1// Iostreams base classes -*- C++ -*-
2
3// Copyright (C) 1997-2017 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#if __cplusplus < 201103L
44# include <stdexcept>
45#else
46# include <system_error>
47#endif
48
49namespace std _GLIBCXX_VISIBILITY(default)
50{
51_GLIBCXX_BEGIN_NAMESPACE_VERSION
52
53 // The following definitions of bitmask types are enums, not ints,
54 // as permitted (but not required) in the standard, in order to provide
55 // better type safety in iostream calls. A side effect is that in C++98
56 // expressions involving them are not compile-time constants.
57 enum _Ios_Fmtflags
58 {
59 _S_boolalpha = 1L << 0,
60 _S_dec = 1L << 1,
61 _S_fixed = 1L << 2,
62 _S_hex = 1L << 3,
63 _S_internal = 1L << 4,
64 _S_left = 1L << 5,
65 _S_oct = 1L << 6,
66 _S_right = 1L << 7,
67 _S_scientific = 1L << 8,
68 _S_showbase = 1L << 9,
69 _S_showpoint = 1L << 10,
70 _S_showpos = 1L << 11,
71 _S_skipws = 1L << 12,
72 _S_unitbuf = 1L << 13,
73 _S_uppercase = 1L << 14,
74 _S_adjustfield = _S_left | _S_right | _S_internal,
75 _S_basefield = _S_dec | _S_oct | _S_hex,
76 _S_floatfield = _S_scientific | _S_fixed,
77 _S_ios_fmtflags_end = 1L << 16,
78 _S_ios_fmtflags_max = __INT_MAX__,
79 _S_ios_fmtflags_min = ~__INT_MAX__
80 };
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, _Ios_Fmtflags __b)
88 { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
89
90 inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
91 operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
92 { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
93
94 inline _GLIBCXX_CONSTEXPR _Ios_Fmtflags
95 operator~(_Ios_Fmtflags __a)
96 { return _Ios_Fmtflags(~static_cast<int>(__a)); }
97
98 inline const _Ios_Fmtflags&
99 operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
100 { return __a = __a | __b; }
101
102 inline const _Ios_Fmtflags&
103 operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
104 { return __a = __a & __b; }
105
106 inline const _Ios_Fmtflags&
107 operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
108 { return __a = __a ^ __b; }
109
110
111 enum _Ios_Openmode
112 {
113 _S_app = 1L << 0,
114 _S_ate = 1L << 1,
115 _S_bin = 1L << 2,
116 _S_in = 1L << 3,
117 _S_out = 1L << 4,
118 _S_trunc = 1L << 5,
119 _S_ios_openmode_end = 1L << 16,
120 _S_ios_openmode_max = __INT_MAX__,
121 _S_ios_openmode_min = ~__INT_MAX__
122 };
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, _Ios_Openmode __b)
130 { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
131
132 inline _GLIBCXX_CONSTEXPR _Ios_Openmode
133 operator^(_Ios_Openmode __a, _Ios_Openmode __b)
134 { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
135
136 inline _GLIBCXX_CONSTEXPR _Ios_Openmode
137 operator~(_Ios_Openmode __a)
138 { return _Ios_Openmode(~static_cast<int>(__a)); }
139
140 inline const _Ios_Openmode&
141 operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
142 { return __a = __a | __b; }
143
144 inline const _Ios_Openmode&
145 operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
146 { return __a = __a & __b; }
147
148 inline const _Ios_Openmode&
149 operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
150 { return __a = __a ^ __b; }
151
152
153 enum _Ios_Iostate
154 {
155 _S_goodbit = 0,
156 _S_badbit = 1L << 0,
157 _S_eofbit = 1L << 1,
158 _S_failbit = 1L << 2,
159 _S_ios_iostate_end = 1L << 16,
160 _S_ios_iostate_max = __INT_MAX__,
161 _S_ios_iostate_min = ~__INT_MAX__
162 };
163
164 inline _GLIBCXX_CONSTEXPR _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 _GLIBCXX_CONSTEXPR _Ios_Iostate
