1// Iostreams base classes -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4// 2006, 2007, 2008, 2009, 2010
5// Free Software Foundation, Inc.
6//
7// This file is part of the GNU ISO C++ Library.  This library is free
8// software; you can redistribute it and/or modify it under the
9// terms of the GNU General Public License as published by the
10// Free Software Foundation; either version 3, or (at your option)
11// any later version.
12
13// This library is distributed in the hope that it will be useful,
14// but WITHOUT ANY WARRANTY; without even the implied warranty of
15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16// GNU General Public License for more details.
17
18// Under Section 7 of GPL version 3, you are granted additional
19// permissions described in the GCC Runtime Library Exception, version
20// 3.1, as published by the Free Software Foundation.
21
22// You should have received a copy of the GNU General Public License and
23// a copy of the GCC Runtime Library Exception along with this program;
24// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
25// <http://www.gnu.org/licenses/>.
26
27/** @file bits/ios_base.h
28 *  This is an internal header file, included by other library headers.
29 *  Do not attempt to use it directly. @headername{ios}
30 */
31
32//
33// ISO C++ 14882: 27.4  Iostreams base classes
34//
35
36#ifndef _IOS_BASE_H
37#define _IOS_BASE_H 1
38
39#pragma GCC system_header
40
41#include <ext/atomicity.h>
42#include <bits/localefwd.h>
43#include <bits/locale_classes.h>
44
45namespace std _GLIBCXX_VISIBILITY(default)
46{
47_GLIBCXX_BEGIN_NAMESPACE_VERSION
48
49  // The following definitions of bitmask types are enums, not ints,
50  // as permitted (but not required) in the standard, in order to provide
51  // better type safety in iostream calls.  A side effect is that
52  // expressions involving them are no longer compile-time constants.
53  enum _Ios_Fmtflags
54    {
55      _S_boolalpha 	= 1L << 0,
56      _S_dec 		= 1L << 1,
57      _S_fixed 		= 1L << 2,
58      _S_hex 		= 1L << 3,
59      _S_internal 	= 1L << 4,
60      _S_left 		= 1L << 5,
61      _S_oct 		= 1L << 6,
62      _S_right 		= 1L << 7,
63      _S_scientific 	= 1L << 8,
64      _S_showbase 	= 1L << 9,
65      _S_showpoint 	= 1L << 10,
66      _S_showpos 	= 1L << 11,
67      _S_skipws 	= 1L << 12,
68      _S_unitbuf 	= 1L << 13,
69      _S_uppercase 	= 1L << 14,
70      _S_adjustfield 	= _S_left | _S_right | _S_internal,
71      _S_basefield 	= _S_dec | _S_oct | _S_hex,
72      _S_floatfield 	= _S_scientific | _S_fixed,
73      _S_ios_fmtflags_end = 1L << 16
74    };
75
76  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
77  operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
78  { return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
79
80  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
81  operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
82  { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
83
84  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
85  operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
86  { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
87
88  inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
89  operator~(_Ios_Fmtflags __a)
90  { return _Ios_Fmtflags(~static_cast<int>(__a)); }
91
92  inline const _Ios_Fmtflags&
93  operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
94  { return __a = __a | __b; }
95
96  inline const _Ios_Fmtflags&
97  operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
98  { return __a = __a & __b; }
99
100  inline const _Ios_Fmtflags&
101  operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
102  { return __a = __a ^ __b; }
103
104
105  enum _Ios_Openmode
106    {
107      _S_app 		= 1L << 0,
108      _S_ate 		= 1L << 1,
109      _S_bin 		= 1L << 2,
110      _S_in 		= 1L << 3,
111      _S_out 		= 1L << 4,
112      _S_trunc 		= 1L << 5,
113      _S_ios_openmode_end = 1L << 16
114    };
115
116  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
117  operator&(_Ios_Openmode __a, _Ios_Openmode __b)
118  { return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
119
120  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
121  operator|(_Ios_Openmode __a, _Ios_Openmode __b)
122  { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
123
124  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
125  operator^(_Ios_Openmode __a, _Ios_Openmode __b)
126  { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
127
128  inline _GLIBCXX_CONSTEXPR _Ios_Openmode
129  operator~(_Ios_Openmode __a)
130  { return _Ios_Openmode(~static_cast<int>(__a)); }
131
132  inline const _Ios_Openmode&
