]>
Commit | Line | Data |
---|---|---|
d27bba5e BK |
1 | // Stream iterators |
2 | ||
7adcbafe | 3 | // Copyright (C) 2001-2022 Free Software Foundation, Inc. |
d27bba5e BK |
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 | |
748086b7 | 8 | // Free Software Foundation; either version 3, or (at your option) |
d27bba5e BK |
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 | ||
748086b7 JJ |
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. | |
d27bba5e | 19 | |
748086b7 JJ |
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/>. | |
d27bba5e | 24 | |
f910786b | 25 | /** @file bits/stream_iterator.h |
729e3d3f | 26 | * This is an internal header file, included by other library headers. |
f910786b | 27 | * Do not attempt to use it directly. @headername{iterator} |
729e3d3f PE |
28 | */ |
29 | ||
3d7c150e BK |
30 | #ifndef _STREAM_ITERATOR_H |
31 | #define _STREAM_ITERATOR_H 1 | |
d27bba5e BK |
32 | |
33 | #pragma GCC system_header | |
34 | ||
285b36d6 BK |
35 | #include <debug/debug.h> |
36 | ||
12ffa228 BK |
37 | namespace std _GLIBCXX_VISIBILITY(default) |
38 | { | |
39 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
3cbc7af0 | 40 | |
8e32aa11 BK |
41 | /** |
42 | * @addtogroup iterators | |
43 | * @{ | |
44 | */ | |
45 | ||
de196e5d JW |
46 | // Ignore warnings about std::iterator. |
47 | #pragma GCC diagnostic push | |
48 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations" | |
49 | ||
ffcec5c8 | 50 | /// Provides input iterator semantics for streams. |
ed6814f7 BI |
51 | template<typename _Tp, typename _CharT = char, |
52 | typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t> | |
53 | class istream_iterator | |
15d72060 | 54 | : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&> |
d27bba5e BK |
55 | { |
56 | public: | |
57 | typedef _CharT char_type; | |
58 | typedef _Traits traits_type; | |
59 | typedef basic_istream<_CharT, _Traits> istream_type; | |
60 | ||
61 | private: | |
ed6814f7 BI |
62 | istream_type* _M_stream; |
63 | _Tp _M_value; | |
638ad333 JW |
64 | // This bool becomes false at end-of-stream. It should be sufficient to |
65 | // check _M_stream != nullptr instead, but historically we did not set | |
66 | // _M_stream to null when reaching the end, so we need to keep this flag. | |
ed6814f7 | 67 | bool _M_ok; |
d27bba5e | 68 | |
ffcec5c8 JQ |
69 | public: |
70 | /// Construct end of input stream iterator. | |
94a86be0 | 71 | _GLIBCXX_CONSTEXPR istream_iterator() |
901fa4cc | 72 | _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Tp>::value) |
8b5bc374 | 73 | : _M_stream(0), _M_value(), _M_ok(false) {} |
75bef434 | 74 | |
ffcec5c8 | 75 | /// Construct start of input stream iterator. |
15d72060 | 76 | istream_iterator(istream_type& __s) |
638ad333 | 77 | : _M_stream(std::__addressof(__s)), _M_ok(true) |
15d72060 | 78 | { _M_read(); } |
d27bba5e | 79 | |
ed6814f7 | 80 | istream_iterator(const istream_iterator& __obj) |
901fa4cc | 81 | _GLIBCXX_NOEXCEPT_IF(is_nothrow_copy_constructible<_Tp>::value) |
ed6814f7 BI |
82 | : _M_stream(__obj._M_stream), _M_value(__obj._M_value), |
83 | _M_ok(__obj._M_ok) | |
75bef434 BK |
84 | { } |
85 | ||
07522ae9 | 86 | #if __cplusplus > 201703L && __cpp_lib_concepts |
120e8734 | 87 | constexpr |
8566286e JW |
88 | istream_iterator(default_sentinel_t) |
89 | noexcept(is_nothrow_default_constructible_v<_Tp>) | |
120e8734 JW |
90 | : istream_iterator() { } |
91 | #endif | |
92 | ||
a1417556 JW |
93 | #if __cplusplus >= 201103L |