169 operator|(_Ios_Iostate __a, _Ios_Iostate __b)
170 { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
171
172 inline _GLIBCXX_CONSTEXPR _Ios_Iostate
173 operator^(_Ios_Iostate __a, _Ios_Iostate __b)
174 { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
175
176 inline _GLIBCXX_CONSTEXPR _Ios_Iostate
177 operator~(_Ios_Iostate __a)
178 { return _Ios_Iostate(~static_cast<int>(__a)); }
179
180 inline const _Ios_Iostate&
181 operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
182 { return __a = __a | __b; }
183
184 inline const _Ios_Iostate&
185 operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
186 { return __a = __a & __b; }
187
188 inline const _Ios_Iostate&
189 operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
190 { return __a = __a ^ __b; }
191
192
193 enum _Ios_Seekdir
194 {
195 _S_beg = 0,
196 _S_cur = _GLIBCXX_STDIO_SEEK_CUR,
197 _S_end = _GLIBCXX_STDIO_SEEK_END,
198 _S_ios_seekdir_end = 1L << 16
199 };
200
201#if __cplusplus >= 201103L
202 /// I/O error code
203 enum class io_errc { stream = 1 };
204
205 template <> struct is_error_code_enum<io_errc> : public true_type { };
206
207 const error_category& iostream_category() noexcept;
208
209 inline error_code
210 make_error_code(io_errc __e) noexcept
211 { return error_code(static_cast<int>(__e), iostream_category()); }
212
213 inline error_condition
214 make_error_condition(io_errc __e) noexcept
215 { return error_condition(static_cast<int>(__e), iostream_category()); }
216#endif
217
218 // 27.4.2 Class ios_base
219 /**
220 * @brief The base of the I/O class hierarchy.
221 * @ingroup io
222 *
223 * This class defines everything that can be defined about I/O that does
224 * not depend on the type of characters being input or output. Most
225 * people will only see @c ios_base when they need to specify the full
226 * name of the various I/O flags (e.g., the openmodes).
227 */
228 class ios_base
229 {
230#if _GLIBCXX_USE_CXX11_ABI
231#if __cplusplus < 201103L
232 // Type that is layout-compatible with std::system_error
233 struct system_error : std::runtime_error
234 {
235 // Type that is layout-compatible with std::error_code
236 struct error_code
237 {
238 error_code() { }
239 private:
240 int _M_value;
241 const void* _M_cat;
242 } _M_code;
243 };
244#endif
245#endif
246 public:
247
248 /**
249 * @brief These are thrown to indicate problems with io.
250 * @ingroup exceptions
251 *
252 * 27.4.2.1.1 Class ios_base::failure
253 */
254#if _GLIBCXX_USE_CXX11_ABI
255 class _GLIBCXX_ABI_TAG_CXX11 failure : public system_error
256 {
257 public:
258 explicit
259 failure(const string& __str);
260
261#if __cplusplus >= 201103L
262 explicit
263 failure(const string&, const error_code&);
264
265 explicit
266 failure(const char*, const error_code& = io_errc::stream);
267#endif
268
269 virtual
270 ~failure() throw();
271
272 virtual const char*
273 what() const throw();
274 };
275#else
276 class failure : public exception
277 {
278 public:
279 // _GLIBCXX_RESOLVE_LIB_DEFECTS
280 // 48. Use of non-existent exception constructor
281 explicit
282 failure(const string& __str) throw();
283
284 // This declaration is not useless:
285 // http://gcc.gnu.org/onlinedocs/gcc-4.3.2/gcc/Vague-Linkage.html
286 virtual
287 ~failure() throw();
288
289 virtual const char*
290 what() const throw();
291
292 private:
293 string _M_msg;
294 };
295#endif
296
297 // 27.4.2.1.2 Type ios_base::fmtflags
298 /**
299 * @brief This is a bitmask type.
