Import pre-release gcc-5.0 to new vendor branch
[dragonfly.git] / contrib / gcc-5.0 / libstdc++-v3 / include / bits / istream.tcc
1 // istream classes -*- C++ -*-
2
3 // Copyright (C) 1997-2015 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 #pragma GCC system_header
38
39 #include <bits/cxxabi_forced.h>
40
41 namespace std _GLIBCXX_VISIBILITY(default)
42 {
43 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44
45   template<typename _CharT, typename _Traits>
46     basic_istream<_CharT, _Traits>::sentry::
47     sentry(basic_istream<_CharT, _Traits>& __in, bool __noskip) : _M_ok(false)
48     {
49       ios_base::iostate __err = ios_base::goodbit;
50       if (__in.good())
51         {
52           if (__in.tie())
53             __in.tie()->flush();
54           if (!__noskip && bool(__in.flags() & ios_base::skipws))
55             {
56               const __int_type __eof = traits_type::eof();
57               __streambuf_type* __sb = __in.rdbuf();
58               __int_type __c = __sb->sgetc();
59
60               const __ctype_type& __ct = __check_facet(__in._M_ctype);
61               while (!traits_type::eq_int_type(__c, __eof)
62                      && __ct.is(ctype_base::space, 
63                                 traits_type::to_char_type(__c)))
64                 __c = __sb->snextc();
65
66               // _GLIBCXX_RESOLVE_LIB_DEFECTS
67               // 195. Should basic_istream::sentry's constructor ever
68               // set eofbit?
69               if (traits_type::eq_int_type(__c, __eof))
70                 __err |= ios_base::eofbit;
71             }
72         }
73
74       if (__in.good() && __err == ios_base::goodbit)
75         _M_ok = true;
76       else
77         {
78           __err |= ios_base::failbit;
79           __in.setstate(__err);
80         }
81     }
82
83   template<typename _CharT, typename _Traits>
84     template<typename _ValueT>
85       basic_istream<_CharT, _Traits>&
86       basic_istream<_CharT, _Traits>::
87       _M_extract(_ValueT& __v)
88       {
89         sentry __cerb(*this, false);
90         if (__cerb)
91           {
92             ios_base::iostate __err = ios_base::goodbit;
93             __try
94               {
95                 const __num_get_type& __ng = __check_facet(this->_M_num_get);
96                 __ng.get(*this, 0, *this, __err, __v);
97               }
98             __catch(__cxxabiv1::__forced_unwind&)
99               {
100                 this->_M_setstate(ios_base::badbit);
101                 __throw_exception_again;
102               }
103             __catch(...)
104               { this->_M_setstate(ios_base::badbit); }
105             if (__err)
106               this->setstate(__err);
107           }
108         return *this;
109       }
110
111   template<typename _CharT, typename _Traits>
112     basic_istream<_CharT, _Traits>&
113     basic_istream<_CharT, _Traits>::
114     operator>>(short& __n)
115     {
116       // _GLIBCXX_RESOLVE_LIB_DEFECTS
117       // 118. basic_istream uses nonexistent num_get member functions.
118       sentry __cerb(*this, false);
119       if (__cerb)
120         {
121           ios_base::iostate __err = ios_base::goodbit;
122           __try
123             {
124               long __l;
125               const __num_get_type& __ng = __check_facet(this->_M_num_get);
126               __ng.get(*this, 0, *this, __err, __l);
127
128               // _GLIBCXX_RESOLVE_LIB_DEFECTS
129               // 696. istream::operator>>(int&) broken.
130               if (__l < __gnu_cxx::__numeric_traits<short>::__min)
131                 {
132                   __err |= ios_base::failbit;
133                   __n = __gnu_cxx::__numeric_traits<short>::__min;
134                 }
135               else if (__l > __gnu_cxx::__numeric_traits<short>::__max)
136                 {
137                   __err |= ios_base::failbit;
138                   __n = __gnu_cxx::__numeric_traits<short>::__max;
139                 }
140               else
141                 __n = short(__l);
142             }
143           __catch(__cxxabiv1::__forced_unwind&)
144             {
145               this->_M_setstate(ios_base::badbit);
146               __throw_exception_again;
147             }
148           __catch(...)
149             { this->_M_setstate(ios_base::badbit); }
150           if (__err)
151             this->setstate(__err);
152         }
153       return *this;
154     }
155
156   template<typename _CharT, typename _Traits>
157     basic_istream<_CharT, _Traits>&
158     basic_istream<_CharT, _Traits>::
159     operator>>(int& __n)
160     {
161       // _GLIBCXX_RESOLVE_LIB_DEFECTS
162       // 118. basic_istream uses nonexistent num_get member functions.
