ios_base.h revision 146897
1// Iostreams base classes -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31//
32// ISO C++ 14882: 27.4  Iostreams base classes
33//
34
35/** @file ios_base.h
36 *  This is an internal header file, included by other library headers.
37 *  You should not attempt to use it directly.
38 */
39
40#ifndef _IOS_BASE_H
41#define _IOS_BASE_H 1
42
43#pragma GCC system_header
44
45#include <bits/atomicity.h>
46#include <bits/localefwd.h>
47#include <bits/locale_classes.h>
48
49namespace std
50{
51  // The following definitions of bitmask types are enums, not ints,
52  // as permitted (but not required) in the standard, in order to provide
53  // better type safety in iostream calls.  A side effect is that
54  // expressions involving them are no longer compile-time constants.
55  enum _Ios_Fmtflags
56    {
57      _S_boolalpha 	= 1L << 0,
58      _S_dec 		= 1L << 1,
59      _S_fixed 		= 1L << 2,
60      _S_hex 		= 1L << 3,
61      _S_internal 	= 1L << 4,
62      _S_left 		= 1L << 5,
63      _S_oct 		= 1L << 6,
64      _S_right 		= 1L << 7,
65      _S_scientific 	= 1L << 8,
66      _S_showbase 	= 1L << 9,
67      _S_showpoint 	= 1L << 10,
68      _S_showpos 	= 1L << 11,
69      _S_skipws 	= 1L << 12,
70      _S_unitbuf 	= 1L << 13,
71      _S_uppercase 	= 1L << 14,
72      _S_adjustfield 	= _S_left | _S_right | _S_internal,
73      _S_basefield 	= _S_dec | _S_oct | _S_hex,
74      _S_floatfield 	= _S_scientific | _S_fixed,
75      _S_ios_fmtflags_end = 1L << 16
76    };
77
78  inline _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 _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 _Ios_Fmtflags
87  operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
88  { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
89
90  inline _Ios_Fmtflags&
91  operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
92  { return __a = __a | __b; }
93
94  inline _Ios_Fmtflags&
95  operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
96  { return __a = __a & __b; }
97
98  inline _Ios_Fmtflags&
99  operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
100  { return __a = __a ^ __b; }
101
102  inline _Ios_Fmtflags
103  operator~(_Ios_Fmtflags __a)
104  { return _Ios_Fmtflags(~static_cast<int>(__a)); }
105
106
107  enum _Ios_Openmode
108    {
109      _S_app 		= 1L << 0,
110      _S_ate 		= 1L << 1,
111      _S_bin 		= 1L << 2,
112      _S_in 		= 1L << 3,
113      _S_out 		= 1L << 4,
114      _S_trunc 		= 1L << 5,
115      _S_ios_openmode_end = 1L << 16
116    };
117
118  inline _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 _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 _Ios_Openmode
127  operator^(_Ios_Openmode __a, _Ios_Openmode __b)
128  { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
129
130  inline _Ios_Openmode&
131  operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
132  { return __a = __a | __b; }
133
134  inline _Ios_Openmode&
135  operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
136  { return __a = __a & __b; }
137
138  inline _Ios_Openmode&
139  operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
140  { return __a = __a ^ __b; }
141
142  inline _Ios_Openmode
143  operator~(_Ios_Openmode __a)
144  { return _Ios_Openmode(~static_cast<int>(__a)); }
145
146
147  enum _Ios_Iostate
148    {
149      _S_goodbit 		= 0,
150      _S_badbit 		= 1L << 0,
151      _S_eofbit 		= 1L << 1,
152      _S_failbit		= 1L << 2,
153      _S_ios_iostate_end = 1L << 16
154    };
155
156  inline _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 _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 _Ios_Iostate
165  operator^(_Ios_Iostate __a, _Ios_Iostate __b)
166  { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
167
168  inline _Ios_Iostate&
169  operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
170  { return __a = __a | __b; }
171
172  inline _Ios_Iostate&
173  operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
174  { return __a = __a & __b; }
175
176  inline _Ios_Iostate&
177  operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
178  { return __a = __a ^ __b; }
179
180  inline _Ios_Iostate
181  operator~(_Ios_Iostate __a)
182  { return _Ios_Iostate(~static_cast<int>(__a)); }
183
184  enum _Ios_Seekdir
185    {
186      _S_beg = 0,
187      _S_cur = SEEK_CUR,
188      _S_end = SEEK_END,
189      _S_ios_seekdir_end = 1L << 16
190    };
191
192  // 27.4.2  Class ios_base
193  /**
194   *  @brief  The very top of the I/O class hierarchy.
