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 _STREAM_ITERATOR_H
  36 #define _STREAM_ITERATOR_H 1
  37
  38 #pragma GCC system_header
  39
  40 #include <debug/debug.h>
  41
  42 namespace std
  43 {
  44   template<typename _Tp, typename _CharT = char,
  45            typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
  46     class istream_iterator
  47       : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
  48     {
  49     public:
  50       typedef _CharT                         char_type;
  51       typedef _Traits                        traits_type;
  52       typedef basic_istream<_CharT, _Traits> istream_type;
  53
  54     private:
  55       istream_type*     _M_stream;
  56       _Tp               _M_value;
  57       bool              _M_ok;
  58
  59     public:
  60       istream_iterator() : _M_stream(0), _M_ok(false) {}
  61
  62       istream_iterator(istream_type& __s) : _M_stream(&__s) { _M_read(); }
  63
  64       istream_iterator(const istream_iterator& __obj)
  65       : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
  66         _M_ok(__obj._M_ok)
  67       { }
  68
  69       const _Tp&
  70       operator*() const
  71       {
  72         __glibcxx_requires_cond(_M_ok,
  73                                 _M_message(__gnu_debug::__msg_deref_istream)
  74                                 ._M_iterator(*this));
  75         return _M_value;
  76       }
  77
  78       const _Tp*
  79       operator->() const { return &(operator*()); }
  80
  81       istream_iterator&
  82       operator++()
  83       {
  84         __glibcxx_requires_cond(_M_ok,
  85                                 _M_message(__gnu_debug::__msg_inc_istream)
  86                                 ._M_iterator(*this));
  87         _M_read();
  88         return *this;
  89       }
  90
  91       istream_iterator
  92       operator++(int)
  93       {
  94         __glibcxx_requires_cond(_M_ok,
  95                                 _M_message(__gnu_debug::__msg_inc_istream)
  96                                 ._M_iterator(*this));
  97         istream_iterator __tmp = *this;
  98         _M_read();
  99         return __tmp;
 100       }
 101
 102       bool
 103       _M_equal(const istream_iterator& __x) const
 104       { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream);}
 105
 106     private:
 107       void
 108       _M_read()
 109       {
 110         _M_ok = (_M_stream && *_M_stream) ? true : false;
 111         if (_M_ok)
 112           {
 113             *_M_stream >> _M_value;
 114             _M_ok = *_M_stream ? true : false;
 115           }
 116       }
 117     };
 118
 119   template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
 120     inline bool
 121     operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
 122                const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
 123     { return __x._M_equal(__y); }
 124
 125   template <class _Tp, class _CharT, class _Traits, class _Dist>
 126     inline bool
 127     operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
 128                const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
 129     { return !__x._M_equal(__y); }
 130
 131
 132   template<typename _Tp, typename _CharT = char,
 133            typename _Traits = char_traits<_CharT> >
 134     class ostream_iterator
 135       : public iterator<output_iterator_tag, void, void, void, void>
 136     {
 137     public:
 138       typedef _CharT                         char_type;
 139       typedef _Traits                        traits_type;
 140       typedef basic_ostream<_CharT, _Traits> ostream_type;
 141
 142     private:
 143       ostream_type*     _M_stream;
 144       const _CharT*     _M_string;
 145
 146     public:
 147       ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
 148
 149       ostream_iterator(ostream_type& __s, const _CharT* __c)
 150       : _M_stream(&__s), _M_string(__c)  { }
 151
 152       ostream_iterator(const ostream_iterator& __obj)
 153       : _M_stream(__obj._M_stream), _M_string(__obj._M_string)  { }
 154
 155       ostream_iterator&
 156       operator=(const _Tp& __value)
 157       {
 158         __glibcxx_requires_cond(_M_stream != 0,
 159                                 _M_message(__gnu_debug::__msg_output_ostream)
 160                                 ._M_iterator(*this));
 161         *_M_stream << __value;
 162         if (_M_string) *_M_stream << _M_string;
 163         return *this;
 164       }
 165
 166       ostream_iterator&
 167       operator*() { return *this; }
 168
 169       ostream_iterator&
 170       operator++() { return *this; }
 171
 172       ostream_iterator&
 173       operator++(int) { return *this; }
 174     };
 175 } // namespace std
 176 #endif