1 // Iostreams base classes -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING. If not, write to the Free
19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
32 // ISO C++ 14882: 27.4 Iostreams base classes
36 * This is an internal header file, included by other library headers.
37 * You should not attempt to use it directly.
43 #pragma GCC system_header
45 #include <bits/atomicity.h>
46 #include <bits/localefwd.h>
47 #include <bits/locale_classes.h>
51 // The following definitions of bitmask types are enums, not ints,
52 // as permitted (but not required) in the standard, in order to provide
53 // better type safety in iostream calls. A side effect is that
54 // expressions involving them are no longer compile-time constants.
55 enum _Ios_Fmtflags
{ _S_ios_fmtflags_end
= 1L << 16 };
58 operator&(_Ios_Fmtflags __a
, _Ios_Fmtflags __b
)
59 { return _Ios_Fmtflags(static_cast<int>(__a
) & static_cast<int>(__b
)); }
62 operator|(_Ios_Fmtflags __a
, _Ios_Fmtflags __b
)
63 { return _Ios_Fmtflags(static_cast<int>(__a
) | static_cast<int>(__b
)); }
66 operator^(_Ios_Fmtflags __a
, _Ios_Fmtflags __b
)
67 { return _Ios_Fmtflags(static_cast<int>(__a
) ^ static_cast<int>(__b
)); }
70 operator|=(_Ios_Fmtflags
& __a
, _Ios_Fmtflags __b
)
71 { return __a
= __a
| __b
; }
74 operator&=(_Ios_Fmtflags
& __a
, _Ios_Fmtflags __b
)
75 { return __a
= __a
& __b
; }
78 operator^=(_Ios_Fmtflags
& __a
, _Ios_Fmtflags __b
)
79 { return __a
= __a
^ __b
; }
82 operator~(_Ios_Fmtflags __a
)
83 { return _Ios_Fmtflags(~static_cast<int>(__a
)); }
86 enum _Ios_Openmode
{ _S_ios_openmode_end
= 1L << 16 };
89 operator&(_Ios_Openmode __a
, _Ios_Openmode __b
)
90 { return _Ios_Openmode(static_cast<int>(__a
) & static_cast<int>(__b
)); }
93 operator|(_Ios_Openmode __a
, _Ios_Openmode __b
)
94 { return _Ios_Openmode(static_cast<int>(__a
) | static_cast<int>(__b
)); }
97 operator^(_Ios_Openmode __a
, _Ios_Openmode __b
)
98 { return _Ios_Openmode(static_cast<int>(__a
) ^ static_cast<int>(__b
)); }
101 operator|=(_Ios_Openmode
& __a
, _Ios_Openmode __b
)
102 { return __a
= __a
| __b
; }
105 operator&=(_Ios_Openmode
& __a
, _Ios_Openmode __b
)
106 { return __a
= __a
& __b
; }
109 operator^=(_Ios_Openmode
& __a
, _Ios_Openmode __b
)
110 { return __a
= __a
^ __b
; }
113 operator~(_Ios_Openmode __a
)
114 { return _Ios_Openmode(~static_cast<int>(__a
)); }
117 enum _Ios_Iostate
{ _S_ios_iostate_end
= 1L << 16 };
120 operator&(_Ios_Iostate __a
, _Ios_Iostate __b
)
121 { return _Ios_Iostate(static_cast<int>(__a
) & static_cast<int>(__b
)); }
124 operator|(_Ios_Iostate __a
, _Ios_Iostate __b
)
125 { return _Ios_Iostate(static_cast<int>(__a
) | static_cast<int>(__b
)); }
128 operator^(_Ios_Iostate __a
, _Ios_Iostate __b
)
129 { return _Ios_Iostate(static_cast<int>(__a
) ^ static_cast<int>(__b
)); }
132 operator|=(_Ios_Iostate
& __a
, _Ios_Iostate __b
)
133 { return __a
= __a
| __b
; }
136 operator&=(_Ios_Iostate
& __a
, _Ios_Iostate __b
)
137 { return __a
= __a
& __b
; }
140 operator^=(_Ios_Iostate
& __a
, _Ios_Iostate __b
)
141 { return __a
= __a
^ __b
; }
144 operator~(_Ios_Iostate __a
)
145 { return _Ios_Iostate(~static_cast<int>(__a
)); }
147 enum _Ios_Seekdir
{ _S_ios_seekdir_end
= 1L << 16 };
149 // 27.4.2 Class ios_base
151 * @brief The very top of the I/O class hierarchy.