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    // 27.4.2.1.1  Class ios_base::failure
206    /// These are thrown to indicate problems.  Doc me.
207    class failure : public exception
208    {
209    public:
210      // _GLIBCXX_RESOLVE_LIB_DEFECTS
211      // 48.  Use of non-existent exception constructor
212      explicit
213      failure(const string& __str) throw();
214
215      // This declaration is not useless:
216      // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
217      virtual
218      ~failure() throw();
219
220      virtual const char*
221      what() const throw();
222
223    private:
224      string _M_msg;
225    };
226
227    // 27.4.2.1.2  Type ios_base::fmtflags
228    /**
229     *  @brief This is a bitmask type.
230     *
231     *  @c "_Ios_Fmtflags" is implementation-defined, but it is valid to
232     *  perform bitwise operations on these values and expect the Right
233     *  Thing to happen.  Defined objects of type fmtflags are:
234     *  - boolalpha
235     *  - dec
236     *  - fixed
237     *  - hex
238     *  - internal
239     *  - left
240     *  - oct
241     *  - right
242     *  - scientific
243     *  - showbase
244     *  - showpoint
245     *  - showpos
246     *  - skipws
247     *  - unitbuf
248     *  - uppercase
249     *  - adjustfield
250     *  - basefield
251     *  - floatfield
252    */
253    typedef _Ios_Fmtflags fmtflags;
254
255    /// Insert/extract @c bool in alphabetic rather than numeric format.
256    static const fmtflags boolalpha =   fmtflags(__ios_flags::_S_boolalpha);
257
258    /// Converts integer input or generates integer output in decimal base.
259    static const fmtflags dec =         fmtflags(__ios_flags::_S_dec);
260
261    /// Generate floating-point output in fixed-point notation.
262    static const fmtflags fixed =       fmtflags(__ios_flags::_S_fixed);
263
264    /// Converts integer input or generates integer output in hexadecimal base.
265    static const fmtflags hex =         fmtflags(__ios_flags::_S_hex);
266
267    /// Adds fill characters at a designated internal point in certain
268    /// generated output, or identical to @c right if no such point is
269    /// designated.
270    static const fmtflags internal =    fmtflags(__ios_flags::_S_internal);
271
272    /// Adds fill characters on the right (final positions) of certain
273    /// generated output.  (I.e., the thing you print is flush left.)
274    static const fmtflags left =        fmtflags(__ios_flags::_S_left);
275
276    /// Converts integer input or generates integer output in octal base.
277    static const fmtflags oct =         fmtflags(__ios_flags::_S_oct);
278
279    /// Adds fill characters on the left (initial positions) of certain
280    /// generated output.  (I.e., the thing you print is flush right.)
281    static const fmtflags right =       fmtflags(__ios_flags::_S_right);
282
283    /// Generates floating-point output in scientific notation.
284    static const fmtflags scientific =  fmtflags(__ios_flags::_S_scientific);
285
286    /// Generates a prefix indicating the numeric base of generated integer
287    /// output.
288    static const fmtflags showbase =    fmtflags(__ios_flags::_S_showbase);
289
290    /// Generates a decimal-point character unconditionally in generated
291    /// floating-point output.
292    static const fmtflags showpoint =   fmtflags(__ios_flags::_S_showpoint);
293
294    /// Generates a + sign in non-negative generated numeric output.
295    static const fmtflags showpos =     fmtflags(__ios_flags::_S_showpos);
296
297    /// Skips leading white space before certain input operations.
298    static const fmtflags skipws =      fmtflags(__ios_flags::_S_skipws);
299
300    /// Flushes output after each output operation.
301    static const fmtflags unitbuf =     fmtflags(__ios_flags::_S_unitbuf);
302
303    /// Replaces certain lowercase letters with their uppercase equivalents
304    /// in generated output.