133  operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
134  { return __a = __a | __b; }
135
136  inline const _Ios_Openmode&
137  operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
138  { return __a = __a & __b; }
139
140  inline const _Ios_Openmode&
141  operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
142  { return __a = __a ^ __b; }
143
144
145  enum _Ios_Iostate
146    {
147      _S_goodbit 		= 0,
148      _S_badbit 		= 1L << 0,
149      _S_eofbit 		= 1L << 1,
150      _S_failbit		= 1L << 2,
151      _S_ios_iostate_end = 1L << 16
152    };
153
154  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
155  operator&(_Ios_Iostate __a, _Ios_Iostate __b)
156  { return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
157
158  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
159  operator|(_Ios_Iostate __a, _Ios_Iostate __b)
160  { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
161
162  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
163  operator^(_Ios_Iostate __a, _Ios_Iostate __b)
164  { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
165
166  inline _GLIBCXX_CONSTEXPR _Ios_Iostate
167  operator~(_Ios_Iostate __a)
168  { return _Ios_Iostate(~static_cast<int>(__a)); }
169
170  inline const _Ios_Iostate&
171  operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
172  { return __a = __a | __b; }
173
174  inline const _Ios_Iostate&
175  operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
176  { return __a = __a & __b; }
177
178  inline const  _Ios_Iostate&
179  operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
180  { return __a = __a ^ __b; }
181
182
183  enum _Ios_Seekdir
184    {
185      _S_beg = 0,
186      _S_cur = _GLIBCXX_STDIO_SEEK_CUR,
187      _S_end = _GLIBCXX_STDIO_SEEK_END,
188      _S_ios_seekdir_end = 1L << 16
189    };
190
191  // 27.4.2  Class ios_base
192  /**
193   *  @brief  The base of the I/O class hierarchy.
194   *  @ingroup io
195   *
196   *  This class defines everything that can be defined about I/O that does
197   *  not depend on the type of characters being input or output.  Most
198   *  people will only see @c ios_base when they need to specify the full
199   *  name of the various I/O flags (e.g., the openmodes).
200  */
201  class ios_base
202  {
203  public:
204
205    /**
206     *  @brief These are thrown to indicate problems with io.
207     *  @ingroup exceptions
208     *
209     *  27.4.2.1.1  Class ios_base::failure
210     */
211    class failure : public exception
212    {
213    public:
214      // _GLIBCXX_RESOLVE_LIB_DEFECTS
215      // 48.  Use of non-existent exception constructor
216      explicit
217      failure(const string& __str) throw();
218
219      // This declaration is not useless:
220      // http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/Vague-Linkage.html
221      virtual
222      ~failure() throw();
223
224      virtual const char*
225      what() const throw();
226
227    private:
228      string _M_msg;
229    };
230
231    // 27.4.2.1.2  Type ios_base::fmtflags
232    /**
233     *  @brief This is a bitmask type.
234     *
235     *  @c @a _Ios_Fmtflags is implementation-defined, but it is valid to
236     *  perform bitwise operations on these values and expect the Right
237     *  Thing to happen.  Defined objects of type fmtflags are:
238     *  - boolalpha
239     *  - dec
240     *  - fixed
241     *  - hex
242     *  - internal
243     *  - left
244     *  - oct
245     *  - right
246     *  - scientific
247     *  - showbase
248     *  - showpoint
249     *  - showpos
250     *  - skipws
251     *  - unitbuf
252     *  - uppercase
253     *  - adjustfield
254     *  - basefield
255     *  - floatfield
256    */
257    typedef _Ios_Fmtflags fmtflags;
258
259    /// Insert/extract @c bool in alphabetic rather than numeric format.
260    static const fmtflags boolalpha =   _S_boolalpha;
261
262    /// Converts integer input or generates integer output in decimal base.
263    static const fmtflags dec =         _S_dec;
264
265    /// Generate floating-point output in fixed-point notation.
266    static const fmtflags fixed =       _S_fixed;
267
268    /// Converts integer input or generates integer output in hexadecimal base.
269    static const fmtflags hex =         _S_hex;
270
271    /// Adds fill characters at a designated internal point in certain
272    /// generated output, or identical to @c right if no such point is
273    /// designated.
274    static const fmtflags internal =    _S_internal;
275
276    /// Adds fill characters on the right (final positions) of certain
277    /// generated output.  (I.e., the thing you print is flush left.)
