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PR libstdc++/87704 fix unique_ptr(nullptr_t) constructors
[official-gcc.git] / libstdc++-v3 / include / bits / streambuf_iterator.h
blob8a3a382325a0e92d8e2bf9debdf199d6e6fa7702
1 // Streambuf iterators
2
3 // Copyright (C) 1997-2018 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 _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
108 : _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 istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT
118 : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { }
119
120 /// Construct start of streambuf iterator.
121 istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT
122 : _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 operator*() const
134 {
135 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 return traits_type::to_char_type(__c);
145 }
146
147 /// Advance the iterator. Calls streambuf.sbumpc().
148 istreambuf_iterator&
149 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 _M_sbuf->sbumpc();
157 _M_c = traits_type::eof();
158 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 equal(const istreambuf_iterator& __b) const
182 { 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 _M_at_eof() const
196 { return _S_is_eof(_M_get()); }
197
198 static bool
199 _S_is_eof(int_type __c)
200 {
201 const int_type __eof = traits_type::eof();
202 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 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a,
215 const istreambuf_iterator<_CharT, _Traits>& __b)
216 { 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 ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT
246 : _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 operator=(_CharT __c)
255 {
256 if (!_M_failed &&
257 _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof()))
258 _M_failed = true;
259 return *this;
260 }
261
262 /// Return *this.
263 ostreambuf_iterator&
264 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 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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