1 | // Streambuf iterators |
2 | |
3 | // Copyright (C) 1997-2021 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/streambuf_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 _STREAMBUF_ITERATOR_H |
31 | #define _STREAMBUF_ITERATOR_H 1 |
32 | |
33 | #pragma GCC system_header |
34 | |
35 | #include <streambuf> |
36 | #include <debug/debug.h> |
37 | |
38 | namespace std _GLIBCXX_VISIBILITY(default) |
39 | { |
40 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
41 | |
42 | /** |
43 | * @addtogroup iterators |
44 | * @{ |
45 | */ |
46 | |
47 | // 24.5.3 Template class istreambuf_iterator |
48 | /// Provides input iterator semantics for streambufs. |
49 | template<typename _CharT, typename _Traits> |
50 | class istreambuf_iterator |
51 | : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, |
52 | _CharT*, _CharT> |
53 | { |
54 | public: |
55 | // Types: |
56 | ///@{ |
57 | /// Public typedefs |
58 | #if __cplusplus < 201103L |
59 | typedef _CharT& reference; // Changed to _CharT by LWG 445 |
60 | #elif __cplusplus > 201703L |
61 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
62 | // 3188. istreambuf_iterator::pointer should not be unspecified |
63 | using pointer = void; |
64 | #endif |
65 | |
66 | typedef _CharT char_type; |
67 | typedef _Traits traits_type; |
68 | typedef typename _Traits::int_type int_type; |
69 | typedef basic_streambuf<_CharT, _Traits> streambuf_type; |
70 | typedef basic_istream<_CharT, _Traits> istream_type; |
71 | ///@} |
72 | |
73 | template<typename _CharT2> |
74 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
75 | ostreambuf_iterator<_CharT2> >::__type |
76 | copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, |
77 | ostreambuf_iterator<_CharT2>); |
78 | |
79 | template<bool _IsMove, typename _CharT2> |
80 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
81 | _CharT2*>::__type |
82 | __copy_move_a2(istreambuf_iterator<_CharT2>, |
83 | istreambuf_iterator<_CharT2>, _CharT2*); |
84 | |
85 | template<typename _CharT2, typename _Size> |
86 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
87 | _CharT2*>::__type |
88 | __copy_n_a(istreambuf_iterator<_CharT2>, _Size, _CharT2*, bool); |
89 | |
90 | template<typename _CharT2> |
91 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
92 | istreambuf_iterator<_CharT2> >::__type |
93 | find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, |
94 | const _CharT2&); |
95 | |
96 | template<typename _CharT2, typename _Distance> |
97 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
98 | void>::__type |
99 | advance(istreambuf_iterator<_CharT2>&, _Distance); |
100 | |
101 | private: |
102 | // 24.5.3 istreambuf_iterator |
103 | // p 1 |
104 | // If the end of stream is reached (streambuf_type::sgetc() |
105 | // returns traits_type::eof()), the iterator becomes equal to |
106 | // the "end of stream" iterator value. |
107 | // NB: This implementation assumes the "end of stream" value |
108 | // is EOF, or -1. |
109 | mutable streambuf_type* _M_sbuf; |
110 | int_type _M_c; |
111 | |
112 | public: |
113 | /// Construct end of input stream iterator. |
114 | _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT |
115 | : _M_sbuf(0), _M_c(traits_type::eof()) { } |
116 | |
117 | #if __cplusplus > 201703L && __cpp_lib_concepts |
118 | constexpr istreambuf_iterator(default_sentinel_t) noexcept |
119 | : istreambuf_iterator() { } |
120 | #endif |
121 | |
122 | #if __cplusplus >= 201103L |
123 | istreambuf_iterator(const istreambuf_iterator&) noexcept = default; |
124 | |
125 | ~istreambuf_iterator() = default; |
126 | #endif |
127 | |
128 | /// Construct start of input stream iterator. |
129 | istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT |
130 | : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { } |
131 | |
132 | /// Construct start of streambuf iterator. |
133 | istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT |
134 | : _M_sbuf(__s), _M_c(traits_type::eof()) { } |
135 | |
136 | #if __cplusplus >= 201103L |
137 | istreambuf_iterator& |
