libstdc++
ios_base.h
Go to the documentation of this file.
1 // Iostreams base classes -*- C++ -*-
2 
3 // Copyright (C) 1997-2014 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/ios_base.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{ios}
28  */
29 
30 //
31 // ISO C++ 14882: 27.4 Iostreams base classes
32 //
33 
34 #ifndef _IOS_BASE_H
35 #define _IOS_BASE_H 1
36 
37 #pragma GCC system_header
38 
39 #include <ext/atomicity.h>
40 #include <bits/localefwd.h>
41 #include <bits/locale_classes.h>
42 
43 namespace std _GLIBCXX_VISIBILITY(default)
44 {
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
46 
47  // The following definitions of bitmask types are enums, not ints,
48  // as permitted (but not required) in the standard, in order to provide
49  // better type safety in iostream calls. A side effect is that
50  // expressions involving them are no longer compile-time constants.
51  enum _Ios_Fmtflags
52  {
53  _S_boolalpha = 1L << 0,
54  _S_dec = 1L << 1,
55  _S_fixed = 1L << 2,
56  _S_hex = 1L << 3,
57  _S_internal = 1L << 4,
58  _S_left = 1L << 5,
59  _S_oct = 1L << 6,
60  _S_right = 1L << 7,
61  _S_scientific = 1L << 8,
62  _S_showbase = 1L << 9,
63  _S_showpoint = 1L << 10,
64  _S_showpos = 1L << 11,
65  _S_skipws = 1L << 12,
66  _S_unitbuf = 1L << 13,
67  _S_uppercase = 1L << 14,
68  _S_adjustfield = _S_left | _S_right | _S_internal,
69  _S_basefield = _S_dec | _S_oct | _S_hex,
70  _S_floatfield = _S_scientific | _S_fixed,
71  _S_ios_fmtflags_end = 1L << 16
72  };
73 
74  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
75  operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
76  { return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
77 
78  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
79  operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
80  { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
81 
82  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
83  operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
84  { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
85 
86  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
87  operator~(_Ios_Fmtflags __a)
88  { return _Ios_Fmtflags(~static_cast<int>(__a)); }
89 
90  inline const _Ios_Fmtflags&
91  operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
92  { return __a = __a | __b; }
93 
94  inline const _Ios_Fmtflags&
95  operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
96  { return __a = __a & __b; }
97 
98  inline const _Ios_Fmtflags&
99  operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
100  { return __a = __a ^ __b; }
101 
102 
103  enum _Ios_Openmode
104  {
105  _S_app = 1L << 0,
106  _S_ate = 1L << 1,
107  _S_bin = 1L << 2,
108  _S_in = 1L << 3,
109  _S_out = 1L << 4,
110  _S_trunc = 1L << 5,
111  _S_ios_openmode_end = 1L << 16
112  };
113 
114  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
115  operator&(_Ios_Openmode __a, _Ios_Openmode __b)
116  { return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
117 
118  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
119  operator|(_Ios_Openmode __a, _Ios_Openmode __b)
120  { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
121 
122  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
123  operator^(_Ios_Openmode __a, _Ios_Openmode __b)
124  { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
125 
126  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
127  operator~(_Ios_Openmode __a)
128  { return _Ios_Openmode(~static_cast<int>(__a)); }
129 
130  inline const _Ios_Openmode&
131  operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
132  { return __a = __a | __b; }
133 
134  inline const _Ios_Openmode&
135  operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
136  { return __a = __a & __b; }
137 
138  inline const _Ios_Openmode&
139  operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
140  { return __a = __a ^ __b; }
141 
142 
143  enum _Ios_Iostate
144  {
145  _S_goodbit = 0,
146  _S_badbit = 1L << 0,
147  _S_eofbit = 1L << 1,
148  _S_failbit = 1L << 2,
149  _S_ios_iostate_end = 1L << 16
150  };
151 
152  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
153  operator&(_Ios_Iostate __a, _Ios_Iostate __b)
154  { return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
155 
156  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
157  operator|(_Ios_Iostate __a, _Ios_Iostate __b)
158  { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
159 
160  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
161  operator^(_Ios_Iostate __a, _Ios_Iostate __b)
162  { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
163 
164  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
165  operator~(_Ios_Iostate __a)
166  { return _Ios_Iostate(~static_cast<int>(__a)); }
167 
168  inline const _Ios_Iostate&
169  operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
170  { return __a = __a | __b; }
171 
172  inline const _Ios_Iostate&
173  operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
174  { return __a = __a & __b; }
175 
176  inline const _Ios_Iostate&
177  operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
178  { return __a = __a ^ __b; }
179 
180 
181  enum _Ios_Seekdir
182  {
183  _S_beg = 0,
184  _S_cur = _GLIBCXX_STDIO_SEEK_CUR,
185  _S_end = _GLIBCXX_STDIO_SEEK_END,
186  _S_ios_seekdir_end = 1L << 16
187  };
188 
189  // 27.4.2 Class ios_base
190  /**
191  * @brief The base of the I/O class hierarchy.