278    static const fmtflags left =        _S_left;
279
280    /// Converts integer input or generates integer output in octal base.
281    static const fmtflags oct =         _S_oct;
282
283    /// Adds fill characters on the left (initial positions) of certain
284    /// generated output.  (I.e., the thing you print is flush right.)
285    static const fmtflags right =       _S_right;
286
287    /// Generates floating-point output in scientific notation.
288    static const fmtflags scientific =  _S_scientific;
289
290    /// Generates a prefix indicating the numeric base of generated integer
291    /// output.
292    static const fmtflags showbase =    _S_showbase;
293
294    /// Generates a decimal-point character unconditionally in generated
295    /// floating-point output.
296    static const fmtflags showpoint =   _S_showpoint;
297
298    /// Generates a + sign in non-negative generated numeric output.
299    static const fmtflags showpos =     _S_showpos;
300
301    /// Skips leading white space before certain input operations.
302    static const fmtflags skipws =      _S_skipws;
303
304    /// Flushes output after each output operation.
305    static const fmtflags unitbuf =     _S_unitbuf;
306
307    /// Replaces certain lowercase letters with their uppercase equivalents
308    /// in generated output.
309    static const fmtflags uppercase =   _S_uppercase;
310
311    /// A mask of left|right|internal.  Useful for the 2-arg form of @c setf.
312    static const fmtflags adjustfield = _S_adjustfield;
313
314    /// A mask of dec|oct|hex.  Useful for the 2-arg form of @c setf.
315    static const fmtflags basefield =   _S_basefield;
316
317    /// A mask of scientific|fixed.  Useful for the 2-arg form of @c setf.
318    static const fmtflags floatfield =  _S_floatfield;
319
320    // 27.4.2.1.3  Type ios_base::iostate
321    /**
322     *  @brief This is a bitmask type.
323     *
324     *  @c @a _Ios_Iostate is implementation-defined, but it is valid to
325     *  perform bitwise operations on these values and expect the Right
326     *  Thing to happen.  Defined objects of type iostate are:
327     *  - badbit
328     *  - eofbit
329     *  - failbit
330     *  - goodbit
331    */
332    typedef _Ios_Iostate iostate;
333
334    /// Indicates a loss of integrity in an input or output sequence (such
335    /// as an irrecoverable read error from a file).
336    static const iostate badbit =	_S_badbit;
337
338    /// Indicates that an input operation reached the end of an input sequence.
339    static const iostate eofbit =	_S_eofbit;
340
341    /// Indicates that an input operation failed to read the expected
342    /// characters, or that an output operation failed to generate the
343    /// desired characters.
344    static const iostate failbit =	_S_failbit;
345
346    /// Indicates all is well.
347    static const iostate goodbit =	_S_goodbit;
348
349    // 27.4.2.1.4  Type ios_base::openmode
350    /**
351     *  @brief This is a bitmask type.
352     *
353     *  @c @a _Ios_Openmode is implementation-defined, but it is valid to
354     *  perform bitwise operations on these values and expect the Right
355     *  Thing to happen.  Defined objects of type openmode are:
356     *  - app
357     *  - ate
358     *  - binary
359     *  - in
360     *  - out
361     *  - trunc
362    */
363    typedef _Ios_Openmode openmode;
364
365    /// Seek to end before each write.
366    static const openmode app =		_S_app;
367
368    /// Open and seek to end immediately after opening.
369    static const openmode ate =		_S_ate;
370
371    /// Perform input and output in binary mode (as opposed to text mode).
372    /// This is probably not what you think it is; see
373    /// http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch27s02.html
374    static const openmode binary =	_S_bin;
375
376    /// Open for input.  Default for @c ifstream and fstream.
377    static const openmode in =		_S_in;
378
379    /// Open for output.  Default for @c ofstream and fstream.
380    static const openmode out =		_S_out;
381
382    /// Open for input.  Default for @c ofstream.
383    static const openmode trunc =	_S_trunc;
384
385    // 27.4.2.1.5  Type ios_base::seekdir
386    /**
387     *  @brief This is an enumerated type.
388     *
389     *  @c @a _Ios_Seekdir is implementation-defined.  Defined values
390     *  of type seekdir are:
391     *  - beg
392     *  - cur, equivalent to @c SEEK_CUR in the C standard library.