300 *
301 * @c @a _Ios_Fmtflags is implementation-defined, but it is valid to
302 * perform bitwise operations on these values and expect the Right
303 * Thing to happen. Defined objects of type fmtflags are:
304 * - boolalpha
305 * - dec
306 * - fixed
307 * - hex
308 * - internal
309 * - left
310 * - oct
311 * - right
312 * - scientific
313 * - showbase
314 * - showpoint
315 * - showpos
316 * - skipws
317 * - unitbuf
318 * - uppercase
319 * - adjustfield
320 * - basefield
321 * - floatfield
322 */
323 typedef _Ios_Fmtflags fmtflags;
324
325 /// Insert/extract @c bool in alphabetic rather than numeric format.
326 static const fmtflags boolalpha = _S_boolalpha;
327
328 /// Converts integer input or generates integer output in decimal base.
329 static const fmtflags dec = _S_dec;
330
331 /// Generate floating-point output in fixed-point notation.
332 static const fmtflags fixed = _S_fixed;
333
334 /// Converts integer input or generates integer output in hexadecimal base.
335 static const fmtflags hex = _S_hex;
336
337 /// Adds fill characters at a designated internal point in certain
338 /// generated output, or identical to @c right if no such point is
339 /// designated.
340 static const fmtflags internal = _S_internal;
341
342 /// Adds fill characters on the right (final positions) of certain
343 /// generated output. (I.e., the thing you print is flush left.)
344 static const fmtflags left = _S_left;
345
346 /// Converts integer input or generates integer output in octal base.
347 static const fmtflags oct = _S_oct;
348
349 /// Adds fill characters on the left (initial positions) of certain
350 /// generated output. (I.e., the thing you print is flush right.)
351 static const fmtflags right = _S_right;
352
353 /// Generates floating-point output in scientific notation.
354 static const fmtflags scientific = _S_scientific;
355
356 /// Generates a prefix indicating the numeric base of generated integer
357 /// output.
358 static const fmtflags showbase = _S_showbase;
359
360 /// Generates a decimal-point character unconditionally in generated
361 /// floating-point output.
362 static const fmtflags showpoint = _S_showpoint;
363
364 /// Generates a + sign in non-negative generated numeric output.
365 static const fmtflags showpos = _S_showpos;
366
367 /// Skips leading white space before certain input operations.
368 static const fmtflags skipws = _S_skipws;
369
370 /// Flushes output after each output operation.
371 static const fmtflags unitbuf = _S_unitbuf;
372
373 /// Replaces certain lowercase letters with their uppercase equivalents
374 /// in generated output.
375 static const fmtflags uppercase = _S_uppercase;
376
377 /// A mask of left|right|internal. Useful for the 2-arg form of @c setf.
378 static const fmtflags adjustfield = _S_adjustfield;
379
380 /// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf.
381 static const fmtflags basefield = _S_basefield;
382
383 /// A mask of scientific|fixed. Useful for the 2-arg form of @c setf.
384 static const fmtflags floatfield = _S_floatfield;
385
386 // 27.4.2.1.3 Type ios_base::iostate
387 /**
388 * @brief This is a bitmask type.
389 *
390 * @c @a _Ios_Iostate is implementation-defined, but it is valid to
391 * perform bitwise operations on these values and expect the Right
392 * Thing to happen. Defined objects of type iostate are:
393 * - badbit
394 * - eofbit
395 * - failbit
396 * - goodbit
397 */
398 typedef _Ios_Iostate iostate;
399
400 /// Indicates a loss of integrity in an input or output sequence (such
401 /// as an irrecoverable read error from a file).
402 static const iostate badbit = _S_badbit;
403
404 /// Indicates that an input operation reached the end of an input sequence.