192  * @ingroup io
193  *
194  * This class defines everything that can be defined about I/O that does
195  * not depend on the type of characters being input or output. Most
196  * people will only see @c ios_base when they need to specify the full
197  * name of the various I/O flags (e.g., the openmodes).
198  */
199  class ios_base
200  {
201  public:
202 
203  /**
204  * @brief These are thrown to indicate problems with io.
205  * @ingroup exceptions
206  *
207  * 27.4.2.1.1 Class ios_base::failure
208  */
209  class failure : public exception
210  {
211  public:
212  // _GLIBCXX_RESOLVE_LIB_DEFECTS
213  // 48. Use of non-existent exception constructor
214  explicit
215  failure(const string& __str) throw();
216 
217  // This declaration is not useless:
218  // http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/Vague-Linkage.html
219  virtual
220  ~failure() throw();
221 
222  virtual const char*
223  what() const throw();
224 
225  private:
226  string _M_msg;
227  };
228 
229  // 27.4.2.1.2 Type ios_base::fmtflags
230  /**
231  * @brief This is a bitmask type.
232  *
233  * @c @a _Ios_Fmtflags is implementation-defined, but it is valid to
234  * perform bitwise operations on these values and expect the Right
235  * Thing to happen. Defined objects of type fmtflags are:
236  * - boolalpha
237  * - dec
238  * - fixed
239  * - hex
240  * - internal
241  * - left
242  * - oct
243  * - right
244  * - scientific
245  * - showbase
246  * - showpoint
247  * - showpos
248  * - skipws
249  * - unitbuf
250  * - uppercase
251  * - adjustfield
252  * - basefield
253  * - floatfield
254  */
255  typedef _Ios_Fmtflags fmtflags;
256 
257  /// Insert/extract @c bool in alphabetic rather than numeric format.
258  static const fmtflags boolalpha = _S_boolalpha;
259 
260  /// Converts integer input or generates integer output in decimal base.
261  static const fmtflags dec = _S_dec;
262 
263  /// Generate floating-point output in fixed-point notation.
264  static const fmtflags fixed = _S_fixed;
265 
266  /// Converts integer input or generates integer output in hexadecimal base.
267  static const fmtflags hex = _S_hex;
268 
269  /// Adds fill characters at a designated internal point in certain
270  /// generated output, or identical to @c right if no such point is
271  /// designated.
272  static const fmtflags internal = _S_internal;
273 
274  /// Adds fill characters on the right (final positions) of certain
275  /// generated output. (I.e., the thing you print is flush left.)
276  static const fmtflags left = _S_left;
277 
278  /// Converts integer input or generates integer output in octal base.
279  static const fmtflags oct = _S_oct;
280 
281  /// Adds fill characters on the left (initial positions) of certain
282  /// generated output. (I.e., the thing you print is flush right.)
283  static const fmtflags right = _S_right;
284 
285  /// Generates floating-point output in scientific notation.
286  static const fmtflags scientific = _S_scientific;
287 
288  /// Generates a prefix indicating the numeric base of generated integer
289  /// output.
290  static const fmtflags showbase = _S_showbase;
291 
292  /// Generates a decimal-point character unconditionally in generated
293  /// floating-point output.
294  static const fmtflags showpoint = _S_showpoint;
295 
296  /// Generates a + sign in non-negative generated numeric output.
297  static const fmtflags showpos = _S_showpos;
298 
299  /// Skips leading white space before certain input operations.
