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1 : // Streambuf iterators
2 :
3 : // Copyright (C) 1997-2019 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/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*,
53 : #if __cplusplus >= 201103L
54 : // LWG 445.
55 : _CharT>
56 : #else
57 : _CharT&>
58 : #endif
59 : {
60 : public:
61 : // Types:
62 : ///@{
63 : /// Public typedefs
64 : typedef _CharT char_type;
65 : typedef _Traits traits_type;
66 : typedef typename _Traits::int_type int_type;
67 : typedef basic_streambuf<_CharT, _Traits> streambuf_type;
68 : typedef basic_istream<_CharT, _Traits> istream_type;
69 : ///@}
70 :
71 : template<typename _CharT2>
72 : friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
73 : ostreambuf_iterator<_CharT2> >::__type
74 : copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
75 : ostreambuf_iterator<_CharT2>);
76 :
77 : template<bool _IsMove, typename _CharT2>
78 : friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
79 : _CharT2*>::__type
80 : __copy_move_a2(istreambuf_iterator<_CharT2>,
81 : istreambuf_iterator<_CharT2>, _CharT2*);
82 :
83 : template<typename _CharT2>
84 : friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
85 : istreambuf_iterator<_CharT2> >::__type
86 : find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
87 : const _CharT2&);
88 :
89 : template<typename _CharT2, typename _Distance>
90 : friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
91 : void>::__type
92 : advance(istreambuf_iterator<_CharT2>&, _Distance);
93 :
94 : private:
95 : // 24.5.3 istreambuf_iterator
96 : // p 1
97 : // If the end of stream is reached (streambuf_type::sgetc()
98 : // returns traits_type::eof()), the iterator becomes equal to
99 : // the "end of stream" iterator value.
100 : // NB: This implementation assumes the "end of stream" value
101 : // is EOF, or -1.
102 : mutable streambuf_type* _M_sbuf;
103 : int_type _M_c;
104 :
105 : public:
106 : /// Construct end of input stream iterator.
107 0 : _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
108 0 : : _M_sbuf(0), _M_c(traits_type::eof()) { }
109 :
110 : #if __cplusplus >= 201103L
111 : istreambuf_iterator(const istreambuf_iterator&) noexcept = default;
112 :
113 : ~istreambuf_iterator() = default;
114 : #endif
115 :
116 : /// Construct start of input stream iterator.
117 0 : istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT
118 0 : : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
119 :
120 : /// Construct start of streambuf iterator.
121 0 : istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
122 0 : : _M_sbuf(__s), _M_c(traits_type::eof()) { }
123 :
124 : #if __cplusplus >= 201103L
125 : istreambuf_iterator&
126 : operator=(const istreambuf_iterator&) noexcept = default;
127 : #endif
128 :
129 : /// Return the current character pointed to by iterator. This returns
130 : /// streambuf.sgetc(). It cannot be assigned. NB: The result of
131 : /// operator*() on an end of stream is undefined.
132 : char_type
133 0 : operator*() const
134 : {
135 0 : int_type __c = _M_get();
136 :
137 : #ifdef _GLIBCXX_DEBUG_PEDANTIC
138 : // Dereferencing a past-the-end istreambuf_iterator is a
139 : // libstdc++ extension
140 : __glibcxx_requires_cond(!_S_is_eof(__c),
141 : _M_message(__gnu_debug::__msg_deref_istreambuf)
142 : ._M_iterator(*this));
143 : #endif
144 0 : return traits_type::to_char_type(__c);
145 : }
146 :
147 : /// Advance the iterator. Calls streambuf.sbumpc().
148 : istreambuf_iterator&
149 0 : operator++()
150 : {
151 : __glibcxx_requires_cond(_M_sbuf &&
152 : (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())),
153 : _M_message(__gnu_debug::__msg_inc_istreambuf)
154 : ._M_iterator(*this));
155 :
156 0 : _M_sbuf->sbumpc();
157 0 : _M_c = traits_type::eof();
158 0 : return *this;
159 : }
160 :
161 : /// Advance the iterator. Calls streambuf.sbumpc().
162 : istreambuf_iterator
163 : operator++(int)
164 : {
165 : __glibcxx_requires_cond(_M_sbuf &&
166 : (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())),
167 : _M_message(__gnu_debug::__msg_inc_istreambuf)
168 : ._M_iterator(*this));
169 :
170 : istreambuf_iterator __old = *this;
171 : __old._M_c = _M_sbuf->sbumpc();
172 : _M_c = traits_type::eof();
173 : return __old;
174 : }
175 :
176 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
177 : // 110 istreambuf_iterator::equal not const
178 : // NB: there is also number 111 (NAD) relevant to this function.
179 : /// Return true both iterators are end or both are not end.
