1 | // Input streams -*- C++ -*- |
2 | |
3 | // Copyright (C) 1997-2017 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 | // |
26 | // ISO C++ 14882: 27.6.1 Input streams |
27 | // |
28 | |
29 | /** @file include/istream |
30 | * This is a Standard C++ Library header. |
31 | */ |
32 | |
33 | #ifndef _GLIBCXX_ISTREAM |
34 | #define _GLIBCXX_ISTREAM 1 |
35 | |
36 | #pragma GCC system_header |
37 | |
38 | #include <ios> |
39 | #include <ostream> |
40 | |
41 | namespace std _GLIBCXX_VISIBILITY(default) |
42 | { |
43 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
44 | |
45 | /** |
46 | * @brief Template class basic_istream. |
47 | * @ingroup io |
48 | * |
49 | * @tparam _CharT Type of character stream. |
50 | * @tparam _Traits Traits for character type, defaults to |
51 | * char_traits<_CharT>. |
52 | * |
53 | * This is the base class for all input streams. It provides text |
54 | * formatting of all builtin types, and communicates with any class |
55 | * derived from basic_streambuf to do the actual input. |
56 | */ |
57 | template<typename _CharT, typename _Traits> |
58 | class basic_istream : virtual public basic_ios<_CharT, _Traits> |
59 | { |
60 | public: |
61 | // Types (inherited from basic_ios (27.4.4)): |
62 | typedef _CharT char_type; |
63 | typedef typename _Traits::int_type int_type; |
64 | typedef typename _Traits::pos_type pos_type; |
65 | typedef typename _Traits::off_type off_type; |
66 | typedef _Traits traits_type; |
67 | |
68 | // Non-standard Types: |
69 | typedef basic_streambuf<_CharT, _Traits> __streambuf_type; |
70 | typedef basic_ios<_CharT, _Traits> __ios_type; |
71 | typedef basic_istream<_CharT, _Traits> __istream_type; |
72 | typedef num_get<_CharT, istreambuf_iterator<_CharT, _Traits> > |
73 | __num_get_type; |
74 | typedef ctype<_CharT> __ctype_type; |
75 | |
76 | protected: |
77 | // Data Members: |
78 | /** |
79 | * The number of characters extracted in the previous unformatted |
80 | * function; see gcount(). |
81 | */ |
82 | streamsize _M_gcount; |
83 | |
84 | public: |
85 | /** |
86 | * @brief Base constructor. |
87 | * |
88 | * This ctor is almost never called by the user directly, rather from |
89 | * derived classes' initialization lists, which pass a pointer to |
90 | * their own stream buffer. |
91 | */ |
92 | explicit |
93 | basic_istream(__streambuf_type* __sb) |
94 | : _M_gcount(streamsize(0)) |
95 | { this->init(__sb); } |
96 | |
97 | /** |
98 | * @brief Base destructor. |
99 | * |
100 | * This does very little apart from providing a virtual base dtor. |
101 | */ |
102 | virtual |
103 | ~basic_istream() |
104 | { _M_gcount = streamsize(0); } |
105 | |
106 | /// Safe prefix/suffix operations. |
107 | class sentry; |
108 | friend class sentry; |
109 | |
110 | //@{ |
111 | /** |
112 | * @brief Interface for manipulators. |
113 | * |
114 | * Manipulators such as @c std::ws and @c std::dec use these |
115 | * functions in constructs like |
116 | * <code>std::cin >> std::ws</code>. |
117 | * For more information, see the iomanip header. |
118 | */ |
119 | __istream_type& |
120 | operator>>(__istream_type& (*__pf)(__istream_type&)) |
121 | { return __pf(*this); } |
122 | |
123 | __istream_type& |
124 | operator>>(__ios_type& (*__pf)(__ios_type&)) |
125 | { |
126 | __pf(*this); |
127 | return *this; |
128 | } |
129 | |
130 | __istream_type& |
131 | operator>>(ios_base& (*__pf)(ios_base&)) |
132 | { |
133 | __pf(*this); |
134 | return *this; |
135 | } |
136 | //@} |
137 | |
138 | //@{ |
139 | /** |
140 | * @name Extractors |
141 | * |
142 | * All the @c operator>> functions (aka <em>formatted input |
143 | * functions</em>) have some common behavior. Each starts by |
144 | * constructing a temporary object of type std::basic_istream::sentry |
145 | * with the second argument (noskipws) set to false. This has several |
146 | * effects, concluding with the setting of a status flag; see the |
147 | * sentry documentation for more. |
148 | * |
149 | * If the sentry status is good, the function tries to extract |
150 | * whatever data is appropriate for the type of the argument. |
151 | * |
152 | * If an exception is thrown during extraction, ios_base::badbit |
153 | * will be turned on in the stream's error state (without causing an |