300  static const fmtflags skipws = _S_skipws;
301 
302  /// Flushes output after each output operation.
303  static const fmtflags unitbuf = _S_unitbuf;
304 
305  /// Replaces certain lowercase letters with their uppercase equivalents
306  /// in generated output.
307  static const fmtflags uppercase = _S_uppercase;
308 
309  /// A mask of left|right|internal. Useful for the 2-arg form of @c setf.
310  static const fmtflags adjustfield = _S_adjustfield;
311 
312  /// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf.
313  static const fmtflags basefield = _S_basefield;
314 
315  /// A mask of scientific|fixed. Useful for the 2-arg form of @c setf.
316  static const fmtflags floatfield = _S_floatfield;
317 
318  // 27.4.2.1.3 Type ios_base::iostate
319  /**
320  * @brief This is a bitmask type.
321  *
322  * @c @a _Ios_Iostate is implementation-defined, but it is valid to
323  * perform bitwise operations on these values and expect the Right
324  * Thing to happen. Defined objects of type iostate are:
325  * - badbit
326  * - eofbit
327  * - failbit
328  * - goodbit
329  */
330  typedef _Ios_Iostate iostate;
331 
332  /// Indicates a loss of integrity in an input or output sequence (such
333  /// as an irrecoverable read error from a file).
334  static const iostate badbit = _S_badbit;
335 
336  /// Indicates that an input operation reached the end of an input sequence.
337  static const iostate eofbit = _S_eofbit;
338 
339  /// Indicates that an input operation failed to read the expected
340  /// characters, or that an output operation failed to generate the
341  /// desired characters.
342  static const iostate failbit = _S_failbit;
343 
344  /// Indicates all is well.
345  static const iostate goodbit = _S_goodbit;
346 
347  // 27.4.2.1.4 Type ios_base::openmode
348  /**
349  * @brief This is a bitmask type.
350  *
351  * @c @a _Ios_Openmode is implementation-defined, but it is valid to
352  * perform bitwise operations on these values and expect the Right
353  * Thing to happen. Defined objects of type openmode are:
354  * - app
355  * - ate
356  * - binary
357  * - in
358  * - out
359  * - trunc
360  */
361  typedef _Ios_Openmode openmode;
362 
363  /// Seek to end before each write.
364  static const openmode app = _S_app;
365 
366  /// Open and seek to end immediately after opening.
367  static const openmode ate = _S_ate;
368 
369  /// Perform input and output in binary mode (as opposed to text mode).
370  /// This is probably not what you think it is; see
371  /// http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch27s02.html
372  static const openmode binary = _S_bin;
373 
374  /// Open for input. Default for @c ifstream and fstream.
375  static const openmode in = _S_in;
376 
377  /// Open for output. Default for @c ofstream and fstream.
378  static const openmode out = _S_out;
379 
380  /// Open for input. Default for @c ofstream.
381  static const openmode trunc = _S_trunc;
382 
383  // 27.4.2.1.5 Type ios_base::seekdir
384  /**
385  * @brief This is an enumerated type.
386  *
387  * @c @a _Ios_Seekdir is implementation-defined. Defined values
388  * of type seekdir are:
389  * - beg
390  * - cur, equivalent to @c SEEK_CUR in the C standard library.
391  * - end, equivalent to @c SEEK_END in the C standard library.
392  */
393  typedef _Ios_Seekdir seekdir;
394 
395  /// Request a seek relative to the beginning of the stream.
396  static const seekdir beg = _S_beg;
397 
398  /// Request a seek relative to the current position within the sequence.
399  static const seekdir cur = _S_cur;
400 
401  /// Request a seek relative to the current end of the sequence.
402  static const seekdir end = _S_end;
403 
404  // Annex D.6
405  typedef int io_state;
406  typedef int open_mode;
407  typedef int seek_dir;
408 
409  typedef std::streampos streampos;
410  typedef std::streamoff streamoff;
411 
412  // Callbacks;
413  /**
414  * @brief The set of events that may be passed to an event callback.
415  *
416  * erase_event is used during ~ios() and copyfmt(). imbue_event is used
417  * during imbue(). copyfmt_event is used during copyfmt().
418  */
419  enum event
420  {
421  erase_event,
422  imbue_event,
423  copyfmt_event
424  };
425 
426  /**
427  * @brief The type of an event callback function.
