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d27bba5e BK |
1 | // Stream iterators |
2 | ||
83ffe9cd | 3 | // Copyright (C) 2001-2023 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 | ||
d31e19e4 JW |
35 | #include <iosfwd> |
36 | #include <bits/move.h> | |
37 | #include <bits/stl_iterator_base_types.h> | |
285b36d6 BK |
38 | #include <debug/debug.h> |
39 | ||
12ffa228 BK |
40 | namespace std _GLIBCXX_VISIBILITY(default) |
41 | { | |
42 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
3cbc7af0 | 43 | |
8e32aa11 BK |
44 | /** |
45 | * @addtogroup iterators | |
46 | * @{ | |
47 | */ | |
48 | ||
de196e5d JW |
49 | // Ignore warnings about std::iterator. |
50 | #pragma GCC diagnostic push | |
51 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations" | |
52 | ||
ffcec5c8 | 53 | /// Provides input iterator semantics for streams. |
ed6814f7 BI |
54 | template<typename _Tp, typename _CharT = char, |
55 | typename _Traits = char_traits<_CharT>, typename _Dist = ptrdiff_t> | |
56 | class istream_iterator | |
15d72060 | 57 | : public iterator<input_iterator_tag, _Tp, _Dist, const _Tp*, const _Tp&> |
d27bba5e BK |
58 | { |
59 | public: | |
60 | typedef _CharT char_type; | |
61 | typedef _Traits traits_type; | |
62 | typedef basic_istream<_CharT, _Traits> istream_type; | |
63 | ||
64 | private: | |
ed6814f7 BI |
65 | istream_type* _M_stream; |
66 | _Tp _M_value; | |
638ad333 JW |
67 | // This bool becomes false at end-of-stream. It should be sufficient to |
68 | // check _M_stream != nullptr instead, but historically we did not set | |
69 | // _M_stream to null when reaching the end, so we need to keep this flag. | |
ed6814f7 | 70 | bool _M_ok; |
d27bba5e | 71 | |
ffcec5c8 JQ |
72 | public: |
73 | /// Construct end of input stream iterator. | |
94a86be0 | 74 | _GLIBCXX_CONSTEXPR istream_iterator() |
901fa4cc | 75 | _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Tp>::value) |
8b5bc374 | 76 | : _M_stream(0), _M_value(), _M_ok(false) {} |
75bef434 | 77 | |
ffcec5c8 | 78 | /// Construct start of input stream iterator. |
15d72060 | 79 | istream_iterator(istream_type& __s) |
638ad333 | 80 | : _M_stream(std::__addressof(__s)), _M_ok(true) |
15d72060 | 81 | { _M_read(); } |
d27bba5e | 82 | |
ed6814f7 | 83 | istream_iterator(const istream_iterator& __obj) |
901fa4cc | 84 | _GLIBCXX_NOEXCEPT_IF(is_nothrow_copy_constructible<_Tp>::value) |
ed6814f7 BI |
85 | : _M_stream(__obj._M_stream), _M_value(__obj._M_value), |
86 | _M_ok(__obj._M_ok) | |
75bef434 BK |
87 | { } |
88 | ||
07522ae9 | 89 | #if __cplusplus > 201703L && __cpp_lib_concepts |
120e8734 | 90 | constexpr |
8566286e JW |
91 | istream_iterator(default_sentinel_t) |
92 | noexcept(is_nothrow_default_constructible_v<_Tp>) | |
120e8734 JW |
93 | : istream_iterator() { } |
94 | #endif | |
95 | ||
a1417556 JW |
96 | #if __cplusplus >= 201103L |
97 | istream_iterator& operator=(const istream_iterator&) = default; | |
638ad333 | 98 | ~istream_iterator() = default; |
a1417556 JW |
99 | #endif |
100 | ||
240b01b0 | 101 | _GLIBCXX_NODISCARD |
d27bba5e | 102 | const _Tp& |
901fa4cc | 103 | operator*() const _GLIBCXX_NOEXCEPT |
ed6814f7 | 104 | { |
285b36d6 BK |
105 | __glibcxx_requires_cond(_M_ok, |
106 | _M_message(__gnu_debug::__msg_deref_istream) | |
107 | ._M_iterator(*this)); | |