180 : bool
181 0 : equal(const istreambuf_iterator& __b) const
182 0 : { return _M_at_eof() == __b._M_at_eof(); }
183 :
184 : private:
185 : int_type
186 : _M_get() const
187 : {
188 : int_type __ret = _M_c;
189 : if (_M_sbuf && _S_is_eof(__ret) && _S_is_eof(__ret = _M_sbuf->sgetc()))
190 : _M_sbuf = 0;
191 : return __ret;
192 : }
193 :
194 : bool
195 0 : _M_at_eof() const
196 0 : { return _S_is_eof(_M_get()); }
197 :
198 : static bool
199 0 : _S_is_eof(int_type __c)
200 : {
201 0 : const int_type __eof = traits_type::eof();
202 0 : return traits_type::eq_int_type(__c, __eof);
203 : }
204 : };
205 :
206 : template<typename _CharT, typename _Traits>
207 : inline bool
208 : operator==(const istreambuf_iterator<_CharT, _Traits>& __a,
209 : const istreambuf_iterator<_CharT, _Traits>& __b)
210 : { return __a.equal(__b); }
211 :
212 : template<typename _CharT, typename _Traits>
213 : inline bool
214 0 : operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
215 : const istreambuf_iterator<_CharT, _Traits>& __b)
216 0 : { return !__a.equal(__b); }
217 :
218 : /// Provides output iterator semantics for streambufs.
219 : template<typename _CharT, typename _Traits>
220 : class ostreambuf_iterator
221 : : public iterator<output_iterator_tag, void, void, void, void>
222 : {
223 : public:
224 : // Types:
225 : ///@{
226 : /// Public typedefs
227 : typedef _CharT char_type;
228 : typedef _Traits traits_type;
229 : typedef basic_streambuf<_CharT, _Traits> streambuf_type;
230 : typedef basic_ostream<_CharT, _Traits> ostream_type;
231 : ///@}
232 :
233 : template<typename _CharT2>
234 : friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
235 : ostreambuf_iterator<_CharT2> >::__type
236 : copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>,
237 : ostreambuf_iterator<_CharT2>);
238 :
239 : private:
240 : streambuf_type* _M_sbuf;
241 : bool _M_failed;
242 :
243 : public:
244 : /// Construct output iterator from ostream.
245 0 : ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT
246 0 : : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { }
247 :
248 : /// Construct output iterator from streambuf.
249 : ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
250 : : _M_sbuf(__s), _M_failed(!_M_sbuf) { }
251 :
252 : /// Write character to streambuf. Calls streambuf.sputc().
253 : ostreambuf_iterator&
254 0 : operator=(_CharT __c)
255 : {
256 0 : if (!_M_failed &&
257 0 : _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
258 0 : _M_failed = true;
259 0 : return *this;
260 : }
261 :
262 : /// Return *this.
263 : ostreambuf_iterator&
264 0 : operator*()
265 : { return *this; }
266 :
267 : /// Return *this.
268 : ostreambuf_iterator&
269 : operator++(int)
270 : { return *this; }
271 :
272 : /// Return *this.
273 : ostreambuf_iterator&
274 0 : operator++()
275 : { return *this; }
276 :
277 : /// Return true if previous operator=() failed.
278 : bool
279 : failed() const _GLIBCXX_USE_NOEXCEPT
280 : { return _M_failed; }
281 :
282 : ostreambuf_iterator&
283 : _M_put(const _CharT* __ws, streamsize __len)
284 : {
285 : if (__builtin_expect(!_M_failed, true)
286 : && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len,
287 : false))
288 : _M_failed = true;
289 : return *this;
290 : }
291 : };
292 :
293 : // Overloads for streambuf iterators.