428  * @param __e One of the members of the event enum.
429  * @param __b Reference to the ios_base object.
430  * @param __i The integer provided when the callback was registered.
431  *
432  * Event callbacks are user defined functions that get called during
433  * several ios_base and basic_ios functions, specifically imbue(),
434  * copyfmt(), and ~ios().
435  */
436  typedef void (*event_callback) (event __e, ios_base& __b, int __i);
437 
438  /**
439  * @brief Add the callback __fn with parameter __index.
440  * @param __fn The function to add.
441  * @param __index The integer to pass to the function when invoked.
442  *
443  * Registers a function as an event callback with an integer parameter to
444  * be passed to the function when invoked. Multiple copies of the
445  * function are allowed. If there are multiple callbacks, they are
446  * invoked in the order they were registered.
447  */
448  void
449  register_callback(event_callback __fn, int __index);
450 
451  protected:
452  streamsize _M_precision;
453  streamsize _M_width;
454  fmtflags _M_flags;
455  iostate _M_exception;
456  iostate _M_streambuf_state;
457 
458  // 27.4.2.6 Members for callbacks
459  // 27.4.2.6 ios_base callbacks
460  struct _Callback_list
461  {
462  // Data Members
463  _Callback_list* _M_next;
465  int _M_index;
466  _Atomic_word _M_refcount; // 0 means one reference.
467 
468  _Callback_list(ios_base::event_callback __fn, int __index,
469  _Callback_list* __cb)
470  : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
471 
472  void
473  _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
474 
475  // 0 => OK to delete.
476  int
477  _M_remove_reference()
478  {
479  // Be race-detector-friendly. For more info see bits/c++config.
480  _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
481  int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
482  if (__res == 0)
483  {
484  _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
485  }
486  return __res;
487  }
488  };
489 
490  _Callback_list* _M_callbacks;
491 
492  void
493  _M_call_callbacks(event __ev) throw();
494 
495  void
496  _M_dispose_callbacks(void) throw();
497 
498  // 27.4.2.5 Members for iword/pword storage
499  struct _Words
500  {
501  void* _M_pword;
502  long _M_iword;
503  _Words() : _M_pword(0), _M_iword(0) { }
504  };
505 
506  // Only for failed iword/pword calls.
507  _Words _M_word_zero;
508 
509  // Guaranteed storage.
510  // The first 5 iword and pword slots are reserved for internal use.
511  enum { _S_local_word_size = 8 };
512  _Words _M_local_word[_S_local_word_size];
513 
514  // Allocated storage.
515  int _M_word_size;
516  _Words* _M_word;
517 
518  _Words&
519  _M_grow_words(int __index, bool __iword);
520 
521  // Members for locale and locale caching.
522  locale _M_ios_locale;
523 
524  void
525  _M_init() throw();
526 
527  public:
528 
529  // 27.4.2.1.6 Class ios_base::Init
530  // Used to initialize standard streams. In theory, g++ could use
531  // -finit-priority to order this stuff correctly without going
532  // through these machinations.
533  class Init
534  {
535  friend class ios_base;
536  public:
537  Init();
538  ~Init();
539 
540  private:
541  static _Atomic_word _S_refcount;
542  static bool _S_synced_with_stdio;
543  };
544 
545  // [27.4.2.2] fmtflags state functions
546  /**
547  * @brief Access to format flags.
548  * @return The format control flags for both input and output.
549  */
550  fmtflags
551  flags() const
552  { return _M_flags; }
553 
554  /**
555  * @brief Setting new format flags all at once.
556  * @param __fmtfl The new flags to set.
557  * @return The previous format control flags.
558  *
559  * This function overwrites all the format flags with @a __fmtfl.
560  */
561  fmtflags
562  flags(fmtflags __fmtfl)
563  {
564  fmtflags __old = _M_flags;
565  _M_flags = __fmtfl;
566  return __old;
567  }
568 
569  /**
570  * @brief Setting new format flags.
571  * @param __fmtfl Additional flags to set.
572  * @return The previous format control flags.
573  *
574  * This function sets additional flags in format control. Flags that
575  * were previously set remain set.