108 | return _M_value; | |
109 | } | |
d27bba5e | 110 | |
240b01b0 | 111 | _GLIBCXX_NODISCARD |
d27bba5e | 112 | const _Tp* |
901fa4cc JW |
113 | operator->() const _GLIBCXX_NOEXCEPT |
114 | { return std::__addressof((operator*())); } | |
d27bba5e | 115 | |
ed6814f7 BI |
116 | istream_iterator& |
117 | operator++() | |
118 | { | |
285b36d6 BK |
119 | __glibcxx_requires_cond(_M_ok, |
120 | _M_message(__gnu_debug::__msg_inc_istream) | |
121 | ._M_iterator(*this)); | |
ed6814f7 BI |
122 | _M_read(); |
123 | return *this; | |
285b36d6 | 124 | } |
d27bba5e | 125 | |
ed6814f7 BI |
126 | istream_iterator |
127 | operator++(int) | |
d27bba5e | 128 | { |
285b36d6 BK |
129 | __glibcxx_requires_cond(_M_ok, |
130 | _M_message(__gnu_debug::__msg_inc_istream) | |
ed6814f7 | 131 | ._M_iterator(*this)); |
d27bba5e BK |
132 | istream_iterator __tmp = *this; |
133 | _M_read(); | |
134 | return __tmp; | |
135 | } | |
136 | ||
638ad333 | 137 | private: |
ed6814f7 | 138 | bool |
901fa4cc | 139 | _M_equal(const istream_iterator& __x) const _GLIBCXX_NOEXCEPT |
638ad333 JW |
140 | { |
141 | // Ideally this would just return _M_stream == __x._M_stream, | |
142 | // but code compiled with old versions never sets _M_stream to null. | |
143 | return (_M_ok == __x._M_ok) && (!_M_ok || _M_stream == __x._M_stream); | |
144 | } | |
d27bba5e | 145 | |
ed6814f7 BI |
146 | void |
147 | _M_read() | |
d27bba5e | 148 | { |
638ad333 JW |
149 | if (_M_stream && !(*_M_stream >> _M_value)) |
150 | { | |
151 | _M_stream = 0; | |
152 | _M_ok = false; | |
153 | } | |
d27bba5e | 154 | } |
ed6814f7 | 155 | |
638ad333 JW |
156 | /// Return true if the iterators refer to the same stream, |
157 | /// or are both at end-of-stream. | |
240b01b0 | 158 | _GLIBCXX_NODISCARD |
638ad333 JW |
159 | friend bool |
160 | operator==(const istream_iterator& __x, const istream_iterator& __y) | |
901fa4cc | 161 | _GLIBCXX_NOEXCEPT |
638ad333 JW |
162 | { return __x._M_equal(__y); } |
163 | ||
240b01b0 | 164 | #if __cpp_impl_three_way_comparison < 201907L |
638ad333 JW |
165 | /// Return true if the iterators refer to different streams, |
166 | /// or if one is at end-of-stream and the other is not. | |
240b01b0 | 167 | _GLIBCXX_NODISCARD |
638ad333 JW |
168 | friend bool |
169 | operator!=(const istream_iterator& __x, const istream_iterator& __y) | |
901fa4cc | 170 | _GLIBCXX_NOEXCEPT |
638ad333 | 171 | { return !__x._M_equal(__y); } |
240b01b0 | 172 | #endif |
120e8734 | 173 | |
07522ae9 | 174 | #if __cplusplus > 201703L && __cpp_lib_concepts |
240b01b0 | 175 | [[nodiscard]] |
120e8734 | 176 | friend bool |
901fa4cc | 177 | operator==(const istream_iterator& __i, default_sentinel_t) noexcept |
120e8734 JW |
178 | { return !__i._M_stream; } |
179 | #endif | |
638ad333 | 180 | }; |
d27bba5e | 181 | |
ffcec5c8 JQ |
182 | /** |
183 | * @brief Provides output iterator semantics for streams. | |
184 | * | |
185 | * This class provides an iterator to write to an ostream. The type Tp is | |
186 | * the only type written by this iterator and there must be an | |
187 | * operator<<(Tp) defined. | |
188 | * | |
93c66bc6 BK |
189 | * @tparam _Tp The type to write to the ostream. |
190 | * @tparam _CharT The ostream char_type. | |
191 | * @tparam _Traits The ostream char_traits. | |
ffcec5c8 | 192 | */ |