138 | operator=(const istreambuf_iterator&) noexcept = default; |
139 | #endif |
140 | |
141 | /// Return the current character pointed to by iterator. This returns |
142 | /// streambuf.sgetc(). It cannot be assigned. NB: The result of |
143 | /// operator*() on an end of stream is undefined. |
144 | char_type |
145 | operator*() const |
146 | { |
147 | int_type __c = _M_get(); |
148 | |
149 | #ifdef _GLIBCXX_DEBUG_PEDANTIC |
150 | // Dereferencing a past-the-end istreambuf_iterator is a |
151 | // libstdc++ extension |
152 | __glibcxx_requires_cond(!_S_is_eof(__c), |
153 | _M_message(__gnu_debug::__msg_deref_istreambuf) |
154 | ._M_iterator(*this)); |
155 | #endif |
156 | return traits_type::to_char_type(__c); |
157 | } |
158 | |
159 | /// Advance the iterator. Calls streambuf.sbumpc(). |
160 | istreambuf_iterator& |
161 | operator++() |
162 | { |
163 | __glibcxx_requires_cond(_M_sbuf && |
164 | (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), |
165 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
166 | ._M_iterator(*this)); |
167 | |
168 | _M_sbuf->sbumpc(); |
169 | _M_c = traits_type::eof(); |
170 | return *this; |
171 | } |
172 | |
173 | /// Advance the iterator. Calls streambuf.sbumpc(). |
174 | istreambuf_iterator |
175 | operator++(int) |
176 | { |
177 | __glibcxx_requires_cond(_M_sbuf && |
178 | (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), |
179 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
180 | ._M_iterator(*this)); |
181 | |
182 | istreambuf_iterator __old = *this; |
183 | __old._M_c = _M_sbuf->sbumpc(); |
184 | _M_c = traits_type::eof(); |
185 | return __old; |
186 | } |
187 | |
188 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
189 | // 110 istreambuf_iterator::equal not const |
190 | // NB: there is also number 111 (NAD) relevant to this function. |
191 | /// Return true both iterators are end or both are not end. |
192 | bool |
193 | equal(const istreambuf_iterator& __b) const |
194 | { return _M_at_eof() == __b._M_at_eof(); } |
195 | |
196 | private: |
197 | int_type |
198 | _M_get() const |
199 | { |
200 | int_type __ret = _M_c; |
201 | if (_M_sbuf && _S_is_eof(c: __ret) && _S_is_eof(c: __ret = _M_sbuf->sgetc())) |
202 | _M_sbuf = 0; |
203 | return __ret; |
204 | } |
205 | |
206 | bool |
207 | _M_at_eof() const |
208 | { return _S_is_eof(c: _M_get()); } |
209 | |
210 | static bool |
211 | _S_is_eof(int_type __c) |
212 | { |
213 | const int_type __eof = traits_type::eof(); |
214 | return traits_type::eq_int_type(__c, __eof); |
215 | } |
216 | |
217 | #if __cplusplus > 201703L && __cpp_lib_concepts |
218 | friend bool |
219 | operator==(const istreambuf_iterator& __i, default_sentinel_t __s) |
220 | { return __i._M_at_eof(); } |
221 | #endif |
222 | }; |
223 | |
224 | template<typename _CharT, typename _Traits> |
225 | inline bool |
226 | operator==(const istreambuf_iterator<_CharT, _Traits>& __a, |
227 | const istreambuf_iterator<_CharT, _Traits>& __b) |
228 | { return __a.equal(__b); } |
229 | |
230 | template<typename _CharT, typename _Traits> |
231 | inline bool |
232 | operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, |
233 | const istreambuf_iterator<_CharT, _Traits>& __b) |
234 | { return !__a.equal(__b); } |
235 | |
236 | /// Provides output iterator semantics for streambufs. |
237 | template<typename _CharT, typename _Traits> |
238 | class ostreambuf_iterator |
239 | : public iterator<output_iterator_tag, void, void, void, void> |
240 | { |
241 | public: |
242 | // Types: |
243 | ///@{ |
244 | /// Public typedefs |
245 | #if __cplusplus > 201703L |
246 | using difference_type = ptrdiff_t; |
247 | #endif |
248 | typedef _CharT char_type; |
249 | typedef _Traits traits_type; |
250 | typedef basic_streambuf<_CharT, _Traits> streambuf_type; |
251 | typedef basic_ostream<_CharT, _Traits> ostream_type; |
252 | ///@} |
253 | |
254 | template<typename _CharT2> |
255 | friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, |
256 | ostreambuf_iterator<_CharT2> >::__type |