576  */
577  fmtflags
578  setf(fmtflags __fmtfl)
579  {
580  fmtflags __old = _M_flags;
581  _M_flags |= __fmtfl;
582  return __old;
583  }
584 
585  /**
586  * @brief Setting new format flags.
587  * @param __fmtfl Additional flags to set.
588  * @param __mask The flags mask for @a fmtfl.
589  * @return The previous format control flags.
590  *
591  * This function clears @a mask in the format flags, then sets
592  * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
593  */
594  fmtflags
595  setf(fmtflags __fmtfl, fmtflags __mask)
596  {
597  fmtflags __old = _M_flags;
598  _M_flags &= ~__mask;
599  _M_flags |= (__fmtfl & __mask);
600  return __old;
601  }
602 
603  /**
604  * @brief Clearing format flags.
605  * @param __mask The flags to unset.
606  *
607  * This function clears @a __mask in the format flags.
608  */
609  void
610  unsetf(fmtflags __mask)
611  { _M_flags &= ~__mask; }
612 
613  /**
614  * @brief Flags access.
615  * @return The precision to generate on certain output operations.
616  *
617  * Be careful if you try to give a definition of @a precision here; see
618  * DR 189.
619  */
620  streamsize
621  precision() const
622  { return _M_precision; }
623 
624  /**
625  * @brief Changing flags.
626  * @param __prec The new precision value.
627  * @return The previous value of precision().
628  */
629  streamsize
631  {
632  streamsize __old = _M_precision;
633  _M_precision = __prec;
634  return __old;
635  }
636 
637  /**
638  * @brief Flags access.
639  * @return The minimum field width to generate on output operations.
640  *
641  * <em>Minimum field width</em> refers to the number of characters.
642  */
643  streamsize
644  width() const
645  { return _M_width; }
646 
647  /**
648  * @brief Changing flags.
649  * @param __wide The new width value.
650  * @return The previous value of width().
651  */
652  streamsize
654  {
655  streamsize __old = _M_width;
656  _M_width = __wide;
657  return __old;
658  }
659 
660  // [27.4.2.4] ios_base static members
661  /**
662  * @brief Interaction with the standard C I/O objects.
663  * @param __sync Whether to synchronize or not.
664  * @return True if the standard streams were previously synchronized.
665  *
666  * The synchronization referred to is @e only that between the standard
667  * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
668  * cout). User-declared streams are unaffected. See
669  * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch28s02.html
670  */
671  static bool
672  sync_with_stdio(bool __sync = true);
673 
674  // [27.4.2.3] ios_base locale functions
675  /**
676  * @brief Setting a new locale.
677  * @param __loc The new locale.
678  * @return The previous locale.
679  *
680  * Sets the new locale for this stream, and then invokes each callback
681  * with imbue_event.
682  */
683  locale
684  imbue(const locale& __loc) throw();
685 
686  /**
687  * @brief Locale access
688  * @return A copy of the current locale.
689  *
690  * If @c imbue(loc) has previously been called, then this function
691  * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
692  * the global C++ locale.
693  */
694  locale
695  getloc() const
696  { return _M_ios_locale; }
697 
698  /**
699  * @brief Locale access
700  * @return A reference to the current locale.
701  *
702  * Like getloc above, but returns a reference instead of
703  * generating a copy.
704  */
705  const locale&
706  _M_getloc() const
707  { return _M_ios_locale; }
708 
709  // [27.4.2.5] ios_base storage functions
710  /**
711  * @brief Access to unique indices.
712  * @return An integer different from all previous calls.
713  *
714  * This function returns a unique integer every time it is called. It
715  * can be used for any purpose, but is primarily intended to be a unique
716  * index for the iword and pword functions. The expectation is that an
717  * application calls xalloc in order to obtain an index in the iword and
718  * pword arrays that can be used without fear of conflict.
719  *
720  * The implementation maintains a static variable that is incremented and
721  * returned on each invocation. xalloc is guaranteed to return an index
722  * that is safe to use in the iword and pword arrays.
723  */
724  static int
725  xalloc() throw();
726 
727  /**
728  * @brief Access to integer array.
729  * @param __ix Index into the array.
730  * @return A reference to an integer associated with the index.
731  *
732  * The iword function provides access to an array of integers that can be
733  * used for any purpose. The array grows as required to hold the
734  * supplied index. All integers in the array are initialized to 0.