153 * This class defines everything that can be defined about I/O that does
154 * not depend on the type of characters being input or output. Most
155 * people will only see @c ios_base when they need to specify the full
156 * name of the various I/O flags (e.g., the openmodes).
162 // 27.4.2.1.1 Class ios_base::failure
163 /// These are thrown to indicate problems. Doc me.
164 class failure
: public exception
167 // _GLIBCXX_RESOLVE_LIB_DEFECTS
168 // 48. Use of non-existent exception constructor
170 failure(const string
& __str
) throw();
172 // This declaration is not useless:
173 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
178 what() const throw();
184 // 27.4.2.1.2 Type ios_base::fmtflags
186 * @brief This is a bitmask type.
188 * @c "_Ios_Fmtflags" is implementation-defined, but it is valid to
189 * perform bitwise operations on these values and expect the Right
190 * Thing to happen. Defined objects of type fmtflags are:
210 typedef _Ios_Fmtflags fmtflags
;
212 /// Insert/extract @c bool in alphabetic rather than numeric format.
213 static const fmtflags boolalpha
= fmtflags(__ios_flags::_S_boolalpha
);
215 /// Converts integer input or generates integer output in decimal base.
216 static const fmtflags dec
= fmtflags(__ios_flags::_S_dec
);
218 /// Generate floating-point output in fixed-point notation.
219 static const fmtflags fixed
= fmtflags(__ios_flags::_S_fixed
);
221 /// Converts integer input or generates integer output in hexadecimal base.
222 static const fmtflags hex
= fmtflags(__ios_flags::_S_hex
);
224 /// Adds fill characters at a designated internal point in certain
225 /// generated output, or identical to @c right if no such point is
227 static const fmtflags internal
= fmtflags(__ios_flags::_S_internal
);
229 /// Adds fill characters on the right (final positions) of certain
230 /// generated output. (I.e., the thing you print is flush left.)
231 static const fmtflags left
= fmtflags(__ios_flags::_S_left
);
233 /// Converts integer input or generates integer output in octal base.
234 static const fmtflags oct
= fmtflags(__ios_flags::_S_oct
);
236 /// Adds fill characters on the left (initial positions) of certain
237 /// generated output. (I.e., the thing you print is flush right.)
238 static const fmtflags right
= fmtflags(__ios_flags::_S_right
);
240 /// Generates floating-point output in scientific notation.
241 static const fmtflags scientific
= fmtflags(__ios_flags::_S_scientific
);
243 /// Generates a prefix indicating the numeric base of generated integer
245 static const fmtflags showbase
= fmtflags(__ios_flags::_S_showbase
);
247 /// Generates a decimal-point character unconditionally in generated
248 /// floating-point output.
249 static const fmtflags showpoint
= fmtflags(__ios_flags::_S_showpoint
);
251 /// Generates a + sign in non-negative generated numeric output.
252 static const fmtflags showpos
= fmtflags(__ios_flags::_S_showpos
);
254 /// Skips leading white space before certain input operations.
255 static const fmtflags skipws
= fmtflags(__ios_flags::_S_skipws
);
257 /// Flushes output after each output operation.
258 static const fmtflags unitbuf
= fmtflags(__ios_flags::_S_unitbuf
);
260 /// Replaces certain lowercase letters with their uppercase equivalents
261 /// in generated output.
262 static const fmtflags uppercase
= fmtflags(__ios_flags::_S_uppercase
);
264 /// A mask of left|right|internal. Useful for the 2-arg form of @c setf.