405 static const iostate eofbit = _S_eofbit;
406
407 /// Indicates that an input operation failed to read the expected
408 /// characters, or that an output operation failed to generate the
409 /// desired characters.
410 static const iostate failbit = _S_failbit;
411
412 /// Indicates all is well.
413 static const iostate goodbit = _S_goodbit;
414
415 // 27.4.2.1.4 Type ios_base::openmode
416 /**
417 * @brief This is a bitmask type.
418 *
419 * @c @a _Ios_Openmode is implementation-defined, but it is valid to
420 * perform bitwise operations on these values and expect the Right
421 * Thing to happen. Defined objects of type openmode are:
422 * - app
423 * - ate
424 * - binary
425 * - in
426 * - out
427 * - trunc
428 */
429 typedef _Ios_Openmode openmode;
430
431 /// Seek to end before each write.
432 static const openmode app = _S_app;
433
434 /// Open and seek to end immediately after opening.
435 static const openmode ate = _S_ate;
436
437 /// Perform input and output in binary mode (as opposed to text mode).
438 /// This is probably not what you think it is; see
439 /// https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
440 static const openmode binary = _S_bin;
441
442 /// Open for input. Default for @c ifstream and fstream.
443 static const openmode in = _S_in;
444
445 /// Open for output. Default for @c ofstream and fstream.
446 static const openmode out = _S_out;
447
448 /// Open for input. Default for @c ofstream.
449 static const openmode trunc = _S_trunc;
450
451 // 27.4.2.1.5 Type ios_base::seekdir
452 /**
453 * @brief This is an enumerated type.
454 *
455 * @c @a _Ios_Seekdir is implementation-defined. Defined values
456 * of type seekdir are:
457 * - beg
458 * - cur, equivalent to @c SEEK_CUR in the C standard library.
459 * - end, equivalent to @c SEEK_END in the C standard library.
460 */
461 typedef _Ios_Seekdir seekdir;
462
463 /// Request a seek relative to the beginning of the stream.
464 static const seekdir beg = _S_beg;
465
466 /// Request a seek relative to the current position within the sequence.
467 static const seekdir cur = _S_cur;
468
469 /// Request a seek relative to the current end of the sequence.
470 static const seekdir end = _S_end;
471
472#if __cplusplus <= 201402L
473 // Annex D.6 (removed in C++17)
474 typedef int io_state;
475 typedef int open_mode;
476 typedef int seek_dir;
477
478 typedef std::streampos streampos;
479 typedef std::streamoff streamoff;
480#endif
481
482 // Callbacks;
483 /**
484 * @brief The set of events that may be passed to an event callback.
485 *
486 * erase_event is used during ~ios() and copyfmt(). imbue_event is used
487 * during imbue(). copyfmt_event is used during copyfmt().
488 */
489 enum event
490 {
491 erase_event,
492 imbue_event,
493 copyfmt_event
494 };
495
496 /**
497 * @brief The type of an event callback function.
498 * @param __e One of the members of the event enum.
499 * @param __b Reference to the ios_base object.
500 * @param __i The integer provided when the callback was registered.
501 *
502 * Event callbacks are user defined functions that get called during
503 * several ios_base and basic_ios functions, specifically imbue(),
504 * copyfmt(), and ~ios().
505 */
506 typedef void (*event_callback) (event __e, ios_base& __b, int __i);
507
508 /**
509 * @brief Add the callback __fn with parameter __index.
510 * @param __fn The function to add.
511 * @param __index The integer to pass to the function when invoked.
512 *
513 * Registers a function as an event callback with an integer parameter to
514 * be passed to the function when invoked. Multiple copies of the
515 * function are allowed. If there are multiple callbacks, they are
516 * invoked in the order they were registered.
