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
_GLIBCXX_VISIBILITY(default)49 namespace 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 /// Truncate an existing stream when opening. 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 _GLIBCXX_DEPRECATED_SUGGEST("std::iostate");
476 typedef int open_mode
477 _GLIBCXX_DEPRECATED_SUGGEST("std::openmode");
478 typedef int seek_dir
479 _GLIBCXX_DEPRECATED_SUGGEST("std::seekdir");
480
481 typedef std::streampos streampos
482 _GLIBCXX_DEPRECATED_SUGGEST("std::streampos");
483 typedef std::streamoff streamoff
484 _GLIBCXX_DEPRECATED_SUGGEST("std::streamoff");
485 #endif
486
487 // Callbacks;
488 /**
489 * @brief The set of events that may be passed to an event callback.
490 *
491 * erase_event is used during ~ios() and copyfmt(). imbue_event is used
492 * during imbue(). copyfmt_event is used during copyfmt().
493 */
494 enum event
495 {
496 erase_event,
497 imbue_event,
498 copyfmt_event
499 };
500
501 /**
502 * @brief The type of an event callback function.
503 * @param __e One of the members of the event enum.
504 * @param __b Reference to the ios_base object.
505 * @param __i The integer provided when the callback was registered.
506 *
507 * Event callbacks are user defined functions that get called during
508 * several ios_base and basic_ios functions, specifically imbue(),
509 * copyfmt(), and ~ios().
510 */
511 typedef void (*event_callback) (event __e, ios_base& __b, int __i);
512
513 /**
514 * @brief Add the callback __fn with parameter __index.
515 * @param __fn The function to add.
516 * @param __index The integer to pass to the function when invoked.
517 *
518 * Registers a function as an event callback with an integer parameter to
519 * be passed to the function when invoked. Multiple copies of the
520 * function are allowed. If there are multiple callbacks, they are
521 * invoked in the order they were registered.
522 */
523 void
524 register_callback(event_callback __fn, int __index);
525
526 protected:
527 streamsize _M_precision;
528 streamsize _M_width;
529 fmtflags _M_flags;
530 iostate _M_exception;
531 iostate _M_streambuf_state;
532
533 // 27.4.2.6 Members for callbacks
534 // 27.4.2.6 ios_base callbacks
535 struct _Callback_list
536 {
537 // Data Members
538 _Callback_list* _M_next;
539 ios_base::event_callback _M_fn;
540 int _M_index;
541 _Atomic_word _M_refcount; // 0 means one reference.
542
543 _Callback_list(ios_base::event_callback __fn, int __index,
544 _Callback_list* __cb)
545 : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
546
547 void
548 _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
549
550 // 0 => OK to delete.
551 int
552 _M_remove_reference()
553 {
554 // Be race-detector-friendly. For more info see bits/c++config.
555 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
556 int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
557 if (__res == 0)
558 {
559 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
560 }
561 return __res;
562 }
563 };
564
565 _Callback_list* _M_callbacks;
566
567 void
568 _M_call_callbacks(event __ev) throw();
569
570 void
571 _M_dispose_callbacks(void) throw();
572
573 // 27.4.2.5 Members for iword/pword storage
574 struct _Words
575 {
576 void* _M_pword;
577 long _M_iword;
578 _Words() : _M_pword(0), _M_iword(0) { }
579 };
580
581 // Only for failed iword/pword calls.
582 _Words _M_word_zero;
583
584 // Guaranteed storage.
585 // The first 5 iword and pword slots are reserved for internal use.
586 enum { _S_local_word_size = 8 };
587 _Words _M_local_word[_S_local_word_size];
588
589 // Allocated storage.
590 int _M_word_size;
591 _Words* _M_word;
592
593 _Words&
594 _M_grow_words(int __index, bool __iword);
595
596 // Members for locale and locale caching.
597 locale _M_ios_locale;
598
599 void
600 _M_init() throw();
601
602 public:
603
604 // 27.4.2.1.6 Class ios_base::Init
605 // Used to initialize standard streams. In theory, g++ could use
606 // -finit-priority to order this stuff correctly without going
607 // through these machinations.
608 class Init
609 {
610 friend class ios_base;
611 public:
612 Init();
613 ~Init();
614
615 #if __cplusplus >= 201103L
616 Init(const Init&) = default;
617 Init& operator=(const Init&) = default;
618 #endif
619
620 private:
621 static _Atomic_word _S_refcount;
622 static bool _S_synced_with_stdio;
623 };
624
625 // [27.4.2.2] fmtflags state functions
626 /**
627 * @brief Access to format flags.