163       sentry __cerb(*this, false);
164       if (__cerb)
165         {
166           ios_base::iostate __err = ios_base::goodbit;
167           __try
168             {
169               long __l;
170               const __num_get_type& __ng = __check_facet(this->_M_num_get);
171               __ng.get(*this, 0, *this, __err, __l);
172
173               // _GLIBCXX_RESOLVE_LIB_DEFECTS
174               // 696. istream::operator>>(int&) broken.
175               if (__l < __gnu_cxx::__numeric_traits<int>::__min)
176                 {
177                   __err |= ios_base::failbit;
178                   __n = __gnu_cxx::__numeric_traits<int>::__min;
179                 }
180               else if (__l > __gnu_cxx::__numeric_traits<int>::__max)
181                 {
182                   __err |= ios_base::failbit;         
183                   __n = __gnu_cxx::__numeric_traits<int>::__max;
184                 }
185               else
186                 __n = int(__l);
187             }
188           __catch(__cxxabiv1::__forced_unwind&)
189             {
190               this->_M_setstate(ios_base::badbit);
191               __throw_exception_again;
192             }
193           __catch(...)
194             { this->_M_setstate(ios_base::badbit); }
195           if (__err)
196             this->setstate(__err);
197         }
198       return *this;
199     }
200
201   template<typename _CharT, typename _Traits>
202     basic_istream<_CharT, _Traits>&
203     basic_istream<_CharT, _Traits>::
204     operator>>(__streambuf_type* __sbout)
205     {
206       ios_base::iostate __err = ios_base::goodbit;
207       sentry __cerb(*this, false);
208       if (__cerb && __sbout)
209         {
210           __try
211             {
212               bool __ineof;
213               if (!__copy_streambufs_eof(this->rdbuf(), __sbout, __ineof))
214                 __err |= ios_base::failbit;
215               if (__ineof)
216                 __err |= ios_base::eofbit;
217             }
218           __catch(__cxxabiv1::__forced_unwind&)
219             {
220               this->_M_setstate(ios_base::failbit);
221               __throw_exception_again;
222             }
223           __catch(...)
224             { this->_M_setstate(ios_base::failbit); }
225         }
226       else if (!__sbout)
227         __err |= ios_base::failbit;
228       if (__err)
229         this->setstate(__err);
230       return *this;
231     }
232
233   template<typename _CharT, typename _Traits>
234     typename basic_istream<_CharT, _Traits>::int_type
235     basic_istream<_CharT, _Traits>::
236     get(void)
237     {
238       const int_type __eof = traits_type::eof();
239       int_type __c = __eof;
240       _M_gcount = 0;
241       ios_base::iostate __err = ios_base::goodbit;
242       sentry __cerb(*this, true);
243       if (__cerb)
244         {
245           __try
246             {
247               __c = this->rdbuf()->sbumpc();
248               // 27.6.1.1 paragraph 3
249               if (!traits_type::eq_int_type(__c, __eof))
250                 _M_gcount = 1;
251               else
252                 __err |= ios_base::eofbit;
253             }
254           __catch(__cxxabiv1::__forced_unwind&)
255             {
256               this->_M_setstate(ios_base::badbit);
257               __throw_exception_again;
258             }
259           __catch(...)
260             { this->_M_setstate(ios_base::badbit); }
261         }
262       if (!_M_gcount)
263         __err |= ios_base::failbit;
264       if (__err)
265         this->setstate(__err);
266       return __c;
267     }
268
269   template<typename _CharT, typename _Traits>
270     basic_istream<_CharT, _Traits>&
271     basic_istream<_CharT, _Traits>::
272     get(char_type& __c)
273     {
274       _M_gcount = 0;
275       ios_base::iostate __err = ios_base::goodbit;
276       sentry __cerb(*this, true);
277       if (__cerb)
278         {
279           __try
280             {
281               const int_type __cb = this->rdbuf()->sbumpc();
282               // 27.6.1.1 paragraph 3
283               if (!traits_type::eq_int_type(__cb, traits_type::eof()))
284                 {
285                   _M_gcount = 1;
286                   __c = traits_type::to_char_type(__cb);
287                 }
288               else
289                 __err |= ios_base::eofbit;
290             }
291           __catch(__cxxabiv1::__forced_unwind&)
292             {
293               this->_M_setstate(ios_base::badbit);
294               __throw_exception_again;
295             }
296           __catch(...)