154 | * ios_base::failure to be thrown) and the original exception will |
155 | * be rethrown if badbit is set in the exceptions mask. |
156 | */ |
157 | |
158 | //@{ |
159 | /** |
160 | * @brief Integer arithmetic extractors |
161 | * @param __n A variable of builtin integral type. |
162 | * @return @c *this if successful |
163 | * |
164 | * These functions use the stream's current locale (specifically, the |
165 | * @c num_get facet) to parse the input data. |
166 | */ |
167 | __istream_type& |
168 | operator>>(bool& __n) |
169 | { return _M_extract(__n); } |
170 | |
171 | __istream_type& |
172 | operator>>(short& __n); |
173 | |
174 | __istream_type& |
175 | operator>>(unsigned short& __n) |
176 | { return _M_extract(__n); } |
177 | |
178 | __istream_type& |
179 | operator>>(int& __n); |
180 | |
181 | __istream_type& |
182 | operator>>(unsigned int& __n) |
183 | { return _M_extract(__n); } |
184 | |
185 | __istream_type& |
186 | operator>>(long& __n) |
187 | { return _M_extract(__n); } |
188 | |
189 | __istream_type& |
190 | operator>>(unsigned long& __n) |
191 | { return _M_extract(__n); } |
192 | |
193 | #ifdef _GLIBCXX_USE_LONG_LONG |
194 | __istream_type& |
195 | operator>>(long long& __n) |
196 | { return _M_extract(__n); } |
197 | |
198 | __istream_type& |
199 | operator>>(unsigned long long& __n) |
200 | { return _M_extract(__n); } |
201 | #endif |
202 | //@} |
203 | |
204 | //@{ |
205 | /** |
206 | * @brief Floating point arithmetic extractors |
207 | * @param __f A variable of builtin floating point type. |
208 | * @return @c *this if successful |
209 | * |
210 | * These functions use the stream's current locale (specifically, the |
211 | * @c num_get facet) to parse the input data. |
212 | */ |
213 | __istream_type& |
214 | operator>>(float& __f) |
215 | { return _M_extract(__f); } |
216 | |
217 | __istream_type& |
218 | operator>>(double& __f) |
219 | { return _M_extract(__f); } |
220 | |
221 | __istream_type& |
222 | operator>>(long double& __f) |
223 | { return _M_extract(__f); } |
224 | //@} |
225 | |
226 | /** |
227 | * @brief Basic arithmetic extractors |
228 | * @param __p A variable of pointer type. |
229 | * @return @c *this if successful |
230 | * |
231 | * These functions use the stream's current locale (specifically, the |
232 | * @c num_get facet) to parse the input data. |
233 | */ |
234 | __istream_type& |
235 | operator>>(void*& __p) |
236 | { return _M_extract(__p); } |
237 | |
238 | /** |
239 | * @brief Extracting into another streambuf. |
240 | * @param __sb A pointer to a streambuf |
241 | * |
242 | * This function behaves like one of the basic arithmetic extractors, |
243 | * in that it also constructs a sentry object and has the same error |
244 | * handling behavior. |
245 | * |
246 | * If @p __sb is NULL, the stream will set failbit in its error state. |
247 | * |
248 | * Characters are extracted from this stream and inserted into the |
249 | * @p __sb streambuf until one of the following occurs: |
250 | * |
251 | * - the input stream reaches end-of-file, |
252 | * - insertion into the output buffer fails (in this case, the |
253 | * character that would have been inserted is not extracted), or |
254 | * - an exception occurs (and in this case is caught) |
255 | * |
256 | * If the function inserts no characters, failbit is set. |
257 | */ |
258 | __istream_type& |
259 | operator>>(__streambuf_type* __sb); |
260 | //@} |
261 | |
262 | // [27.6.1.3] unformatted input |
263 | /** |
264 | * @brief Character counting |
265 | * @return The number of characters extracted by the previous |
266 | * unformatted input function dispatched for this stream. |
267 | */ |
268 | streamsize |
269 | gcount() const |
270 | { return _M_gcount; } |
271 | |
272 | //@{ |
273 | /** |
274 | * @name Unformatted Input Functions |
275 | * |
276 | * All the unformatted input functions have some common behavior. |
277 | * Each starts by constructing a temporary object of type |
278 | * std::basic_istream::sentry with the second argument (noskipws) |
279 | * set to true. This has several effects, concluding with the |
280 | * setting of a status flag; see the sentry documentation for more. |
281 | * |
282 | * If the sentry status is good, the function tries to extract |