257 | copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, |
258 | ostreambuf_iterator<_CharT2>); |
259 | |
260 | private: |
261 | streambuf_type* _M_sbuf; |
262 | bool _M_failed; |
263 | |
264 | public: |
265 | |
266 | #if __cplusplus > 201703L |
267 | constexpr |
268 | ostreambuf_iterator() noexcept |
269 | : _M_sbuf(nullptr), _M_failed(true) { } |
270 | #endif |
271 | |
272 | /// Construct output iterator from ostream. |
273 | ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT |
274 | : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { } |
275 | |
276 | /// Construct output iterator from streambuf. |
277 | ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT |
278 | : _M_sbuf(__s), _M_failed(!_M_sbuf) { } |
279 | |
280 | /// Write character to streambuf. Calls streambuf.sputc(). |
281 | ostreambuf_iterator& |
282 | operator=(_CharT __c) |
283 | { |
284 | if (!_M_failed && |
285 | _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof())) |
286 | _M_failed = true; |
287 | return *this; |
288 | } |
289 | |
290 | /// Return *this. |
291 | ostreambuf_iterator& |
292 | operator*() |
293 | { return *this; } |
294 | |
295 | /// Return *this. |
296 | ostreambuf_iterator& |
297 | operator++(int) |
298 | { return *this; } |
299 | |
300 | /// Return *this. |
301 | ostreambuf_iterator& |
302 | operator++() |
303 | { return *this; } |
304 | |
305 | /// Return true if previous operator=() failed. |
306 | bool |
307 | failed() const _GLIBCXX_USE_NOEXCEPT |
308 | { return _M_failed; } |
309 | |
310 | ostreambuf_iterator& |
311 | _M_put(const _CharT* __ws, streamsize __len) |
312 | { |
313 | if (__builtin_expect(!_M_failed, true) |
314 | && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len, |
315 | false)) |
316 | _M_failed = true; |
317 | return *this; |
318 | } |
319 | }; |
320 | |
321 | // Overloads for streambuf iterators. |
322 | template<typename _CharT> |
323 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
324 | ostreambuf_iterator<_CharT> >::__type |
325 | copy(istreambuf_iterator<_CharT> __first, |
326 | istreambuf_iterator<_CharT> __last, |
327 | ostreambuf_iterator<_CharT> __result) |
328 | { |
329 | if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed) |
330 | { |
331 | bool __ineof; |
332 | __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof); |
333 | if (!__ineof) |
334 | __result._M_failed = true; |
335 | } |
336 | return __result; |
337 | } |
338 | |
339 | template<bool _IsMove, typename _CharT> |
340 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
341 | ostreambuf_iterator<_CharT> >::__type |
342 | __copy_move_a2(_CharT* __first, _CharT* __last, |
343 | ostreambuf_iterator<_CharT> __result) |
344 | { |
345 | const streamsize __num = __last - __first; |
346 | if (__num > 0) |
347 | __result._M_put(__first, __num); |
348 | return __result; |
349 | } |
350 | |
351 | template<bool _IsMove, typename _CharT> |
352 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
353 | ostreambuf_iterator<_CharT> >::__type |
354 | __copy_move_a2(const _CharT* __first, const _CharT* __last, |
355 | ostreambuf_iterator<_CharT> __result) |
356 | { |
357 | const streamsize __num = __last - __first; |
358 | if (__num > 0) |
359 | __result._M_put(__first, __num); |
360 | return __result; |
361 | } |
362 | |
363 | template<bool _IsMove, typename _CharT> |
364 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
365 | _CharT*>::__type |
366 | __copy_move_a2(istreambuf_iterator<_CharT> __first, |
367 | istreambuf_iterator<_CharT> __last, _CharT* __result) |
368 | { |
369 | typedef istreambuf_iterator<_CharT> __is_iterator_type; |
370 | typedef typename __is_iterator_type::traits_type traits_type; |
371 | typedef typename __is_iterator_type::streambuf_type streambuf_type; |
372 | typedef typename traits_type::int_type int_type; |
373 | |
374 | if (__first._M_sbuf && !__last._M_sbuf) |
375 | { |
376 | streambuf_type* __sb = __first._M_sbuf; |
377 | int_type __c = __sb->sgetc(); |
378 | while (!traits_type::eq_int_type(__c, traits_type::eof())) |
