifndef _CPP_BITS_STREAM_ITERATOR_H
  36 #define _CPP_BITS_STREAM_ITERATOR_H 1
  37
  38 #pragma GCC system_header
  39
  40 namespace std
  41 {
  42   template<typename _Tp, typename _CharT = char,
  43            typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
  44     class istream_iterator
  45       : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
  46     {
  47     public:
  48       typedef _CharT                         char_type;
  49       typedef _Traits                        traits_type;
  50       typedef basic_istream<_CharT, _Traits> istream_type;
  51
  52     private:
  53       istream_type*     _M_stream;
  54       _Tp               _M_value;
  55       bool              _M_ok;
  56
  57     public:
  58       istream_iterator() : _M_stream(0), _M_ok(false) {}
  59
  60       istream_iterator(istream_type& __s) : _M_stream(&__s) { _M_read(); }
  61
  62       istream_iterator(const istream_iterator& __obj)
  63       : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
  64         _M_ok(__obj._M_ok)
  65       { }
  66
  67       const _Tp&
  68       operator*() const { return _M_value; }
  69
  70       const _Tp*
  71       operator->() const { return &(operator*()); }
  72
  73       istream_iterator&
  74       operator++()
  75       { _M_read(); return *this; }
  76
  77       istream_iterator
  78       operator++(int)
  79       {
  80         istream_iterator __tmp = *this;
  81         _M_read();
  82         return __tmp;
  83       }
  84
  85       bool
  86       _M_equal(const istream_iterator& __x) const
  87       { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream);}
  88
  89     private:
  90       void
  91       _M_read()
  92       {
  93         _M_ok = (_M_stream && *_M_stream) ? true : false;
  94         if (_M_ok)
  95           {
  96             *_M_stream >> _M_value;
  97             _M_ok = *_M_stream ? true : false;
  98           }
  99       }
 100     };
 101
 102   template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
 103     inline bool
 104     operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
 105                const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
 106     { return __x._M_equal(__y); }
 107
 108   template <class _Tp, class _CharT, class _Traits, class _Dist>
 109     inline bool
 110     operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
 111                const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
 112     { return !__x._M_equal(__y); }
 113
 114
 115   template<typename _Tp, typename _CharT = char,
 116            typename _Traits = char_traits<_CharT> >
 117     class ostream_iterator
 118       : public iterator<output_iterator_tag, void, void, void, void>
 119     {
 120     public:
 121       typedef _CharT                         char_type;
 122       typedef _Traits                        traits_type;
 123       typedef basic_ostream<_CharT, _Traits> ostream_type;
 124
 125     private:
 126       ostream_type*     _M_stream;
 127       const _CharT*     _M_string;
 128
 129     public:
 130       ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
 131
 132       ostream_iterator(ostream_type& __s, const _CharT* __c)
 133       : _M_stream(&__s), _M_string(__c)  { }
 134
 135       ostream_iterator(const ostream_iterator& __obj)
 136       : _M_stream(__obj._M_stream), _M_string(__obj._M_string)  { }
 137
 138       ostream_iterator&
 139       operator=(const _Tp& __value)
 140       {
 141         *_M_stream << __value;
 142         if (_M_string) *_M_stream << _M_string;
 143         return *this;
 144       }
 145
 146       ostream_iterator&
 147       operator*() { return *this; }
 148
 149       ostream_iterator&
 150       operator++() { return *this; }
 151
 152       ostream_iterator&
 153       operator++(int) { return *this; }
 154     };
 155 } // namespace std
 156 #endif