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1 : // Iostreams base classes -*- C++ -*-
2 :
3 : // Copyright (C) 1997-2016 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
56 : // expressions involving them are no longer 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 23 : operator|(_Ios_Openmode __a, _Ios_Openmode __b)
130 23 : { 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 : // Annex D.6
473 : typedef int io_state;
474 : typedef int open_mode;
475 : typedef int seek_dir;
476 :
477 : typedef std::streampos streampos;
478 : typedef std::streamoff streamoff;
479 :
480 : // Callbacks;
481 : /**
482 : * @brief The set of events that may be passed to an event callback.
483 : *
484 : * erase_event is used during ~ios() and copyfmt(). imbue_event is used
485 : * during imbue(). copyfmt_event is used during copyfmt().
486 : */
487 : enum event
488 : {
489 : erase_event,
490 : imbue_event,
491 : copyfmt_event
492 : };
493 :
494 : /**
495 : * @brief The type of an event callback function.
496 : * @param __e One of the members of the event enum.
497 : * @param __b Reference to the ios_base object.
498 : * @param __i The integer provided when the callback was registered.
499 : *
500 : * Event callbacks are user defined functions that get called during
501 : * several ios_base and basic_ios functions, specifically imbue(),
502 : * copyfmt(), and ~ios().
503 : */
504 : typedef void (*event_callback) (event __e, ios_base& __b, int __i);
505 :
506 : /**
507 : * @brief Add the callback __fn with parameter __index.
508 : * @param __fn The function to add.
509 : * @param __index The integer to pass to the function when invoked.
510 : *
511 : * Registers a function as an event callback with an integer parameter to
512 : * be passed to the function when invoked. Multiple copies of the
513 : * function are allowed. If there are multiple callbacks, they are
514 : * invoked in the order they were registered.
515 : */
516 : void
517 : register_callback(event_callback __fn, int __index);
518 :
519 : protected:
520 : streamsize _M_precision;
521 : streamsize _M_width;
522 : fmtflags _M_flags;
523 : iostate _M_exception;
524 : iostate _M_streambuf_state;
525 :
526 : // 27.4.2.6 Members for callbacks
527 : // 27.4.2.6 ios_base callbacks
528 : struct _Callback_list
529 : {
530 : // Data Members
531 : _Callback_list* _M_next;
532 : ios_base::event_callback _M_fn;
533 : int _M_index;
534 : _Atomic_word _M_refcount; // 0 means one reference.
535 :
536 : _Callback_list(ios_base::event_callback __fn, int __index,
537 : _Callback_list* __cb)
538 : : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
539 :
540 : void
541 : _M_add_reference() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
542 :
543 : // 0 => OK to delete.
544 : int
545 : _M_remove_reference()
546 : {
547 : // Be race-detector-friendly. For more info see bits/c++config.
548 : _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
549 : int __res = __gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1);
550 : if (__res == 0)
551 : {
552 : _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
553 : }
554 : return __res;
555 : }
556 : };
557 :
558 : _Callback_list* _M_callbacks;
559 :
560 : void
561 : _M_call_callbacks(event __ev) throw();
562 :
563 : void
564 : _M_dispose_callbacks(void) throw();
565 :
566 : // 27.4.2.5 Members for iword/pword storage
567 : struct _Words
568 : {
569 : void* _M_pword;
570 : long _M_iword;
571 : _Words() : _M_pword(0), _M_iword(0) { }
572 : };
573 :
574 : // Only for failed iword/pword calls.
575 : _Words _M_word_zero;
576 :
577 : // Guaranteed storage.
578 : // The first 5 iword and pword slots are reserved for internal use.
579 : enum { _S_local_word_size = 8 };
580 : _Words _M_local_word[_S_local_word_size];
581 :
582 : // Allocated storage.
