libstdc++
istream.tcc
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1 // istream classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2025 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/istream.tcc
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{istream}
28  */
29 
30 //
31 // ISO C++ 14882: 27.6.1 Input streams
32 //
33 
34 #ifndef _ISTREAM_TCC
35 #define _ISTREAM_TCC 1
36 
37 #ifdef _GLIBCXX_SYSHDR
38 #pragma GCC system_header
39 #endif
40 
41 #pragma GCC diagnostic push
42 #pragma GCC diagnostic ignored "-Wc++11-extensions" // extern template
43 
44 #include <bits/cxxabi_forced.h>
45 
46 namespace std _GLIBCXX_VISIBILITY(default)
47 {
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 
50  template<typename _CharT, typename _Traits>
51  basic_istream<_CharT, _Traits>::sentry::
52  sentry(basic_istream<_CharT, _Traits>& __in, bool __noskip) : _M_ok(false)
53  {
54  ios_base::iostate __err = ios_base::goodbit;
55  if (__in.good())
56  {
57  __try
58  {
59  if (__in.tie())
60  __in.tie()->flush();
61  if (!__noskip && bool(__in.flags() & ios_base::skipws))
62  {
63  const __int_type __eof = traits_type::eof();
64  __streambuf_type* __sb = __in.rdbuf();
65  __int_type __c = __sb->sgetc();
66 
67  const __ctype_type& __ct = __check_facet(__in._M_ctype);
68  while (!traits_type::eq_int_type(__c, __eof)
69  && __ct.is(ctype_base::space,
70  traits_type::to_char_type(__c)))
71  __c = __sb->snextc();
72 
73  // _GLIBCXX_RESOLVE_LIB_DEFECTS
74  // 195. Should basic_istream::sentry's constructor ever
75  // set eofbit?
76  if (traits_type::eq_int_type(__c, __eof))
77  __err |= ios_base::eofbit;
78  }
79  }
80  __catch(__cxxabiv1::__forced_unwind&)
81  {
82  __in._M_setstate(ios_base::badbit);
83  __throw_exception_again;
84  }
85  __catch(...)
86  { __in._M_setstate(ios_base::badbit); }
87  }
88 
89  if (__in.good() && __err == ios_base::goodbit)
90  _M_ok = true;
91  else
92  {
93  __err |= ios_base::failbit;
94  __in.setstate(__err);
95  }
96  }
97 
98  template<typename _CharT, typename _Traits>
99  template<typename _ValueT>
100  basic_istream<_CharT, _Traits>&
101  basic_istream<_CharT, _Traits>::
102  _M_extract(_ValueT& __v)
103  {
104  sentry __cerb(*this, false);
105  if (__cerb)
106  {
107  ios_base::iostate __err = ios_base::goodbit;
108  __try
109  {
110 #ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
111  const __num_get_type& __ng = __check_facet(this->_M_num_get);
112 #else
113  const __num_get_type& __ng
114  = use_facet<__num_get_type>(this->_M_ios_locale);
115 #endif
116  __ng.get(*this, 0, *this, __err, __v);
117  }
118  __catch(__cxxabiv1::__forced_unwind&)
119  {
120  this->_M_setstate(ios_base::badbit);
121  __throw_exception_again;
122  }
123  __catch(...)
124  { this->_M_setstate(ios_base::badbit); }
125  if (__err)
126  this->setstate(__err);
127  }
128  return *this;
129  }
130 
131  template<typename _CharT, typename _Traits>
132  basic_istream<_CharT, _Traits>&
133  basic_istream<_CharT, _Traits>::
134  operator>>(short& __n)
135  {
136  // _GLIBCXX_RESOLVE_LIB_DEFECTS
137  // 118. basic_istream uses nonexistent num_get member functions.
138  sentry __cerb(*this, false);
139  if (__cerb)
140  {
141  ios_base::iostate __err = ios_base::goodbit;
142  __try
143  {
144  long __l;
145 #ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
146  const __num_get_type& __ng = __check_facet(this->_M_num_get);
147 #else
148  const __num_get_type& __ng
149  = use_facet<__num_get_type>(this->_M_ios_locale);
150 #endif
151  __ng.get(*this, 0, *this, __err, __l);
152 
153  // _GLIBCXX_RESOLVE_LIB_DEFECTS
154  // 696. istream::operator>>(int&) broken.
155  if (__l < __gnu_cxx::__numeric_traits<short>::__min)
156  {
157  __err |= ios_base::failbit;
158  __n = __gnu_cxx::__numeric_traits<short>::__min;
159  }
160  else if (__l > __gnu_cxx::__numeric_traits<short>::__max)
161  {
162  __err |= ios_base::failbit;
163  __n = __gnu_cxx::__numeric_traits<short>::__max;
164  }
165  else
166  __n = short(__l);
167  }
168  __catch(__cxxabiv1::__forced_unwind&)
169  {
170  this->_M_setstate(ios_base::badbit);
171  __throw_exception_again;
172  }
173  __catch(...)
174  { this->_M_setstate(ios_base::badbit); }
175  if (__err)
176  this->setstate(__err);
177  }
178  return *this;
179  }
180 
181  template<typename _CharT, typename _Traits>
182  basic_istream<_CharT, _Traits>&
183  basic_istream<_CharT, _Traits>::
184  operator>>(int& __n)
185  {
186  // _GLIBCXX_RESOLVE_LIB_DEFECTS
187  // 118. basic_istream uses nonexistent num_get member functions.