305    static const fmtflags uppercase =   fmtflags(__ios_flags::_S_uppercase);
306
307    /// A mask of left|right|internal.  Useful for the 2-arg form of @c setf.
308    static const fmtflags adjustfield = fmtflags(__ios_flags::_S_adjustfield);
309
310    /// A mask of dec|oct|hex.  Useful for the 2-arg form of @c setf.
311    static const fmtflags basefield =   fmtflags(__ios_flags::_S_basefield);
312
313    /// A mask of scientific|fixed.  Useful for the 2-arg form of @c setf.
314    static const fmtflags floatfield =  fmtflags(__ios_flags::_S_floatfield);
315
316    // 27.4.2.1.3  Type ios_base::iostate
317    /**
318     *  @brief This is a bitmask type.
319     *
320     *  @c "_Ios_Iostate" is implementation-defined, but it is valid to
321     *  perform bitwise operations on these values and expect the Right
322     *  Thing to happen.  Defined objects of type iostate are:
323     *  - badbit
324     *  - eofbit
325     *  - failbit
326     *  - goodbit
327    */
328    typedef _Ios_Iostate iostate;
329
330    /// Indicates a loss of integrity in an input or output sequence (such
331    /// as an irrecoverable read error from a file).
332    static const iostate badbit =	iostate(__ios_flags::_S_badbit);
333
334    /// Indicates that an input operation reached the end of an input sequence.
335    static const iostate eofbit =	iostate(__ios_flags::_S_eofbit);
336
337    /// Indicates that an input operation failed to read the expected
338    /// characters, or that an output operation failed to generate the
339    /// desired characters.
340    static const iostate failbit =	iostate(__ios_flags::_S_failbit);
341
342    /// Indicates all is well.
343    static const iostate goodbit =	iostate(0);
344
345    // 27.4.2.1.4  Type ios_base::openmode
346    /**
347     *  @brief This is a bitmask type.
348     *
349     *  @c "_Ios_Openmode" is implementation-defined, but it is valid to
350     *  perform bitwise operations on these values and expect the Right
351     *  Thing to happen.  Defined objects of type openmode are:
352     *  - app
353     *  - ate
354     *  - binary
355     *  - in
356     *  - out
357     *  - trunc
358    */
359    typedef _Ios_Openmode openmode;
360
361    /// Seek to end before each write.
362    static const openmode app =		openmode(__ios_flags::_S_app);
363
364    /// Open and seek to end immediately after opening.
365    static const openmode ate =		openmode(__ios_flags::_S_ate);
366
367    /// Perform input and output in binary mode (as opposed to text mode).
368    /// This is probably not what you think it is; see
369    /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#3 and
370    /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#7 for more.
371    static const openmode binary =	openmode(__ios_flags::_S_bin);
372
373    /// Open for input.  Default for @c ifstream and fstream.
374    static const openmode in =		openmode(__ios_flags::_S_in);
375
376    /// Open for output.  Default for @c ofstream and fstream.
377    static const openmode out =		openmode(__ios_flags::_S_out);
378
379    /// Open for input.  Default for @c ofstream.
380    static const openmode trunc =	openmode(__ios_flags::_S_trunc);
381
382    // 27.4.2.1.5  Type ios_base::seekdir
383    /**
384     *  @brief This is an enumerated type.
385     *
386     *  @c "_Ios_Seekdir" is implementation-defined.  Defined values
387     *  of type seekdir are:
388     *  - beg
389     *  - cur, equivalent to @c SEEK_CUR in the C standard library.
390     *  - end, equivalent to @c SEEK_END in the C standard library.
391    */
392    typedef _Ios_Seekdir seekdir;
393
394    /// Request a seek relative to the beginning of the stream.
395    static const seekdir beg =		seekdir(0);
396
397    /// Request a seek relative to the current position within the sequence.
398    static const seekdir cur =		seekdir(SEEK_CUR);
399
400    /// Request a seek relative to the current end of the sequence.
401    static const seekdir end =		seekdir(SEEK_END);
402
403#ifdef _GLIBCXX_DEPRECATED
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#endif
412
413    // Callbacks;
414    /**
415     *  @brief  The set of events that may be passed to an event callback.