583 : int _M_word_size;
584 : _Words* _M_word;
585 :
586 : _Words&
587 : _M_grow_words(int __index, bool __iword);
588 :
589 : // Members for locale and locale caching.
590 : locale _M_ios_locale;
591 :
592 : void
593 : _M_init() throw();
594 :
595 : public:
596 :
597 : // 27.4.2.1.6 Class ios_base::Init
598 : // Used to initialize standard streams. In theory, g++ could use
599 : // -finit-priority to order this stuff correctly without going
600 : // through these machinations.
601 : class Init
602 : {
603 : friend class ios_base;
604 : public:
605 : Init();
606 : ~Init();
607 :
608 : private:
609 : static _Atomic_word _S_refcount;
610 : static bool _S_synced_with_stdio;
611 : };
612 :
613 : // [27.4.2.2] fmtflags state functions
614 : /**
615 : * @brief Access to format flags.
616 : * @return The format control flags for both input and output.
617 : */
618 : fmtflags
619 : flags() const
620 : { return _M_flags; }
621 :
622 : /**
623 : * @brief Setting new format flags all at once.
624 : * @param __fmtfl The new flags to set.
625 : * @return The previous format control flags.
626 : *
627 : * This function overwrites all the format flags with @a __fmtfl.
628 : */
629 : fmtflags
630 : flags(fmtflags __fmtfl)
631 : {
632 : fmtflags __old = _M_flags;
633 : _M_flags = __fmtfl;
634 : return __old;
635 : }
636 :
637 : /**
638 : * @brief Setting new format flags.
639 : * @param __fmtfl Additional flags to set.
640 : * @return The previous format control flags.
641 : *
642 : * This function sets additional flags in format control. Flags that
643 : * were previously set remain set.
644 : */
645 : fmtflags
646 : setf(fmtflags __fmtfl)
647 : {
648 : fmtflags __old = _M_flags;
649 : _M_flags |= __fmtfl;
650 : return __old;
651 : }
652 :
653 : /**
654 : * @brief Setting new format flags.
655 : * @param __fmtfl Additional flags to set.
656 : * @param __mask The flags mask for @a fmtfl.
657 : * @return The previous format control flags.
658 : *
659 : * This function clears @a mask in the format flags, then sets
660 : * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
661 : */
662 : fmtflags
663 : setf(fmtflags __fmtfl, fmtflags __mask)
664 : {
665 : fmtflags __old = _M_flags;
666 : _M_flags &= ~__mask;
667 : _M_flags |= (__fmtfl & __mask);
668 : return __old;
669 : }
670 :
671 : /**
672 : * @brief Clearing format flags.
673 : * @param __mask The flags to unset.
674 : *
675 : * This function clears @a __mask in the format flags.
676 : */
677 : void
678 : unsetf(fmtflags __mask)
679 : { _M_flags &= ~__mask; }
680 :
681 : /**
682 : * @brief Flags access.
683 : * @return The precision to generate on certain output operations.
684 : *
685 : * Be careful if you try to give a definition of @a precision here; see
686 : * DR 189.
687 : */
688 : streamsize
689 : precision() const
690 : { return _M_precision; }
691 :
692 : /**
693 : * @brief Changing flags.
694 : * @param __prec The new precision value.
695 : * @return The previous value of precision().
696 : */
697 : streamsize
698 : precision(streamsize __prec)
699 : {
700 : streamsize __old = _M_precision;
701 : _M_precision = __prec;
702 : return __old;
703 : }
704 :
705 : /**
706 : * @brief Flags access.
707 : * @return The minimum field width to generate on output operations.
708 : *
709 : * <em>Minimum field width</em> refers to the number of characters.
710 : */
711 : streamsize
712 : width() const
713 : { return _M_width; }
714 :
715 : /**
716 : * @brief Changing flags.
717 : * @param __wide The new width value.
718 : * @return The previous value of width().