283 | * whatever data is appropriate for the type of the argument. |
284 | * |
285 | * The number of characters extracted is stored for later retrieval |
286 | * by gcount(). |
287 | * |
288 | * If an exception is thrown during extraction, ios_base::badbit |
289 | * will be turned on in the stream's error state (without causing an |
290 | * ios_base::failure to be thrown) and the original exception will |
291 | * be rethrown if badbit is set in the exceptions mask. |
292 | */ |
293 | |
294 | /** |
295 | * @brief Simple extraction. |
296 | * @return A character, or eof(). |
297 | * |
298 | * Tries to extract a character. If none are available, sets failbit |
299 | * and returns traits::eof(). |
300 | */ |
301 | int_type |
302 | get(); |
303 | |
304 | /** |
305 | * @brief Simple extraction. |
306 | * @param __c The character in which to store data. |
307 | * @return *this |
308 | * |
309 | * Tries to extract a character and store it in @a __c. If none are |
310 | * available, sets failbit and returns traits::eof(). |
311 | * |
312 | * @note This function is not overloaded on signed char and |
313 | * unsigned char. |
314 | */ |
315 | __istream_type& |
316 | get(char_type& __c); |
317 | |
318 | /** |
319 | * @brief Simple multiple-character extraction. |
320 | * @param __s Pointer to an array. |
321 | * @param __n Maximum number of characters to store in @a __s. |
322 | * @param __delim A "stop" character. |
323 | * @return *this |
324 | * |
325 | * Characters are extracted and stored into @a __s until one of the |
326 | * following happens: |
327 | * |
328 | * - @c __n-1 characters are stored |
329 | * - the input sequence reaches EOF |
330 | * - the next character equals @a __delim, in which case the character |
331 | * is not extracted |
332 | * |
333 | * If no characters are stored, failbit is set in the stream's error |
334 | * state. |
335 | * |
336 | * In any case, a null character is stored into the next location in |
337 | * the array. |
338 | * |
339 | * @note This function is not overloaded on signed char and |
340 | * unsigned char. |
341 | */ |
342 | __istream_type& |
343 | get(char_type* __s, streamsize __n, char_type __delim); |
344 | |
345 | /** |
346 | * @brief Simple multiple-character extraction. |
347 | * @param __s Pointer to an array. |
348 | * @param __n Maximum number of characters to store in @a s. |
349 | * @return *this |
350 | * |
351 | * Returns @c get(__s,__n,widen('\\n')). |
352 | */ |
353 | __istream_type& |
354 | get(char_type* __s, streamsize __n) |
355 | { return this->get(__s, __n, this->widen('\n')); } |
356 | |
357 | /** |
358 | * @brief Extraction into another streambuf. |
359 | * @param __sb A streambuf in which to store data. |
360 | * @param __delim A "stop" character. |
361 | * @return *this |
362 | * |
363 | * Characters are extracted and inserted into @a __sb until one of the |
364 | * following happens: |
365 | * |
366 | * - the input sequence reaches EOF |
367 | * - insertion into the output buffer fails (in this case, the |
368 | * character that would have been inserted is not extracted) |
369 | * - the next character equals @a __delim (in this case, the character |
370 | * is not extracted) |
371 | * - an exception occurs (and in this case is caught) |
372 | * |
373 | * If no characters are stored, failbit is set in the stream's error |
374 | * state. |
375 | */ |
376 | __istream_type& |
377 | get(__streambuf_type& __sb, char_type __delim); |
378 | |
379 | /** |
380 | * @brief Extraction into another streambuf. |
381 | * @param __sb A streambuf in which to store data. |
382 | * @return *this |
383 | * |
384 | * Returns @c get(__sb,widen('\\n')). |
385 | */ |
386 | __istream_type& |
387 | get(__streambuf_type& __sb) |
388 | { return this->get(__sb, this->widen('\n')); } |
389 | |
390 | /** |
391 | * @brief String extraction. |
392 | * @param __s A character array in which to store the data. |
393 | * @param __n Maximum number of characters to extract. |
394 | * @param __delim A "stop" character. |
395 | * @return *this |
396 | * |
397 | * Extracts and stores characters into @a __s until one of the |
398 | * following happens. Note that these criteria are required to be |
399 | * tested in the order listed here, to allow an input line to exactly |
