1 // Streambuf iterators
2 
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library.  This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
10 // any later version.
11 
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 // GNU General Public License for more details.
16 
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING.  If not, write to the Free
19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20 // USA.
21 
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction.  Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License.  This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
30 
31 // XXX Should specialize copy, find algorithms for streambuf iterators.
32 
33 /** @file streambuf_iterator.h
34  *  This is an internal header file, included by other library headers.
35  *  You should not attempt to use it directly.
36  */
37 
38 #ifndef _CPP_BITS_STREAMBUF_ITERATOR_H
39 #define _CPP_BITS_STREAMBUF_ITERATOR_H 1
40 
41 #pragma GCC system_header
42 
43 namespace std
44 {
45   // 24.5.3 Template class istreambuf_iterator
46   template<typename _CharT, typename _Traits>
47     class istreambuf_iterator
48     : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type,
49     		      _CharT*, _CharT&>
50     {
51     public:
52       // Types:
53       typedef _CharT                         		char_type;
54       typedef _Traits                        		traits_type;
55       typedef typename _Traits::int_type     		int_type;
56       typedef basic_streambuf<_CharT, _Traits> 		streambuf_type;
57       typedef basic_istream<_CharT, _Traits>         	istream_type;
58 
59     private:
60       // 24.5.3 istreambuf_iterator
61       // p 1
62       // If the end of stream is reached (streambuf_type::sgetc()
63       // returns traits_type::eof()), the iterator becomes equal to
64       // the "end of stream" iterator value.
65       // NB: This implementation assumes the "end of stream" value
66       // is EOF, or -1.
67       mutable streambuf_type* 	_M_sbuf;
68       int_type 			_M_c;
69 
70     public:
71       istreambuf_iterator() throw()
72       : _M_sbuf(0), _M_c(traits_type::eof()) { }
73 
74       istreambuf_iterator(istream_type& __s) throw()
75       : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
76 
77       istreambuf_iterator(streambuf_type* __s) throw()
78       : _M_sbuf(__s), _M_c(traits_type::eof()) { }
79 
80       // NB: The result of operator*() on an end of stream is undefined.
81       char_type
82       operator*() const
83       { return traits_type::to_char_type(_M_get()); }
84 
85       istreambuf_iterator&
86       operator++()
87       {
88 	const int_type __eof = traits_type::eof();
89 	if (_M_sbuf && traits_type::eq_int_type(_M_sbuf->sbumpc(), __eof))
90 	  _M_sbuf = 0;
91 	else
92 	  _M_c = __eof;
93 	return *this;
94       }
95 
96       istreambuf_iterator
97       operator++(int)
98       {
99 	const int_type __eof = traits_type::eof();
100 	istreambuf_iterator __old = *this;
101 	if (_M_sbuf
102 	    && traits_type::eq_int_type((__old._M_c = _M_sbuf->sbumpc()),
103 					__eof))
104 	  _M_sbuf = 0;
105 	else
106 	  _M_c = __eof;
107 	return __old;
108       }
109 
110 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
111       // 110 istreambuf_iterator::equal not const
112       // NB: there is also number 111 (NAD, Future) pending on this function.
113       bool
114       equal(const istreambuf_iterator& __b) const
115       {
116 	const int_type __eof = traits_type::eof();
117 	bool __thiseof = traits_type::eq_int_type(_M_get(), __eof);
118 	bool __beof = traits_type::eq_int_type(__b._M_get(), __eof);
119 	return (__thiseof && __beof || (!__thiseof && !__beof));
120       }
121 #endif
122 
123     private:
124       int_type
125       _M_get() const
126       {
127 	const int_type __eof = traits_type::eof();
128 	int_type __ret = __eof;
129 	if (_M_sbuf)
130 	  {
131 	    if (!traits_type::eq_int_type(_M_c, __eof))
132 	      __ret = _M_c;
133 	    else
134 	      if (traits_type::eq_int_type((__ret = _M_sbuf->sgetc()), __eof))
135 		_M_sbuf = 0;
136 	  }
137 	return __ret;
138       }
139     };
140 
141   template<typename _CharT, typename _Traits>
142     inline bool
143     operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
144 	       const istreambuf_iterator<_CharT, _Traits>& __b)
145     { return __a.equal(__b); }
146 
147   template<typename _CharT, typename _Traits>
148     inline bool
149     operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
150 	       const istreambuf_iterator<_CharT, _Traits>& __b)
151     { return !__a.equal(__b); }
152 
153   template<typename _CharT, typename _Traits>
154     class ostreambuf_iterator
155     : public iterator<output_iterator_tag, void, void, void, void>
156     {
157     public:
158       // Types:
159       typedef _CharT                           char_type;
160       typedef _Traits                          traits_type;
161       typedef basic_streambuf<_CharT, _Traits> streambuf_type;
162       typedef basic_ostream<_CharT, _Traits>   ostream_type;
163 
164     private:
165       streambuf_type* 	_M_sbuf;
166       bool 		_M_failed;
167 
168     public:
169       inline
170       ostreambuf_iterator(ostream_type& __s) throw ()
171       : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
172 
173       ostreambuf_iterator(streambuf_type* __s) throw ()
174       : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
175 
176       ostreambuf_iterator&
177       operator=(_CharT __c);
178 
179       ostreambuf_iterator&
180       operator*() throw()
181       { return *this; }
182 
183       ostreambuf_iterator&
184       operator++(int) throw()
185       { return *this; }
186 
187       ostreambuf_iterator&
188       operator++() throw()
189       { return *this; }
190 
191       bool
192       failed() const throw()
193       { return _M_failed; }
194     };
195 
196   template<typename _CharT, typename _Traits>
197     inline ostreambuf_iterator<_CharT, _Traits>&
198     ostreambuf_iterator<_CharT, _Traits>::operator=(_CharT __c)
199     {
200       if (!_M_failed &&
201           _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
202 	_M_failed = true;
203       return *this;
204     }
205 } // namespace std
206 #endif
207