ed6814f7 | 193 | template<typename _Tp, typename _CharT = char, |
d27bba5e | 194 | typename _Traits = char_traits<_CharT> > |
ed6814f7 | 195 | class ostream_iterator |
15d72060 | 196 | : public iterator<output_iterator_tag, void, void, void, void> |
d27bba5e BK |
197 | { |
198 | public: | |
f0b88346 | 199 | ///@{ |
ffcec5c8 | 200 | /// Public typedef |
120e8734 JW |
201 | #if __cplusplus > 201703L |
202 | using difference_type = ptrdiff_t; | |
203 | #endif | |
d27bba5e BK |
204 | typedef _CharT char_type; |
205 | typedef _Traits traits_type; | |
206 | typedef basic_ostream<_CharT, _Traits> ostream_type; | |
f0b88346 | 207 | ///@} |
d27bba5e BK |
208 | |
209 | private: | |
ed6814f7 BI |
210 | ostream_type* _M_stream; |
211 | const _CharT* _M_string; | |
d27bba5e BK |
212 | |
213 | public: | |
ffcec5c8 | 214 | /// Construct from an ostream. |
901fa4cc | 215 | ostream_iterator(ostream_type& __s) _GLIBCXX_NOEXCEPT |
9f9eb84e | 216 | : _M_stream(std::__addressof(__s)), _M_string(0) {} |
75bef434 | 217 | |
ffcec5c8 JQ |
218 | /** |
219 | * Construct from an ostream. | |
220 | * | |
221 | * The delimiter string @a c is written to the stream after every Tp | |
222 | * written to the stream. The delimiter is not copied, and thus must | |
223 | * not be destroyed while this iterator is in use. | |
224 | * | |
93c66bc6 BK |
225 | * @param __s Underlying ostream to write to. |
226 | * @param __c CharT delimiter string to insert. | |
ffcec5c8 | 227 | */ |
901fa4cc | 228 | ostream_iterator(ostream_type& __s, const _CharT* __c) _GLIBCXX_NOEXCEPT |
638ad333 | 229 | : _M_stream(std::__addressof(__s)), _M_string(__c) { } |
75bef434 | 230 | |
ffcec5c8 | 231 | /// Copy constructor. |
901fa4cc | 232 | ostream_iterator(const ostream_iterator& __obj) _GLIBCXX_NOEXCEPT |
75bef434 | 233 | : _M_stream(__obj._M_stream), _M_string(__obj._M_string) { } |
d27bba5e | 234 | |
a1417556 JW |
235 | #if __cplusplus >= 201103L |
236 | ostream_iterator& operator=(const ostream_iterator&) = default; | |
237 | #endif | |
238 | ||
ffcec5c8 JQ |
239 | /// Writes @a value to underlying ostream using operator<<. If |
240 | /// constructed with delimiter string, writes delimiter to ostream. | |
ed6814f7 BI |
241 | ostream_iterator& |
242 | operator=(const _Tp& __value) | |
243 | { | |
285b36d6 BK |
244 | __glibcxx_requires_cond(_M_stream != 0, |
245 | _M_message(__gnu_debug::__msg_output_ostream) | |
246 | ._M_iterator(*this)); | |
d27bba5e | 247 | *_M_stream << __value; |
638ad333 JW |
248 | if (_M_string) |
249 | *_M_stream << _M_string; | |
d27bba5e BK |
250 | return *this; |
251 | } | |
ed6814f7 | 252 | |
240b01b0 | 253 | _GLIBCXX_NODISCARD |
ed6814f7 | 254 | ostream_iterator& |
901fa4cc | 255 | operator*() _GLIBCXX_NOEXCEPT |
15d72060 | 256 | { return *this; } |
ed6814f7 BI |
257 | |
258 | ostream_iterator& | |
901fa4cc | 259 | operator++() _GLIBCXX_NOEXCEPT |
ed6814f7 BI |
260 | { return *this; } |
261 | ||
262 | ostream_iterator& | |
901fa4cc | 263 | operator++(int) _GLIBCXX_NOEXCEPT |
ed6814f7 | 264 | { return *this; } |
d27bba5e | 265 | }; |
de196e5d | 266 | #pragma GCC diagnostic pop |
3cbc7af0 | 267 | |
f0b88346 | 268 | /// @} group iterators |
8e32aa11 | 269 | |
12ffa228 BK |
270 | _GLIBCXX_END_NAMESPACE_VERSION |
271 | } // namespace | |
3cbc7af0 | 272 | |
d27bba5e | 273 | #endif |