400 | * fill the @a __s array without setting failbit. |
401 | * |
402 | * -# the input sequence reaches end-of-file, in which case eofbit |
403 | * is set in the stream error state |
404 | * -# the next character equals @c __delim, in which case the character |
405 | * is extracted (and therefore counted in @c gcount()) but not stored |
406 | * -# @c __n-1 characters are stored, in which case failbit is set |
407 | * in the stream error state |
408 | * |
409 | * If no characters are extracted, failbit is set. (An empty line of |
410 | * input should therefore not cause failbit to be set.) |
411 | * |
412 | * In any case, a null character is stored in the next location in |
413 | * the array. |
414 | */ |
415 | __istream_type& |
416 | getline(char_type* __s, streamsize __n, char_type __delim); |
417 | |
418 | /** |
419 | * @brief String extraction. |
420 | * @param __s A character array in which to store the data. |
421 | * @param __n Maximum number of characters to extract. |
422 | * @return *this |
423 | * |
424 | * Returns @c getline(__s,__n,widen('\\n')). |
425 | */ |
426 | __istream_type& |
427 | getline(char_type* __s, streamsize __n) |
428 | { return this->getline(__s, __n, this->widen('\n')); } |
429 | |
430 | /** |
431 | * @brief Discarding characters |
432 | * @param __n Number of characters to discard. |
433 | * @param __delim A "stop" character. |
434 | * @return *this |
435 | * |
436 | * Extracts characters and throws them away until one of the |
437 | * following happens: |
438 | * - if @a __n @c != @c std::numeric_limits<int>::max(), @a __n |
439 | * characters are extracted |
440 | * - the input sequence reaches end-of-file |
441 | * - the next character equals @a __delim (in this case, the character |
442 | * is extracted); note that this condition will never occur if |
443 | * @a __delim equals @c traits::eof(). |
444 | * |
445 | * NB: Provide three overloads, instead of the single function |
446 | * (with defaults) mandated by the Standard: this leads to a |
447 | * better performing implementation, while still conforming to |
448 | * the Standard. |
449 | */ |
450 | __istream_type& |
451 | ignore(streamsize __n, int_type __delim); |
452 | |
453 | __istream_type& |
454 | ignore(streamsize __n); |
455 | |
456 | __istream_type& |
457 | ignore(); |
458 | |
459 | /** |
460 | * @brief Looking ahead in the stream |
461 | * @return The next character, or eof(). |
462 | * |
463 | * If, after constructing the sentry object, @c good() is false, |
464 | * returns @c traits::eof(). Otherwise reads but does not extract |
465 | * the next input character. |
466 | */ |
467 | int_type |
468 | peek(); |
469 | |
470 | /** |
471 | * @brief Extraction without delimiters. |
472 | * @param __s A character array. |
473 | * @param __n Maximum number of characters to store. |
474 | * @return *this |
475 | * |
476 | * If the stream state is @c good(), extracts characters and stores |
477 | * them into @a __s until one of the following happens: |
478 | * - @a __n characters are stored |
479 | * - the input sequence reaches end-of-file, in which case the error |
480 | * state is set to @c failbit|eofbit. |
481 | * |
482 | * @note This function is not overloaded on signed char and |
483 | * unsigned char. |
484 | */ |
485 | __istream_type& |
486 | read(char_type* __s, streamsize __n); |
487 | |
488 | /** |
489 | * @brief Extraction until the buffer is exhausted, but no more. |
490 | * @param __s A character array. |
491 | * @param __n Maximum number of characters to store. |
492 | * @return The number of characters extracted. |
493 | * |
494 | * Extracts characters and stores them into @a __s depending on the |
495 | * number of characters remaining in the streambuf's buffer, |
496 | * @c rdbuf()->in_avail(), called @c A here: |
497 | * - if @c A @c == @c -1, sets eofbit and extracts no characters |
498 | * - if @c A @c == @c 0, extracts no characters |
499 | * - if @c A @c > @c 0, extracts @c min(A,n) |
500 | * |
501 | * The goal is to empty the current buffer, and to not request any |
502 | * more from the external input sequence controlled by the streambuf. |
503 | */ |
504 | streamsize |
505 | readsome(char_type* __s, streamsize __n); |
506 | |