188  sentry __cerb(*this, false);
189  if (__cerb)
190  {
191  ios_base::iostate __err = ios_base::goodbit;
192  __try
193  {
194  long __l;
195 #ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
196  const __num_get_type& __ng = __check_facet(this->_M_num_get);
197 #else
198  const __num_get_type& __ng
199  = use_facet<__num_get_type>(this->_M_ios_locale);
200 #endif
201  __ng.get(*this, 0, *this, __err, __l);
202 
203  // _GLIBCXX_RESOLVE_LIB_DEFECTS
204  // 696. istream::operator>>(int&) broken.
205  if (__l < __gnu_cxx::__numeric_traits<int>::__min)
206  {
207  __err |= ios_base::failbit;
208  __n = __gnu_cxx::__numeric_traits<int>::__min;
209  }
210  else if (__l > __gnu_cxx::__numeric_traits<int>::__max)
211  {
212  __err |= ios_base::failbit;
213  __n = __gnu_cxx::__numeric_traits<int>::__max;
214  }
215  else
216  __n = int(__l);
217  }
218  __catch(__cxxabiv1::__forced_unwind&)
219  {
220  this->_M_setstate(ios_base::badbit);
221  __throw_exception_again;
222  }
223  __catch(...)
224  { this->_M_setstate(ios_base::badbit); }
225  if (__err)
226  this->setstate(__err);
227  }
228  return *this;
229  }
230 
231  template<typename _CharT, typename _Traits>
232  basic_istream<_CharT, _Traits>&
233  basic_istream<_CharT, _Traits>::
234  operator>>(__streambuf_type* __sbout)
235  {
236  ios_base::iostate __err = ios_base::goodbit;
237  sentry __cerb(*this, false);
238  if (__cerb && __sbout)
239  {
240  __try
241  {
242  bool __ineof;
243  if (!__copy_streambufs_eof(this->rdbuf(), __sbout, __ineof))
244  __err |= ios_base::failbit;
245  if (__ineof)
246  __err |= ios_base::eofbit;
247  }
248  __catch(__cxxabiv1::__forced_unwind&)
249  {
250  this->_M_setstate(ios_base::failbit);
251  __throw_exception_again;
252  }
253  __catch(...)
254  { this->_M_setstate(ios_base::failbit); }
255  }
256  else if (!__sbout)
257  __err |= ios_base::failbit;
258  if (__err)
259  this->setstate(__err);
260  return *this;
261  }
262 
263  template<typename _CharT, typename _Traits>
264  typename basic_istream<_CharT, _Traits>::int_type
265  basic_istream<_CharT, _Traits>::
266  get(void)
267  {
268  const int_type __eof = traits_type::eof();
269  int_type __c = __eof;
270  _M_gcount = 0;
271  ios_base::iostate __err = ios_base::goodbit;
272  sentry __cerb(*this, true);
273  if (__cerb)
274  {
275  __try
276  {
277  __c = this->rdbuf()->sbumpc();
278  // 27.6.1.1 paragraph 3
279  if (!traits_type::eq_int_type(__c, __eof))
280  _M_gcount = 1;
281  else
282  __err |= ios_base::eofbit;
283  }
284  __catch(__cxxabiv1::__forced_unwind&)
285  {
286  this->_M_setstate(ios_base::badbit);
287  __throw_exception_again;
288  }
289  __catch(...)
290  { this->_M_setstate(ios_base::badbit); }
291  }
292  if (!_M_gcount)
293  __err |= ios_base::failbit;
294  if (__err)
295  this->setstate(__err);
296  return __c;
297  }
298 
299  template<typename _CharT, typename _Traits>
300  basic_istream<_CharT, _Traits>&
301  basic_istream<_CharT, _Traits>::
302  get(char_type& __c)
303  {
304  _M_gcount = 0;
305  ios_base::iostate __err = ios_base::goodbit;
306  sentry __cerb(*this, true);
307  if (__cerb)
308  {
309  __try
310  {
311  const int_type __cb = this->rdbuf()->sbumpc();
312  // 27.6.1.1 paragraph 3
313  if (!traits_type::eq_int_type(__cb, traits_type::eof()))
314  {
315  _M_gcount = 1;
316  __c = traits_type::to_char_type(__cb);
317  }
318  else
319  __err |= ios_base::eofbit;
320  }
321  __catch(__cxxabiv1::__forced_unwind&)
322  {
323  this->_M_setstate(ios_base::badbit);
324  __throw_exception_again;
325  }
326  __catch(...)
327  { this->_M_setstate(ios_base::badbit); }
328  }
329  if (!_M_gcount)
330  __err |= ios_base::failbit;
331  if (__err)
332  this->setstate(__err);
333  return *this;
334  }
335 
336  template<typename _CharT, typename _Traits>
337  basic_istream<_CharT, _Traits>&
338  basic_istream<_CharT, _Traits>::
339  get(char_type* __s, streamsize __n, char_type __delim)
340  {
341  _M_gcount = 0;
342  ios_base::iostate __err = ios_base::goodbit;
343  sentry __cerb(*this, true);
344  if (__cerb)
345  {
346  __try
347  {
348  const int_type __idelim = traits_type::to_int_type(__delim);
349  const int_type __eof = traits_type::eof();
350  __streambuf_type* __sb = this->rdbuf();
351  int_type __c = __sb->sgetc();
352 
353  while (_M_gcount + 1 < __n
354  && !traits_type::eq_int_type(__c, __eof)
355  && !traits_type::eq_int_type(__c, __idelim))
356  {
357  *__s++ = traits_type::to_char_type(__c);
358  ++_M_gcount;
359  __c = __sb->snextc();
360  }
361  if (traits_type::eq_int_type(__c, __eof))
362  __err |= ios_base::eofbit;
363  }
364  __catch(__cxxabiv1::__forced_unwind&)
365  {
366  this->_M_setstate(ios_base::badbit);
367  __throw_exception_again;
368  }
369  __catch(...)
