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1 : // Stream iterators
2 :
3 : // Copyright (C) 2001-2014 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 3, 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 : // Under Section 7 of GPL version 3, you are granted additional
17 : // permissions described in the GCC Runtime Library Exception, version
18 : // 3.1, as published by the Free Software Foundation.
19 :
20 : // You should have received a copy of the GNU General Public License and
21 : // a copy of the GCC Runtime Library Exception along with this program;
22 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 : // <http://www.gnu.org/licenses/>.
24 :
25 : /** @file bits/stream_iterator.h
26 : * This is an internal header file, included by other library headers.
27 : * Do not attempt to use it directly. @headername{iterator}
28 : */
29 :
30 : #ifndef _STREAM_ITERATOR_H
31 : #define _STREAM_ITERATOR_H 1
32 :
33 : #pragma GCC system_header
34 :
35 : #include <debug/debug.h>
36 :
37 : namespace std _GLIBCXX_VISIBILITY(default)
38 : {
39 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
40 :
41 : /**
42 : * @addtogroup iterators
43 : * @{
44 : */
45 :
46 : /// Provides input iterator semantics for streams.
47 : template<typename _Tp, typename _CharT = char,
48 : typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t>
49 : class istream_iterator
50 : : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&>
51 : {
52 : public:
53 : typedef _CharT char_type;
54 : typedef _Traits traits_type;
55 : typedef basic_istream<_CharT, _Traits> istream_type;
56 :
57 : private:
58 : istream_type* _M_stream;
59 : _Tp _M_value;
60 : bool _M_ok;
61 :
62 : public:
63 : /// Construct end of input stream iterator.
64 : _GLIBCXX_CONSTEXPR istream_iterator()
65 : : _M_stream(0), _M_value(), _M_ok(false) {}
66 :
67 : /// Construct start of input stream iterator.
68 : istream_iterator(istream_type& __s)
69 : : _M_stream(&__s)
70 : { _M_read(); }
71 :
72 : istream_iterator(const istream_iterator& __obj)
73 : : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
74 : _M_ok(__obj._M_ok)
75 : { }
76 :
77 : const _Tp&
78 : operator*() const
79 : {
80 : __glibcxx_requires_cond(_M_ok,
81 : _M_message(__gnu_debug::__msg_deref_istream)
82 : ._M_iterator(*this));
83 : return _M_value;
84 : }
85 :
86 : const _Tp*
87 : operator->() const { return &(operator*()); }
88 :
89 : istream_iterator&
90 : operator++()
91 : {
92 : __glibcxx_requires_cond(_M_ok,
93 : _M_message(__gnu_debug::__msg_inc_istream)
94 : ._M_iterator(*this));
95 : _M_read();
96 : return *this;
97 : }
98 :
99 : istream_iterator
100 : operator++(int)
101 : {
102 : __glibcxx_requires_cond(_M_ok,
103 : _M_message(__gnu_debug::__msg_inc_istream)
104 : ._M_iterator(*this));
105 : istream_iterator __tmp = *this;
106 : _M_read();
107 : return __tmp;
108 : }
109 :
110 : bool
111 : _M_equal(const istream_iterator& __x) const
112 : { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); }
113 :
114 : private:
115 : void
116 : _M_read()
117 : {
118 : _M_ok = (_M_stream && *_M_stream) ? true : false;
119 : if (_M_ok)
120 : {
121 : *_M_stream >> _M_value;
122 : _M_ok = *_M_stream ? true : false;
123 : }
124 : }
125 : };
126 :
127 : /// Return true if x and y are both end or not end, or x and y are the same.
128 : template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
129 : inline bool
130 : operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
131 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
132 : { return __x._M_equal(__y); }
133 :
134 : /// Return false if x and y are both end or not end, or x and y are the same.
135 : template <class _Tp, class _CharT, class _Traits, class _Dist>
136 : inline bool
137 : operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
138 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
139 : { return !__x._M_equal(__y); }
140 :
141 : /**
142 : * @brief Provides output iterator semantics for streams.
143 : *
144 : * This class provides an iterator to write to an ostream. The type Tp is
145 : * the only type written by this iterator and there must be an
146 : * operator<<(Tp) defined.
147 : *
148 : * @tparam _Tp The type to write to the ostream.
149 : * @tparam _CharT The ostream char_type.
150 : * @tparam _Traits The ostream char_traits.
151 : */
152 : template<typename _Tp, typename _CharT = char,
153 : typename _Traits = char_traits<_CharT> >
154 : class ostream_iterator
155 : : public iterator<output_iterator_tag, void, void, void, void>
156 : {
157 : public:
158 : //@{
159 : /// Public typedef
160 : typedef _CharT char_type;
161 : typedef _Traits traits_type;
162 : typedef basic_ostream<_CharT, _Traits> ostream_type;
163 : //@}
164 :
165 : private:
166 : ostream_type* _M_stream;
167 : const _CharT* _M_string;
168 :
169 : public:
170 : /// Construct from an ostream.
171 : ostream_iterator(ostream_type& __s) : _M_stream(&__s), _M_string(0) {}
172 :
173 : /**
174 : * Construct from an ostream.
175 : *
176 : * The delimiter string @a c is written to the stream after every Tp
177 : * written to the stream. The delimiter is not copied, and thus must
178 : * not be destroyed while this iterator is in use.
179 : *
180 : * @param __s Underlying ostream to write to.
181 : * @param __c CharT delimiter string to insert.
182 : */
183 0 : ostream_iterator(ostream_type& __s, const _CharT* __c)
184 0 : : _M_stream(&__s), _M_string(__c) { }
185 :
186 : /// Copy constructor.
187 0 : ostream_iterator(const ostream_iterator& __obj)
188 0 : : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { }
189 :
190 : /// Writes @a value to underlying ostream using operator<<. If
191 : /// constructed with delimiter string, writes delimiter to ostream.
192 : ostream_iterator&
193 0 : operator=(const _Tp& __value)
194 : {
195 : __glibcxx_requires_cond(_M_stream != 0,
196 : _M_message(__gnu_debug::__msg_output_ostream)
197 : ._M_iterator(*this));
198 0 : *_M_stream << __value;
199 0 : if (_M_string) *_M_stream << _M_string;
200 0 : return *this;
201 : }
202 :
203 : ostream_iterator&
204 0 : operator*()
205 0 : { return *this; }
206 :
207 : ostream_iterator&
208 0 : operator++()
209 0 : { return *this; }
210 :
211 : ostream_iterator&
212 : operator++(int)
213 : { return *this; }
214 : };
215 :
216 : // @} group iterators
217 :
218 : _GLIBCXX_END_NAMESPACE_VERSION
219 : } // namespace
220 :
221 : #endif
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