94 | istream_iterator& operator=(const istream_iterator&) = default; | |
638ad333 | 95 | ~istream_iterator() = default; |
a1417556 JW |
96 | #endif |
97 | ||
240b01b0 | 98 | _GLIBCXX_NODISCARD |
d27bba5e | 99 | const _Tp& |
901fa4cc | 100 | operator*() const _GLIBCXX_NOEXCEPT |
ed6814f7 | 101 | { |
285b36d6 BK |
102 | __glibcxx_requires_cond(_M_ok, |
103 | _M_message(__gnu_debug::__msg_deref_istream) | |
104 | ._M_iterator(*this)); | |
105 | return _M_value; | |
106 | } | |
d27bba5e | 107 | |
240b01b0 | 108 | _GLIBCXX_NODISCARD |
d27bba5e | 109 | const _Tp* |
901fa4cc JW |
110 | operator->() const _GLIBCXX_NOEXCEPT |
111 | { return std::__addressof((operator*())); } | |
d27bba5e | 112 | |
ed6814f7 BI |
113 | istream_iterator& |
114 | operator++() | |
115 | { | |
285b36d6 BK |
116 | __glibcxx_requires_cond(_M_ok, |
117 | _M_message(__gnu_debug::__msg_inc_istream) | |
118 | ._M_iterator(*this)); | |
ed6814f7 BI |
119 | _M_read(); |
120 | return *this; | |
285b36d6 | 121 | } |
d27bba5e | 122 | |
ed6814f7 BI |
123 | istream_iterator |
124 | operator++(int) | |
d27bba5e | 125 | { |
285b36d6 BK |
126 | __glibcxx_requires_cond(_M_ok, |
127 | _M_message(__gnu_debug::__msg_inc_istream) | |
ed6814f7 | 128 | ._M_iterator(*this)); |
d27bba5e BK |
129 | istream_iterator __tmp = *this; |
130 | _M_read(); | |
131 | return __tmp; | |
132 | } | |
133 | ||
638ad333 | 134 | private: |
ed6814f7 | 135 | bool |
901fa4cc | 136 | _M_equal(const istream_iterator& __x) const _GLIBCXX_NOEXCEPT |
638ad333 JW |
137 | { |
138 | // Ideally this would just return _M_stream == __x._M_stream, | |
139 | // but code compiled with old versions never sets _M_stream to null. | |
140 | return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); | |
141 | } | |
d27bba5e | 142 | |
ed6814f7 BI |
143 | void |
144 | _M_read() | |
d27bba5e | 145 | { |
638ad333 JW |
146 | if (_M_stream && !(*_M_stream >> _M_value)) |
147 | { | |
148 | _M_stream = 0; | |
149 | _M_ok = false; | |
150 | } | |
d27bba5e | 151 | } |
ed6814f7 | 152 | |
638ad333 JW |
153 | /// Return true if the iterators refer to the same stream, |
154 | /// or are both at end-of-stream. | |
240b01b0 | 155 | _GLIBCXX_NODISCARD |
638ad333 JW |
156 | friend bool |
157 | operator==(const istream_iterator& __x, const istream_iterator& __y) | |
901fa4cc | 158 | _GLIBCXX_NOEXCEPT |
638ad333 JW |
159 | { return __x._M_equal(__y); } |
160 | ||
240b01b0 | 161 | #if __cpp_impl_three_way_comparison < 201907L |
638ad333 JW |
162 | /// Return true if the iterators refer to different streams, |
163 | /// or if one is at end-of-stream and the other is not. | |
240b01b0 | 164 | _GLIBCXX_NODISCARD |
638ad333 JW |
165 | friend bool |
166 | operator!=(const istream_iterator& __x, const istream_iterator& __y) | |
901fa4cc | 167 | _GLIBCXX_NOEXCEPT |
638ad333 | 168 | { return !__x._M_equal(__y); } |
240b01b0 | 169 | #endif |
120e8734 | 170 | |
07522ae9 | 171 | #if __cplusplus > 201703L && __cpp_lib_concepts |
240b01b0 | 172 | [[nodiscard]] |
120e8734 | 173 | friend bool |
901fa4cc | 174 | operator==(const istream_iterator& __i, default_sentinel_t) noexcept |
120e8734 JW |
175 | { return !__i._M_stream; } |
176 | #endif | |
638ad333 | 177 | }; |
d27bba5e | 178 | |
ffcec5c8 JQ |
179 | /** |
180 | * @brief Provides output iterator semantics for streams. | |
181 | * | |
182 | * This class provides an iterator to write to an ostream. The type Tp is | |
183 | * the only type written by this iterator and there must be an | |
184 | * operator<<(Tp) defined. | |
185 | * | |
