1// Iostreams base classes -*- C++ -*-
2
3// Copyright (C) 1997-2019 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#if __cplusplus >= 201103L
611 Init(const Init&) = default;
612 Init& operator=(const Init&) = default;
613#endif
614
615 private:
616 static _Atomic_word _S_refcount;
617 static bool _S_synced_with_stdio;
618 };
619
620 // [27.4.2.2] fmtflags state functions
621 /**
622 * @brief Access to format flags.
623 * @return The format control flags for both input and output.
624 */
625 fmtflags
626 flags() const
627 { return _M_flags; }
628
629 /**
630 * @brief Setting new format flags all at once.
631 * @param __fmtfl The new flags to set.
632 * @return The previous format control flags.
633 *
634 * This function overwrites all the format flags with @a __fmtfl.
635 */
636 fmtflags
637 flags(fmtflags __fmtfl)
638 {
639 fmtflags __old = _M_flags;
640 _M_flags = __fmtfl;
641 return __old;
642 }
643
644 /**
645 * @brief Setting new format flags.
646 * @param __fmtfl Additional flags to set.
647 * @return The previous format control flags.
648 *
649 * This function sets additional flags in format control. Flags that
650 * were previously set remain set.
651 */
652 fmtflags
653 setf(fmtflags __fmtfl)
654 {
655 fmtflags __old = _M_flags;
656 _M_flags |= __fmtfl;
657 return __old;
658 }
659
660 /**
661 * @brief Setting new format flags.
662 * @param __fmtfl Additional flags to set.
663 * @param __mask The flags mask for @a fmtfl.
664 * @return The previous format control flags.
665 *
666 * This function clears @a mask in the format flags, then sets
667 * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
668 */
669 fmtflags
670 setf(fmtflags __fmtfl, fmtflags __mask)
671 {
672 fmtflags __old = _M_flags;
673 _M_flags &= ~__mask;
674 _M_flags |= (__fmtfl & __mask);
675 return __old;
676 }
677
678 /**
679 * @brief Clearing format flags.
680 * @param __mask The flags to unset.
681 *
682 * This function clears @a __mask in the format flags.
683 */
684 void
685 unsetf(fmtflags __mask)
686 { _M_flags &= ~__mask; }
687
688 /**
689 * @brief Flags access.
690 * @return The precision to generate on certain output operations.
691 *
692 * Be careful if you try to give a definition of @a precision here; see
693 * DR 189.
694 */
695 streamsize
696 precision() const
697 { return _M_precision; }
698
699 /**
700 * @brief Changing flags.
701 * @param __prec The new precision value.
702 * @return The previous value of precision().
703 */
704 streamsize
705 precision(streamsize __prec)
706 {
707 streamsize __old = _M_precision;
708 _M_precision = __prec;
709 return __old;
710 }
711
712 /**
713 * @brief Flags access.
714 * @return The minimum field width to generate on output operations.
715 *
716 * <em>Minimum field width</em> refers to the number of characters.
717 */
718 streamsize
719 width() const
720 { return _M_width; }
721
722 /**
723 * @brief Changing flags.
724 * @param __wide The new width value.
725 * @return The previous value of width().
726 */
727 streamsize
728 width(streamsize __wide)
729 {
730 streamsize __old = _M_width;
731 _M_width = __wide;
732 return __old;
733 }
734
735 // [27.4.2.4] ios_base static members
736 /**
737 * @brief Interaction with the standard C I/O objects.
738 * @param __sync Whether to synchronize or not.
739 * @return True if the standard streams were previously synchronized.
740 *
741 * The synchronization referred to is @e only that between the standard
742 * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
743 * cout). User-declared streams are unaffected. See
744 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
745 */
746 static bool
747 sync_with_stdio(bool __sync = true);
748
749 // [27.4.2.3] ios_base locale functions
750 /**
751 * @brief Setting a new locale.
752 * @param __loc The new locale.
753 * @return The previous locale.
754 *
755 * Sets the new locale for this stream, and then invokes each callback
756 * with imbue_event.
757 */
758 locale
759 imbue(const locale& __loc) throw();
760
761 /**
762 * @brief Locale access
763 * @return A copy of the current locale.
764 *
765 * If @c imbue(loc) has previously been called, then this function
766 * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
767 * the global C++ locale.
768 */
769 locale
770 getloc() const
771 { return _M_ios_locale; }
772
773 /**
774 * @brief Locale access
775 * @return A reference to the current locale.
776 *
777 * Like getloc above, but returns a reference instead of
778 * generating a copy.
