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1 : // Stream iterators
2 :
3 : // Copyright (C) 2001-2019 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 0 : istream_iterator(istream_type& __s)
69 0 : : _M_stream(std::__addressof(__s))
70 0 : { _M_read(); }
71 :
72 0 : istream_iterator(const istream_iterator& __obj)
73 0 : : _M_stream(__obj._M_stream), _M_value(__obj._M_value),
74 0 : _M_ok(__obj._M_ok)
75 : { }
76 :
77 : #if __cplusplus >= 201103L
78 : istream_iterator& operator=(const istream_iterator&) = default;
79 : #endif
80 :
81 : const _Tp&
82 0 : operator*() const
83 : {
84 : __glibcxx_requires_cond(_M_ok,
85 : _M_message(__gnu_debug::__msg_deref_istream)
86 : ._M_iterator(*this));
87 : return _M_value;
88 : }
89 :
90 : const _Tp*
91 : operator->() const { return std::__addressof((operator*())); }
92 :
93 : istream_iterator&
94 : operator++()
95 : {
96 : __glibcxx_requires_cond(_M_ok,
97 : _M_message(__gnu_debug::__msg_inc_istream)
98 : ._M_iterator(*this));
99 : _M_read();
100 : return *this;
101 : }
102 :
103 : istream_iterator
104 0 : operator++(int)
105 : {
106 : __glibcxx_requires_cond(_M_ok,
107 : _M_message(__gnu_debug::__msg_inc_istream)
108 : ._M_iterator(*this));
109 0 : istream_iterator __tmp = *this;
110 0 : _M_read();
111 0 : return __tmp;
112 : }
113 :
114 : bool
115 : _M_equal(const istream_iterator& __x) const
116 : { return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); }
117 :
118 : private:
119 : void
120 0 : _M_read()
121 : {
122 0 : _M_ok = (_M_stream && *_M_stream) ? true : false;
123 0 : if (_M_ok)
124 : {
125 0 : *_M_stream >> _M_value;
126 0 : _M_ok = *_M_stream ? true : false;
127 : }
128 0 : }
129 : };
130 :
131 : /// Return true if x and y are both end or not end, or x and y are the same.
132 : template<typename _Tp, typename _CharT, typename _Traits, typename _Dist>
133 : inline bool
134 : operator==(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
135 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
136 : { return __x._M_equal(__y); }
137 :
138 : /// Return false if x and y are both end or not end, or x and y are the same.
139 : template <class _Tp, class _CharT, class _Traits, class _Dist>
140 : inline bool
141 : operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __x,
142 : const istream_iterator<_Tp, _CharT, _Traits, _Dist>& __y)
143 : { return !__x._M_equal(__y); }
144 :
145 : /**
146 : * @brief Provides output iterator semantics for streams.
147 : *
148 : * This class provides an iterator to write to an ostream. The type Tp is
149 : * the only type written by this iterator and there must be an
150 : * operator<<(Tp) defined.
151 : *
152 : * @tparam _Tp The type to write to the ostream.
153 : * @tparam _CharT The ostream char_type.
154 : * @tparam _Traits The ostream char_traits.
155 : */
156 : template<typename _Tp, typename _CharT = char,
157 : typename _Traits = char_traits<_CharT> >
158 : class ostream_iterator
159 : : public iterator<output_iterator_tag, void, void, void, void>
160 : {
161 : public:
162 : ///@{
163 : /// Public typedef
164 : typedef _CharT char_type;
165 : typedef _Traits traits_type;
166 : typedef basic_ostream<_CharT, _Traits> ostream_type;
167 : ///@}
168 :
169 : private:
170 : ostream_type* _M_stream;
171 : const _CharT* _M_string;
172 :
173 : public:
174 : /// Construct from an ostream.
175 0 : ostream_iterator(ostream_type& __s)
176 0 : : _M_stream(std::__addressof(__s)), _M_string(0) {}
177 :
178 : /**
179 : * Construct from an ostream.
180 : *
181 : * The delimiter string @a c is written to the stream after every Tp
182 : * written to the stream. The delimiter is not copied, and thus must
183 : * not be destroyed while this iterator is in use.
184 : *
185 : * @param __s Underlying ostream to write to.
186 : * @param __c CharT delimiter string to insert.
187 : */
188 0 : ostream_iterator(ostream_type& __s, const _CharT* __c)
189 : : _M_stream(&__s), _M_string(__c) { }
190 :
191 : /// Copy constructor.
192 0 : ostream_iterator(const ostream_iterator& __obj)
193 0 : : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { }
194 :
195 : #if __cplusplus >= 201103L
196 : ostream_iterator& operator=(const ostream_iterator&) = default;
197 : #endif
198 :
199 : /// Writes @a value to underlying ostream using operator<<. If
200 : /// constructed with delimiter string, writes delimiter to ostream.
201 : ostream_iterator&
202 0 : operator=(const _Tp& __value)
203 : {
204 : __glibcxx_requires_cond(_M_stream != 0,
205 : _M_message(__gnu_debug::__msg_output_ostream)
206 : ._M_iterator(*this));
207 0 : *_M_stream << __value;
208 0 : if (_M_string) *_M_stream << _M_string;
209 0 : return *this;
210 : }
211 :
212 : ostream_iterator&
213 0 : operator*()
214 : { return *this; }
215 :
216 : ostream_iterator&
217 0 : operator++()
218 0 : { return *this; }
219 :
220 : ostream_iterator&
221 : operator++(int)
222 : { return *this; }
223 : };
224 :
225 : /// @} group iterators
226 :
227 : _GLIBCXX_END_NAMESPACE_VERSION
228 : } // namespace
229 :
230 : #endif
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