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1 : // Iostreams base classes -*- C++ -*-
2 :
3 : // Copyright (C) 1997-2018 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 :
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 79853 : operator|(_Ios_Openmode __a, _Ios_Openmode __b)
130 79853 : { 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 : 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 */
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