735  *
736  * The implementation reserves several indices. You should use xalloc to
737  * obtain an index that is safe to use. Also note that since the array
738  * can grow dynamically, it is not safe to hold onto the reference.
739  */
740  long&
741  iword(int __ix)
742  {
743  _Words& __word = (__ix < _M_word_size)
744  ? _M_word[__ix] : _M_grow_words(__ix, true);
745  return __word._M_iword;
746  }
747 
748  /**
749  * @brief Access to void pointer array.
750  * @param __ix Index into the array.
751  * @return A reference to a void* associated with the index.
752  *
753  * The pword function provides access to an array of pointers that can be
754  * used for any purpose. The array grows as required to hold the
755  * supplied index. All pointers in the array are initialized to 0.
756  *
757  * The implementation reserves several indices. You should use xalloc to
758  * obtain an index that is safe to use. Also note that since the array
759  * can grow dynamically, it is not safe to hold onto the reference.
760  */
761  void*&
762  pword(int __ix)
763  {
764  _Words& __word = (__ix < _M_word_size)
765  ? _M_word[__ix] : _M_grow_words(__ix, false);
766  return __word._M_pword;
767  }
768 
769  // Destructor
770  /**
771  * Invokes each callback with erase_event. Destroys local storage.
772  *
773  * Note that the ios_base object for the standard streams never gets
774  * destroyed. As a result, any callbacks registered with the standard
775  * streams will not get invoked with erase_event (unless copyfmt is
776  * used).
777  */
778  virtual ~ios_base();
779 
780  protected:
781  ios_base() throw ();
782 
783  // _GLIBCXX_RESOLVE_LIB_DEFECTS
784  // 50. Copy constructor and assignment operator of ios_base
785  private:
786  ios_base(const ios_base&);
787 
788  ios_base&
789  operator=(const ios_base&);
790  };
791 
792  // [27.4.5.1] fmtflags manipulators
793  /// Calls base.setf(ios_base::boolalpha).
794  inline ios_base&
795  boolalpha(ios_base& __base)
796  {
797  __base.setf(ios_base::boolalpha);
798  return __base;
799  }
800 
801  /// Calls base.unsetf(ios_base::boolalpha).
802  inline ios_base&
804  {
805  __base.unsetf(ios_base::boolalpha);
806  return __base;
807  }
808 
809  /// Calls base.setf(ios_base::showbase).
810  inline ios_base&
812  {
813  __base.setf(ios_base::showbase);
814  return __base;
815  }
816 
817  /// Calls base.unsetf(ios_base::showbase).
818  inline ios_base&
820  {
821  __base.unsetf(ios_base::showbase);
822  return __base;
823  }
824 
825  /// Calls base.setf(ios_base::showpoint).
826  inline ios_base&
828  {
829  __base.setf(ios_base::showpoint);
830  return __base;
831  }
832 
833  /// Calls base.unsetf(ios_base::showpoint).
834  inline ios_base&
836  {
837  __base.unsetf(ios_base::showpoint);
838  return __base;
839  }
840 
841  /// Calls base.setf(ios_base::showpos).
842  inline ios_base&
844  {
845  __base.setf(ios_base::showpos);
846  return __base;
847  }
848 
849  /// Calls base.unsetf(ios_base::showpos).
850  inline ios_base&
852  {
853  __base.unsetf(ios_base::showpos);
854  return __base;
855  }
856 
857  /// Calls base.setf(ios_base::skipws).
858  inline ios_base&
860  {
861  __base.setf(ios_base::skipws);
862  return __base;
863  }
864 
865  /// Calls base.unsetf(ios_base::skipws).
866  inline ios_base&
868  {
869  __base.unsetf(ios_base::skipws);
870  return __base;
871  }
872 
873  /// Calls base.setf(ios_base::uppercase).
874  inline ios_base&
876  {
877  __base.setf(ios_base::uppercase);
878  return __base;
879  }
880 
881  /// Calls base.unsetf(ios_base::uppercase).
882  inline ios_base&
884  {
885  __base.unsetf(ios_base::uppercase);
886  return __base;
887  }
888 
889  /// Calls base.setf(ios_base::unitbuf).