393     *  - end, equivalent to @c SEEK_END in the C standard library.
394    */
395    typedef _Ios_Seekdir seekdir;
396
397    /// Request a seek relative to the beginning of the stream.
398    static const seekdir beg =		_S_beg;
399
400    /// Request a seek relative to the current position within the sequence.
401    static const seekdir cur =		_S_cur;
402
403    /// Request a seek relative to the current end of the sequence.
404    static const seekdir end =		_S_end;
405
406    // Annex D.6
407    typedef int io_state;
408    typedef int open_mode;
409    typedef int seek_dir;
410
411    typedef std::streampos streampos;
412    typedef std::streamoff streamoff;
413
414    // Callbacks;
415    /**
416     *  @brief  The set of events that may be passed to an event callback.
417     *
418     *  erase_event is used during ~ios() and copyfmt().  imbue_event is used
419     *  during imbue().  copyfmt_event is used during copyfmt().
420    */
421    enum event
422    {
423      erase_event,
424      imbue_event,
425      copyfmt_event
426    };
427
428    /**
429     *  @brief  The type of an event callback function.
430     *  @param  __e  One of the members of the event enum.
431     *  @param  __b  Reference to the ios_base object.
432     *  @param  __i  The integer provided when the callback was registered.
433     *
434     *  Event callbacks are user defined functions that get called during
435     *  several ios_base and basic_ios functions, specifically imbue(),
436     *  copyfmt(), and ~ios().
437    */
438    typedef void (*event_callback) (event __e, ios_base& __b, int __i);
439
440    /**
441     *  @brief  Add the callback __fn with parameter __index.
442     *  @param  __fn  The function to add.
443     *  @param  __index  The integer to pass to the function when invoked.
444     *
445     *  Registers a function as an event callback with an integer parameter to
446     *  be passed to the function when invoked.  Multiple copies of the
447     *  function are allowed.  If there are multiple callbacks, they are
448     *  invoked in the order they were registered.
449    */
450    void
451    register_callback(event_callback __fn, int __index);
452
453  protected:
454    streamsize		_M_precision;
455    streamsize		_M_width;
456    fmtflags		_M_flags;
457    iostate		_M_exception;
458    iostate		_M_streambuf_state;
459
460    // 27.4.2.6  Members for callbacks
461    // 27.4.2.6  ios_base callbacks
462    struct _Callback_list
463    {
464      // Data Members
465      _Callback_list*		_M_next;
466      ios_base::event_callback	_M_fn;
467      int			_M_index;
468      _Atomic_word		_M_refcount;  // 0 means one reference.
469
470      _Callback_list(ios_base::event_callback __fn, int __index,
471		     _Callback_list* __cb)
472      : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
473
474      void
475      _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
476
477      // 0 => OK to delete.
478      int
479      _M_remove_reference()
480      {
481        // Be race-detector-friendly.  For more info see bits/c++config.
482        _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
483        int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
484        if (__res == 0)
485          {
486            _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
487          }
488        return __res;
489      }
490    };
491
492     _Callback_list*	_M_callbacks;
493
494    void
495    _M_call_callbacks(event __ev) throw();
496
497    void
498    _M_dispose_callbacks(void) throw();
499
500    // 27.4.2.5  Members for iword/pword storage
501    struct _Words
502    {
503      void*	_M_pword;
504      long	_M_iword;
505      _Words() : _M_pword(0), _M_iword(0) { }
506    };
507
508    // Only for failed iword/pword calls.
509    _Words		_M_word_zero;
510
511    // Guaranteed storage.
512    // The first 5 iword and pword slots are reserved for internal use.
513    enum { _S_local_word_size = 8 };
514    _Words		_M_local_word[_S_local_word_size];
515
516    // Allocated storage.
517    int			_M_word_size;
518    _Words*		_M_word;
519
520    _Words&
521    _M_grow_words(int __index, bool __iword);
522
523    // Members for locale and locale caching.
524    locale		_M_ios_locale;
525
526    void
527    _M_init() throw();
528
529  public:
530
531    // 27.4.2.1.6  Class ios_base::Init
532    // Used to initialize standard streams. In theory, g++ could use
533    // -finit-priority to order this stuff correctly without going
534    // through these machinations.