416     *
417     *  erase_event is used during ~ios() and copyfmt().  imbue_event is used
418     *  during imbue().  copyfmt_event is used during copyfmt().
419    */
420    enum event
421    {
422      erase_event,
423      imbue_event,
424      copyfmt_event
425    };
426
427    /**
428     *  @brief  The type of an event callback function.
429     *  @param  event  One of the members of the event enum.
430     *  @param  ios_base  Reference to the ios_base object.
431     *  @param  int  The integer provided when the callback was registered.
432     *
433     *  Event callbacks are user defined functions that get called during
434     *  several ios_base and basic_ios functions, specifically imbue(),
435     *  copyfmt(), and ~ios().
436    */
437    typedef void (*event_callback) (event, ios_base&, int);
438
439    /**
440     *  @brief  Add the callback __fn with parameter __index.
441     *  @param  __fn  The function to add.
442     *  @param  __index  The integer to pass to the function when invoked.
443     *
444     *  Registers a function as an event callback with an integer parameter to
445     *  be passed to the function when invoked.  Multiple copies of the
446     *  function are allowed.  If there are multiple callbacks, they are
447     *  invoked in the order they were registered.
448    */
449    void
450    register_callback(event_callback __fn, int __index);
451
452  protected:
453    //@{
454    /**
455     *  @if maint
456     *  ios_base data members (doc me)
457     *  @endif
458    */
459    streamsize		_M_precision;
460    streamsize		_M_width;
461    fmtflags		_M_flags;
462    iostate		_M_exception;
463    iostate		_M_streambuf_state;
464    //@}
465
466    // 27.4.2.6  Members for callbacks
467    // 27.4.2.6  ios_base callbacks
468    struct _Callback_list
469    {
470      // Data Members
471      _Callback_list*		_M_next;
472      ios_base::event_callback	_M_fn;
473      int			_M_index;
474      _Atomic_word		_M_refcount;  // 0 means one reference.
475
476      _Callback_list(ios_base::event_callback __fn, int __index,
477		     _Callback_list* __cb)
478      : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
479
480      void
481      _M_add_reference() { __gnu_cxx::__atomic_add(&_M_refcount, 1); }
482
483      // 0 => OK to delete.
484      int
485      _M_remove_reference()
486      { return __gnu_cxx::__exchange_and_add(&_M_refcount, -1); }
487    };
488
489     _Callback_list*	_M_callbacks;
490
491    void
492    _M_call_callbacks(event __ev) throw();
493
494    void
495    _M_dispose_callbacks(void);
496
497    // 27.4.2.5  Members for iword/pword storage
498    struct _Words
499    {
500      void*	_M_pword;
501      long	_M_iword;
502      _Words() : _M_pword(0), _M_iword(0) { }
503    };
504
505    // Only for failed iword/pword calls.
506    _Words		_M_word_zero;
507
508    // Guaranteed storage.
509    // The first 5 iword and pword slots are reserved for internal use.
510    static const int	_S_local_word_size = 8;
511    _Words		_M_local_word[_S_local_word_size];
512
513    // Allocated storage.
514    int			_M_word_size;
515    _Words*		_M_word;
516
517    _Words&
518    _M_grow_words(int __index, bool __iword);
519
520    // Members for locale and locale caching.
521    locale		_M_ios_locale;
522
523    void
524    _M_init();
525
526  public:
527
528    // 27.4.2.1.6  Class ios_base::Init
529    // Used to initialize standard streams. In theory, g++ could use
530    // -finit-priority to order this stuff correctly without going
531    // through these machinations.
532    class Init
533    {
534      friend class ios_base;
535    public:
536      Init();
537      ~Init();
538
539    private:
540      static _Atomic_word	_S_refcount;
541      static bool		_S_synced_with_stdio;
542    };
543
544    // [27.4.2.2] fmtflags state functions
545    /**
546     *  @brief  Access to format flags.
547     *  @return  The format control flags for both input and output.
548    */
549    inline fmtflags
550    flags() const { return _M_flags; }
551
552    /**
553     *  @brief  Setting new format flags all at once.
554     *  @param  fmtfl  The new flags to set.