628 * @return The format control flags for both input and output.
629 */
630 fmtflags
631 flags() const
632 { return _M_flags; }
633
634 /**
635 * @brief Setting new format flags all at once.
636 * @param __fmtfl The new flags to set.
637 * @return The previous format control flags.
638 *
639 * This function overwrites all the format flags with @a __fmtfl.
640 */
641 fmtflags
642 flags(fmtflags __fmtfl)
643 {
644 fmtflags __old = _M_flags;
645 _M_flags = __fmtfl;
646 return __old;
647 }
648
649 /**
650 * @brief Setting new format flags.
651 * @param __fmtfl Additional flags to set.
652 * @return The previous format control flags.
653 *
654 * This function sets additional flags in format control. Flags that
655 * were previously set remain set.
656 */
657 fmtflags
658 setf(fmtflags __fmtfl)
659 {
660 fmtflags __old = _M_flags;
661 _M_flags |= __fmtfl;
662 return __old;
663 }
664
665 /**
666 * @brief Setting new format flags.
667 * @param __fmtfl Additional flags to set.
668 * @param __mask The flags mask for @a fmtfl.
669 * @return The previous format control flags.
670 *
671 * This function clears @a mask in the format flags, then sets
672 * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
673 */
674 fmtflags
675 setf(fmtflags __fmtfl, fmtflags __mask)
676 {
677 fmtflags __old = _M_flags;
678 _M_flags &= ~__mask;
679 _M_flags |= (__fmtfl & __mask);
680 return __old;
681 }
682
683 /**
684 * @brief Clearing format flags.
685 * @param __mask The flags to unset.
686 *
687 * This function clears @a __mask in the format flags.
688 */
689 void
690 unsetf(fmtflags __mask)
691 { _M_flags &= ~__mask; }
692
693 /**
694 * @brief Flags access.
695 * @return The precision to generate on certain output operations.
696 *
697 * Be careful if you try to give a definition of @a precision here; see
698 * DR 189.
699 */
700 streamsize
701 precision() const
702 { return _M_precision; }
703
704 /**
705 * @brief Changing flags.
706 * @param __prec The new precision value.
707 * @return The previous value of precision().
708 */
709 streamsize
710 precision(streamsize __prec)
711 {
712 streamsize __old = _M_precision;
713 _M_precision = __prec;
714 return __old;
715 }
716
717 /**
718 * @brief Flags access.
719 * @return The minimum field width to generate on output operations.
720 *
721 * <em>Minimum field width</em> refers to the number of characters.
722 */
723 streamsize
724 width() const
725 { return _M_width; }
726
727 /**
728 * @brief Changing flags.
729 * @param __wide The new width value.
730 * @return The previous value of width().
731 */
732 streamsize
733 width(streamsize __wide)
734 {
735 streamsize __old = _M_width;
736 _M_width = __wide;
737 return __old;
738 }
739
740 // [27.4.2.4] ios_base static members
741 /**
742 * @brief Interaction with the standard C I/O objects.
743 * @param __sync Whether to synchronize or not.
744 * @return True if the standard streams were previously synchronized.
745 *
746 * The synchronization referred to is @e only that between the standard
747 * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
748 * cout). User-declared streams are unaffected. See
749 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
750 */
751 static bool
752 sync_with_stdio(bool __sync = true);
753
754 // [27.4.2.3] ios_base locale functions
755 /**
756 * @brief Setting a new locale.
757 * @param __loc The new locale.
758 * @return The previous locale.
759 *
760 * Sets the new locale for this stream, and then invokes each callback
761 * with imbue_event.
762 */
763 locale
764 imbue(const locale& __loc) throw();
765
766 /**
767 * @brief Locale access
768 * @return A copy of the current locale.
769 *
770 * If @c imbue(loc) has previously been called, then this function
771 * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
772 * the global C++ locale.
773 */
774 locale
775 getloc() const
776 { return _M_ios_locale; }
777
778 /**
779 * @brief Locale access
780 * @return A reference to the current locale.
781 *
782 * Like getloc above, but returns a reference instead of
783 * generating a copy.
784 */
785 const locale&
786 _M_getloc() const
787 { return _M_ios_locale; }
788
789 // [27.4.2.5] ios_base storage functions
790 /**
791 * @brief Access to unique indices.
792 * @return An integer different from all previous calls.