265 static const fmtflags adjustfield
= fmtflags(__ios_flags::_S_adjustfield
);
267 /// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf.
268 static const fmtflags basefield
= fmtflags(__ios_flags::_S_basefield
);
270 /// A mask of scientific|fixed. Useful for the 2-arg form of @c setf.
271 static const fmtflags floatfield
= fmtflags(__ios_flags::_S_floatfield
);
273 // 27.4.2.1.3 Type ios_base::iostate
275 * @brief This is a bitmask type.
277 * @c "_Ios_Iostate" is implementation-defined, but it is valid to
278 * perform bitwise operations on these values and expect the Right
279 * Thing to happen. Defined objects of type iostate are:
285 typedef _Ios_Iostate iostate
;
287 /// Indicates a loss of integrity in an input or output sequence (such
288 /// as an irrecoverable read error from a file).
289 static const iostate badbit
= iostate(__ios_flags::_S_badbit
);
291 /// Indicates that an input operation reached the end of an input sequence.
292 static const iostate eofbit
= iostate(__ios_flags::_S_eofbit
);
294 /// Indicates that an input operation failed to read the expected
295 /// characters, or that an output operation failed to generate the
296 /// desired characters.
297 static const iostate failbit
= iostate(__ios_flags::_S_failbit
);
299 /// Indicates all is well.
300 static const iostate goodbit
= iostate(0);
302 // 27.4.2.1.4 Type ios_base::openmode
304 * @brief This is a bitmask type.
306 * @c "_Ios_Openmode" is implementation-defined, but it is valid to
307 * perform bitwise operations on these values and expect the Right
308 * Thing to happen. Defined objects of type openmode are:
316 typedef _Ios_Openmode openmode
;
318 /// Seek to end before each write.
319 static const openmode app
= openmode(__ios_flags::_S_app
);
321 /// Open and seek to end immediately after opening.
322 static const openmode ate
= openmode(__ios_flags::_S_ate
);
324 /// Perform input and output in binary mode (as opposed to text mode).
325 /// This is probably not what you think it is; see
326 /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#3 and
327 /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#7 for more.
328 static const openmode binary
= openmode(__ios_flags::_S_bin
);
330 /// Open for input. Default for @c ifstream and fstream.
331 static const openmode in
= openmode(__ios_flags::_S_in
);
333 /// Open for output. Default for @c ofstream and fstream.
334 static const openmode out
= openmode(__ios_flags::_S_out
);
336 /// Open for input. Default for @c ofstream.
337 static const openmode trunc
= openmode(__ios_flags::_S_trunc
);
339 // 27.4.2.1.5 Type ios_base::seekdir
341 * @brief This is an enumerated type.
343 * @c "_Ios_Seekdir" is implementation-defined. Defined values
344 * of type seekdir are:
346 * - cur, equivalent to @c SEEK_CUR in the C standard library.
347 * - end, equivalent to @c SEEK_END in the C standard library.
349 typedef _Ios_Seekdir seekdir
;
351 /// Request a seek relative to the beginning of the stream.
352 static const seekdir beg
= seekdir(0);
354 /// Request a seek relative to the current position within the sequence.
355 static const seekdir cur
= seekdir(SEEK_CUR
);
357 /// Request a seek relative to the current end of the sequence.
358 static const seekdir end
= seekdir(SEEK_END
);
360 #ifdef _GLIBCXX_DEPRECATED
362 typedef int io_state
;
363 typedef int open_mode
;
364 typedef int seek_dir
;
366 typedef std::streampos streampos
;
367 typedef std::streamoff streamoff
;
372 * @brief The set of events that may be passed to an event callback.
374 * erase_event is used during ~ios() and copyfmt(). imbue_event is used
375 * during imbue(). copyfmt_event is used during copyfmt().
385 * @brief The type of an event callback function.
386 * @param event One of the members of the event enum.
387 * @param ios_base Reference to the ios_base object.
388 * @param int The integer provided when the callback was registered.