517 */
518 void
519 register_callback(event_callback __fn, int __index);
520
521 protected:
522 streamsize _M_precision;
523 streamsize _M_width;
524 fmtflags _M_flags;
525 iostate _M_exception;
526 iostate _M_streambuf_state;
527
528 // 27.4.2.6 Members for callbacks
529 // 27.4.2.6 ios_base callbacks
530 struct _Callback_list
531 {
532 // Data Members
533 _Callback_list* _M_next;
534 ios_base::event_callback _M_fn;
535 int _M_index;
536 _Atomic_word _M_refcount; // 0 means one reference.
537
538 _Callback_list(ios_base::event_callback __fn, int __index,
539 _Callback_list* __cb)
540 : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
541
542 void
543 _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
544
545 // 0 => OK to delete.
546 int
547 _M_remove_reference()
548 {
549 // Be race-detector-friendly. For more info see bits/c++config.
550 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
551 int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
552 if (__res == 0)
553 {
554 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
555 }
556 return __res;
557 }
558 };
559
560 _Callback_list* _M_callbacks;
561
562 void
563 _M_call_callbacks(event __ev) throw();
564
565 void
566 _M_dispose_callbacks(void) throw();
567
568 // 27.4.2.5 Members for iword/pword storage
569 struct _Words
570 {
571 void* _M_pword;
572 long _M_iword;
573 _Words() : _M_pword(0), _M_iword(0) { }
574 };
575
576 // Only for failed iword/pword calls.
577 _Words _M_word_zero;
578
579 // Guaranteed storage.
580 // The first 5 iword and pword slots are reserved for internal use.
581 enum { _S_local_word_size = 8 };
582 _Words _M_local_word[_S_local_word_size];
583
584 // Allocated storage.
585 int _M_word_size;
586 _Words* _M_word;
587
588 _Words&
589 _M_grow_words(int __index, bool __iword);
590
591 // Members for locale and locale caching.
592 locale _M_ios_locale;
593
594 void
595 _M_init() throw();
596
597 public:
598
599 // 27.4.2.1.6 Class ios_base::Init
600 // Used to initialize standard streams. In theory, g++ could use
601 // -finit-priority to order this stuff correctly without going
602 // through these machinations.
603 class Init
604 {
605 friend class ios_base;
606 public:
607 Init();
608 ~Init();
609
610 private:
611 static _Atomic_word _S_refcount;
612 static bool _S_synced_with_stdio;
613 };
614
615 // [27.4.2.2] fmtflags state functions
616 /**
617 * @brief Access to format flags.
618 * @return The format control flags for both input and output.
619 */
620 fmtflags
621 flags() const
622 { return _M_flags; }
623
624 /**
625 * @brief Setting new format flags all at once.
626 * @param __fmtfl The new flags to set.
627 * @return The previous format control flags.
628 *
629 * This function overwrites all the format flags with @a __fmtfl.
630 */
631 fmtflags
632 flags(fmtflags __fmtfl)
633 {
634 fmtflags __old = _M_flags;
635 _M_flags = __fmtfl;
636 return __old;
637 }
638
639 /**
640 * @brief Setting new format flags.
641 * @param __fmtfl Additional flags to set.
642 * @return The previous format control flags.
643 *
644 * This function sets additional flags in format control. Flags that
645 * were previously set remain set.
646 */
647 fmtflags
648 setf(fmtflags __fmtfl)
649 {
650 fmtflags __old = _M_flags;
651 _M_flags |= __fmtfl;
652 return __old;
653 }
654
655 /**
656 * @brief Setting new format flags.
657 * @param __fmtfl Additional flags to set.
658 * @param __mask The flags mask for @a fmtfl.
659 * @return The previous format control flags.
660 *
661 * This function clears @a mask in the format flags, then sets
662 * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
663 */
664 fmtflags
665 setf(fmtflags __fmtfl, fmtflags __mask)
666 {
667 fmtflags __old = _M_flags;
668 _M_flags &= ~__mask;
669 _M_flags |= (__fmtfl & __mask);
670 return __old;
671 }
672
673 /**
674 * @brief Clearing format flags.