555     *  @return  The previous format control flags.
556     *
557     *  This function overwrites all the format flags with @a fmtfl.
558    */
559    inline fmtflags
560    flags(fmtflags __fmtfl)
561    {
562      fmtflags __old = _M_flags;
563      _M_flags = __fmtfl;
564      return __old;
565    }
566
567    /**
568     *  @brief  Setting new format flags.
569     *  @param  fmtfl  Additional flags to set.
570     *  @return  The previous format control flags.
571     *
572     *  This function sets additional flags in format control.  Flags that
573     *  were previously set remain set.
574    */
575    inline fmtflags
576    setf(fmtflags __fmtfl)
577    {
578      fmtflags __old = _M_flags;
579      _M_flags |= __fmtfl;
580      return __old;
581    }
582
583    /**
584     *  @brief  Setting new format flags.
585     *  @param  fmtfl  Additional flags to set.
586     *  @param  mask  The flags mask for @a fmtfl.
587     *  @return  The previous format control flags.
588     *
589     *  This function clears @a mask in the format flags, then sets
590     *  @a fmtfl @c & @a mask.  An example mask is @c ios_base::adjustfield.
591    */
592    inline fmtflags
593    setf(fmtflags __fmtfl, fmtflags __mask)
594    {
595      fmtflags __old = _M_flags;
596      _M_flags &= ~__mask;
597      _M_flags |= (__fmtfl & __mask);
598      return __old;
599    }
600
601    /**
602     *  @brief  Clearing format flags.
603     *  @param  mask  The flags to unset.
604     *
605     *  This function clears @a mask in the format flags.
606    */
607    inline void
608    unsetf(fmtflags __mask) { _M_flags &= ~__mask; }
609
610    /**
611     *  @brief  Flags access.
612     *  @return  The precision to generate on certain output operations.
613     *
614     *  @if maint
615     *  Be careful if you try to give a definition of "precision" here; see
616     *  DR 189.
617     *  @endif
618    */
619    inline streamsize
620    precision() const { return _M_precision; }
621
622    /**
623     *  @brief  Changing flags.
624     *  @param  prec  The new precision value.
625     *  @return  The previous value of precision().
626    */
627    inline streamsize
628    precision(streamsize __prec)
629    {
630      streamsize __old = _M_precision;
631      _M_precision = __prec;
632      return __old;
633    }
634
635    /**
636     *  @brief  Flags access.
637     *  @return  The minimum field width to generate on output operations.
638     *
639     *  "Minimum field width" refers to the number of characters.
640    */
641    inline streamsize
642    width() const { return _M_width; }
643
644    /**
645     *  @brief  Changing flags.
646     *  @param  wide  The new width value.
647     *  @return  The previous value of width().
648    */
649    inline streamsize
650    width(streamsize __wide)
651    {
652      streamsize __old = _M_width;
653      _M_width = __wide;
654      return __old;
655    }
656
657    // [27.4.2.4] ios_base static members
658    /**
659     *  @brief  Interaction with the standard C I/O objects.
660     *  @param  sync  Whether to synchronize or not.
661     *  @return  True if the standard streams were previously synchronized.
662     *
663     *  The synchronization referred to is @e only that between the standard
664     *  C facilities (e.g., stdout) and the standard C++ objects (e.g.,
665     *  cout).  User-declared streams are unaffected.  See
666     *  http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#8 for more.
667    */
668    static bool
669    sync_with_stdio(bool __sync = true);
670
671    // [27.4.2.3] ios_base locale functions
672    /**
673     *  @brief  Setting a new locale.
674     *  @param  loc  The new locale.
675     *  @return  The previous locale.
676     *
677     *  Sets the new locale for this stream, and then invokes each callback
678     *  with imbue_event.
679    */
680    locale
681    imbue(const locale& __loc);
682
683    /**
684     *  @brief  Locale access
685     *  @return  A copy of the current locale.
686     *
687     *  If @c imbue(loc) has previously been called, then this function
688     *  returns @c loc.  Otherwise, it returns a copy of @c std::locale(),
689     *  the global C++ locale.
690    */
691    inline locale
692    getloc() const { return _M_ios_locale; }
693
694    /**
695     *  @brief  Locale access
696     *  @return  A reference to the current locale.