793 *
794 * This function returns a unique integer every time it is called. It
795 * can be used for any purpose, but is primarily intended to be a unique
796 * index for the iword and pword functions. The expectation is that an
797 * application calls xalloc in order to obtain an index in the iword and
798 * pword arrays that can be used without fear of conflict.
799 *
800 * The implementation maintains a static variable that is incremented and
801 * returned on each invocation. xalloc is guaranteed to return an index
802 * that is safe to use in the iword and pword arrays.
803 */
804 static int
805 xalloc() throw();
806
807 /**
808 * @brief Access to integer array.
809 * @param __ix Index into the array.
810 * @return A reference to an integer associated with the index.
811 *
812 * The iword function provides access to an array of integers that can be
813 * used for any purpose. The array grows as required to hold the
814 * supplied index. All integers in the array are initialized to 0.
815 *
816 * The implementation reserves several indices. You should use xalloc to
817 * obtain an index that is safe to use. Also note that since the array
818 * can grow dynamically, it is not safe to hold onto the reference.
819 */
820 long&
821 iword(int __ix)
822 {
823 _Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
824 ? _M_word[__ix] : _M_grow_words(__ix, true);
825 return __word._M_iword;
826 }
827
828 /**
829 * @brief Access to void pointer array.
830 * @param __ix Index into the array.
831 * @return A reference to a void* associated with the index.
832 *
833 * The pword function provides access to an array of pointers that can be
834 * used for any purpose. The array grows as required to hold the
835 * supplied index. All pointers in the array are initialized to 0.
836 *
837 * The implementation reserves several indices. You should use xalloc to
838 * obtain an index that is safe to use. Also note that since the array
839 * can grow dynamically, it is not safe to hold onto the reference.
840 */
841 void*&
842 pword(int __ix)
843 {
844 _Words& __word = ((unsigned)__ix < (unsigned)_M_word_size)
845 ? _M_word[__ix] : _M_grow_words(__ix, false);
846 return __word._M_pword;
847 }
848
849 // Destructor
850 /**
851 * Invokes each callback with erase_event. Destroys local storage.
852 *
853 * Note that the ios_base object for the standard streams never gets
854 * destroyed. As a result, any callbacks registered with the standard
855 * streams will not get invoked with erase_event (unless copyfmt is
856 * used).
857 */
858 virtual ~ios_base();
859
860 protected:
861 ios_base() throw ();
862
863 #if __cplusplus < 201103L
864 // _GLIBCXX_RESOLVE_LIB_DEFECTS
865 // 50. Copy constructor and assignment operator of ios_base
866 private:
867 ios_base(const ios_base&);
868
869 ios_base&
870 operator=(const ios_base&);
871 #else
872 public:
873 ios_base(const ios_base&) = delete;
874
875 ios_base&
876 operator=(const ios_base&) = delete;
877
878 protected:
879 void
880 _M_move(ios_base&) noexcept;
881
882 void
883 _M_swap(ios_base& __rhs) noexcept;
884 #endif
885 };
886
887 // [27.4.5.1] fmtflags manipulators
888 /// Calls base.setf(ios_base::boolalpha).
889 inline ios_base&
890 boolalpha(ios_base& __base)
891 {
892 __base.setf(ios_base::boolalpha);
893 return __base;
894 }
895
896 /// Calls base.unsetf(ios_base::boolalpha).
897 inline ios_base&
898 noboolalpha(ios_base& __base)
899 {
900 __base.unsetf(ios_base::boolalpha);
901 return __base;
902 }
903
904 /// Calls base.setf(ios_base::showbase).
905 inline ios_base&
906 showbase(ios_base& __base)
907 {
908 __base.setf(ios_base::showbase);
909 return __base;
910 }
911
912 /// Calls base.unsetf(ios_base::showbase).
913 inline ios_base&
914 noshowbase(ios_base& __base)
915 {
916 __base.unsetf(ios_base::showbase);
917 return __base;
918 }
919
920 /// Calls base.setf(ios_base::showpoint).
921 inline ios_base&
922 showpoint(ios_base& __base)
923 {
924 __base.setf(ios_base::showpoint);
925 return __base;
926 }
927
928 /// Calls base.unsetf(ios_base::showpoint).
929 inline ios_base&
930 noshowpoint(ios_base& __base)
931 {
932 __base.unsetf(ios_base::showpoint);
933 return __base;
934 }
935
936 /// Calls base.setf(ios_base::showpos).