370  { this->_M_setstate(ios_base::badbit); }
371  }
372  // _GLIBCXX_RESOLVE_LIB_DEFECTS
373  // 243. get and getline when sentry reports failure.
374  if (__n > 0)
375  *__s = char_type();
376  if (!_M_gcount)
377  __err |= ios_base::failbit;
378  if (__err)
379  this->setstate(__err);
380  return *this;
381  }
382 
383  template<typename _CharT, typename _Traits>
384  basic_istream<_CharT, _Traits>&
385  basic_istream<_CharT, _Traits>::
386  get(__streambuf_type& __sb, char_type __delim)
387  {
388  _M_gcount = 0;
389  ios_base::iostate __err = ios_base::goodbit;
390  sentry __cerb(*this, true);
391  if (__cerb)
392  {
393  __try
394  {
395  const int_type __idelim = traits_type::to_int_type(__delim);
396  const int_type __eof = traits_type::eof();
397  __streambuf_type* __this_sb = this->rdbuf();
398  int_type __c = __this_sb->sgetc();
399  char_type __c2 = traits_type::to_char_type(__c);
400 #pragma GCC diagnostic push
401 #pragma GCC diagnostic ignored "-Wlong-long"
402  unsigned long long __gcount = 0;
403 #pragma GCC diagnostic pop
404 
405  while (!traits_type::eq_int_type(__c, __eof)
406  && !traits_type::eq_int_type(__c, __idelim)
407  && !traits_type::eq_int_type(__sb.sputc(__c2), __eof))
408  {
409  ++__gcount;
410  __c = __this_sb->snextc();
411  __c2 = traits_type::to_char_type(__c);
412  }
413  if (traits_type::eq_int_type(__c, __eof))
414  __err |= ios_base::eofbit;
415  // _GLIBCXX_RESOLVE_LIB_DEFECTS
416  // 3464. istream::gcount() can overflow
417  if (__gcount <= __gnu_cxx::__numeric_traits<streamsize>::__max)
418  _M_gcount = __gcount;
419  else
420  _M_gcount = __gnu_cxx::__numeric_traits<streamsize>::__max;
421  }
422  __catch(__cxxabiv1::__forced_unwind&)
423  {
424  this->_M_setstate(ios_base::badbit);
425  __throw_exception_again;
426  }
427  __catch(...)
428  { this->_M_setstate(ios_base::badbit); }
429  }
430  if (!_M_gcount)
431  __err |= ios_base::failbit;
432  if (__err)
433  this->setstate(__err);
434  return *this;
435  }
436 
437  template<typename _CharT, typename _Traits>
438  basic_istream<_CharT, _Traits>&
439  basic_istream<_CharT, _Traits>::
440  getline(char_type* __s, streamsize __n, char_type __delim)
441  {
442  _M_gcount = 0;
443  ios_base::iostate __err = ios_base::goodbit;
444  sentry __cerb(*this, true);
445  if (__cerb)
446  {
447  __try
448  {
449  const int_type __idelim = traits_type::to_int_type(__delim);
450  const int_type __eof = traits_type::eof();
451  __streambuf_type* __sb = this->rdbuf();
452  int_type __c = __sb->sgetc();
453 
454  while (_M_gcount + 1 < __n
455  && !traits_type::eq_int_type(__c, __eof)
456  && !traits_type::eq_int_type(__c, __idelim))
457  {
458  *__s++ = traits_type::to_char_type(__c);
459  __c = __sb->snextc();
460  ++_M_gcount;
461  }
462  if (traits_type::eq_int_type(__c, __eof))
463  __err |= ios_base::eofbit;
464  else
465  {
466  if (traits_type::eq_int_type(__c, __idelim))
467  {
468  __sb->sbumpc();
469  ++_M_gcount;
470  }
471  else
472  __err |= ios_base::failbit;
473  }
474  }
475  __catch(__cxxabiv1::__forced_unwind&)
476  {
477  this->_M_setstate(ios_base::badbit);
478  __throw_exception_again;
479  }
480  __catch(...)
481  { this->_M_setstate(ios_base::badbit); }
482  }
483  // _GLIBCXX_RESOLVE_LIB_DEFECTS
484  // 243. get and getline when sentry reports failure.
485  if (__n > 0)
486  *__s = char_type();
487  if (!_M_gcount)
488  __err |= ios_base::failbit;
489  if (__err)
490  this->setstate(__err);
491  return *this;
492  }
493 
494  // We provide three overloads, since the first two are much simpler
495  // than the general case. Also, the latter two can thus adopt the
496  // same "batchy" strategy used by getline above.
497  template<typename _CharT, typename _Traits>
498  basic_istream<_CharT, _Traits>&
499  basic_istream<_CharT, _Traits>::
500  ignore(void)
501  {
502  _M_gcount = 0;
503  sentry __cerb(*this, true);
504  if (__cerb)
505  {
506  ios_base::iostate __err = ios_base::goodbit;
507  __try
508  {
509  const int_type __eof = traits_type::eof();
510  __streambuf_type* __sb = this->rdbuf();
511 
512  if (traits_type::eq_int_type(__sb->sbumpc(), __eof))
513  __err |= ios_base::eofbit;
514  else
515  _M_gcount = 1;
516  }
517  __catch(__cxxabiv1::__forced_unwind&)
518  {
519  this->_M_setstate(ios_base::badbit);
520  __throw_exception_again;
521  }
522  __catch(...)