890  inline ios_base&
892  {
893  __base.setf(ios_base::unitbuf);
894  return __base;
895  }
896 
897  /// Calls base.unsetf(ios_base::unitbuf).
898  inline ios_base&
900  {
901  __base.unsetf(ios_base::unitbuf);
902  return __base;
903  }
904 
905  // [27.4.5.2] adjustfield manipulators
906  /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
907  inline ios_base&
908  internal(ios_base& __base)
909  {
911  return __base;
912  }
913 
914  /// Calls base.setf(ios_base::left, ios_base::adjustfield).
915  inline ios_base&
917  {
919  return __base;
920  }
921 
922  /// Calls base.setf(ios_base::right, ios_base::adjustfield).
923  inline ios_base&
925  {
927  return __base;
928  }
929 
930  // [27.4.5.3] basefield manipulators
931  /// Calls base.setf(ios_base::dec, ios_base::basefield).
932  inline ios_base&
934  {
936  return __base;
937  }
938 
939  /// Calls base.setf(ios_base::hex, ios_base::basefield).
940  inline ios_base&
942  {
944  return __base;
945  }
946 
947  /// Calls base.setf(ios_base::oct, ios_base::basefield).
948  inline ios_base&
950  {
952  return __base;
953  }
954 
955  // [27.4.5.4] floatfield manipulators
956  /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
957  inline ios_base&
959  {
961  return __base;
962  }
963 
964  /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
965  inline ios_base&
967  {
969  return __base;
970  }
971 
972 _GLIBCXX_END_NAMESPACE_VERSION
973 } // namespace
974 
975 #endif /* _IOS_BASE_H */
Container class for localization functionality.The locale class is first a class wrapper for C librar...
long & iword(int __ix)
Access to integer array.
Definition: ios_base.h:741
static const fmtflags left
Adds fill characters on the right (final positions) of certain generated output. (I.e., the thing you print is flush left.)
Definition: ios_base.h:276
static const openmode ate
Open and seek to end immediately after opening.
Definition: ios_base.h:367
static const seekdir cur
Request a seek relative to the current position within the sequence.
Definition: ios_base.h:399
_Ios_Openmode openmode
This is a bitmask type.
Definition: ios_base.h:361
fmtflags flags(fmtflags __fmtfl)
Setting new format flags all at once.
Definition: ios_base.h:562
streamsize precision() const
Flags access.
Definition: ios_base.h:621
static const iostate eofbit
Indicates that an input operation reached the end of an input sequence.
Definition: ios_base.h:337
_Ios_Fmtflags fmtflags
This is a bitmask type.
Definition: ios_base.h:255
static const fmtflags uppercase
Replaces certain lowercase letters with their uppercase equivalents in generated output.
Definition: ios_base.h:307
void *& pword(int __ix)
Access to void pointer array.
Definition: ios_base.h:762
fmtflags flags() const
Access to format flags.
Definition: ios_base.h:551
ios_base & nounitbuf(ios_base &__base)
Calls base.unsetf(ios_base::unitbuf).
Definition: ios_base.h:899
streamsize precision(streamsize __prec)
Changing flags.
Definition: ios_base.h:630
static const fmtflags showpoint
Generates a decimal-point character unconditionally in generated floating-point output.
Definition: ios_base.h:294
static const openmode app
Seek to end before each write.
Definition: ios_base.h:364
static const fmtflags scientific
Generates floating-point output in scientific notation.
Definition: ios_base.h:286
streamsize width(streamsize __wide)
Changing flags.
Definition: ios_base.h:653
static const fmtflags unitbuf
Flushes output after each output operation.
Definition: ios_base.h:303
locale imbue(const locale &__loc)
Setting a new locale.
These are thrown to indicate problems with io.27.4.2.1.1 Class ios_base::failure. ...
Definition: ios_base.h:209
event
The set of events that may be passed to an event callback.
Definition: ios_base.h:419
long long streamoff
Type used by fpos, char_traits, and char_traits.
Definition: postypes.h:94
static const iostate goodbit
Indicates all is well.
Definition: ios_base.h:345
static const iostate failbit
Indicates that an input operation failed to read the expected characters, or that an output operation...
Definition: ios_base.h:342
static const openmode in
Open for input. Default for ifstream and fstream.