297             { this->_M_setstate(ios_base::badbit); }
298         }
299       if (!_M_gcount)
300         __err |= ios_base::failbit;
301       if (__err)
302         this->setstate(__err);
303       return *this;
304     }
305
306   template<typename _CharT, typename _Traits>
307     basic_istream<_CharT, _Traits>&
308     basic_istream<_CharT, _Traits>::
309     get(char_type* __s, streamsize __n, char_type __delim)
310     {
311       _M_gcount = 0;
312       ios_base::iostate __err = ios_base::goodbit;
313       sentry __cerb(*this, true);
314       if (__cerb)
315         {
316           __try
317             {
318               const int_type __idelim = traits_type::to_int_type(__delim);
319               const int_type __eof = traits_type::eof();
320               __streambuf_type* __sb = this->rdbuf();
321               int_type __c = __sb->sgetc();
322
323               while (_M_gcount + 1 < __n
324                      && !traits_type::eq_int_type(__c, __eof)
325                      && !traits_type::eq_int_type(__c, __idelim))
326                 {
327                   *__s++ = traits_type::to_char_type(__c);
328                   ++_M_gcount;
329                   __c = __sb->snextc();
330                 }
331               if (traits_type::eq_int_type(__c, __eof))
332                 __err |= ios_base::eofbit;
333             }
334           __catch(__cxxabiv1::__forced_unwind&)
335             {
336               this->_M_setstate(ios_base::badbit);
337               __throw_exception_again;
338             }
339           __catch(...)
340             { this->_M_setstate(ios_base::badbit); }
341         }
342       // _GLIBCXX_RESOLVE_LIB_DEFECTS
343       // 243. get and getline when sentry reports failure.
344       if (__n > 0)
345         *__s = char_type();
346       if (!_M_gcount)
347         __err |= ios_base::failbit;
348       if (__err)
349         this->setstate(__err);
350       return *this;
351     }
352
353   template<typename _CharT, typename _Traits>
354     basic_istream<_CharT, _Traits>&
355     basic_istream<_CharT, _Traits>::
356     get(__streambuf_type& __sb, char_type __delim)
357     {
358       _M_gcount = 0;
359       ios_base::iostate __err = ios_base::goodbit;
360       sentry __cerb(*this, true);
361       if (__cerb)
362         {
363           __try
364             {
365               const int_type __idelim = traits_type::to_int_type(__delim);
366               const int_type __eof = traits_type::eof();
367               __streambuf_type* __this_sb = this->rdbuf();
368               int_type __c = __this_sb->sgetc();
369               char_type __c2 = traits_type::to_char_type(__c);
370
371               while (!traits_type::eq_int_type(__c, __eof)
372                      && !traits_type::eq_int_type(__c, __idelim)
373                      && !traits_type::eq_int_type(__sb.sputc(__c2), __eof))
374                 {
375                   ++_M_gcount;
376                   __c = __this_sb->snextc();
377                   __c2 = traits_type::to_char_type(__c);
378                 }
379               if (traits_type::eq_int_type(__c, __eof))
380                 __err |= ios_base::eofbit;
381             }
382           __catch(__cxxabiv1::__forced_unwind&)
383             {
384               this->_M_setstate(ios_base::badbit);
385               __throw_exception_again;
386             }
387           __catch(...)
388             { this->_M_setstate(ios_base::badbit); }
389         }
390       if (!_M_gcount)
391         __err |= ios_base::failbit;
392       if (__err)
393         this->setstate(__err);
394       return *this;
395     }
396
397   template<typename _CharT, typename _Traits>
398     basic_istream<_CharT, _Traits>&
399     basic_istream<_CharT, _Traits>::
400     getline(char_type* __s, streamsize __n, char_type __delim)
401     {
402       _M_gcount = 0;
403       ios_base::iostate __err = ios_base::goodbit;
404       sentry __cerb(*this, true);
405       if (__cerb)
406         {
407           __try
408             {
409               const int_type __idelim = traits_type::to_int_type(__delim);
410               const int_type __eof = traits_type::eof();
411               __streambuf_type* __sb = this->rdbuf();
412               int_type __c = __sb->sgetc();
413
414               while (_M_gcount + 1 < __n
415                      && !traits_type::eq_int_type(__c, __eof)
416                      && !traits_type::eq_int_type(__c, __idelim))
417                 {
418                   *__s++ = traits_type::to_char_type(__c);
419                   __c = __sb->snextc();
420                   ++_M_gcount;
421                 }
422               if (traits_type::eq_int_type(__c, __eof))
423                 __err |= ios_base::eofbit;
424               else
425                 {
426                   if (traits_type::eq_int_type(__c, __idelim))
427                     {
428                       __sb->sbumpc();
429                       ++_M_gcount;
430                     }
431                   else
432                     __err |= ios_base::failbit;
433                 }
434             }
435           __catch(__cxxabiv1::__forced_unwind&)
436             {
437               this->_M_setstate(ios_base::badbit);
438               __throw_exception_again;
439             }
440           __catch(...)