523  { this->_M_setstate(ios_base::badbit); }
524  if (__err)
525  this->setstate(__err);
526  }
527  return *this;
528  }
529 
530  template<typename _CharT, typename _Traits>
531  basic_istream<_CharT, _Traits>&
532  basic_istream<_CharT, _Traits>::
533  ignore(streamsize __n)
534  {
535  _M_gcount = 0;
536  sentry __cerb(*this, true);
537  if (__cerb && __n > 0)
538  {
539  ios_base::iostate __err = ios_base::goodbit;
540  __try
541  {
542  const int_type __eof = traits_type::eof();
543  __streambuf_type* __sb = this->rdbuf();
544  int_type __c = __sb->sgetc();
545 
546  // N.B. On LFS-enabled platforms streamsize is still 32 bits
547  // wide: if we want to implement the standard mandated behavior
548  // for n == max() (see 27.6.1.3/24) we are at risk of signed
549  // integer overflow: thus these contortions. Also note that,
550  // by definition, when more than 2G chars are actually ignored,
551  // _M_gcount (the return value of gcount, that is) cannot be
552  // really correct, being unavoidably too small.
553  bool __large_ignore = false;
554  while (true)
555  {
556  while (_M_gcount < __n
557  && !traits_type::eq_int_type(__c, __eof))
558  {
559  ++_M_gcount;
560  __c = __sb->snextc();
561  }
562  if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max
563  && !traits_type::eq_int_type(__c, __eof))
564  {
565  _M_gcount =
566  __gnu_cxx::__numeric_traits<streamsize>::__min;
567  __large_ignore = true;
568  }
569  else
570  break;
571  }
572 
573  if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max)
574  {
575  if (__large_ignore)
576  _M_gcount = __gnu_cxx::__numeric_traits<streamsize>::__max;
577 
578  if (traits_type::eq_int_type(__c, __eof))
579  __err |= ios_base::eofbit;
580  }
581  else if (_M_gcount < __n)
582  {
583  if (traits_type::eq_int_type(__c, __eof))
584  __err |= ios_base::eofbit;
585  }
586  }
587  __catch(__cxxabiv1::__forced_unwind&)
588  {
589  this->_M_setstate(ios_base::badbit);
590  __throw_exception_again;
591  }
592  __catch(...)
593  { this->_M_setstate(ios_base::badbit); }
594  if (__err)
595  this->setstate(__err);
596  }
597  return *this;
598  }
599 
600  template<typename _CharT, typename _Traits>
601  basic_istream<_CharT, _Traits>&
602  basic_istream<_CharT, _Traits>::
603  ignore(streamsize __n, int_type __delim)
604  {
605  _M_gcount = 0;
606  sentry __cerb(*this, true);
607  if (__cerb && __n > 0)
608  {
609  ios_base::iostate __err = ios_base::goodbit;
610  __try
611  {
612  const int_type __eof = traits_type::eof();
613  __streambuf_type* __sb = this->rdbuf();
614  int_type __c = __sb->sgetc();
615 
616  // See comment above.
617  bool __large_ignore = false;
618  while (true)
619  {
620  while (_M_gcount < __n
621  && !traits_type::eq_int_type(__c, __eof)
622  && !traits_type::eq_int_type(__c, __delim))
623  {
624  ++_M_gcount;
625  __c = __sb->snextc();
626  }
627  if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max
628  && !traits_type::eq_int_type(__c, __eof)
629  && !traits_type::eq_int_type(__c, __delim))
630  {
631  _M_gcount =
632  __gnu_cxx::__numeric_traits<streamsize>::__min;
633  __large_ignore = true;
634  }
635  else
636  break;
637  }
638 
639  if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max)
640  {
641  if (__large_ignore)
642  _M_gcount = __gnu_cxx::__numeric_traits<streamsize>::__max;
643 
644  if (traits_type::eq_int_type(__c, __eof))
645  __err |= ios_base::eofbit;
646  else
647  {
648  if (_M_gcount != __n)
649  ++_M_gcount;
650  __sb->sbumpc();
651  }
652  }
653  else if (_M_gcount < __n) // implies __c == __delim or EOF
654  {
655  if (traits_type::eq_int_type(__c, __eof))
656  __err |= ios_base::eofbit;
657  else
658  {
659  ++_M_gcount;
660  __sb->sbumpc();
661  }
662  }
663  }
664  __catch(__cxxabiv1::__forced_unwind&)
665  {
666  this->_M_setstate(ios_base::badbit);
667  __throw_exception_again;
668  }
669  __catch(...)
670  { this->_M_setstate(ios_base::badbit); }
671  if (__err)
672  this->setstate(__err);
673  }
674  return *this;
675  }
676 
677  template<typename _CharT, typename _Traits>
678  typename basic_istream<_CharT, _Traits>::int_type
679  basic_istream<_CharT, _Traits>::
680  peek(void)
681  {
682  int_type __c = traits_type::eof();
683  _M_gcount = 0;
684  sentry __cerb(*this, true);
685  if (__cerb)
686  {
687  ios_base::iostate __err = ios_base::goodbit;
688  __try
689  {
690  __c = this->rdbuf()->sgetc();
691  if (traits_type::eq_int_type(__c, traits_type::eof()))
692  __err |= ios_base::eofbit;
693  }
694  __catch(__cxxabiv1::__forced_unwind&)
695  {
696  this->_M_setstate(ios_base::badbit);
697  __throw_exception_again;
698  }
699  __catch(...)
700  { this->_M_setstate(ios_base::badbit); }
701  if (__err)
702  this->setstate(__err);
703  }
704  return __c;
705  }
706 
707  template<typename _CharT, typename _Traits>
708  basic_istream<_CharT, _Traits>&
709  basic_istream<_CharT, _Traits>::
710  read(char_type* __s, streamsize __n)
711  {
712  _M_gcount = 0;
713  sentry __cerb(*this, true);
714  if (__cerb)
715  {
716  ios_base::iostate __err = ios_base::goodbit;
717  __try
718  {
719  _M_gcount = this->rdbuf()->sgetn(__s, __n);
720  if (_M_gcount != __n)
721  __err |= (ios_base::eofbit | ios_base::failbit);
722  }
723  __catch(__cxxabiv1::__forced_unwind&)
724  {
725  this->_M_setstate(ios_base::badbit);
726  __throw_exception_again;
727  }
728  __catch(...)