507 | /** |
508 | * @brief Unextracting a single character. |
509 | * @param __c The character to push back into the input stream. |
510 | * @return *this |
511 | * |
512 | * If @c rdbuf() is not null, calls @c rdbuf()->sputbackc(c). |
513 | * |
514 | * If @c rdbuf() is null or if @c sputbackc() fails, sets badbit in |
515 | * the error state. |
516 | * |
517 | * @note This function first clears eofbit. Since no characters |
518 | * are extracted, the next call to @c gcount() will return 0, |
519 | * as required by DR 60. |
520 | */ |
521 | __istream_type& |
522 | putback(char_type __c); |
523 | |
524 | /** |
525 | * @brief Unextracting the previous character. |
526 | * @return *this |
527 | * |
528 | * If @c rdbuf() is not null, calls @c rdbuf()->sungetc(c). |
529 | * |
530 | * If @c rdbuf() is null or if @c sungetc() fails, sets badbit in |
531 | * the error state. |
532 | * |
533 | * @note This function first clears eofbit. Since no characters |
534 | * are extracted, the next call to @c gcount() will return 0, |
535 | * as required by DR 60. |
536 | */ |
537 | __istream_type& |
538 | unget(); |
539 | |
540 | /** |
541 | * @brief Synchronizing the stream buffer. |
542 | * @return 0 on success, -1 on failure |
543 | * |
544 | * If @c rdbuf() is a null pointer, returns -1. |
545 | * |
546 | * Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1, |
547 | * sets badbit and returns -1. |
548 | * |
549 | * Otherwise, returns 0. |
550 | * |
551 | * @note This function does not count the number of characters |
552 | * extracted, if any, and therefore does not affect the next |
553 | * call to @c gcount(). |
554 | */ |
555 | int |
556 | sync(); |
557 | |
558 | /** |
559 | * @brief Getting the current read position. |
560 | * @return A file position object. |
561 | * |
562 | * If @c fail() is not false, returns @c pos_type(-1) to indicate |
563 | * failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,in). |
564 | * |
565 | * @note This function does not count the number of characters |
566 | * extracted, if any, and therefore does not affect the next |
567 | * call to @c gcount(). At variance with putback, unget and |
568 | * seekg, eofbit is not cleared first. |
569 | */ |
570 | pos_type |
571 | tellg(); |
572 | |
573 | /** |
574 | * @brief Changing the current read position. |
575 | * @param __pos A file position object. |
576 | * @return *this |
577 | * |
578 | * If @c fail() is not true, calls @c rdbuf()->pubseekpos(__pos). If |
579 | * that function fails, sets failbit. |
580 | * |
581 | * @note This function first clears eofbit. It does not count the |
582 | * number of characters extracted, if any, and therefore does |
583 | * not affect the next call to @c gcount(). |
584 | */ |
585 | __istream_type& |
586 | seekg(pos_type); |
587 | |
588 | /** |
589 | * @brief Changing the current read position. |
590 | * @param __off A file offset object. |
591 | * @param __dir The direction in which to seek. |
592 | * @return *this |
593 | * |
594 | * If @c fail() is not true, calls @c rdbuf()->pubseekoff(__off,__dir). |
595 | * If that function fails, sets failbit. |
596 | * |
597 | * @note This function first clears eofbit. It does not count the |
598 | * number of characters extracted, if any, and therefore does |
599 | * not affect the next call to @c gcount(). |
600 | */ |
601 | __istream_type& |
602 | seekg(off_type, ios_base::seekdir); |
603 | //@} |
604 | |
605 | protected: |
606 | basic_istream() |
607 | : _M_gcount(streamsize(0)) |
608 | { this->init(0); } |
609 | |
610 | #if __cplusplus >= 201103L |
611 | basic_istream(const basic_istream&) = delete; |
612 | |
613 | basic_istream(basic_istream&& __rhs) |
614 | : __ios_type(), _M_gcount(__rhs._M_gcount) |
615 | { |
616 | __ios_type::move(__rhs); |
617 | __rhs._M_gcount = 0; |
618 | } |
619 | |
620 | // 27.7.3.3 Assign/swap |
621 | |
622 | basic_istream& operator=(const basic_istream&) = delete; |
623 | |
624 | basic_istream& |
625 | operator=(basic_istream&& __rhs) |
626 | { |
627 | swap(__rhs); |
628 | return *this; |
629 | } |
630 | |
631 | void |
632 | swap(basic_istream& __rhs) |
633 | { |
634 | __ios_type::swap(__rhs); |
635 | std::swap(_M_gcount, __rhs._M_gcount); |
636 | } |
637 | #endif |
638 | |