675 * @param __mask The flags to unset.
676 *
677 * This function clears @a __mask in the format flags.
678 */
679 void
680 unsetf(fmtflags __mask)
681 { _M_flags &= ~__mask; }
682
683 /**
684 * @brief Flags access.
685 * @return The precision to generate on certain output operations.
686 *
687 * Be careful if you try to give a definition of @a precision here; see
688 * DR 189.
689 */
690 streamsize
691 precision() const
692 { return _M_precision; }
693
694 /**
695 * @brief Changing flags.
696 * @param __prec The new precision value.
697 * @return The previous value of precision().
698 */
699 streamsize
700 precision(streamsize __prec)
701 {
702 streamsize __old = _M_precision;
703 _M_precision = __prec;
704 return __old;
705 }
706
707 /**
708 * @brief Flags access.
709 * @return The minimum field width to generate on output operations.
710 *
711 * <em>Minimum field width</em> refers to the number of characters.
712 */
713 streamsize
714 width() const
715 { return _M_width; }
716
717 /**
718 * @brief Changing flags.
719 * @param __wide The new width value.
720 * @return The previous value of width().
721 */
722 streamsize
723 width(streamsize __wide)
724 {
725 streamsize __old = _M_width;
726 _M_width = __wide;
727 return __old;
728 }
729
730 // [27.4.2.4] ios_base static members
731 /**
732 * @brief Interaction with the standard C I/O objects.
733 * @param __sync Whether to synchronize or not.
734 * @return True if the standard streams were previously synchronized.
735 *
736 * The synchronization referred to is @e only that between the standard
737 * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
738 * cout). User-declared streams are unaffected. See
739 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
740 */
741 static bool
742 sync_with_stdio(bool __sync = true);
743
744 // [27.4.2.3] ios_base locale functions
745 /**
746 * @brief Setting a new locale.
747 * @param __loc The new locale.
748 * @return The previous locale.
749 *
750 * Sets the new locale for this stream, and then invokes each callback
751 * with imbue_event.
752 */
753 locale
754 imbue(const locale& __loc) throw();
755
756 /**
757 * @brief Locale access
758 * @return A copy of the current locale.
759 *
760 * If @c imbue(loc) has previously been called, then this function
761 * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
762 * the global C++ locale.
763 */
764 locale
765 getloc() const
766 { return _M_ios_locale; }
767
768 /**
769 * @brief Locale access
770 * @return A reference to the current locale.
771 *
772 * Like getloc above, but returns a reference instead of
773 * generating a copy.
774 */
775 const locale&
776 _M_getloc() const
777 { return _M_ios_locale; }
778
779 // [27.4.2.5] ios_base storage functions
780 /**
781 * @brief Access to unique indices.
782 * @return An integer different from all previous calls.
783 *
784 * This function returns a unique integer every time it is called. It
785 * can be used for any purpose, but is primarily intended to be a unique
786 * index for the iword and pword functions. The expectation is that an
787 * application calls xalloc in order to obtain an index in the iword and
788 * pword arrays that can be used without fear of conflict.
789 *
790 * The implementation maintains a static variable that is incremented and
791 * returned on each invocation. xalloc is guaranteed to return an index
792 * that is safe to use in the iword and pword arrays.
793 */
794 static int
795 xalloc() throw();
796
797 /**
798 * @brief Access to integer array.
799 * @param __ix Index into the array.
800 * @return A reference to an integer associated with the index.
801 *
802 * The iword function provides access to an array of integers that can be
803 * used for any purpose. The array grows as required to hold the
804 * supplied index. All integers in the array are initialized to 0.
805 *
806 * The implementation reserves several indices. You should use xalloc to
807 * obtain an index that is safe to use. Also note that since the array
808 * can grow dynamically, it is not safe to hold onto the reference.