729  { this->_M_setstate(ios_base::badbit); }
730  if (__err)
731  this->setstate(__err);
732  }
733  return *this;
734  }
735 
736  template<typename _CharT, typename _Traits>
737  streamsize
738  basic_istream<_CharT, _Traits>::
739  readsome(char_type* __s, streamsize __n)
740  {
741  _M_gcount = 0;
742  sentry __cerb(*this, true);
743  if (__cerb)
744  {
745  ios_base::iostate __err = ios_base::goodbit;
746  __try
747  {
748  // Cannot compare int_type with streamsize generically.
749  const streamsize __num = this->rdbuf()->in_avail();
750  if (__num > 0)
751  _M_gcount = this->rdbuf()->sgetn(__s, std::min(__num, __n));
752  else if (__num == -1)
753  __err |= ios_base::eofbit;
754  }
755  __catch(__cxxabiv1::__forced_unwind&)
756  {
757  this->_M_setstate(ios_base::badbit);
758  __throw_exception_again;
759  }
760  __catch(...)
761  { this->_M_setstate(ios_base::badbit); }
762  if (__err)
763  this->setstate(__err);
764  }
765  return _M_gcount;
766  }
767 
768  template<typename _CharT, typename _Traits>
769  basic_istream<_CharT, _Traits>&
770  basic_istream<_CharT, _Traits>::
771  putback(char_type __c)
772  {
773  // _GLIBCXX_RESOLVE_LIB_DEFECTS
774  // 60. What is a formatted input function?
775  _M_gcount = 0;
776  // Clear eofbit per N3168.
777  this->clear(this->rdstate() & ~ios_base::eofbit);
778  sentry __cerb(*this, true);
779  if (__cerb)
780  {
781  ios_base::iostate __err = ios_base::goodbit;
782  __try
783  {
784  const int_type __eof = traits_type::eof();
785  __streambuf_type* __sb = this->rdbuf();
786  if (!__sb
787  || traits_type::eq_int_type(__sb->sputbackc(__c), __eof))
788  __err |= ios_base::badbit;
789  }
790  __catch(__cxxabiv1::__forced_unwind&)
791  {
792  this->_M_setstate(ios_base::badbit);
793  __throw_exception_again;
794  }
795  __catch(...)
796  { this->_M_setstate(ios_base::badbit); }
797  if (__err)
798  this->setstate(__err);
799  }
800  return *this;
801  }
802 
803  template<typename _CharT, typename _Traits>
804  basic_istream<_CharT, _Traits>&
805  basic_istream<_CharT, _Traits>::
806  unget(void)
807  {
808  // _GLIBCXX_RESOLVE_LIB_DEFECTS
809  // 60. What is a formatted input function?
810  _M_gcount = 0;
811  // Clear eofbit per N3168.
812  this->clear(this->rdstate() & ~ios_base::eofbit);
813  sentry __cerb(*this, true);
814  if (__cerb)
815  {
816  ios_base::iostate __err = ios_base::goodbit;
817  __try
818  {
819  const int_type __eof = traits_type::eof();
820  __streambuf_type* __sb = this->rdbuf();
821  if (!__sb
822  || traits_type::eq_int_type(__sb->sungetc(), __eof))
823  __err |= ios_base::badbit;
824  }
825  __catch(__cxxabiv1::__forced_unwind&)
826  {
827  this->_M_setstate(ios_base::badbit);
828  __throw_exception_again;
829  }
830  __catch(...)
831  { this->_M_setstate(ios_base::badbit); }
832  if (__err)
833  this->setstate(__err);
834  }
835  return *this;
836  }
837 
838  template<typename _CharT, typename _Traits>
839  int
840  basic_istream<_CharT, _Traits>::
841  sync(void)
842  {
843  // _GLIBCXX_RESOLVE_LIB_DEFECTS
844  // DR60. Do not change _M_gcount.
845  int __ret = -1;
846  sentry __cerb(*this, true);
847  if (__cerb)
848  {
849  ios_base::iostate __err = ios_base::goodbit;
850  __try
851  {
852  __streambuf_type* __sb = this->rdbuf();
853  if (__sb)
854  {
855  if (__sb->pubsync() == -1)
856  __err |= ios_base::badbit;
857  else
858  __ret = 0;
859  }
860  }
861  __catch(__cxxabiv1::__forced_unwind&)
862  {
863  this->_M_setstate(ios_base::badbit);
864  __throw_exception_again;
865  }
866  __catch(...)
867  { this->_M_setstate(ios_base::badbit); }
868  if (__err)
869  this->setstate(__err);
870  }
871  return __ret;
872  }
873 
874  template<typename _CharT, typename _Traits>
875  typename basic_istream<_CharT, _Traits>::pos_type
876  basic_istream<_CharT, _Traits>::
877  tellg(void)
878  {
879  // _GLIBCXX_RESOLVE_LIB_DEFECTS
880  // DR60. Do not change _M_gcount.
881  pos_type __ret = pos_type(-1);
882  sentry __cerb(*this, true);
883  if (__cerb)
884  {
885  __try
886  {
887  if (!this->fail())
888  __ret = this->rdbuf()->pubseekoff(0, ios_base::cur,
889  ios_base::in);
890  }
891  __catch(__cxxabiv1::__forced_unwind&)
892  {
893  this->_M_setstate(ios_base::badbit);
894  __throw_exception_again;
895  }
896  __catch(...)