294 : template<typename _CharT>
295 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
296 : ostreambuf_iterator<_CharT> >::__type
297 : copy(istreambuf_iterator<_CharT> __first,
298 : istreambuf_iterator<_CharT> __last,
299 : ostreambuf_iterator<_CharT> __result)
300 : {
301 : if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed)
302 : {
303 : bool __ineof;
304 : __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof);
305 : if (!__ineof)
306 : __result._M_failed = true;
307 : }
308 : return __result;
309 : }
310 :
311 : template<bool _IsMove, typename _CharT>
312 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
313 : ostreambuf_iterator<_CharT> >::__type
314 : __copy_move_a2(_CharT* __first, _CharT* __last,
315 : ostreambuf_iterator<_CharT> __result)
316 : {
317 : const streamsize __num = __last - __first;
318 : if (__num > 0)
319 : __result._M_put(__first, __num);
320 : return __result;
321 : }
322 :
323 : template<bool _IsMove, typename _CharT>
324 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
325 : ostreambuf_iterator<_CharT> >::__type
326 : __copy_move_a2(const _CharT* __first, const _CharT* __last,
327 : ostreambuf_iterator<_CharT> __result)
328 : {
329 : const streamsize __num = __last - __first;
330 : if (__num > 0)
331 : __result._M_put(__first, __num);
332 : return __result;
333 : }
334 :
335 : template<bool _IsMove, typename _CharT>
336 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
337 : _CharT*>::__type
338 : __copy_move_a2(istreambuf_iterator<_CharT> __first,
339 : istreambuf_iterator<_CharT> __last, _CharT* __result)
340 : {
341 : typedef istreambuf_iterator<_CharT> __is_iterator_type;
342 : typedef typename __is_iterator_type::traits_type traits_type;
343 : typedef typename __is_iterator_type::streambuf_type streambuf_type;
344 : typedef typename traits_type::int_type int_type;
345 :
346 : if (__first._M_sbuf && !__last._M_sbuf)
347 : {
348 : streambuf_type* __sb = __first._M_sbuf;
349 : int_type __c = __sb->sgetc();
350 : while (!traits_type::eq_int_type(__c, traits_type::eof()))
351 : {
352 : const streamsize __n = __sb->egptr() - __sb->gptr();
353 : if (__n > 1)
354 : {
355 : traits_type::copy(__result, __sb->gptr(), __n);
356 : __sb->__safe_gbump(__n);
357 : __result += __n;
358 : __c = __sb->underflow();
359 : }
360 : else
361 : {
362 : *__result++ = traits_type::to_char_type(__c);
363 : __c = __sb->snextc();
364 : }
365 : }
366 : }
367 : return __result;
368 : }
369 :
370 : template<typename _CharT>
371 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
372 : istreambuf_iterator<_CharT> >::__type
373 : find(istreambuf_iterator<_CharT> __first,
374 : istreambuf_iterator<_CharT> __last, const _CharT& __val)
375 : {
376 : typedef istreambuf_iterator<_CharT> __is_iterator_type;
377 : typedef typename __is_iterator_type::traits_type traits_type;
378 : typedef typename __is_iterator_type::streambuf_type streambuf_type;
379 : typedef typename traits_type::int_type int_type;
380 : const int_type __eof = traits_type::eof();
381 :
382 : if (__first._M_sbuf && !__last._M_sbuf)
383 : {
384 : const int_type __ival = traits_type::to_int_type(__val);
385 : streambuf_type* __sb = __first._M_sbuf;
386 : int_type __c = __sb->sgetc();
387 : while (!traits_type::eq_int_type(__c, __eof)
388 : && !traits_type::eq_int_type(__c, __ival))
389 : {
390 : streamsize __n = __sb->egptr() - __sb->gptr();
391 : if (__n > 1)
392 : {
393 : const _CharT* __p = traits_type::find(__sb->gptr(),
394 : __n, __val);
395 : if (__p)
396 : __n = __p - __sb->gptr();
397 : __sb->__safe_gbump(__n);
398 : __c = __sb->sgetc();
399 : }
400 : else
401 : __c = __sb->snextc();
402 : }
403 :
404 : __first._M_c = __eof;
405 : }
406 :
407 : return __first;
408 : }
409 :
410 : template<typename _CharT, typename _Distance>
411 : typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value,
412 : void>::__type
413 : advance(istreambuf_iterator<_CharT>& __i, _Distance __n)
414 : {
415 : if (__n == 0)
416 : return;
417 :
418 : __glibcxx_assert(__n > 0);
419 : __glibcxx_requires_cond(!__i._M_at_eof(),
420 : _M_message(__gnu_debug::__msg_inc_istreambuf)
421 : ._M_iterator(__i));
422 :
423 : typedef istreambuf_iterator<_CharT> __is_iterator_type;
424 : typedef typename __is_iterator_type::traits_type traits_type;
425 : typedef typename __is_iterator_type::streambuf_type streambuf_type;
426 : typedef typename traits_type::int_type int_type;
427 : const int_type __eof = traits_type::eof();
428 :
429 : streambuf_type* __sb = __i._M_sbuf;
430 : while (__n > 0)
431 : {
432 : streamsize __size = __sb->egptr() - __sb->gptr();
433 : if (__size > __n)
434 : {
435 : __sb->__safe_gbump(__n);
436 : break;
437 : }
438 :
439 : __sb->__safe_gbump(__size);
440 : __n -= __size;
441 : if (traits_type::eq_int_type(__sb->underflow(), __eof))
442 : {
443 : __glibcxx_requires_cond(__n == 0,
444 : _M_message(__gnu_debug::__msg_inc_istreambuf)
445 : ._M_iterator(__i));
446 : break;
447 : }
448 : }
449 :
450 : __i._M_c = __eof;
451 : }
452 :
453 : /// @} group iterators
454 :
455 : _GLIBCXX_END_NAMESPACE_VERSION
456 : } // namespace
457 :
458 : #endif
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