809 */
810 long&
811 iword(int __ix)
812 {
813 _Words& __word = (__ix < _M_word_size)
814 ? _M_word[__ix] : _M_grow_words(__ix, true);
815 return __word._M_iword;
816 }
817
818 /**
819 * @brief Access to void pointer array.
820 * @param __ix Index into the array.
821 * @return A reference to a void* associated with the index.
822 *
823 * The pword function provides access to an array of pointers that can be
824 * used for any purpose. The array grows as required to hold the
825 * supplied index. All pointers in the array are initialized to 0.
826 *
827 * The implementation reserves several indices. You should use xalloc to
828 * obtain an index that is safe to use. Also note that since the array
829 * can grow dynamically, it is not safe to hold onto the reference.
830 */
831 void*&
832 pword(int __ix)
833 {
834 _Words& __word = (__ix < _M_word_size)
835 ? _M_word[__ix] : _M_grow_words(__ix, false);
836 return __word._M_pword;
837 }
838
839 // Destructor
840 /**
841 * Invokes each callback with erase_event. Destroys local storage.
842 *
843 * Note that the ios_base object for the standard streams never gets
844 * destroyed. As a result, any callbacks registered with the standard
845 * streams will not get invoked with erase_event (unless copyfmt is
846 * used).
847 */
848 virtual ~ios_base();
849
850 protected:
851 ios_base() throw ();
852
853#if __cplusplus < 201103L
854 // _GLIBCXX_RESOLVE_LIB_DEFECTS
855 // 50. Copy constructor and assignment operator of ios_base
856 private:
857 ios_base(const ios_base&);
858
859 ios_base&
860 operator=(const ios_base&);
861#else
862 public:
863 ios_base(const ios_base&) = delete;
864
865 ios_base&
866 operator=(const ios_base&) = delete;
867
868 protected:
869 void
870 _M_move(ios_base&) noexcept;
871
872 void
873 _M_swap(ios_base& __rhs) noexcept;
874#endif
875 };
876
877 // [27.4.5.1] fmtflags manipulators
878 /// Calls base.setf(ios_base::boolalpha).
879 inline ios_base&
880 boolalpha(ios_base& __base)
881 {
882 __base.setf(ios_base::boolalpha);
883 return __base;
884 }
885
886 /// Calls base.unsetf(ios_base::boolalpha).
887 inline ios_base&
888 noboolalpha(ios_base& __base)
889 {
890 __base.unsetf(ios_base::boolalpha);
891 return __base;
892 }
893
894 /// Calls base.setf(ios_base::showbase).
895 inline ios_base&
896 showbase(ios_base& __base)
897 {
898 __base.setf(ios_base::showbase);
899 return __base;
900 }
901
902 /// Calls base.unsetf(ios_base::showbase).
903 inline ios_base&
904 noshowbase(ios_base& __base)
905 {
906 __base.unsetf(ios_base::showbase);
907 return __base;
908 }
909
910 /// Calls base.setf(ios_base::showpoint).
911 inline ios_base&
912 showpoint(ios_base& __base)
913 {
914 __base.setf(ios_base::showpoint);
915 return __base;
916 }
917
918 /// Calls base.unsetf(ios_base::showpoint).
919 inline ios_base&
920 noshowpoint(ios_base& __base)
921 {
922 __base.unsetf(ios_base::showpoint);
923 return __base;
924 }
925
926 /// Calls base.setf(ios_base::showpos).
927 inline ios_base&
928 showpos(ios_base& __base)
929 {
930 __base.setf(ios_base::showpos);
931 return __base;
932 }
933
934 /// Calls base.unsetf(ios_base::showpos).
935 inline ios_base&
936 noshowpos(ios_base& __base)
937 {
938 __base.unsetf(ios_base::showpos);
939 return __base;
940 }
941
942 /// Calls base.setf(ios_base::skipws).
943 inline ios_base&
944 skipws(ios_base& __base)
945 {
946 __base.setf(ios_base::skipws);
947 return __base;
948 }
949
950 /// Calls base.unsetf(ios_base::skipws).