897  { this->_M_setstate(ios_base::badbit); }
898  }
899  return __ret;
900  }
901 
902  template<typename _CharT, typename _Traits>
903  basic_istream<_CharT, _Traits>&
904  basic_istream<_CharT, _Traits>::
905  seekg(pos_type __pos)
906  {
907  // _GLIBCXX_RESOLVE_LIB_DEFECTS
908  // DR60. Do not change _M_gcount.
909  // Clear eofbit per N3168.
910  this->clear(this->rdstate() & ~ios_base::eofbit);
911  sentry __cerb(*this, true);
912  if (__cerb)
913  {
914  ios_base::iostate __err = ios_base::goodbit;
915  __try
916  {
917  if (!this->fail())
918  {
919  // 136. seekp, seekg setting wrong streams?
920  const pos_type __p = this->rdbuf()->pubseekpos(__pos,
921  ios_base::in);
922 
923  // 129. Need error indication from seekp() and seekg()
924  if (__p == pos_type(off_type(-1)))
925  __err |= ios_base::failbit;
926  }
927  }
928  __catch(__cxxabiv1::__forced_unwind&)
929  {
930  this->_M_setstate(ios_base::badbit);
931  __throw_exception_again;
932  }
933  __catch(...)
934  { this->_M_setstate(ios_base::badbit); }
935  if (__err)
936  this->setstate(__err);
937  }
938  return *this;
939  }
940 
941  template<typename _CharT, typename _Traits>
942  basic_istream<_CharT, _Traits>&
943  basic_istream<_CharT, _Traits>::
944  seekg(off_type __off, ios_base::seekdir __dir)
945  {
946  // _GLIBCXX_RESOLVE_LIB_DEFECTS
947  // DR60. Do not change _M_gcount.
948  // Clear eofbit per N3168.
949  this->clear(this->rdstate() & ~ios_base::eofbit);
950  sentry __cerb(*this, true);
951  if (__cerb)
952  {
953  ios_base::iostate __err = ios_base::goodbit;
954  __try
955  {
956  if (!this->fail())
957  {
958  // 136. seekp, seekg setting wrong streams?
959  const pos_type __p = this->rdbuf()->pubseekoff(__off, __dir,
960  ios_base::in);
961 
962  // 129. Need error indication from seekp() and seekg()
963  if (__p == pos_type(off_type(-1)))
964  __err |= ios_base::failbit;
965  }
966  }
967  __catch(__cxxabiv1::__forced_unwind&)
968  {
969  this->_M_setstate(ios_base::badbit);
970  __throw_exception_again;
971  }
972  __catch(...)
973  { this->_M_setstate(ios_base::badbit); }
974  if (__err)
975  this->setstate(__err);
976  }
977  return *this;
978  }
979 
980  // 27.6.1.2.3 Character extraction templates
981  template<typename _CharT, typename _Traits>
982  basic_istream<_CharT, _Traits>&
983  operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
984  {
985  typedef basic_istream<_CharT, _Traits> __istream_type;
986  typedef typename __istream_type::int_type __int_type;
987 
988  typename __istream_type::sentry __cerb(__in, false);
989  if (__cerb)
990  {
991  ios_base::iostate __err = ios_base::goodbit;
992  __try
993  {
994  const __int_type __cb = __in.rdbuf()->sbumpc();
995  if (!_Traits::eq_int_type(__cb, _Traits::eof()))
996  __c = _Traits::to_char_type(__cb);
997  else
998  __err |= (ios_base::eofbit | ios_base::failbit);
999  }
1000  __catch(__cxxabiv1::__forced_unwind&)
1001  {
1002  __in._M_setstate(ios_base::badbit);
1003  __throw_exception_again;
1004  }
1005  __catch(...)
1006  { __in._M_setstate(ios_base::badbit); }
1007  if (__err)
1008  __in.setstate(__err);
1009  }
1010  return __in;
1011  }
1012 
1013  template<typename _CharT, typename _Traits>
1014  void
1015  __istream_extract(basic_istream<_CharT, _Traits>& __in, _CharT* __s,
1016  streamsize __num)
1017  {
1018  typedef basic_istream<_CharT, _Traits> __istream_type;
1019  typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
1020  typedef typename _Traits::int_type int_type;
1021  typedef _CharT char_type;
1022  typedef ctype<_CharT> __ctype_type;
1023 
1024  streamsize __extracted = 0;
1025  ios_base::iostate __err = ios_base::goodbit;
1026  typename __istream_type::sentry __cerb(__in, false);
1027  if (__cerb)
1028  {
1029  __try
1030  {
1031  // Figure out how many characters to extract.
1032  streamsize __width = __in.width();
1033  if (0 < __width && __width < __num)
1034  __num = __width;
1035 
1036  const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
1037 
1038  const int_type __eof = _Traits::eof();
1039  __streambuf_type* __sb = __in.rdbuf();
1040  int_type __c = __sb->sgetc();
1041 
1042  while (__extracted < __num - 1
1043  && !_Traits::eq_int_type(__c, __eof)
1044  && !__ct.is(ctype_base::space,
1045  _Traits::to_char_type(__c)))
1046  {
1047  *__s++ = _Traits::to_char_type(__c);
1048  ++__extracted;
1049  __c = __sb->snextc();
1050  }
1051 
1052  if (__extracted < __num - 1
1053  && _Traits::eq_int_type(__c, __eof))
1054  __err |= ios_base::eofbit;
1055 
1056  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1057  // 68. Extractors for char* should store null at end
1058  *__s = char_type();
1059  __in.width(0);
1060  }
1061  __catch(__cxxabiv1::__forced_unwind&)
1062  {
1063  __in._M_setstate(ios_base::badbit);
1064  __throw_exception_again;
1065  }
1066  __catch(...)