697     *
698     *  Like getloc above, but returns a reference instead of
699     *  generating a copy.
700    */
701    inline const locale&
702    _M_getloc() const { return _M_ios_locale; }
703
704    // [27.4.2.5] ios_base storage functions
705    /**
706     *  @brief  Access to unique indices.
707     *  @return  An integer different from all previous calls.
708     *
709     *  This function returns a unique integer every time it is called.  It
710     *  can be used for any purpose, but is primarily intended to be a unique
711     *  index for the iword and pword functions.  The expectation is that an
712     *  application calls xalloc in order to obtain an index in the iword and
713     *  pword arrays that can be used without fear of conflict.
714     *
715     *  The implementation maintains a static variable that is incremented and
716     *  returned on each invocation.  xalloc is guaranteed to return an index
717     *  that is safe to use in the iword and pword arrays.
718    */
719    static int
720    xalloc() throw();
721
722    /**
723     *  @brief  Access to integer array.
724     *  @param  __ix  Index into the array.
725     *  @return  A reference to an integer associated with the index.
726     *
727     *  The iword function provides access to an array of integers that can be
728     *  used for any purpose.  The array grows as required to hold the
729     *  supplied index.  All integers in the array are initialized to 0.
730     *
731     *  The implementation reserves several indices.  You should use xalloc to
732     *  obtain an index that is safe to use.  Also note that since the array
733     *  can grow dynamically, it is not safe to hold onto the reference.
734    */
735    inline long&
736    iword(int __ix)
737    {
738      _Words& __word = (__ix < _M_word_size)
739			? _M_word[__ix] : _M_grow_words(__ix, true);
740      return __word._M_iword;
741    }
742
743    /**
744     *  @brief  Access to void pointer array.
745     *  @param  __ix  Index into the array.
746     *  @return  A reference to a void* associated with the index.
747     *
748     *  The pword function provides access to an array of pointers that can be
749     *  used for any purpose.  The array grows as required to hold the
750     *  supplied index.  All pointers in the array are initialized to 0.
751     *
752     *  The implementation reserves several indices.  You should use xalloc to
753     *  obtain an index that is safe to use.  Also note that since the array
754     *  can grow dynamically, it is not safe to hold onto the reference.
755    */
756    inline void*&
757    pword(int __ix)
758    {
759      _Words& __word = (__ix < _M_word_size)
760			? _M_word[__ix] : _M_grow_words(__ix, false);
761      return __word._M_pword;
762    }
763
764    // Destructor
765    /**
766     *  Invokes each callback with erase_event.  Destroys local storage.
767     *
768     *  Note that the ios_base object for the standard streams never gets
769     *  destroyed.  As a result, any callbacks registered with the standard
770     *  streams will not get invoked with erase_event (unless copyfmt is
771     *  used).
772    */
773    virtual ~ios_base();
774
775  protected:
776    ios_base();
777
778  // _GLIBCXX_RESOLVE_LIB_DEFECTS
779  // 50.  Copy constructor and assignment operator of ios_base
780  private:
781    ios_base(const ios_base&);
782
783    ios_base&
784    operator=(const ios_base&);
785  };
786
787  // [27.4.5.1] fmtflags manipulators
788  /// Calls base.setf(ios_base::boolalpha).
789  inline ios_base&
790  boolalpha(ios_base& __base)
791  {
792    __base.setf(ios_base::boolalpha);
793    return __base;
794  }
795
796  /// Calls base.unsetf(ios_base::boolalpha).
797  inline ios_base&
798  noboolalpha(ios_base& __base)
799  {
800    __base.unsetf(ios_base::boolalpha);
801    return __base;
802  }
803
804  /// Calls base.setf(ios_base::showbase).
805  inline ios_base&
806  showbase(ios_base& __base)
807  {
808    __base.setf(ios_base::showbase);
809    return __base;
810  }
811
812  /// Calls base.unsetf(ios_base::showbase).
813  inline ios_base&
814  noshowbase(ios_base& __base)
815  {
816    __base.unsetf(ios_base::showbase);
817    return __base;
818  }
819
820  /// Calls base.setf(ios_base::showpoint).
