1 : // Stream iterators
2 :
3 : // Copyright (C) 2001, 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
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 : _GLIBCXX_BEGIN_NAMESPACE(std)
43 :
44 : /// Provides input iterator semantics for streams.
45 : template<typename _Tp, typename _CharT = char,
46 : typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
47 : class istream_iterator
48 : : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
49 32 : {
50 : public:
51 : typedef _CharT char_type;
52 : typedef _Traits traits_type;
53 : typedef basic_istream<_CharT, _Traits> istream_type;
54 :
55 : private:
56 : istream_type* _M_stream;
57 : _Tp _M_value;
58 : bool _M_ok;
59 :
60 : public:
61 : /// Construct end of input stream iterator.
62 16 : istream_iterator()
63 16 : : _M_stream(0), _M_value(), _M_ok(false) {}
64 :
65 : /// Construct start of input stream iterator.
66 16 : istream_iterator(istream_type& __s)
67 16 : : _M_stream(&__s)
68 16 : { _M_read(); }
69 :
70 : istream_iterator(const istream_iterator& __obj)
71 : : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
72 : _M_ok(__obj._M_ok)
73 : { }
74 :
75 : const _Tp&
76 112 : operator*() const
77 : {
78 : __glibcxx_requires_cond(_M_ok,
79 : _M_message(__gnu_debug::__msg_deref_istream)
80 : ._M_iterator(*this));
81 112 : return _M_value;
82 : }
83 :
84 : const _Tp*
85 : operator->() const { return &(operator*()); }
86 :
87 : istream_iterator&
88 64 : operator++()
89 : {
90 : __glibcxx_requires_cond(_M_ok,
91 : _M_message(__gnu_debug::__msg_inc_istream)
92 : ._M_iterator(*this));
93 64 : _M_read();
94 64 : return *this;
95 : }
96 :
97 : istream_iterator
98 : operator++(int)
99 : {
100 : __glibcxx_requires_cond(_M_ok,
101 : _M_message(__gnu_debug::__msg_inc_istream)
102 : ._M_iterator(*this));
103 : istream_iterator __tmp = *this;
104 : _M_read();
105 : return __tmp;
106 : }
107 :
108 : bool
109 80 : _M_equal(const istream_iterator& __x) const
110 80 : { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); }
111 :
112 : private:
113 : void
114 80 : _M_read()
115 : {
116 80 : _M_ok = (_M_stream && *_M_stream) ? true : false;
117 80 : if (_M_ok)
118 : {
119 80 : *_M_stream >> _M_value;
120 80 : _M_ok = *_M_stream ? true : false;
121 : }
122 80 : }
123 : };
124 :
125 : /// Return true if x and y are both end or not end, or x and y are the same.
126 : template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
127 : inline bool
128 : operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
129 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
130 : { return __x._M_equal(__y); }
131 :
132 : /// Return false if x and y are both end or not end, or x and y are the same.
133 : template <class _Tp, class _CharT, class _Traits, class _Dist>
134 : inline bool
135 : operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
136 80 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
137 80 : { return !__x._M_equal(__y); }
138 :
139 : /**
140 : * @brief Provides output iterator semantics for streams.
141 : *
142 : * This class provides an iterator to write to an ostream. The type Tp is
143 : * the only type written by this iterator and there must be an
144 : * operator<<(Tp) defined.
145 : *
146 : * @param Tp The type to write to the ostream.
147 : * @param CharT The ostream char_type.
148 : * @param Traits The ostream char_traits.
149 : */
150 : template<typename _Tp, typename _CharT = char,
151 : typename _Traits = char_traits<_CharT> >
152 : class ostream_iterator
153 : : public iterator<output_iterator_tag, void, void, void, void>
154 : {
155 : public:
156 : //@{
157 : /// Public typedef
158 : typedef _CharT char_type;
159 : typedef _Traits traits_type;
160 : typedef basic_ostream<_CharT, _Traits> ostream_type;
161 : //@}
162 :
163 : private:
164 : ostream_type* _M_stream;
165 : const _CharT* _M_string;
166 :
167 : public:
168 : /// Construct from an ostream.
169 : ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
170 :
171 : /**
172 : * Construct from an ostream.
173 : *
174 : * The delimiter string @a c is written to the stream after every Tp
175 : * written to the stream. The delimiter is not copied, and thus must
176 : * not be destroyed while this iterator is in use.
177 : *
178 : * @param s Underlying ostream to write to.
179 : * @param c CharT delimiter string to insert.
180 : */
181 5 : ostream_iterator(ostream_type& __s, const _CharT* __c)
182 5 : : _M_stream(&__s), _M_string(__c) { }
183 :
184 : /// Copy constructor.
185 25 : ostream_iterator(const ostream_iterator& __obj)
186 25 : : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { }
187 :
188 : /// Writes @a value to underlying ostream using operator<<. If
189 : /// constructed with delimiter string, writes delimiter to ostream.
190 : ostream_iterator&
191 8 : operator=(const _Tp& __value)
192 : {
193 : __glibcxx_requires_cond(_M_stream != 0,
194 : _M_message(__gnu_debug::__msg_output_ostream)
195 : ._M_iterator(*this));
196 8 : *_M_stream << __value;
197 8 : if (_M_string) *_M_stream << _M_string;
198 8 : return *this;
199 : }
200 :
201 : ostream_iterator&
202 8 : operator*()
203 8 : { return *this; }
204 :
205 : ostream_iterator&
206 8 : operator++()
207 8 : { return *this; }
208 :
209 : ostream_iterator&
210 : operator++(int)
211 : { return *this; }
212 : };
213 :
214 : _GLIBCXX_END_NAMESPACE
215 :
216 : #endif
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