1067  { __in._M_setstate(ios_base::badbit); }
1068  }
1069  if (!__extracted)
1070  __err |= ios_base::failbit;
1071  if (__err)
1072  __in.setstate(__err);
1073  }
1074 
1075  // 27.6.1.4 Standard basic_istream manipulators
1076  template<typename _CharT, typename _Traits>
1077  basic_istream<_CharT, _Traits>&
1078  ws(basic_istream<_CharT, _Traits>& __in)
1079  {
1080  typedef basic_istream<_CharT, _Traits> __istream_type;
1081  typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
1082  typedef typename __istream_type::int_type __int_type;
1083  typedef ctype<_CharT> __ctype_type;
1084 
1085  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1086  // 451. behavior of std::ws
1087  typename __istream_type::sentry __cerb(__in, true);
1088  if (__cerb)
1089  {
1090  ios_base::iostate __err = ios_base::goodbit;
1091  __try
1092  {
1093  const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
1094  const __int_type __eof = _Traits::eof();
1095  __streambuf_type* __sb = __in.rdbuf();
1096  __int_type __c = __sb->sgetc();
1097 
1098  while (true)
1099  {
1100  if (_Traits::eq_int_type(__c, __eof))
1101  {
1102  __err = ios_base::eofbit;
1103  break;
1104  }
1105  if (!__ct.is(ctype_base::space, _Traits::to_char_type(__c)))
1106  break;
1107  __c = __sb->snextc();
1108  }
1109  }
1110  __catch (const __cxxabiv1::__forced_unwind&)
1111  {
1112  __in._M_setstate(ios_base::badbit);
1113  __throw_exception_again;
1114  }
1115  __catch (...)
1116  {
1117  __in._M_setstate(ios_base::badbit);
1118  }
1119  if (__err)
1120  __in.setstate(__err);
1121  }
1122  return __in;
1123  }
1124 
1125  // Inhibit implicit instantiations for required instantiations,
1126  // which are defined via explicit instantiations elsewhere.
1127 #if _GLIBCXX_EXTERN_TEMPLATE
1128 #pragma GCC diagnostic push
1129 #pragma GCC diagnostic ignored "-Wc++11-extensions" // extern template
1130 #pragma GCC diagnostic ignored "-Wlong-long"
1131  extern template class basic_istream<char>;
1132  extern template istream& ws(istream&);
1133  extern template istream& operator>>(istream&, char&);
1134  extern template istream& operator>>(istream&, unsigned char&);
1135  extern template istream& operator>>(istream&, signed char&);
1136 
1137  extern template istream& istream::_M_extract(unsigned short&);
1138  extern template istream& istream::_M_extract(unsigned int&);
1139  extern template istream& istream::_M_extract(long&);
1140  extern template istream& istream::_M_extract(unsigned long&);
1141  extern template istream& istream::_M_extract(bool&);
1142 #ifdef _GLIBCXX_USE_LONG_LONG
1143 #pragma GCC diagnostic push
1144 #pragma GCC diagnostic ignored "-Wlong-long"
1145  extern template istream& istream::_M_extract(long long&);
1146  extern template istream& istream::_M_extract(unsigned long long&);
1147 #pragma GCC diagnostic pop
1148 #endif
1149  extern template istream& istream::_M_extract(float&);
1150  extern template istream& istream::_M_extract(double&);
1151  extern template istream& istream::_M_extract(long double&);
1152  extern template istream& istream::_M_extract(void*&);
1153 
1154  extern template class basic_iostream<char>;
1155 
1156 #ifdef _GLIBCXX_USE_WCHAR_T
1157  extern template class basic_istream<wchar_t>;
1158  extern template wistream& ws(wistream&);
1159  extern template wistream& operator>>(wistream&, wchar_t&);
1160  extern template void __istream_extract(wistream&, wchar_t*, streamsize);
1161 
1162  extern template wistream& wistream::_M_extract(unsigned short&);
1163  extern template wistream& wistream::_M_extract(unsigned int&);
1164  extern template wistream& wistream::_M_extract(long&);
1165  extern template wistream& wistream::_M_extract(unsigned long&);
1166  extern template wistream& wistream::_M_extract(bool&);
1167 #ifdef _GLIBCXX_USE_LONG_LONG
1168  extern template wistream& wistream::_M_extract(long long&);
1169  extern template wistream& wistream::_M_extract(unsigned long long&);
1170 #endif
1171  extern template wistream& wistream::_M_extract(float&);
1172  extern template wistream& wistream::_M_extract(double&);
1173  extern template wistream& wistream::_M_extract(long double&);
1174  extern template wistream& wistream::_M_extract(void*&);
1175 
1176  extern template class basic_iostream<wchar_t>;
1177 #endif
1178 #pragma GCC diagnostic pop
1179 #endif
1180 
1181 _GLIBCXX_END_NAMESPACE_VERSION
1182 } // namespace std
1183 
1184 #pragma GCC diagnostic pop
1185 #endif
std::istream
basic_istream< char > istream
Base class for char input streams.
Definition: iosfwd:142
std::basic_streambuf::sputbackc
int_type sputbackc(char_type __c)
Pushing characters back into the input stream.
Definition: streambuf:381
std::basic_istream::peek
int_type peek()
Looking ahead in the stream.
Definition: istream.tcc:680
std::ios_base::flags
fmtflags flags() const
Access to format flags.
Definition: ios_base.h:694
std::basic_ios::clear
void clear(iostate __state=goodbit)
[Re]sets the error state.
Definition: basic_ios.tcc:46
std::ios_base::skipws
static const fmtflags skipws
Skips leading white space before certain input operations.
Definition: ios_base.h:423
std::basic_ios::tie
basic_ostream< _CharT, _Traits > * tie() const
Fetches the current tied stream.