821  inline ios_base&
822  showpoint(ios_base& __base)
823  {
824    __base.setf(ios_base::showpoint);
825    return __base;
826  }
827
828  /// Calls base.unsetf(ios_base::showpoint).
829  inline ios_base&
830  noshowpoint(ios_base& __base)
831  {
832    __base.unsetf(ios_base::showpoint);
833    return __base;
834  }
835
836  /// Calls base.setf(ios_base::showpos).
837  inline ios_base&
838  showpos(ios_base& __base)
839  {
840    __base.setf(ios_base::showpos);
841    return __base;
842  }
843
844  /// Calls base.unsetf(ios_base::showpos).
845  inline ios_base&
846  noshowpos(ios_base& __base)
847  {
848    __base.unsetf(ios_base::showpos);
849    return __base;
850  }
851
852  /// Calls base.setf(ios_base::skipws).
853  inline ios_base&
854  skipws(ios_base& __base)
855  {
856    __base.setf(ios_base::skipws);
857    return __base;
858  }
859
860  /// Calls base.unsetf(ios_base::skipws).
861  inline ios_base&
862  noskipws(ios_base& __base)
863  {
864    __base.unsetf(ios_base::skipws);
865    return __base;
866  }
867
868  /// Calls base.setf(ios_base::uppercase).
869  inline ios_base&
870  uppercase(ios_base& __base)
871  {
872    __base.setf(ios_base::uppercase);
873    return __base;
874  }
875
876  /// Calls base.unsetf(ios_base::uppercase).
877  inline ios_base&
878  nouppercase(ios_base& __base)
879  {
880    __base.unsetf(ios_base::uppercase);
881    return __base;
882  }
883
884  /// Calls base.setf(ios_base::unitbuf).
885  inline ios_base&
886  unitbuf(ios_base& __base)
887  {
888     __base.setf(ios_base::unitbuf);
889     return __base;
890  }
891
892  /// Calls base.unsetf(ios_base::unitbuf).
893  inline ios_base&
894  nounitbuf(ios_base& __base)
895  {
896     __base.unsetf(ios_base::unitbuf);
897     return __base;
898  }
899
900  // [27.4.5.2] adjustfield anipulators
901  /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
902  inline ios_base&
903  internal(ios_base& __base)
904  {
905     __base.setf(ios_base::internal, ios_base::adjustfield);
906     return __base;
907  }
908
909  /// Calls base.setf(ios_base::left, ios_base::adjustfield).
910  inline ios_base&
911  left(ios_base& __base)
912  {
913    __base.setf(ios_base::left, ios_base::adjustfield);
914    return __base;
915  }
916
917  /// Calls base.setf(ios_base::right, ios_base::adjustfield).
918  inline ios_base&
919  right(ios_base& __base)
920  {
921    __base.setf(ios_base::right, ios_base::adjustfield);
922    return __base;
923  }
924
925  // [27.4.5.3] basefield anipulators
926  /// Calls base.setf(ios_base::dec, ios_base::basefield).
927  inline ios_base&
928  dec(ios_base& __base)
929  {
930    __base.setf(ios_base::dec, ios_base::basefield);
931    return __base;
932  }
933
934  /// Calls base.setf(ios_base::hex, ios_base::basefield).
935  inline ios_base&
936  hex(ios_base& __base)
937  {
938    __base.setf(ios_base::hex, ios_base::basefield);
939    return __base;
940  }
941
942  /// Calls base.setf(ios_base::oct, ios_base::basefield).
943  inline ios_base&
944  oct(ios_base& __base)
945  {
946    __base.setf(ios_base::oct, ios_base::basefield);
947    return __base;
948  }
949
950  // [27.4.5.4] floatfield anipulators
951  /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
952  inline ios_base&
953  fixed(ios_base& __base)
954  {
955    __base.setf(ios_base::fixed, ios_base::floatfield);
956    return __base;
957  }
958
959  /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
960  inline ios_base&
961  scientific(ios_base& __base)
962  {
963    __base.setf(ios_base::scientific, ios_base::floatfield);
964    return __base;
965  }
966} // namespace std
967
968#endif /* _IOS_BASE_H */
969
970