441             { this->_M_setstate(ios_base::badbit); }
442         }
443       // _GLIBCXX_RESOLVE_LIB_DEFECTS
444       // 243. get and getline when sentry reports failure.
445       if (__n > 0)
446         *__s = char_type();
447       if (!_M_gcount)
448         __err |= ios_base::failbit;
449       if (__err)
450         this->setstate(__err);
451       return *this;
452     }
453
454   // We provide three overloads, since the first two are much simpler
455   // than the general case. Also, the latter two can thus adopt the
456   // same "batchy" strategy used by getline above.
457   template<typename _CharT, typename _Traits>
458     basic_istream<_CharT, _Traits>&
459     basic_istream<_CharT, _Traits>::
460     ignore(void)
461     {
462       _M_gcount = 0;
463       sentry __cerb(*this, true);
464       if (__cerb)
465         {
466           ios_base::iostate __err = ios_base::goodbit;
467           __try
468             {
469               const int_type __eof = traits_type::eof();
470               __streambuf_type* __sb = this->rdbuf();
471
472               if (traits_type::eq_int_type(__sb->sbumpc(), __eof))
473                 __err |= ios_base::eofbit;
474               else
475                 _M_gcount = 1;
476             }
477           __catch(__cxxabiv1::__forced_unwind&)
478             {
479               this->_M_setstate(ios_base::badbit);
480               __throw_exception_again;
481             }
482           __catch(...)
483             { this->_M_setstate(ios_base::badbit); }
484           if (__err)
485             this->setstate(__err);
486         }
487       return *this;
488     }
489
490   template<typename _CharT, typename _Traits>
491     basic_istream<_CharT, _Traits>&
492     basic_istream<_CharT, _Traits>::
493     ignore(streamsize __n)
494     {
495       _M_gcount = 0;
496       sentry __cerb(*this, true);
497       if (__cerb && __n > 0)
498         {
499           ios_base::iostate __err = ios_base::goodbit;
500           __try
501             {
502               const int_type __eof = traits_type::eof();
503               __streambuf_type* __sb = this->rdbuf();
504               int_type __c = __sb->sgetc();
505
506               // N.B. On LFS-enabled platforms streamsize is still 32 bits
507               // wide: if we want to implement the standard mandated behavior
508               // for n == max() (see 27.6.1.3/24) we are at risk of signed
509               // integer overflow: thus these contortions. Also note that,
510               // by definition, when more than 2G chars are actually ignored,
511               // _M_gcount (the return value of gcount, that is) cannot be
512               // really correct, being unavoidably too small.
513               bool __large_ignore = false;
514               while (true)
515                 {
516                   while (_M_gcount < __n
517                          && !traits_type::eq_int_type(__c, __eof))
518                     {
519                       ++_M_gcount;
520                       __c = __sb->snextc();
521                     }
522                   if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max
523                       && !traits_type::eq_int_type(__c, __eof))
524                     {
525                       _M_gcount =
526                         __gnu_cxx::__numeric_traits<streamsize>::__min;
527                       __large_ignore = true;
528                     }
529                   else
530                     break;
531                 }
532
533               if (__large_ignore)
534                 _M_gcount = __gnu_cxx::__numeric_traits<streamsize>::__max;
535
536               if (traits_type::eq_int_type(__c, __eof))
537                 __err |= ios_base::eofbit;
538             }
539           __catch(__cxxabiv1::__forced_unwind&)
540             {
541               this->_M_setstate(ios_base::badbit);
542               __throw_exception_again;
543             }
544           __catch(...)
545             { this->_M_setstate(ios_base::badbit); }
546           if (__err)
547             this->setstate(__err);
548         }
549       return *this;
550     }
551
552   template<typename _CharT, typename _Traits>
553     basic_istream<_CharT, _Traits>&
554     basic_istream<_CharT, _Traits>::
555     ignore(streamsize __n, int_type __delim)
556     {
557       _M_gcount = 0;
558       sentry __cerb(*this, true);
559       if (__cerb && __n > 0)
560         {
561           ios_base::iostate __err = ios_base::goodbit;
562           __try
563             {
564               const int_type __eof = traits_type::eof();
565               __streambuf_type* __sb = this->rdbuf();
566               int_type __c = __sb->sgetc();
567
568               // See comment above.