Definition: basic_ios.h:310
std::basic_ios::rdstate
iostate rdstate() const
Returns the error state of the stream buffer.
Definition: basic_ios.h:146
std::basic_streambuf::snextc
int_type snextc()
Getting the next character.
Definition: streambuf:307
std::basic_istream::sync
int sync()
Synchronizing the stream buffer.
Definition: istream.tcc:841
std::num_get
Primary class template num_get.This facet encapsulates the code to parse and return a number from a s...
Definition: locale_facets.h:1962
std::basic_ios< char, _Traits >::int_type
_Traits::int_type int_type
Definition: basic_ios.h:83
std::ios_base::in
static const openmode in
Open for input. Default for ifstream and fstream.
Definition: ios_base.h:498
std::basic_istream::operator>>
__istream_type & operator>>(__istream_type &(*__pf)(__istream_type &))
Interface for manipulators.
Definition: istream:124
std::basic_streambuf::sbumpc
int_type sbumpc()
Getting the next character.
Definition: streambuf:325
std::basic_istream::unget
__istream_type & unget()
Unextracting the previous character.
Definition: istream.tcc:806
std::num_get::get
iter_type get(iter_type __in, iter_type __end, ios_base &__io, ios_base::iostate &__err, bool &__v) const
Numeric parsing.
Definition: locale_facets.h:2009
std::basic_ios::fail
bool fail() const
Fast error checking.
Definition: basic_ios.h:213
std::basic_ios::rdbuf
basic_streambuf< _CharT, _Traits > * rdbuf() const
Accessing the underlying buffer.
Definition: basic_ios.h:337
std::basic_istream::putback
__istream_type & putback(char_type __c)
Unextracting a single character.
Definition: istream.tcc:771
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:234
std::basic_istream::sentry::sentry
sentry(basic_istream< _CharT, _Traits > &__is, bool __noskipws=false)
The constructor performs all the work.
Definition: istream.tcc:52
std::basic_istream::readsome
streamsize readsome(char_type *__s, streamsize __n)
Extraction until the buffer is exhausted, but no more.
Definition: istream.tcc:739
std::basic_istream
Template class basic_istream.
Definition: iosfwd:87
std::basic_istream::sentry
Performs setup work for input streams.
Definition: istream:781
std::basic_ios::setstate
void setstate(iostate __state)
Sets additional flags in the error state.
Definition: basic_ios.h:166
std::ios_base::cur
static const seekdir cur
Request a seek relative to the current position within the sequence.
Definition: ios_base.h:529
std::basic_ios< char, _Traits >::pos_type
_Traits::pos_type pos_type
Definition: basic_ios.h:84
__cxxabiv1::__forced_unwind
Thrown as part of forced unwinding.A magic placeholder class that can be caught by reference to recog...
Definition: cxxabi_forced.h:50
std::basic_istream::seekg
__istream_type & seekg(pos_type)
Changing the current read position.
Definition: istream.tcc:905
std::ios_base::failbit
static const iostate failbit
Indicates that an input operation failed to read the expected characters, or that an output operation...
Definition: ios_base.h:465
std::basic_ios::good
bool good() const
Fast error checking.
Definition: basic_ios.h:190
std::ios_base::iostate
_Ios_Iostate iostate
This is a bitmask type.
Definition: ios_base.h:453
std::wistream
basic_istream< wchar_t > wistream
Base class for wchar_t input streams.
Definition: iosfwd:182
std::ios_base::eofbit
static const iostate eofbit
Indicates that an input operation reached the end of an input sequence.
Definition: ios_base.h:460
std::basic_streambuf::sgetc
int_type sgetc()
Getting the next character.
Definition: streambuf:347
std
ISO C++ entities toplevel namespace is std.
std::basic_streambuf::pubsync
int pubsync()
Calls virtual sync function.
Definition: streambuf:280
std::basic_istream::ignore
__istream_type & ignore()
Simple extraction.
Definition: istream.tcc:500
std::basic_streambuf::sungetc
int_type sungetc()
Moving backwards in the input stream.
Definition: streambuf:406
std::ios_base::getloc
locale getloc() const
Locale access.
Definition: ios_base.h:841
std::basic_istream::read
__istream_type & read(char_type *__s, streamsize __n)
Extraction without delimiters.
Definition: istream.tcc:710
std::basic_istream::tellg
pos_type tellg()
Getting the current read position.
Definition: istream.tcc:877
std::basic_streambuf
The actual work of input and output (interface).
Definition: iosfwd:84
std::ws
basic_istream< _CharT, _Traits > & ws(basic_istream< _CharT, _Traits > &__is)
Quick and easy way to eat whitespace.
Definition: istream.tcc:1078
std::basic_istream::_M_gcount
streamsize _M_gcount
Definition: istream:86
std::basic_istream::getline
__istream_type & getline(char_type *__s, streamsize __n, char_type __delim)
String extraction.
Definition: istream.tcc:440
std::basic_ios< char, _Traits >::off_type
_Traits::off_type off_type
Definition: basic_ios.h:85
std::__ctype_abstract_base::is
bool is(mask __m, char_type __c) const
Test char_type classification.
Definition: locale_facets.h:174
std::ios_base::goodbit
static const iostate goodbit
Indicates all is well.
Definition: ios_base.h:468
std::streamsize
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:73
std::basic_istream::get
int_type get()
Simple extraction.
Definition: istream.tcc:266
std::ctype
Primary class template ctype facet.This template class defines classification and conversion function...
Definition: locale_facets.h:617
std::basic_streambuf::sputc
int_type sputc(char_type __c)
Entry point for all single-character output functions.
Definition: streambuf:433
std::ios_base::badbit
static const iostate badbit
Indicates a loss of integrity in an input or output sequence (such as an irrecoverable read error fro...
Definition: ios_base.h:457
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