93c66bc6 BK |
186 | * @tparam _Tp The type to write to the ostream. |
187 | * @tparam _CharT The ostream char_type. | |
188 | * @tparam _Traits The ostream char_traits. | |
ffcec5c8 | 189 | */ |
ed6814f7 | 190 | template<typename _Tp, typename _CharT = char, |
d27bba5e | 191 | typename _Traits = char_traits<_CharT> > |
ed6814f7 | 192 | class ostream_iterator |
15d72060 | 193 | : public iterator<output_iterator_tag, void, void, void, void> |
d27bba5e BK |
194 | { |
195 | public: | |
f0b88346 | 196 | ///@{ |
ffcec5c8 | 197 | /// Public typedef |
120e8734 JW |
198 | #if __cplusplus > 201703L |
199 | using difference_type = ptrdiff_t; | |
200 | #endif | |
d27bba5e BK |
201 | typedef _CharT char_type; |
202 | typedef _Traits traits_type; | |
203 | typedef basic_ostream<_CharT, _Traits> ostream_type; | |
f0b88346 | 204 | ///@} |
d27bba5e BK |
205 | |
206 | private: | |
ed6814f7 BI |
207 | ostream_type* _M_stream; |
208 | const _CharT* _M_string; | |
d27bba5e BK |
209 | |
210 | public: | |
ffcec5c8 | 211 | /// Construct from an ostream. |
901fa4cc | 212 | ostream_iterator(ostream_type& __s) _GLIBCXX_NOEXCEPT |
9f9eb84e | 213 | : _M_stream(std::__addressof(__s)), _M_string(0) {} |
75bef434 | 214 | |
ffcec5c8 JQ |
215 | /** |
216 | * Construct from an ostream. | |
217 | * | |
218 | * The delimiter string @a c is written to the stream after every Tp | |
219 | * written to the stream. The delimiter is not copied, and thus must | |
220 | * not be destroyed while this iterator is in use. | |
221 | * | |
93c66bc6 BK |
222 | * @param __s Underlying ostream to write to. |
223 | * @param __c CharT delimiter string to insert. | |
ffcec5c8 | 224 | */ |
901fa4cc | 225 | ostream_iterator(ostream_type& __s, const _CharT* __c) _GLIBCXX_NOEXCEPT |
638ad333 | 226 | : _M_stream(std::__addressof(__s)), _M_string(__c) { } |
75bef434 | 227 | |
ffcec5c8 | 228 | /// Copy constructor. |
901fa4cc | 229 | ostream_iterator(const ostream_iterator& __obj) _GLIBCXX_NOEXCEPT |
75bef434 | 230 | : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { } |
d27bba5e | 231 | |
a1417556 JW |
232 | #if __cplusplus >= 201103L |
233 | ostream_iterator& operator=(const ostream_iterator&) = default; | |
234 | #endif | |
235 | ||
ffcec5c8 JQ |
236 | /// Writes @a value to underlying ostream using operator<<. If |
237 | /// constructed with delimiter string, writes delimiter to ostream. | |
ed6814f7 BI |
238 | ostream_iterator& |
239 | operator=(const _Tp& __value) | |
240 | { | |
285b36d6 BK |
241 | __glibcxx_requires_cond(_M_stream != 0, |
242 | _M_message(__gnu_debug::__msg_output_ostream) | |
243 | ._M_iterator(*this)); | |
d27bba5e | 244 | *_M_stream << __value; |
638ad333 JW |
245 | if (_M_string) |
246 | *_M_stream << _M_string; | |
d27bba5e BK |
247 | return *this; |
248 | } | |
ed6814f7 | 249 | |
240b01b0 | 250 | _GLIBCXX_NODISCARD |
ed6814f7 | 251 | ostream_iterator& |
901fa4cc | 252 | operator*() _GLIBCXX_NOEXCEPT |
15d72060 | 253 | { return *this; } |
ed6814f7 BI |
254 | |
255 | ostream_iterator& | |
901fa4cc | 256 | operator++() _GLIBCXX_NOEXCEPT |
ed6814f7 BI |
257 | { return *this; } |
258 | ||
259 | ostream_iterator& | |
901fa4cc | 260 | operator++(int) _GLIBCXX_NOEXCEPT |
ed6814f7 | 261 | { return *this; } |
d27bba5e | 262 | }; |
de196e5d | 263 | #pragma GCC diagnostic pop |
3cbc7af0 | 264 | |
f0b88346 | 265 | /// @} group iterators |
8e32aa11 | 266 | |
12ffa228 BK |
267 | _GLIBCXX_END_NAMESPACE_VERSION |
268 | } // namespace | |
3cbc7af0 | 269 | |
d27bba5e | 270 | #endif |