535    class Init
536    {
537      friend class ios_base;
538    public:
539      Init();
540      ~Init();
541
542    private:
543      static _Atomic_word	_S_refcount;
544      static bool		_S_synced_with_stdio;
545    };
546
547    // [27.4.2.2] fmtflags state functions
548    /**
549     *  @brief  Access to format flags.
550     *  @return  The format control flags for both input and output.
551    */
552    fmtflags
553    flags() const
554    { return _M_flags; }
555
556    /**
557     *  @brief  Setting new format flags all at once.
558     *  @param  __fmtfl  The new flags to set.
559     *  @return  The previous format control flags.
560     *
561     *  This function overwrites all the format flags with @a __fmtfl.
562    */
563    fmtflags
564    flags(fmtflags __fmtfl)
565    {
566      fmtflags __old = _M_flags;
567      _M_flags = __fmtfl;
568      return __old;
569    }
570
571    /**
572     *  @brief  Setting new format flags.
573     *  @param  __fmtfl  Additional flags to set.
574     *  @return  The previous format control flags.
575     *
576     *  This function sets additional flags in format control.  Flags that
577     *  were previously set remain set.
578    */
579    fmtflags
580    setf(fmtflags __fmtfl)
581    {
582      fmtflags __old = _M_flags;
583      _M_flags |= __fmtfl;
584      return __old;
585    }
586
587    /**
588     *  @brief  Setting new format flags.
589     *  @param  __fmtfl  Additional flags to set.
590     *  @param  __mask  The flags mask for @a fmtfl.
591     *  @return  The previous format control flags.
592     *
593     *  This function clears @a mask in the format flags, then sets
594     *  @a fmtfl @c & @a mask.  An example mask is @c ios_base::adjustfield.
595    */
596    fmtflags
597    setf(fmtflags __fmtfl, fmtflags __mask)
598    {
599      fmtflags __old = _M_flags;
600      _M_flags &= ~__mask;
601      _M_flags |= (__fmtfl & __mask);
602      return __old;
603    }
604
605    /**
606     *  @brief  Clearing format flags.
607     *  @param  __mask  The flags to unset.
608     *
609     *  This function clears @a __mask in the format flags.
610    */
611    void
612    unsetf(fmtflags __mask)
613    { _M_flags &= ~__mask; }
614
615    /**
616     *  @brief  Flags access.
617     *  @return  The precision to generate on certain output operations.
618     *
619     *  Be careful if you try to give a definition of @a precision here; see
620     *  DR 189.
621    */
622    streamsize
623    precision() const
624    { return _M_precision; }
625
626    /**
627     *  @brief  Changing flags.
628     *  @param  __prec  The new precision value.
629     *  @return  The previous value of precision().
630    */
631    streamsize
632    precision(streamsize __prec)
633    {
634      streamsize __old = _M_precision;
635      _M_precision = __prec;
636      return __old;
637    }
638
639    /**
640     *  @brief  Flags access.
641     *  @return  The minimum field width to generate on output operations.
642     *
643     *  <em>Minimum field width</em> refers to the number of characters.
644    */
645    streamsize
646    width() const
647    { return _M_width; }
648
649    /**
650     *  @brief  Changing flags.
651     *  @param  __wide  The new width value.
652     *  @return  The previous value of width().
653    */
654    streamsize
655    width(streamsize __wide)
656    {
657      streamsize __old = _M_width;
658      _M_width = __wide;
659      return __old;
660    }
661
662    // [27.4.2.4] ios_base static members
663    /**
664     *  @brief  Interaction with the standard C I/O objects.
665     *  @param  __sync  Whether to synchronize or not.
666     *  @return  True if the standard streams were previously synchronized.
667     *
668     *  The synchronization referred to is @e only that between the standard
669     *  C facilities (e.g., stdout) and the standard C++ objects (e.g.,
670     *  cout).  User-declared streams are unaffected.  See
671     *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch28s02.html
672    */
673    static bool
674    sync_with_stdio(bool __sync = true);
675
676    // [27.4.2.3] ios_base locale functions
677    /**
678     *  @brief  Setting a new locale.
679     *  @param  __loc  The new locale.
680     *  @return  The previous locale.
681     *
682     *  Sets the new locale for this stream, and then invokes each callback
683     *  with imbue_event.
684    */
685    locale
686    imbue(const locale& __loc) throw();
687
688    /**
689     *  @brief  Locale access
690     *  @return  A copy of the current locale.