569               bool __large_ignore = false;
570               while (true)
571                 {
572                   while (_M_gcount < __n
573                          && !traits_type::eq_int_type(__c, __eof)
574                          && !traits_type::eq_int_type(__c, __delim))
575                     {
576                       ++_M_gcount;
577                       __c = __sb->snextc();
578                     }
579                   if (__n == __gnu_cxx::__numeric_traits<streamsize>::__max
580                       && !traits_type::eq_int_type(__c, __eof)
581                       && !traits_type::eq_int_type(__c, __delim))
582                     {
583                       _M_gcount =
584                         __gnu_cxx::__numeric_traits<streamsize>::__min;
585                       __large_ignore = true;
586                     }
587                   else
588                     break;
589                 }
590
591               if (__large_ignore)
592                 _M_gcount = __gnu_cxx::__numeric_traits<streamsize>::__max;
593
594               if (traits_type::eq_int_type(__c, __eof))
595                 __err |= ios_base::eofbit;
596               else if (traits_type::eq_int_type(__c, __delim))
597                 {
598                   if (_M_gcount
599                       < __gnu_cxx::__numeric_traits<streamsize>::__max)
600                     ++_M_gcount;
601                   __sb->sbumpc();
602                 }
603             }
604           __catch(__cxxabiv1::__forced_unwind&)
605             {
606               this->_M_setstate(ios_base::badbit);
607               __throw_exception_again;
608             }
609           __catch(...)
610             { this->_M_setstate(ios_base::badbit); }
611           if (__err)
612             this->setstate(__err);
613         }
614       return *this;
615     }
616
617   template<typename _CharT, typename _Traits>
618     typename basic_istream<_CharT, _Traits>::int_type
619     basic_istream<_CharT, _Traits>::
620     peek(void)
621     {
622       int_type __c = traits_type::eof();
623       _M_gcount = 0;
624       sentry __cerb(*this, true);
625       if (__cerb)
626         {
627           ios_base::iostate __err = ios_base::goodbit;
628           __try
629             {
630               __c = this->rdbuf()->sgetc();
631               if (traits_type::eq_int_type(__c, traits_type::eof()))
632                 __err |= ios_base::eofbit;
633             }
634           __catch(__cxxabiv1::__forced_unwind&)
635             {
636               this->_M_setstate(ios_base::badbit);
637               __throw_exception_again;
638             }
639           __catch(...)
640             { this->_M_setstate(ios_base::badbit); }
641           if (__err)
642             this->setstate(__err);
643         }
644       return __c;
645     }
646
647   template<typename _CharT, typename _Traits>
648     basic_istream<_CharT, _Traits>&
649     basic_istream<_CharT, _Traits>::
650     read(char_type* __s, streamsize __n)
651     {
652       _M_gcount = 0;
653       sentry __cerb(*this, true);
654       if (__cerb)
655         {
656           ios_base::iostate __err = ios_base::goodbit;
657           __try
658             {
659               _M_gcount = this->rdbuf()->sgetn(__s, __n);
660               if (_M_gcount != __n)
661                 __err |= (ios_base::eofbit | ios_base::failbit);
662             }
663           __catch(__cxxabiv1::__forced_unwind&)
664             {
665               this->_M_setstate(ios_base::badbit);
666               __throw_exception_again;
667             }
668           __catch(...)
669             { this->_M_setstate(ios_base::badbit); }
670           if (__err)
671             this->setstate(__err);
672         }
673       return *this;
674     }
675
676   template<typename _CharT, typename _Traits>
677     streamsize
678     basic_istream<_CharT, _Traits>::
679     readsome(char_type* __s, streamsize __n)
680     {
681       _M_gcount = 0;
682       sentry __cerb(*this, true);
683       if (__cerb)
684         {
685           ios_base::iostate __err = ios_base::goodbit;
686           __try
687             {
688               // Cannot compare int_type with streamsize generically.
689               const streamsize __num = this->rdbuf()->in_avail();
690               if (__num > 0)
691                 _M_gcount = this->rdbuf()->sgetn(__s, std::min(__num, __n));
692               else if (__num == -1)
693                 __err |= ios_base::eofbit;
694             }
695           __catch(__cxxabiv1::__forced_unwind&)
696             {
697               this->_M_setstate(ios_base::badbit);
698               __throw_exception_again;
699             }
700           __catch(...)
701             { this->_M_setstate(ios_base::badbit); }
702           if (__err)
703             this->setstate(__err);
704         }
705       return _M_gcount;
706     }
707
708   template<typename _CharT, typename _Traits>
709     basic_istream<_CharT, _Traits>&
710     basic_istream<_CharT, _Traits>::
711     putback(char_type __c)
712     {
713       // _GLIBCXX_RESOLVE_LIB_DEFECTS
714       // 60. What is a formatted input function?
715       _M_gcount = 0;
716       // Clear eofbit per N3168.