779 */
780 const locale&
781 _M_getloc() const
782 { return _M_ios_locale; }
783
784 // [27.4.2.5] ios_base storage functions
785 /**
786 * @brief Access to unique indices.
787 * @return An integer different from all previous calls.
788 *
789 * This function returns a unique integer every time it is called. It
790 * can be used for any purpose, but is primarily intended to be a unique
791 * index for the iword and pword functions. The expectation is that an
792 * application calls xalloc in order to obtain an index in the iword and
793 * pword arrays that can be used without fear of conflict.
794 *
795 * The implementation maintains a static variable that is incremented and
796 * returned on each invocation. xalloc is guaranteed to return an index
797 * that is safe to use in the iword and pword arrays.
798 */
799 static int
800 xalloc() throw();
801
802 /**
803 * @brief Access to integer array.
804 * @param __ix Index into the array.
805 * @return A reference to an integer associated with the index.
806 *
807 * The iword function provides access to an array of integers that can be
808 * used for any purpose. The array grows as required to hold the
809 * supplied index. All integers in the array are initialized to 0.
810 *
811 * The implementation reserves several indices. You should use xalloc to
812 * obtain an index that is safe to use. Also note that since the array
813 * can grow dynamically, it is not safe to hold onto the reference.
814 */
815 long&
816 iword(int __ix)
817 {
818 _Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
819 ? _M_word[__ix] : _M_grow_words(__ix, true);
820 return __word._M_iword;
821 }
822
823 /**
824 * @brief Access to void pointer array.
825 * @param __ix Index into the array.
826 * @return A reference to a void* associated with the index.
827 *
828 * The pword function provides access to an array of pointers that can be
829 * used for any purpose. The array grows as required to hold the
830 * supplied index. All pointers in the array are initialized to 0.
831 *
832 * The implementation reserves several indices. You should use xalloc to
833 * obtain an index that is safe to use. Also note that since the array
834 * can grow dynamically, it is not safe to hold onto the reference.
835 */
836 void*&
837 pword(int __ix)
838 {
839 _Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
840 ? _M_word[__ix] : _M_grow_words(__ix, false);
841 return __word._M_pword;
842 }
843
844 // Destructor
845 /**
846 * Invokes each callback with erase_event. Destroys local storage.
847 *
848 * Note that the ios_base object for the standard streams never gets
849 * destroyed. As a result, any callbacks registered with the standard
850 * streams will not get invoked with erase_event (unless copyfmt is
851 * used).
852 */
853 virtual ~ios_base();
854
855 protected:
856 ios_base() throw ();
857
858#if __cplusplus < 201103L
859 // _GLIBCXX_RESOLVE_LIB_DEFECTS
860 // 50. Copy constructor and assignment operator of ios_base
861 private:
862 ios_base(const ios_base&);
863
864 ios_base&
865 operator=(const ios_base&);
866#else
867 public:
868 ios_base(const ios_base&) = delete;
869
870 ios_base&
871 operator=(const ios_base&) = delete;
872
873 protected:
874 void
875 _M_move(ios_base&) noexcept;
876
877 void
878 _M_swap(ios_base& __rhs) noexcept;
879#endif
880 };
881
882 // [27.4.5.1] fmtflags manipulators
883 /// Calls base.setf(ios_base::boolalpha).
884 inline ios_base&
885 boolalpha(ios_base& __base)
886 {
887 __base.setf(ios_base::boolalpha);
888 return __base;
889 }
890
891 /// Calls base.unsetf(ios_base::boolalpha).
892 inline ios_base&
893 noboolalpha(ios_base& __base)
894 {
895 __base.unsetf(ios_base::boolalpha);
896 return __base;
897 }
898
899 /// Calls base.setf(ios_base::showbase).
900 inline ios_base&
901 showbase(ios_base& __base)
902 {
903 __base.setf(ios_base::showbase);
904 return __base;
905 }
906
907 /// Calls base.unsetf(ios_base::showbase).
908 inline ios_base&
909 noshowbase(ios_base& __base)
910 {
911 __base.unsetf(ios_base::showbase);
912 return __base;
913 }
914
915 /// Calls base.setf(ios_base::showpoint).
916 inline ios_base&
917 showpoint(ios_base& __base)
918 {
919 __base.setf(ios_base::showpoint);
920 return __base;
921 }
922
923 /// Calls base.unsetf(ios_base::showpoint).
924 inline ios_base&
925 noshowpoint(ios_base& __base)
926 {
927 __base.unsetf(ios_base::showpoint);
928 return __base;
929 }
930
931 /// Calls base.setf(ios_base::showpos).