691     *
692     *  If @c imbue(loc) has previously been called, then this function
693     *  returns @c loc.  Otherwise, it returns a copy of @c std::locale(),
694     *  the global C++ locale.
695    */
696    locale
697    getloc() const
698    { return _M_ios_locale; }
699
700    /**
701     *  @brief  Locale access
702     *  @return  A reference to the current locale.
703     *
704     *  Like getloc above, but returns a reference instead of
705     *  generating a copy.
706    */
707    const locale&
708    _M_getloc() const
709    { return _M_ios_locale; }
710
711    // [27.4.2.5] ios_base storage functions
712    /**
713     *  @brief  Access to unique indices.
714     *  @return  An integer different from all previous calls.
715     *
716     *  This function returns a unique integer every time it is called.  It
717     *  can be used for any purpose, but is primarily intended to be a unique
718     *  index for the iword and pword functions.  The expectation is that an
719     *  application calls xalloc in order to obtain an index in the iword and
720     *  pword arrays that can be used without fear of conflict.
721     *
722     *  The implementation maintains a static variable that is incremented and
723     *  returned on each invocation.  xalloc is guaranteed to return an index
724     *  that is safe to use in the iword and pword arrays.
725    */
726    static int
727    xalloc() throw();
728
729    /**
730     *  @brief  Access to integer array.
731     *  @param  __ix  Index into the array.
732     *  @return  A reference to an integer associated with the index.
733     *
734     *  The iword function provides access to an array of integers that can be
735     *  used for any purpose.  The array grows as required to hold the
736     *  supplied index.  All integers in the array are initialized to 0.
737     *
738     *  The implementation reserves several indices.  You should use xalloc to
739     *  obtain an index that is safe to use.  Also note that since the array
740     *  can grow dynamically, it is not safe to hold onto the reference.
741    */
742    long&
743    iword(int __ix)
744    {
745      _Words& __word = (__ix < _M_word_size)
746			? _M_word[__ix] : _M_grow_words(__ix, true);
747      return __word._M_iword;
748    }
749
750    /**
751     *  @brief  Access to void pointer array.
752     *  @param  __ix  Index into the array.
753     *  @return  A reference to a void* associated with the index.
754     *
755     *  The pword function provides access to an array of pointers that can be
756     *  used for any purpose.  The array grows as required to hold the
757     *  supplied index.  All pointers in the array are initialized to 0.
758     *
759     *  The implementation reserves several indices.  You should use xalloc to
760     *  obtain an index that is safe to use.  Also note that since the array
761     *  can grow dynamically, it is not safe to hold onto the reference.
762    */
763    void*&
764    pword(int __ix)
765    {
766      _Words& __word = (__ix < _M_word_size)
767			? _M_word[__ix] : _M_grow_words(__ix, false);
768      return __word._M_pword;
769    }
770
771    // Destructor
772    /**
773     *  Invokes each callback with erase_event.  Destroys local storage.
774     *
775     *  Note that the ios_base object for the standard streams never gets
776     *  destroyed.  As a result, any callbacks registered with the standard
777     *  streams will not get invoked with erase_event (unless copyfmt is
778     *  used).
779    */
780    virtual ~ios_base();
781
782  protected:
783    ios_base() throw ();
784
785  // _GLIBCXX_RESOLVE_LIB_DEFECTS
786  // 50.  Copy constructor and assignment operator of ios_base
787  private:
788    ios_base(const ios_base&);
789
790    ios_base&
791    operator=(const ios_base&);
792  };
793
794  // [27.4.5.1] fmtflags manipulators
795  /// Calls base.setf(ios_base::boolalpha).
796  inline ios_base&
797  boolalpha(ios_base& __base)
798  {
799    __base.setf(ios_base::boolalpha);
800    return __base;
801  }
802
803  /// Calls base.unsetf(ios_base::boolalpha).
804  inline ios_base&
805  noboolalpha(ios_base& __base)
806  {
807    __base.unsetf(ios_base::boolalpha);
808    return __base;
809  }
810
811  /// Calls base.setf(ios_base::showbase).
812  inline ios_base&
813  showbase(ios_base& __base)
814  {
815    __base.setf(ios_base::showbase);
816    return __base;
817  }
818
819  /// Calls base.unsetf(ios_base::showbase).