719 : */
720 : streamsize
721 : width(streamsize __wide)
722 : {
723 : streamsize __old = _M_width;
724 : _M_width = __wide;
725 : return __old;
726 : }
727 :
728 : // [27.4.2.4] ios_base static members
729 : /**
730 : * @brief Interaction with the standard C I/O objects.
731 : * @param __sync Whether to synchronize or not.
732 : * @return True if the standard streams were previously synchronized.
733 : *
734 : * The synchronization referred to is @e only that between the standard
735 : * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
736 : * cout). User-declared streams are unaffected. See
737 : * https://gcc.gnu.org/onlinedocs/libstdc++/manual/fstreams.html#std.io.filestreams.binary
738 : */
739 : static bool
740 : sync_with_stdio(bool __sync = true);
741 :
742 : // [27.4.2.3] ios_base locale functions
743 : /**
744 : * @brief Setting a new locale.
745 : * @param __loc The new locale.
746 : * @return The previous locale.
747 : *
748 : * Sets the new locale for this stream, and then invokes each callback
749 : * with imbue_event.
750 : */
751 : locale
752 : imbue(const locale& __loc) throw();
753 :
754 : /**
755 : * @brief Locale access
756 : * @return A copy of the current locale.
757 : *
758 : * If @c imbue(loc) has previously been called, then this function
759 : * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
760 : * the global C++ locale.
761 : */
762 : locale
763 : getloc() const
764 : { return _M_ios_locale; }
765 :
766 : /**
767 : * @brief Locale access
768 : * @return A reference to the current locale.
769 : *
770 : * Like getloc above, but returns a reference instead of
771 : * generating a copy.
772 : */
773 : const locale&
774 : _M_getloc() const
775 : { return _M_ios_locale; }
776 :
777 : // [27.4.2.5] ios_base storage functions
778 : /**
779 : * @brief Access to unique indices.
780 : * @return An integer different from all previous calls.
781 : *
782 : * This function returns a unique integer every time it is called. It
783 : * can be used for any purpose, but is primarily intended to be a unique
784 : * index for the iword and pword functions. The expectation is that an
785 : * application calls xalloc in order to obtain an index in the iword and
786 : * pword arrays that can be used without fear of conflict.
787 : *
788 : * The implementation maintains a static variable that is incremented and
789 : * returned on each invocation. xalloc is guaranteed to return an index
790 : * that is safe to use in the iword and pword arrays.
791 : */
792 : static int
793 : xalloc() throw();
794 :
795 : /**
796 : * @brief Access to integer array.
797 : * @param __ix Index into the array.
798 : * @return A reference to an integer associated with the index.
799 : *
800 : * The iword function provides access to an array of integers that can be
801 : * used for any purpose. The array grows as required to hold the
802 : * supplied index. All integers in the array are initialized to 0.
803 : *
804 : * The implementation reserves several indices. You should use xalloc to
805 : * obtain an index that is safe to use. Also note that since the array
806 : * can grow dynamically, it is not safe to hold onto the reference.
807 : */
808 : long&
809 : iword(int __ix)
810 : {
811 : _Words& __word = (__ix < _M_word_size)
812 : ? _M_word[__ix] : _M_grow_words(__ix, true);
813 : return __word._M_iword;
814 : }
815 :
816 : /**
817 : * @brief Access to void pointer array.
818 : * @param __ix Index into the array.
819 : * @return A reference to a void* associated with the index.
820 : *
821 : * The pword function provides access to an array of pointers that can be
822 : * used for any purpose. The array grows as required to hold the
823 : * supplied index. All pointers in the array are initialized to 0.
824 : *
825 : * The implementation reserves several indices. You should use xalloc to
826 : * obtain an index that is safe to use. Also note that since the array
827 : * can grow dynamically, it is not safe to hold onto the reference.