Definition: ios_base.h:375
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:98
_Siter_base< _Iterator >::iterator_type __base(_Iterator __it)
Definition: functions.h:558
ISO C++ entities toplevel namespace is std.
ios_base & noboolalpha(ios_base &__base)
Calls base.unsetf(ios_base::boolalpha).
Definition: ios_base.h:803
static const fmtflags floatfield
A mask of scientific|fixed. Useful for the 2-arg form of setf.
Definition: ios_base.h:316
static const seekdir beg
Request a seek relative to the beginning of the stream.
Definition: ios_base.h:396
ios_base & noskipws(ios_base &__base)
Calls base.unsetf(ios_base::skipws).
Definition: ios_base.h:867
static const openmode binary
Perform input and output in binary mode (as opposed to text mode). This is probably not what you thin...
Definition: ios_base.h:372
_Ios_Iostate iostate
This is a bitmask type.
Definition: ios_base.h:330
static const fmtflags fixed
Generate floating-point output in fixed-point notation.
Definition: ios_base.h:264
static const openmode out
Open for output. Default for ofstream and fstream.
Definition: ios_base.h:378
void unsetf(fmtflags __mask)
Clearing format flags.
Definition: ios_base.h:610
const locale & _M_getloc() const
Locale access.
Definition: ios_base.h:706
static const fmtflags basefield
A mask of dec|oct|hex. Useful for the 2-arg form of setf.
Definition: ios_base.h:313
ios_base & noshowpos(ios_base &__base)
Calls base.unsetf(ios_base::showpos).
Definition: ios_base.h:851
static int xalloc()
Access to unique indices.
locale getloc() const
Locale access.
Definition: ios_base.h:695
static const seekdir end
Request a seek relative to the current end of the sequence.
Definition: ios_base.h:402
Class representing stream positions.
Definition: postypes.h:112
static const openmode trunc
Open for input. Default for ofstream.
Definition: ios_base.h:381
static const fmtflags hex
Converts integer input or generates integer output in hexadecimal base.
Definition: ios_base.h:267
ios_base & nouppercase(ios_base &__base)
Calls base.unsetf(ios_base::uppercase).
Definition: ios_base.h:883
static const fmtflags internal
Adds fill characters at a designated internal point in certain generated output, or identical to righ...
Definition: ios_base.h:272
The base of the I/O class hierarchy.This class defines everything that can be defined about I/O that ...
Definition: ios_base.h:199
ios_base & noshowbase(ios_base &__base)
Calls base.unsetf(ios_base::showbase).
Definition: ios_base.h:819
streamsize width() const
Flags access.
Definition: ios_base.h:644
static const fmtflags right
Adds fill characters on the left (initial positions) of certain generated output. (I...
Definition: ios_base.h:283
static const fmtflags adjustfield
A mask of left|right|internal. Useful for the 2-arg form of setf.
Definition: ios_base.h:310
static const fmtflags showbase
Generates a prefix indicating the numeric base of generated integer output.
Definition: ios_base.h:290
virtual ~ios_base()
_Ios_Seekdir seekdir
This is an enumerated type.
Definition: ios_base.h:393
static const fmtflags dec
Converts integer input or generates integer output in decimal base.
Definition: ios_base.h:261
fmtflags setf(fmtflags __fmtfl, fmtflags __mask)
Setting new format flags.
Definition: ios_base.h:595
void(* event_callback)(event __e, ios_base &__b, int __i)
The type of an event callback function.
Definition: ios_base.h:436
static const fmtflags oct
Converts integer input or generates integer output in octal base.
Definition: ios_base.h:279
ios_base & noshowpoint(ios_base &__base)
Calls base.unsetf(ios_base::showpoint).
Definition: ios_base.h:835
static bool sync_with_stdio(bool __sync=true)
Interaction with the standard C I/O objects.
void register_callback(event_callback __fn, int __index)
Add the callback __fn with parameter __index.
static const fmtflags skipws
Skips leading white space before certain input operations.
Definition: ios_base.h:300
fmtflags setf(fmtflags __fmtfl)
Setting new format flags.
Definition: ios_base.h:578
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:334
static const fmtflags boolalpha
Insert/extract bool in alphabetic rather than numeric format.
Definition: ios_base.h:258
static const fmtflags showpos
Generates a + sign in non-negative generated numeric output.
Definition: ios_base.h:297