820  inline ios_base&
821  noshowbase(ios_base& __base)
822  {
823    __base.unsetf(ios_base::showbase);
824    return __base;
825  }
826
827  /// Calls base.setf(ios_base::showpoint).
828  inline ios_base&
829  showpoint(ios_base& __base)
830  {
831    __base.setf(ios_base::showpoint);
832    return __base;
833  }
834
835  /// Calls base.unsetf(ios_base::showpoint).
836  inline ios_base&
837  noshowpoint(ios_base& __base)
838  {
839    __base.unsetf(ios_base::showpoint);
840    return __base;
841  }
842
843  /// Calls base.setf(ios_base::showpos).
844  inline ios_base&
845  showpos(ios_base& __base)
846  {
847    __base.setf(ios_base::showpos);
848    return __base;
849  }
850
851  /// Calls base.unsetf(ios_base::showpos).
852  inline ios_base&
853  noshowpos(ios_base& __base)
854  {
855    __base.unsetf(ios_base::showpos);
856    return __base;
857  }
858
859  /// Calls base.setf(ios_base::skipws).
860  inline ios_base&
861  skipws(ios_base& __base)
862  {
863    __base.setf(ios_base::skipws);
864    return __base;
865  }
866
867  /// Calls base.unsetf(ios_base::skipws).
868  inline ios_base&
869  noskipws(ios_base& __base)
870  {
871    __base.unsetf(ios_base::skipws);
872    return __base;
873  }
874
875  /// Calls base.setf(ios_base::uppercase).
876  inline ios_base&
877  uppercase(ios_base& __base)
878  {
879    __base.setf(ios_base::uppercase);
880    return __base;
881  }
882
883  /// Calls base.unsetf(ios_base::uppercase).
884  inline ios_base&
885  nouppercase(ios_base& __base)
886  {
887    __base.unsetf(ios_base::uppercase);
888    return __base;
889  }
890
891  /// Calls base.setf(ios_base::unitbuf).
892  inline ios_base&
893  unitbuf(ios_base& __base)
894  {
895     __base.setf(ios_base::unitbuf);
896     return __base;
897  }
898
899  /// Calls base.unsetf(ios_base::unitbuf).
900  inline ios_base&
901  nounitbuf(ios_base& __base)
902  {
903     __base.unsetf(ios_base::unitbuf);
904     return __base;
905  }
906
907  // [27.4.5.2] adjustfield manipulators
908  /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
909  inline ios_base&
910  internal(ios_base& __base)
911  {
912     __base.setf(ios_base::internal, ios_base::adjustfield);
913     return __base;
914  }
915
916  /// Calls base.setf(ios_base::left, ios_base::adjustfield).
917  inline ios_base&
918  left(ios_base& __base)
919  {
920    __base.setf(ios_base::left, ios_base::adjustfield);
921    return __base;
922  }
923
924  /// Calls base.setf(ios_base::right, ios_base::adjustfield).
925  inline ios_base&
926  right(ios_base& __base)
927  {
928    __base.setf(ios_base::right, ios_base::adjustfield);
929    return __base;
930  }
931
932  // [27.4.5.3] basefield manipulators
933  /// Calls base.setf(ios_base::dec, ios_base::basefield).
934  inline ios_base&
935  dec(ios_base& __base)
936  {
937    __base.setf(ios_base::dec, ios_base::basefield);
938    return __base;
939  }
940
941  /// Calls base.setf(ios_base::hex, ios_base::basefield).
942  inline ios_base&
943  hex(ios_base& __base)
944  {
945    __base.setf(ios_base::hex, ios_base::basefield);
946    return __base;
947  }
948
949  /// Calls base.setf(ios_base::oct, ios_base::basefield).
950  inline ios_base&
951  oct(ios_base& __base)
952  {
953    __base.setf(ios_base::oct, ios_base::basefield);
954    return __base;
955  }
956
957  // [27.4.5.4] floatfield manipulators
958  /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
959  inline ios_base&
960  fixed(ios_base& __base)
961  {
962    __base.setf(ios_base::fixed, ios_base::floatfield);
963    return __base;
964  }
965
966  /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
967  inline ios_base&
968  scientific(ios_base& __base)
969  {
970    __base.setf(ios_base::scientific, ios_base::floatfield);
971    return __base;
972  }
973
974_GLIBCXX_END_NAMESPACE_VERSION
975} // namespace
976
977#endif /* _IOS_BASE_H */
978