828 : */
829 : void*&
830 : pword(int __ix)
831 : {
832 : _Words& __word = (__ix < _M_word_size)
833 : ? _M_word[__ix] : _M_grow_words(__ix, false);
834 : return __word._M_pword;
835 : }
836 :
837 : // Destructor
838 : /**
839 : * Invokes each callback with erase_event. Destroys local storage.
840 : *
841 : * Note that the ios_base object for the standard streams never gets
842 : * destroyed. As a result, any callbacks registered with the standard
843 : * streams will not get invoked with erase_event (unless copyfmt is
844 : * used).
845 : */
846 : virtual ~ios_base();
847 :
848 : protected:
849 : ios_base() throw ();
850 :
851 : #if __cplusplus < 201103L
852 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
853 : // 50. Copy constructor and assignment operator of ios_base
854 : private:
855 : ios_base(const ios_base&);
856 :
857 : ios_base&
858 : operator=(const ios_base&);
859 : #else
860 : public:
861 : ios_base(const ios_base&) = delete;
862 :
863 : ios_base&
864 : operator=(const ios_base&) = delete;
865 :
866 : protected:
867 : void
868 : _M_move(ios_base&) noexcept;
869 :
870 : void
871 : _M_swap(ios_base& __rhs) noexcept;
872 : #endif
873 : };
874 :
875 : // [27.4.5.1] fmtflags manipulators
876 : /// Calls base.setf(ios_base::boolalpha).
877 : inline ios_base&
878 : boolalpha(ios_base& __base)
879 : {
880 : __base.setf(ios_base::boolalpha);
881 : return __base;
882 : }
883 :
884 : /// Calls base.unsetf(ios_base::boolalpha).
885 : inline ios_base&
886 : noboolalpha(ios_base& __base)
887 : {
888 : __base.unsetf(ios_base::boolalpha);
889 : return __base;
890 : }
891 :
892 : /// Calls base.setf(ios_base::showbase).
893 : inline ios_base&
894 : showbase(ios_base& __base)
895 : {
896 : __base.setf(ios_base::showbase);
897 : return __base;
898 : }
899 :
900 : /// Calls base.unsetf(ios_base::showbase).
901 : inline ios_base&
902 : noshowbase(ios_base& __base)
903 : {
904 : __base.unsetf(ios_base::showbase);
905 : return __base;
906 : }
907 :
908 : /// Calls base.setf(ios_base::showpoint).
909 : inline ios_base&
910 : showpoint(ios_base& __base)
911 : {
912 : __base.setf(ios_base::showpoint);
913 : return __base;
914 : }
915 :
916 : /// Calls base.unsetf(ios_base::showpoint).
917 : inline ios_base&
918 : noshowpoint(ios_base& __base)
919 : {
920 : __base.unsetf(ios_base::showpoint);
921 : return __base;
922 : }
923 :
924 : /// Calls base.setf(ios_base::showpos).
925 : inline ios_base&
926 : showpos(ios_base& __base)
927 : {
928 : __base.setf(ios_base::showpos);
929 : return __base;
930 : }
931 :
932 : /// Calls base.unsetf(ios_base::showpos).
933 : inline ios_base&
934 : noshowpos(ios_base& __base)
935 : {
936 : __base.unsetf(ios_base::showpos);
937 : return __base;
938 : }
939 :
940 : /// Calls base.setf(ios_base::skipws).
941 : inline ios_base&
942 : skipws(ios_base& __base)
943 : {
944 : __base.setf(ios_base::skipws);
945 : return __base;
946 : }
947 :
948 : /// Calls base.unsetf(ios_base::skipws).
949 : inline ios_base&
950 : noskipws(ios_base& __base)
951 : {
952 : __base.unsetf(ios_base::skipws);
953 : return __base;
954 : }
955 :
956 : /// Calls base.setf(ios_base::uppercase).
957 : inline ios_base&
958 : uppercase(ios_base& __base)
959 : {
960 : __base.setf(ios_base::uppercase);
961 : return __base;
962 : }
963 :
964 : /// Calls base.unsetf(ios_base::uppercase).