390 * Event callbacks are user defined functions that get called during
391 * several ios_base and basic_ios functions, specifically imbue(),
392 * copyfmt(), and ~ios().
394 typedef void (*event_callback
) (event
, ios_base
&, int);
397 * @brief Add the callback __fn with parameter __index.
398 * @param __fn The function to add.
399 * @param __index The integer to pass to the function when invoked.
401 * Registers a function as an event callback with an integer parameter to
402 * be passed to the function when invoked. Multiple copies of the
403 * function are allowed. If there are multiple callbacks, they are
404 * invoked in the order they were registered.
407 register_callback(event_callback __fn
, int __index
);
413 * ios_base data members (doc me)
416 streamsize _M_precision
;
419 iostate _M_exception
;
420 iostate _M_streambuf_state
;
423 // 27.4.2.6 Members for callbacks
424 // 27.4.2.6 ios_base callbacks
425 struct _Callback_list
428 _Callback_list
* _M_next
;
429 ios_base::event_callback _M_fn
;
431 _Atomic_word _M_refcount
; // 0 means one reference.
433 _Callback_list(ios_base::event_callback __fn
, int __index
,
434 _Callback_list
* __cb
)
435 : _M_next(__cb
), _M_fn(__fn
), _M_index(__index
), _M_refcount(0) { }
438 _M_add_reference() { __gnu_cxx::__atomic_add(&_M_refcount
, 1); }
440 // 0 => OK to delete.
442 _M_remove_reference()
443 { return __gnu_cxx::__exchange_and_add(&_M_refcount
, -1); }
446 _Callback_list
* _M_callbacks
;
449 _M_call_callbacks(event __ev
) throw();
452 _M_dispose_callbacks(void);
454 // 27.4.2.5 Members for iword/pword storage
459 _Words() : _M_pword(0), _M_iword(0) { }
462 // Only for failed iword/pword calls.
465 // Guaranteed storage.
466 // The first 5 iword and pword slots are reserved for internal use.
467 static const int _S_local_word_size
= 8;
468 _Words _M_local_word
[_S_local_word_size
];
470 // Allocated storage.
475 _M_grow_words(int __index
, bool __iword
);
477 // Members for locale and locale caching.
478 locale _M_ios_locale
;
485 // 27.4.2.1.6 Class ios_base::Init
486 // Used to initialize standard streams. In theory, g++ could use
487 // -finit-priority to order this stuff correctly without going
488 // through these machinations.
491 friend class ios_base
;
497 static _Atomic_word _S_refcount
;
498 static bool _S_synced_with_stdio
;
501 // [27.4.2.2] fmtflags state functions
503 * @brief Access to format flags.
504 * @return The format control flags for both input and output.
507 flags() const { return _M_flags
; }
510 * @brief Setting new format flags all at once.
511 * @param fmtfl The new flags to set.
512 * @return The previous format control flags.
514 * This function overwrites all the format flags with @a fmtfl.
517 flags(fmtflags __fmtfl
)
519 fmtflags __old
= _M_flags
;
525 * @brief Setting new format flags.
526 * @param fmtfl Additional flags to set.
527 * @return The previous format control flags.
529 * This function sets additional flags in format control. Flags that
530 * were previously set remain set.
533 setf(fmtflags __fmtfl
)
535 fmtflags __old
= _M_flags
;
541 * @brief Setting new format flags.
542 * @param fmtfl Additional flags to set.
543 * @param mask The flags mask for @a fmtfl.
544 * @return The previous format control flags.
546 * This function clears @a mask in the format flags, then sets
547 * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield.
550 setf(fmtflags __fmtfl
, fmtflags __mask
)
552 fmtflags __old
= _M_flags
;
554 _M_flags
|= (__fmtfl
& __mask
);
559 * @brief Clearing format flags.
560 * @param mask The flags to unset.
562 * This function clears @a mask in the format flags.
565 unsetf(fmtflags __mask
) { _M_flags
&= ~__mask
; }
568 * @brief Flags access.