717       this->clear(this->rdstate() & ~ios_base::eofbit);
718       sentry __cerb(*this, true);
719       if (__cerb)
720         {
721           ios_base::iostate __err = ios_base::goodbit;
722           __try
723             {
724               const int_type __eof = traits_type::eof();
725               __streambuf_type* __sb = this->rdbuf();
726               if (!__sb
727                   || traits_type::eq_int_type(__sb->sputbackc(__c), __eof))
728                 __err |= ios_base::badbit;
729             }
730           __catch(__cxxabiv1::__forced_unwind&)
731             {
732               this->_M_setstate(ios_base::badbit);
733               __throw_exception_again;
734             }
735           __catch(...)
736             { this->_M_setstate(ios_base::badbit); }
737           if (__err)
738             this->setstate(__err);
739         }
740       return *this;
741     }
742
743   template<typename _CharT, typename _Traits>
744     basic_istream<_CharT, _Traits>&
745     basic_istream<_CharT, _Traits>::
746     unget(void)
747     {
748       // _GLIBCXX_RESOLVE_LIB_DEFECTS
749       // 60. What is a formatted input function?
750       _M_gcount = 0;
751       // Clear eofbit per N3168.
752       this->clear(this->rdstate() & ~ios_base::eofbit);
753       sentry __cerb(*this, true);
754       if (__cerb)
755         {
756           ios_base::iostate __err = ios_base::goodbit;
757           __try
758             {
759               const int_type __eof = traits_type::eof();
760               __streambuf_type* __sb = this->rdbuf();
761               if (!__sb
762                   || traits_type::eq_int_type(__sb->sungetc(), __eof))
763                 __err |= ios_base::badbit;
764             }
765           __catch(__cxxabiv1::__forced_unwind&)
766             {
767               this->_M_setstate(ios_base::badbit);
768               __throw_exception_again;
769             }
770           __catch(...)
771             { this->_M_setstate(ios_base::badbit); }
772           if (__err)
773             this->setstate(__err);
774         }
775       return *this;
776     }
777
778   template<typename _CharT, typename _Traits>
779     int
780     basic_istream<_CharT, _Traits>::
781     sync(void)
782     {
783       // _GLIBCXX_RESOLVE_LIB_DEFECTS
784       // DR60.  Do not change _M_gcount.
785       int __ret = -1;
786       sentry __cerb(*this, true);
787       if (__cerb)
788         {
789           ios_base::iostate __err = ios_base::goodbit;
790           __try
791             {
792               __streambuf_type* __sb = this->rdbuf();
793               if (__sb)
794                 {
795                   if (__sb->pubsync() == -1)
796                     __err |= ios_base::badbit;
797                   else
798                     __ret = 0;
799                 }
800             }
801           __catch(__cxxabiv1::__forced_unwind&)
802             {
803               this->_M_setstate(ios_base::badbit);
804               __throw_exception_again;
805             }
806           __catch(...)
807             { this->_M_setstate(ios_base::badbit); }
808           if (__err)
809             this->setstate(__err);
810         }
811       return __ret;
812     }
813
814   template<typename _CharT, typename _Traits>
815     typename basic_istream<_CharT, _Traits>::pos_type
816     basic_istream<_CharT, _Traits>::
817     tellg(void)
818     {
819       // _GLIBCXX_RESOLVE_LIB_DEFECTS
820       // DR60.  Do not change _M_gcount.
821       pos_type __ret = pos_type(-1);
822       sentry __cerb(*this, true);
823       if (__cerb)
824         {
825           __try
826             {
827               if (!this->fail())
828                 __ret = this->rdbuf()->pubseekoff(0, ios_base::cur,
829                                                   ios_base::in);
830             }
831           __catch(__cxxabiv1::__forced_unwind&)
832             {
833               this->_M_setstate(ios_base::badbit);
834               __throw_exception_again;
835             }
836           __catch(...)
837             { this->_M_setstate(ios_base::badbit); }
838         }
839       return __ret;
840     }
841
842   template<typename _CharT, typename _Traits>
843     basic_istream<_CharT, _Traits>&
844     basic_istream<_CharT, _Traits>::
845     seekg(pos_type __pos)
846     {
847       // _GLIBCXX_RESOLVE_LIB_DEFECTS
848       // DR60.  Do not change _M_gcount.
849       // Clear eofbit per N3168.
850       this->clear(this->rdstate() & ~ios_base::eofbit);
851       sentry __cerb(*this, true);
852       if (__cerb)
853         {
854           ios_base::iostate __err = ios_base::goodbit;
855           __try
856             {
857               if (!this->fail())
858                 {
859                   // 136.  seekp, seekg setting wrong streams?