639 | template<typename _ValueT> |
640 | __istream_type& |
641 | (_ValueT& __v); |
642 | }; |
643 | |
644 | /// Explicit specialization declarations, defined in src/istream.cc. |
645 | template<> |
646 | basic_istream<char>& |
647 | basic_istream<char>:: |
648 | getline(char_type* __s, streamsize __n, char_type __delim); |
649 | |
650 | template<> |
651 | basic_istream<char>& |
652 | basic_istream<char>:: |
653 | ignore(streamsize __n); |
654 | |
655 | template<> |
656 | basic_istream<char>& |
657 | basic_istream<char>:: |
658 | ignore(streamsize __n, int_type __delim); |
659 | |
660 | #ifdef _GLIBCXX_USE_WCHAR_T |
661 | template<> |
662 | basic_istream<wchar_t>& |
663 | basic_istream<wchar_t>:: |
664 | getline(char_type* __s, streamsize __n, char_type __delim); |
665 | |
666 | template<> |
667 | basic_istream<wchar_t>& |
668 | basic_istream<wchar_t>:: |
669 | ignore(streamsize __n); |
670 | |
671 | template<> |
672 | basic_istream<wchar_t>& |
673 | basic_istream<wchar_t>:: |
674 | ignore(streamsize __n, int_type __delim); |
675 | #endif |
676 | |
677 | /** |
678 | * @brief Performs setup work for input streams. |
679 | * |
680 | * Objects of this class are created before all of the standard |
681 | * extractors are run. It is responsible for <em>exception-safe |
682 | * prefix and suffix operations,</em> although only prefix actions |
683 | * are currently required by the standard. |
684 | */ |
685 | template<typename _CharT, typename _Traits> |
686 | class basic_istream<_CharT, _Traits>::sentry |
687 | { |
688 | // Data Members. |
689 | bool _M_ok; |
690 | |
691 | public: |
692 | /// Easy access to dependent types. |
693 | typedef _Traits traits_type; |
694 | typedef basic_streambuf<_CharT, _Traits> __streambuf_type; |
695 | typedef basic_istream<_CharT, _Traits> __istream_type; |
696 | typedef typename __istream_type::__ctype_type __ctype_type; |
697 | typedef typename _Traits::int_type __int_type; |
698 | |
699 | /** |
700 | * @brief The constructor performs all the work. |
701 | * @param __is The input stream to guard. |
702 | * @param __noskipws Whether to consume whitespace or not. |
703 | * |
704 | * If the stream state is good (@a __is.good() is true), then the |
705 | * following actions are performed, otherwise the sentry state |
706 | * is false (<em>not okay</em>) and failbit is set in the |
707 | * stream state. |
708 | * |
709 | * The sentry's preparatory actions are: |
710 | * |
711 | * -# if the stream is tied to an output stream, @c is.tie()->flush() |
712 | * is called to synchronize the output sequence |
713 | * -# if @a __noskipws is false, and @c ios_base::skipws is set in |
714 | * @c is.flags(), the sentry extracts and discards whitespace |
715 | * characters from the stream. The currently imbued locale is |
716 | * used to determine whether each character is whitespace. |
717 | * |
718 | * If the stream state is still good, then the sentry state becomes |
719 | * true (@a okay). |
720 | */ |
721 | explicit |
722 | sentry(basic_istream<_CharT, _Traits>& __is, bool __noskipws = false); |
723 | |
724 | /** |
725 | * @brief Quick status checking. |
726 | * @return The sentry state. |
727 | * |
728 | * For ease of use, sentries may be converted to booleans. The |
729 | * return value is that of the sentry state (true == okay). |
730 | */ |
731 | #if __cplusplus >= 201103L |
732 | explicit |
733 | #endif |
734 | operator bool() const |
735 | { return _M_ok; } |
736 | }; |
737 | |
738 | //@{ |
739 | /** |
740 | * @brief Character extractors |
741 | * @param __in An input stream. |
742 | * @param __c A character reference. |
743 | * @return in |
744 | * |
745 | * Behaves like one of the formatted arithmetic extractors described in |
746 | * std::basic_istream. After constructing a sentry object with good |
747 | * status, this function extracts a character (if one is available) and |
748 | * stores it in @a __c. Otherwise, sets failbit in the input stream. |
749 | */ |
750 | template<typename _CharT, typename _Traits> |
751 | basic_istream<_CharT, _Traits>& |
752 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c); |
753 | |
754 | template<class _Traits> |
755 | inline basic_istream<char, _Traits>& |
756 | operator>>(basic_istream<char, _Traits>& __in, unsigned char& __c) |