569 * @return The precision to generate on certain output operations.
572 * Be careful if you try to give a definition of "precision" here; see
577 precision() const { return _M_precision
; }
580 * @brief Changing flags.
581 * @param prec The new precision value.
582 * @return The previous value of precision().
585 precision(streamsize __prec
)
587 streamsize __old
= _M_precision
;
588 _M_precision
= __prec
;
593 * @brief Flags access.
594 * @return The minimum field width to generate on output operations.
596 * "Minimum field width" refers to the number of characters.
599 width() const { return _M_width
; }
602 * @brief Changing flags.
603 * @param wide The new width value.
604 * @return The previous value of width().
607 width(streamsize __wide
)
609 streamsize __old
= _M_width
;
614 // [27.4.2.4] ios_base static members
616 * @brief Interaction with the standard C I/O objects.
617 * @param sync Whether to synchronize or not.
618 * @return True if the standard streams were previously synchronized.
620 * The synchronization referred to is @e only that between the standard
621 * C facilities (e.g., stdout) and the standard C++ objects (e.g.,
622 * cout). User-declared streams are unaffected. See
623 * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#8 for more.
626 sync_with_stdio(bool __sync
= true);
628 // [27.4.2.3] ios_base locale functions
630 * @brief Setting a new locale.
631 * @param loc The new locale.
632 * @return The previous locale.
634 * Sets the new locale for this stream, and then invokes each callback
638 imbue(const locale
& __loc
);
641 * @brief Locale access
642 * @return A copy of the current locale.
644 * If @c imbue(loc) has previously been called, then this function
645 * returns @c loc. Otherwise, it returns a copy of @c std::locale(),
646 * the global C++ locale.
649 getloc() const { return _M_ios_locale
; }
652 * @brief Locale access
653 * @return A reference to the current locale.
655 * Like getloc above, but returns a reference instead of
659 _M_getloc() const { return _M_ios_locale
; }
661 // [27.4.2.5] ios_base storage functions
663 * @brief Access to unique indices.
664 * @return An integer different from all previous calls.
666 * This function returns a unique integer every time it is called. It
667 * can be used for any purpose, but is primarily intended to be a unique
668 * index for the iword and pword functions. The expectation is that an
669 * application calls xalloc in order to obtain an index in the iword and
670 * pword arrays that can be used without fear of conflict.
672 * The implementation maintains a static variable that is incremented and
673 * returned on each invocation. xalloc is guaranteed to return an index
674 * that is safe to use in the iword and pword arrays.
680 * @brief Access to integer array.
681 * @param __ix Index into the array.
682 * @return A reference to an integer associated with the index.
684 * The iword function provides access to an array of integers that can be
685 * used for any purpose. The array grows as required to hold the
686 * supplied index. All integers in the array are initialized to 0.
688 * The implementation reserves several indices. You should use xalloc to
689 * obtain an index that is safe to use. Also note that since the array
690 * can grow dynamically, it is not safe to hold onto the reference.
695 _Words
& __word
= (__ix
< _M_word_size
)
696 ? _M_word
[__ix
] : _M_grow_words(__ix
, true);
697 return __word
._M_iword
;
701 * @brief Access to void pointer array.
702 * @param __ix Index into the array.
703 * @return A reference to a void* associated with the index.
705 * The pword function provides access to an array of pointers that can be
706 * used for any purpose. The array grows as required to hold the
707 * supplied index. All pointers in the array are initialized to 0.
709 * The implementation reserves several indices. You should use xalloc to
710 * obtain an index that is safe to use. Also note that since the array
711 * can grow dynamically, it is not safe to hold onto the reference.
716 _Words
& __word
= (__ix
< _M_word_size
)
717 ? _M_word
[__ix
] : _M_grow_words(__ix
, false);
718 return __word
._M_pword
;
723 * Invokes each callback with erase_event. Destroys local storage.