860                   const pos_type __p = this->rdbuf()->pubseekpos(__pos,
861                                                                  ios_base::in);
862                   
863                   // 129.  Need error indication from seekp() and seekg()
864                   if (__p == pos_type(off_type(-1)))
865                     __err |= ios_base::failbit;
866                 }
867             }
868           __catch(__cxxabiv1::__forced_unwind&)
869             {
870               this->_M_setstate(ios_base::badbit);
871               __throw_exception_again;
872             }
873           __catch(...)
874             { this->_M_setstate(ios_base::badbit); }
875           if (__err)
876             this->setstate(__err);
877         }
878       return *this;
879     }
880
881   template<typename _CharT, typename _Traits>
882     basic_istream<_CharT, _Traits>&
883     basic_istream<_CharT, _Traits>::
884     seekg(off_type __off, ios_base::seekdir __dir)
885     {
886       // _GLIBCXX_RESOLVE_LIB_DEFECTS
887       // DR60.  Do not change _M_gcount.
888       // Clear eofbit per N3168.
889       this->clear(this->rdstate() & ~ios_base::eofbit);
890       sentry __cerb(*this, true);
891       if (__cerb)
892         {
893           ios_base::iostate __err = ios_base::goodbit;
894           __try
895             {
896               if (!this->fail())
897                 {
898                   // 136.  seekp, seekg setting wrong streams?
899                   const pos_type __p = this->rdbuf()->pubseekoff(__off, __dir,
900                                                                  ios_base::in);
901               
902                   // 129.  Need error indication from seekp() and seekg()
903                   if (__p == pos_type(off_type(-1)))
904                     __err |= ios_base::failbit;
905                 }
906             }
907           __catch(__cxxabiv1::__forced_unwind&)
908             {
909               this->_M_setstate(ios_base::badbit);
910               __throw_exception_again;
911             }
912           __catch(...)
913             { this->_M_setstate(ios_base::badbit); }
914           if (__err)
915             this->setstate(__err);
916         }
917       return *this;
918     }
919
920   // 27.6.1.2.3 Character extraction templates
921   template<typename _CharT, typename _Traits>
922     basic_istream<_CharT, _Traits>&
923     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT& __c)
924     {
925       typedef basic_istream<_CharT, _Traits>            __istream_type;
926       typedef typename __istream_type::int_type         __int_type;
927
928       typename __istream_type::sentry __cerb(__in, false);
929       if (__cerb)
930         {
931           ios_base::iostate __err = ios_base::goodbit;
932           __try
933             {
934               const __int_type __cb = __in.rdbuf()->sbumpc();
935               if (!_Traits::eq_int_type(__cb, _Traits::eof()))
936                 __c = _Traits::to_char_type(__cb);
937               else
938                 __err |= (ios_base::eofbit | ios_base::failbit);
939             }
940           __catch(__cxxabiv1::__forced_unwind&)
941             {
942               __in._M_setstate(ios_base::badbit);
943               __throw_exception_again;
944             }
945           __catch(...)
946             { __in._M_setstate(ios_base::badbit); }
947           if (__err)
948             __in.setstate(__err);
949         }
950       return __in;
951     }
952
953   template<typename _CharT, typename _Traits>
954     basic_istream<_CharT, _Traits>&
955     operator>>(basic_istream<_CharT, _Traits>& __in, _CharT* __s)
956     {
957       typedef basic_istream<_CharT, _Traits>            __istream_type;
958       typedef basic_streambuf<_CharT, _Traits>          __streambuf_type;
959       typedef typename _Traits::int_type                int_type;
960       typedef _CharT                                    char_type;
961       typedef ctype<_CharT>                             __ctype_type;
962
963       streamsize __extracted = 0;
964       ios_base::iostate __err = ios_base::goodbit;
965       typename __istream_type::sentry __cerb(__in, false);
966       if (__cerb)
967         {
968           __try
969             {
970               // Figure out how many characters to extract.
971               streamsize __num = __in.width();
972               if (__num <= 0)
973                 __num = __gnu_cxx::__numeric_traits<streamsize>::__max;
974
975               const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
976
977               const int_type __eof = _Traits::eof();
978               __streambuf_type* __sb = __in.rdbuf();
979               int_type __c = __sb->sgetc();
980
981               while (__extracted < __num - 1
982                      && !_Traits::eq_int_type(__c, __eof)
983                      && !__ct.is(ctype_base::space,
984                                  _Traits::to_char_type(__c)))
985                 {
986                   *__s++ = _Traits::to_char_type(__c);
987                   ++__extracted;
988                   __c = __sb->snextc();
989                 }
990               if (_Traits::eq_int_type(__c, __eof))
991                 __err |= ios_base::eofbit;
992
993               // _GLIBCXX_RESOLVE_LIB_DEFECTS
994               // 68.  Extractors for char* should store null at end
995               *__s = char_type();
996               __in.width(0);
997             }
998           __catch(__cxxabiv1::__forced_unwind&)
999             {
1000               __in._M_setstate(ios_base::badbit);
1001               __throw_exception_again;
1002             }
1003           __catch(...)