757 | { return (__in >> reinterpret_cast<char&>(__c)); } |
758 | |
759 | template<class _Traits> |
760 | inline basic_istream<char, _Traits>& |
761 | operator>>(basic_istream<char, _Traits>& __in, signed char& __c) |
762 | { return (__in >> reinterpret_cast<char&>(__c)); } |
763 | //@} |
764 | |
765 | //@{ |
766 | /** |
767 | * @brief Character string extractors |
768 | * @param __in An input stream. |
769 | * @param __s A pointer to a character array. |
770 | * @return __in |
771 | * |
772 | * Behaves like one of the formatted arithmetic extractors described in |
773 | * std::basic_istream. After constructing a sentry object with good |
774 | * status, this function extracts up to @c n characters and stores them |
775 | * into the array starting at @a __s. @c n is defined as: |
776 | * |
777 | * - if @c width() is greater than zero, @c n is width() otherwise |
778 | * - @c n is <em>the number of elements of the largest array of * |
779 | * - @c char_type that can store a terminating @c eos.</em> |
780 | * - [27.6.1.2.3]/6 |
781 | * |
782 | * Characters are extracted and stored until one of the following happens: |
783 | * - @c n-1 characters are stored |
784 | * - EOF is reached |
785 | * - the next character is whitespace according to the current locale |
786 | * - the next character is a null byte (i.e., @c charT() ) |
787 | * |
788 | * @c width(0) is then called for the input stream. |
789 | * |
790 | * If no characters are extracted, sets failbit. |
791 | */ |
792 | template<typename _CharT, typename _Traits> |
793 | basic_istream<_CharT, _Traits>& |
794 | operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s); |
795 | |
796 | // Explicit specialization declaration, defined in src/istream.cc. |
797 | template<> |
798 | basic_istream<char>& |
799 | operator>>(basic_istream<char>& __in, char* __s); |
800 | |
801 | template<class _Traits> |
802 | inline basic_istream<char, _Traits>& |
803 | operator>>(basic_istream<char, _Traits>& __in, unsigned char* __s) |
804 | { return (__in >> reinterpret_cast<char*>(__s)); } |
805 | |
806 | template<class _Traits> |
807 | inline basic_istream<char, _Traits>& |
808 | operator>>(basic_istream<char, _Traits>& __in, signed char* __s) |
809 | { return (__in >> reinterpret_cast<char*>(__s)); } |
810 | //@} |
811 | |
812 | /** |
813 | * @brief Template class basic_iostream |
814 | * @ingroup io |
815 | * |
816 | * @tparam _CharT Type of character stream. |
817 | * @tparam _Traits Traits for character type, defaults to |
818 | * char_traits<_CharT>. |
819 | * |
820 | * This class multiply inherits from the input and output stream classes |
821 | * simply to provide a single interface. |
822 | */ |
823 | template<typename _CharT, typename _Traits> |
824 | class basic_iostream |
825 | : public basic_istream<_CharT, _Traits>, |
826 | public basic_ostream<_CharT, _Traits> |
827 | { |
828 | public: |
829 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
830 | // 271. basic_iostream missing typedefs |
831 | // Types (inherited): |
832 | typedef _CharT char_type; |
833 | typedef typename _Traits::int_type int_type; |
834 | typedef typename _Traits::pos_type pos_type; |
835 | typedef typename _Traits::off_type off_type; |
836 | typedef _Traits traits_type; |
837 | |
838 | // Non-standard Types: |
839 | typedef basic_istream<_CharT, _Traits> __istream_type; |
840 | typedef basic_ostream<_CharT, _Traits> __ostream_type; |
841 | |
842 | /** |
843 | * @brief Constructor does nothing. |
844 | * |
845 | * Both of the parent classes are initialized with the same |
846 | * streambuf pointer passed to this constructor. |
847 | */ |
848 | explicit |
849 | basic_iostream(basic_streambuf<_CharT, _Traits>* __sb) |
850 | : __istream_type(__sb), __ostream_type(__sb) { } |
851 | |
852 | /** |
853 | * @brief Destructor does nothing. |
854 | */ |
855 | virtual |
856 | ~basic_iostream() { } |
857 | |
858 | protected: |
859 | basic_iostream() |
860 | : __istream_type(), __ostream_type() { } |
861 | |
862 | #if __cplusplus >= 201103L |
863 | basic_iostream(const basic_iostream&) = delete; |
864 | |
865 | basic_iostream(basic_iostream&& __rhs) |
866 | : __istream_type(std::move(__rhs)), __ostream_type(*this) |
867 | { } |
868 | |
869 | // 27.7.3.3 Assign/swap |