937 inline ios_base&
938 showpos(ios_base& __base)
939 {
940 __base.setf(ios_base::showpos);
941 return __base;
942 }
943
944 /// Calls base.unsetf(ios_base::showpos).
945 inline ios_base&
946 noshowpos(ios_base& __base)
947 {
948 __base.unsetf(ios_base::showpos);
949 return __base;
950 }
951
952 /// Calls base.setf(ios_base::skipws).
953 inline ios_base&
954 skipws(ios_base& __base)
955 {
956 __base.setf(ios_base::skipws);
957 return __base;
958 }
959
960 /// Calls base.unsetf(ios_base::skipws).
961 inline ios_base&
962 noskipws(ios_base& __base)
963 {
964 __base.unsetf(ios_base::skipws);
965 return __base;
966 }
967
968 /// Calls base.setf(ios_base::uppercase).
969 inline ios_base&
970 uppercase(ios_base& __base)
971 {
972 __base.setf(ios_base::uppercase);
973 return __base;
974 }
975
976 /// Calls base.unsetf(ios_base::uppercase).
977 inline ios_base&
978 nouppercase(ios_base& __base)
979 {
980 __base.unsetf(ios_base::uppercase);
981 return __base;
982 }
983
984 /// Calls base.setf(ios_base::unitbuf).
985 inline ios_base&
986 unitbuf(ios_base& __base)
987 {
988 __base.setf(ios_base::unitbuf);
989 return __base;
990 }
991
992 /// Calls base.unsetf(ios_base::unitbuf).
993 inline ios_base&
994 nounitbuf(ios_base& __base)
995 {
996 __base.unsetf(ios_base::unitbuf);
997 return __base;
998 }
999
1000 // [27.4.5.2] adjustfield manipulators
1001 /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
1002 inline ios_base&
1003 internal(ios_base& __base)
1004 {
1005 __base.setf(ios_base::internal, ios_base::adjustfield);
1006 return __base;
1007 }
1008
1009 /// Calls base.setf(ios_base::left, ios_base::adjustfield).
1010 inline ios_base&
1011 left(ios_base& __base)
1012 {
1013 __base.setf(ios_base::left, ios_base::adjustfield);
1014 return __base;
1015 }
1016
1017 /// Calls base.setf(ios_base::right, ios_base::adjustfield).
1018 inline ios_base&
1019 right(ios_base& __base)
1020 {
1021 __base.setf(ios_base::right, ios_base::adjustfield);
1022 return __base;
1023 }
1024
1025 // [27.4.5.3] basefield manipulators
1026 /// Calls base.setf(ios_base::dec, ios_base::basefield).
1027 inline ios_base&
1028 dec(ios_base& __base)
1029 {
1030 __base.setf(ios_base::dec, ios_base::basefield);
1031 return __base;
1032 }
1033
1034 /// Calls base.setf(ios_base::hex, ios_base::basefield).
1035 inline ios_base&
1036 hex(ios_base& __base)
1037 {
1038 __base.setf(ios_base::hex, ios_base::basefield);
1039 return __base;
1040 }
1041
1042 /// Calls base.setf(ios_base::oct, ios_base::basefield).
1043 inline ios_base&
1044 oct(ios_base& __base)
1045 {
1046 __base.setf(ios_base::oct, ios_base::basefield);
1047 return __base;
1048 }
1049
1050 // [27.4.5.4] floatfield manipulators
1051 /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
1052 inline ios_base&
1053 fixed(ios_base& __base)
1054 {
1055 __base.setf(ios_base::fixed, ios_base::floatfield);
1056 return __base;
1057 }
1058
1059 /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
1060 inline ios_base&
1061 scientific(ios_base& __base)
1062 {
1063 __base.setf(ios_base::scientific, ios_base::floatfield);
1064 return __base;
1065 }
1066
1067 #if __cplusplus >= 201103L
1068 // New C++11 floatfield manipulators
1069
1070 /// Calls
1071 /// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
1072 inline ios_base&
1073 hexfloat(ios_base& __base)
1074 {
1075 __base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
1076 return __base;
1077 }
1078
1079 /// Calls @c base.unsetf(ios_base::floatfield)
1080 inline ios_base&
1081 defaultfloat(ios_base& __base)
1082 {
1083 __base.unsetf(ios_base::floatfield);
1084 return __base;
1085 }
1086 #endif
1087
1088 _GLIBCXX_END_NAMESPACE_VERSION
1089 } // namespace
1090
1091 #endif /* _IOS_BASE_H */
1092