379 | { |
380 | const streamsize __n = __sb->egptr() - __sb->gptr(); |
381 | if (__n > 1) |
382 | { |
383 | traits_type::copy(__result, __sb->gptr(), __n); |
384 | __sb->__safe_gbump(__n); |
385 | __result += __n; |
386 | __c = __sb->underflow(); |
387 | } |
388 | else |
389 | { |
390 | *__result++ = traits_type::to_char_type(__c); |
391 | __c = __sb->snextc(); |
392 | } |
393 | } |
394 | } |
395 | return __result; |
396 | } |
397 | |
398 | template<typename _CharT, typename _Size> |
399 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
400 | _CharT*>::__type |
401 | __copy_n_a(istreambuf_iterator<_CharT> __it, _Size __n, _CharT* __result, |
402 | bool __strict __attribute__((__unused__))) |
403 | { |
404 | if (__n == 0) |
405 | return __result; |
406 | |
407 | __glibcxx_requires_cond(__it._M_sbuf, |
408 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
409 | ._M_iterator(__it)); |
410 | _CharT* __beg = __result; |
411 | __result += __it._M_sbuf->sgetn(__beg, __n); |
412 | __glibcxx_requires_cond(!__strict || __result - __beg == __n, |
413 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
414 | ._M_iterator(__it)); |
415 | return __result; |
416 | } |
417 | |
418 | template<typename _CharT> |
419 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
420 | istreambuf_iterator<_CharT> >::__type |
421 | find(istreambuf_iterator<_CharT> __first, |
422 | istreambuf_iterator<_CharT> __last, const _CharT& __val) |
423 | { |
424 | typedef istreambuf_iterator<_CharT> __is_iterator_type; |
425 | typedef typename __is_iterator_type::traits_type traits_type; |
426 | typedef typename __is_iterator_type::streambuf_type streambuf_type; |
427 | typedef typename traits_type::int_type int_type; |
428 | const int_type __eof = traits_type::eof(); |
429 | |
430 | if (__first._M_sbuf && !__last._M_sbuf) |
431 | { |
432 | const int_type __ival = traits_type::to_int_type(__val); |
433 | streambuf_type* __sb = __first._M_sbuf; |
434 | int_type __c = __sb->sgetc(); |
435 | while (!traits_type::eq_int_type(__c, __eof) |
436 | && !traits_type::eq_int_type(__c, __ival)) |
437 | { |
438 | streamsize __n = __sb->egptr() - __sb->gptr(); |
439 | if (__n > 1) |
440 | { |
441 | const _CharT* __p = traits_type::find(__sb->gptr(), |
442 | __n, __val); |
443 | if (__p) |
444 | __n = __p - __sb->gptr(); |
445 | __sb->__safe_gbump(__n); |
446 | __c = __sb->sgetc(); |
447 | } |
448 | else |
449 | __c = __sb->snextc(); |
450 | } |
451 | |
452 | __first._M_c = __eof; |
453 | } |
454 | |
455 | return __first; |
456 | } |
457 | |
458 | template<typename _CharT, typename _Distance> |
459 | typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, |
460 | void>::__type |
461 | advance(istreambuf_iterator<_CharT>& __i, _Distance __n) |
462 | { |
463 | if (__n == 0) |
464 | return; |
465 | |
466 | __glibcxx_assert(__n > 0); |
467 | __glibcxx_requires_cond(!__i._M_at_eof(), |
468 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
469 | ._M_iterator(__i)); |
470 | |
471 | typedef istreambuf_iterator<_CharT> __is_iterator_type; |
472 | typedef typename __is_iterator_type::traits_type traits_type; |
473 | typedef typename __is_iterator_type::streambuf_type streambuf_type; |
474 | typedef typename traits_type::int_type int_type; |
475 | const int_type __eof = traits_type::eof(); |
476 | |
477 | streambuf_type* __sb = __i._M_sbuf; |
478 | while (__n > 0) |
479 | { |
480 | streamsize __size = __sb->egptr() - __sb->gptr(); |
481 | if (__size > __n) |
482 | { |
483 | __sb->__safe_gbump(__n); |
484 | break; |
485 | } |
486 | |
487 | __sb->__safe_gbump(__size); |
488 | __n -= __size; |
489 | if (traits_type::eq_int_type(__sb->underflow(), __eof)) |
490 | { |
491 | __glibcxx_requires_cond(__n == 0, |
492 | _M_message(__gnu_debug::__msg_inc_istreambuf) |
493 | ._M_iterator(__i)); |
494 | break; |
495 | } |
496 | } |
497 | |
498 | __i._M_c = __eof; |
499 | } |
500 | |
501 | /// @} group iterators |
502 | |
503 | _GLIBCXX_END_NAMESPACE_VERSION |
504 | } // namespace |
505 | |
506 | #endif |
507 | |