870 | |
871 | basic_iostream& operator=(const basic_iostream&) = delete; |
872 | |
873 | basic_iostream& |
874 | operator=(basic_iostream&& __rhs) |
875 | { |
876 | swap(__rhs); |
877 | return *this; |
878 | } |
879 | |
880 | void |
881 | swap(basic_iostream& __rhs) |
882 | { __istream_type::swap(__rhs); } |
883 | #endif |
884 | }; |
885 | |
886 | /** |
887 | * @brief Quick and easy way to eat whitespace |
888 | * |
889 | * This manipulator extracts whitespace characters, stopping when the |
890 | * next character is non-whitespace, or when the input sequence is empty. |
891 | * If the sequence is empty, @c eofbit is set in the stream, but not |
892 | * @c failbit. |
893 | * |
894 | * The current locale is used to distinguish whitespace characters. |
895 | * |
896 | * Example: |
897 | * @code |
898 | * MyClass mc; |
899 | * |
900 | * std::cin >> std::ws >> mc; |
901 | * @endcode |
902 | * will skip leading whitespace before calling operator>> on cin and your |
903 | * object. Note that the same effect can be achieved by creating a |
904 | * std::basic_istream::sentry inside your definition of operator>>. |
905 | */ |
906 | template<typename _CharT, typename _Traits> |
907 | basic_istream<_CharT, _Traits>& |
908 | ws(basic_istream<_CharT, _Traits>& __is); |
909 | |
910 | #if __cplusplus >= 201103L |
911 | template<typename _Ch, typename _Up> |
912 | basic_istream<_Ch, _Up>& |
913 | __is_convertible_to_basic_istream_test(basic_istream<_Ch, _Up>*); |
914 | |
915 | template<typename _Tp, typename = void> |
916 | struct __is_convertible_to_basic_istream_impl |
917 | { |
918 | using __istream_type = void; |
919 | }; |
920 | |
921 | template<typename _Tp> |
922 | using __do_is_convertible_to_basic_istream_impl = |
923 | decltype(__is_convertible_to_basic_istream_test |
924 | (declval<typename remove_reference<_Tp>::type*>())); |
925 | |
926 | template<typename _Tp> |
927 | struct __is_convertible_to_basic_istream_impl |
928 | <_Tp, |
929 | __void_t<__do_is_convertible_to_basic_istream_impl<_Tp>>> |
930 | { |
931 | using __istream_type = |
932 | __do_is_convertible_to_basic_istream_impl<_Tp>; |
933 | }; |
934 | |
935 | template<typename _Tp> |
936 | struct __is_convertible_to_basic_istream |
937 | : __is_convertible_to_basic_istream_impl<_Tp> |
938 | { |
939 | public: |
940 | using type = __not_<is_void< |
941 | typename __is_convertible_to_basic_istream_impl<_Tp>::__istream_type>>; |
942 | constexpr static bool value = type::value; |
943 | }; |
944 | |
945 | template<typename _Istream, typename _Tp, typename = void> |
946 | struct : false_type {}; |
947 | |
948 | template<typename _Istream, typename _Tp> |
949 | struct <_Istream, _Tp, |
950 | __void_t<decltype(declval<_Istream&>() |
951 | >> declval<_Tp>())>> |
952 | : true_type {}; |
953 | |
954 | template<typename _Istream> |
955 | using __rvalue_istream_type = |
956 | typename __is_convertible_to_basic_istream< |
957 | _Istream>::__istream_type; |
958 | |
959 | // [27.7.1.6] Rvalue stream extraction |
960 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
961 | // 2328. Rvalue stream extraction should use perfect forwarding |
962 | /** |
963 | * @brief Generic extractor for rvalue stream |
964 | * @param __is An input stream. |
965 | * @param __x A reference to the extraction target. |
966 | * @return is |
967 | * |
968 | * This is just a forwarding function to allow extraction from |
969 | * rvalue streams since they won't bind to the extractor functions |
970 | * that take an lvalue reference. |
971 | */ |
972 | template<typename _Istream, typename _Tp> |
973 | inline |
974 | typename enable_if<__and_<__not_<is_lvalue_reference<_Istream>>, |
975 | __is_convertible_to_basic_istream<_Istream>, |
976 | __is_extractable< |
977 | __rvalue_istream_type<_Istream>, |
978 | _Tp&&>>::value, |
979 | __rvalue_istream_type<_Istream>>::type |
980 | operator>>(_Istream&& __is, _Tp&& __x) |
981 | { |
982 | __rvalue_istream_type<_Istream> __ret_is = __is; |
983 | __ret_is >> std::forward<_Tp>(__x); |
984 | return __ret_is; |
985 | } |
986 | #endif // C++11 |
987 | |
988 | _GLIBCXX_END_NAMESPACE_VERSION |
989 | } // namespace |
990 | |
991 | #include <bits/istream.tcc> |
992 | |
993 | #endif /* _GLIBCXX_ISTREAM */ |
994 | |