951 inline ios_base&
952 noskipws(ios_base& __base)
953 {
954 __base.unsetf(ios_base::skipws);
955 return __base;
956 }
957
958 /// Calls base.setf(ios_base::uppercase).
959 inline ios_base&
960 uppercase(ios_base& __base)
961 {
962 __base.setf(ios_base::uppercase);
963 return __base;
964 }
965
966 /// Calls base.unsetf(ios_base::uppercase).
967 inline ios_base&
968 nouppercase(ios_base& __base)
969 {
970 __base.unsetf(ios_base::uppercase);
971 return __base;
972 }
973
974 /// Calls base.setf(ios_base::unitbuf).
975 inline ios_base&
976 unitbuf(ios_base& __base)
977 {
978 __base.setf(ios_base::unitbuf);
979 return __base;
980 }
981
982 /// Calls base.unsetf(ios_base::unitbuf).
983 inline ios_base&
984 nounitbuf(ios_base& __base)
985 {
986 __base.unsetf(ios_base::unitbuf);
987 return __base;
988 }
989
990 // [27.4.5.2] adjustfield manipulators
991 /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
992 inline ios_base&
993 internal(ios_base& __base)
994 {
995 __base.setf(ios_base::internal, ios_base::adjustfield);
996 return __base;
997 }
998
999 /// Calls base.setf(ios_base::left, ios_base::adjustfield).
1000 inline ios_base&
1001 left(ios_base& __base)
1002 {
1003 __base.setf(ios_base::left, ios_base::adjustfield);
1004 return __base;
1005 }
1006
1007 /// Calls base.setf(ios_base::right, ios_base::adjustfield).
1008 inline ios_base&
1009 right(ios_base& __base)
1010 {
1011 __base.setf(ios_base::right, ios_base::adjustfield);
1012 return __base;
1013 }
1014
1015 // [27.4.5.3] basefield manipulators
1016 /// Calls base.setf(ios_base::dec, ios_base::basefield).
1017 inline ios_base&
1018 dec(ios_base& __base)
1019 {
1020 __base.setf(ios_base::dec, ios_base::basefield);
1021 return __base;
1022 }
1023
1024 /// Calls base.setf(ios_base::hex, ios_base::basefield).
1025 inline ios_base&
1026 hex(ios_base& __base)
1027 {
1028 __base.setf(ios_base::hex, ios_base::basefield);
1029 return __base;
1030 }
1031
1032 /// Calls base.setf(ios_base::oct, ios_base::basefield).
1033 inline ios_base&
1034 oct(ios_base& __base)
1035 {
1036 __base.setf(ios_base::oct, ios_base::basefield);
1037 return __base;
1038 }
1039
1040 // [27.4.5.4] floatfield manipulators
1041 /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
1042 inline ios_base&
1043 fixed(ios_base& __base)
1044 {
1045 __base.setf(ios_base::fixed, ios_base::floatfield);
1046 return __base;
1047 }
1048
1049 /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
1050 inline ios_base&
1051 scientific(ios_base& __base)
1052 {
1053 __base.setf(ios_base::scientific, ios_base::floatfield);
1054 return __base;
1055 }
1056
1057#if __cplusplus >= 201103L
1058 // New C++11 floatfield manipulators
1059
1060 /// Calls
1061 /// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
1062 inline ios_base&
1063 hexfloat(ios_base& __base)
1064 {
1065 __base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
1066 return __base;
1067 }
1068
1069 /// Calls @c base.unsetf(ios_base::floatfield)
1070 inline ios_base&
1071 defaultfloat(ios_base& __base)
1072 {
1073 __base.unsetf(ios_base::floatfield);
1074 return __base;
1075 }
1076#endif
1077
1078_GLIBCXX_END_NAMESPACE_VERSION
1079} // namespace
1080
1081#endif /* _IOS_BASE_H */
1082