932 inline ios_base&
933 showpos(ios_base& __base)
934 {
935 __base.setf(ios_base::showpos);
936 return __base;
937 }
938
939 /// Calls base.unsetf(ios_base::showpos).
940 inline ios_base&
941 noshowpos(ios_base& __base)
942 {
943 __base.unsetf(ios_base::showpos);
944 return __base;
945 }
946
947 /// Calls base.setf(ios_base::skipws).
948 inline ios_base&
949 skipws(ios_base& __base)
950 {
951 __base.setf(ios_base::skipws);
952 return __base;
953 }
954
955 /// Calls base.unsetf(ios_base::skipws).
956 inline ios_base&
957 noskipws(ios_base& __base)
958 {
959 __base.unsetf(ios_base::skipws);
960 return __base;
961 }
962
963 /// Calls base.setf(ios_base::uppercase).
964 inline ios_base&
965 uppercase(ios_base& __base)
966 {
967 __base.setf(ios_base::uppercase);
968 return __base;
969 }
970
971 /// Calls base.unsetf(ios_base::uppercase).
972 inline ios_base&
973 nouppercase(ios_base& __base)
974 {
975 __base.unsetf(ios_base::uppercase);
976 return __base;
977 }
978
979 /// Calls base.setf(ios_base::unitbuf).
980 inline ios_base&
981 unitbuf(ios_base& __base)
982 {
983 __base.setf(ios_base::unitbuf);
984 return __base;
985 }
986
987 /// Calls base.unsetf(ios_base::unitbuf).
988 inline ios_base&
989 nounitbuf(ios_base& __base)
990 {
991 __base.unsetf(ios_base::unitbuf);
992 return __base;
993 }
994
995 // [27.4.5.2] adjustfield manipulators
996 /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
997 inline ios_base&
998 internal(ios_base& __base)
999 {
1000 __base.setf(ios_base::internal, ios_base::adjustfield);
1001 return __base;
1002 }
1003
1004 /// Calls base.setf(ios_base::left, ios_base::adjustfield).
1005 inline ios_base&
1006 left(ios_base& __base)
1007 {
1008 __base.setf(ios_base::left, ios_base::adjustfield);
1009 return __base;
1010 }
1011
1012 /// Calls base.setf(ios_base::right, ios_base::adjustfield).
1013 inline ios_base&
1014 right(ios_base& __base)
1015 {
1016 __base.setf(ios_base::right, ios_base::adjustfield);
1017 return __base;
1018 }
1019
1020 // [27.4.5.3] basefield manipulators
1021 /// Calls base.setf(ios_base::dec, ios_base::basefield).
1022 inline ios_base&
1023 dec(ios_base& __base)
1024 {
1025 __base.setf(ios_base::dec, ios_base::basefield);
1026 return __base;
1027 }
1028
1029 /// Calls base.setf(ios_base::hex, ios_base::basefield).
1030 inline ios_base&
1031 hex(ios_base& __base)
1032 {
1033 __base.setf(ios_base::hex, ios_base::basefield);
1034 return __base;
1035 }
1036
1037 /// Calls base.setf(ios_base::oct, ios_base::basefield).
1038 inline ios_base&
1039 oct(ios_base& __base)
1040 {
1041 __base.setf(ios_base::oct, ios_base::basefield);
1042 return __base;
1043 }
1044
1045 // [27.4.5.4] floatfield manipulators
1046 /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
1047 inline ios_base&
1048 fixed(ios_base& __base)
1049 {
1050 __base.setf(ios_base::fixed, ios_base::floatfield);
1051 return __base;
1052 }
1053
1054 /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
1055 inline ios_base&
1056 scientific(ios_base& __base)
1057 {
1058 __base.setf(ios_base::scientific, ios_base::floatfield);
1059 return __base;
1060 }
1061
1062#if __cplusplus >= 201103L
1063 // New C++11 floatfield manipulators
1064
1065 /// Calls
1066 /// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
1067 inline ios_base&
1068 hexfloat(ios_base& __base)
1069 {
1070 __base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
1071 return __base;
1072 }
1073
1074 /// Calls @c base.unsetf(ios_base::floatfield)
1075 inline ios_base&
1076 defaultfloat(ios_base& __base)
1077 {
1078 __base.unsetf(ios_base::floatfield);
1079 return __base;
1080 }
1081#endif
1082
1083_GLIBCXX_END_NAMESPACE_VERSION
1084} // namespace
1085
1086#endif /* _IOS_BASE_H */
1087