965 : inline ios_base&
966 : nouppercase(ios_base& __base)
967 : {
968 : __base.unsetf(ios_base::uppercase);
969 : return __base;
970 : }
971 :
972 : /// Calls base.setf(ios_base::unitbuf).
973 : inline ios_base&
974 : unitbuf(ios_base& __base)
975 : {
976 : __base.setf(ios_base::unitbuf);
977 : return __base;
978 : }
979 :
980 : /// Calls base.unsetf(ios_base::unitbuf).
981 : inline ios_base&
982 : nounitbuf(ios_base& __base)
983 : {
984 : __base.unsetf(ios_base::unitbuf);
985 : return __base;
986 : }
987 :
988 : // [27.4.5.2] adjustfield manipulators
989 : /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
990 : inline ios_base&
991 : internal(ios_base& __base)
992 : {
993 : __base.setf(ios_base::internal, ios_base::adjustfield);
994 : return __base;
995 : }
996 :
997 : /// Calls base.setf(ios_base::left, ios_base::adjustfield).
998 : inline ios_base&
999 : left(ios_base& __base)
1000 : {
1001 : __base.setf(ios_base::left, ios_base::adjustfield);
1002 : return __base;
1003 : }
1004 :
1005 : /// Calls base.setf(ios_base::right, ios_base::adjustfield).
1006 : inline ios_base&
1007 : right(ios_base& __base)
1008 : {
1009 : __base.setf(ios_base::right, ios_base::adjustfield);
1010 : return __base;
1011 : }
1012 :
1013 : // [27.4.5.3] basefield manipulators
1014 : /// Calls base.setf(ios_base::dec, ios_base::basefield).
1015 : inline ios_base&
1016 : dec(ios_base& __base)
1017 : {
1018 : __base.setf(ios_base::dec, ios_base::basefield);
1019 : return __base;
1020 : }
1021 :
1022 : /// Calls base.setf(ios_base::hex, ios_base::basefield).
1023 : inline ios_base&
1024 : hex(ios_base& __base)
1025 : {
1026 : __base.setf(ios_base::hex, ios_base::basefield);
1027 : return __base;
1028 : }
1029 :
1030 : /// Calls base.setf(ios_base::oct, ios_base::basefield).
1031 : inline ios_base&
1032 : oct(ios_base& __base)
1033 : {
1034 : __base.setf(ios_base::oct, ios_base::basefield);
1035 : return __base;
1036 : }
1037 :
1038 : // [27.4.5.4] floatfield manipulators
1039 : /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
1040 : inline ios_base&
1041 : fixed(ios_base& __base)
1042 : {
1043 : __base.setf(ios_base::fixed, ios_base::floatfield);
1044 : return __base;
1045 : }
1046 :
1047 : /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
1048 : inline ios_base&
1049 : scientific(ios_base& __base)
1050 : {
1051 : __base.setf(ios_base::scientific, ios_base::floatfield);
1052 : return __base;
1053 : }
1054 :
1055 : #if __cplusplus >= 201103L
1056 : // New C++11 floatfield manipulators
1057 :
1058 : /// Calls
1059 : /// base.setf(ios_base::fixed|ios_base::scientific, ios_base::floatfield)
1060 : inline ios_base&
1061 : hexfloat(ios_base& __base)
1062 : {
1063 : __base.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
1064 : return __base;
1065 : }
1066 :
1067 : /// Calls @c base.unsetf(ios_base::floatfield)
1068 : inline ios_base&
1069 : defaultfloat(ios_base& __base)
1070 : {
1071 : __base.unsetf(ios_base::floatfield);
1072 : return __base;
1073 : }
1074 : #endif
1075 :
1076 : _GLIBCXX_END_NAMESPACE_VERSION
1077 : } // namespace
1078 :
1079 : #endif /* _IOS_BASE_H */
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