1004             { __in._M_setstate(ios_base::badbit); }
1005         }
1006       if (!__extracted)
1007         __err |= ios_base::failbit;
1008       if (__err)
1009         __in.setstate(__err);
1010       return __in;
1011     }
1012
1013   // 27.6.1.4 Standard basic_istream manipulators
1014   template<typename _CharT, typename _Traits>
1015     basic_istream<_CharT, _Traits>&
1016     ws(basic_istream<_CharT, _Traits>& __in)
1017     {
1018       typedef basic_istream<_CharT, _Traits>            __istream_type;
1019       typedef basic_streambuf<_CharT, _Traits>          __streambuf_type;
1020       typedef typename __istream_type::int_type         __int_type;
1021       typedef ctype<_CharT>                             __ctype_type;
1022
1023       const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
1024       const __int_type __eof = _Traits::eof();
1025       __streambuf_type* __sb = __in.rdbuf();
1026       __int_type __c = __sb->sgetc();
1027
1028       while (!_Traits::eq_int_type(__c, __eof)
1029              && __ct.is(ctype_base::space, _Traits::to_char_type(__c)))
1030         __c = __sb->snextc();
1031
1032        if (_Traits::eq_int_type(__c, __eof))
1033          __in.setstate(ios_base::eofbit);
1034       return __in;
1035     }
1036
1037   // Inhibit implicit instantiations for required instantiations,
1038   // which are defined via explicit instantiations elsewhere.
1039 #if _GLIBCXX_EXTERN_TEMPLATE
1040   extern template class basic_istream<char>;
1041   extern template istream& ws(istream&);
1042   extern template istream& operator>>(istream&, char&);
1043   extern template istream& operator>>(istream&, char*);
1044   extern template istream& operator>>(istream&, unsigned char&);
1045   extern template istream& operator>>(istream&, signed char&);
1046   extern template istream& operator>>(istream&, unsigned char*);
1047   extern template istream& operator>>(istream&, signed char*);
1048
1049   extern template istream& istream::_M_extract(unsigned short&);
1050   extern template istream& istream::_M_extract(unsigned int&);  
1051   extern template istream& istream::_M_extract(long&);
1052   extern template istream& istream::_M_extract(unsigned long&);
1053   extern template istream& istream::_M_extract(bool&);
1054 #ifdef _GLIBCXX_USE_LONG_LONG
1055   extern template istream& istream::_M_extract(long long&);
1056   extern template istream& istream::_M_extract(unsigned long long&);
1057 #endif
1058   extern template istream& istream::_M_extract(float&);
1059   extern template istream& istream::_M_extract(double&);
1060   extern template istream& istream::_M_extract(long double&);
1061   extern template istream& istream::_M_extract(void*&);
1062
1063   extern template class basic_iostream<char>;
1064
1065 #ifdef _GLIBCXX_USE_WCHAR_T
1066   extern template class basic_istream<wchar_t>;
1067   extern template wistream& ws(wistream&);
1068   extern template wistream& operator>>(wistream&, wchar_t&);
1069   extern template wistream& operator>>(wistream&, wchar_t*);
1070
1071   extern template wistream& wistream::_M_extract(unsigned short&);
1072   extern template wistream& wistream::_M_extract(unsigned int&);  
1073   extern template wistream& wistream::_M_extract(long&);
1074   extern template wistream& wistream::_M_extract(unsigned long&);
1075   extern template wistream& wistream::_M_extract(bool&);
1076 #ifdef _GLIBCXX_USE_LONG_LONG
1077   extern template wistream& wistream::_M_extract(long long&);
1078   extern template wistream& wistream::_M_extract(unsigned long long&);
1079 #endif
1080   extern template wistream& wistream::_M_extract(float&);
1081   extern template wistream& wistream::_M_extract(double&);
1082   extern template wistream& wistream::_M_extract(long double&);
1083   extern template wistream& wistream::_M_extract(void*&);
1084
1085   extern template class basic_iostream<wchar_t>;
1086 #endif
1087 #endif
1088
1089 _GLIBCXX_END_NAMESPACE_VERSION
1090 } // namespace std
1091
1092 #endif