725 * Note that the ios_base object for the standard streams never gets
726 * destroyed. As a result, any callbacks registered with the standard
727 * streams will not get invoked with erase_event (unless copyfmt is
735 // _GLIBCXX_RESOLVE_LIB_DEFECTS
736 // 50. Copy constructor and assignment operator of ios_base
738 ios_base(const ios_base
&);
741 operator=(const ios_base
&);
744 // [27.4.5.1] fmtflags manipulators
745 /// Calls base.setf(ios_base::boolalpha).
747 boolalpha(ios_base
& __base
)
749 __base
.setf(ios_base::boolalpha
);
753 /// Calls base.unsetf(ios_base::boolalpha).
755 noboolalpha(ios_base
& __base
)
757 __base
.unsetf(ios_base::boolalpha
);
761 /// Calls base.setf(ios_base::showbase).
763 showbase(ios_base
& __base
)
765 __base
.setf(ios_base::showbase
);
769 /// Calls base.unsetf(ios_base::showbase).
771 noshowbase(ios_base
& __base
)
773 __base
.unsetf(ios_base::showbase
);
777 /// Calls base.setf(ios_base::showpoint).
779 showpoint(ios_base
& __base
)
781 __base
.setf(ios_base::showpoint
);
785 /// Calls base.unsetf(ios_base::showpoint).
787 noshowpoint(ios_base
& __base
)
789 __base
.unsetf(ios_base::showpoint
);
793 /// Calls base.setf(ios_base::showpos).
795 showpos(ios_base
& __base
)
797 __base
.setf(ios_base::showpos
);
801 /// Calls base.unsetf(ios_base::showpos).
803 noshowpos(ios_base
& __base
)
805 __base
.unsetf(ios_base::showpos
);
809 /// Calls base.setf(ios_base::skipws).
811 skipws(ios_base
& __base
)
813 __base
.setf(ios_base::skipws
);
817 /// Calls base.unsetf(ios_base::skipws).
819 noskipws(ios_base
& __base
)
821 __base
.unsetf(ios_base::skipws
);
825 /// Calls base.setf(ios_base::uppercase).
827 uppercase(ios_base
& __base
)
829 __base
.setf(ios_base::uppercase
);
833 /// Calls base.unsetf(ios_base::uppercase).
835 nouppercase(ios_base
& __base
)
837 __base
.unsetf(ios_base::uppercase
);
841 /// Calls base.setf(ios_base::unitbuf).
843 unitbuf(ios_base
& __base
)
845 __base
.setf(ios_base::unitbuf
);
849 /// Calls base.unsetf(ios_base::unitbuf).
851 nounitbuf(ios_base
& __base
)
853 __base
.unsetf(ios_base::unitbuf
);
857 // [27.4.5.2] adjustfield anipulators
858 /// Calls base.setf(ios_base::internal, ios_base::adjustfield).
860 internal(ios_base
& __base
)
862 __base
.setf(ios_base::internal
, ios_base::adjustfield
);
866 /// Calls base.setf(ios_base::left, ios_base::adjustfield).
868 left(ios_base
& __base
)
870 __base
.setf(ios_base::left
, ios_base::adjustfield
);
874 /// Calls base.setf(ios_base::right, ios_base::adjustfield).
876 right(ios_base
& __base
)
878 __base
.setf(ios_base::right
, ios_base::adjustfield
);
882 // [27.4.5.3] basefield anipulators
883 /// Calls base.setf(ios_base::dec, ios_base::basefield).
885 dec(ios_base
& __base
)
887 __base
.setf(ios_base::dec
, ios_base::basefield
);
891 /// Calls base.setf(ios_base::hex, ios_base::basefield).
893 hex(ios_base
& __base
)
895 __base
.setf(ios_base::hex
, ios_base::basefield
);
899 /// Calls base.setf(ios_base::oct, ios_base::basefield).
901 oct(ios_base
& __base
)
903 __base
.setf(ios_base::oct
, ios_base::basefield
);
907 // [27.4.5.4] floatfield anipulators
908 /// Calls base.setf(ios_base::fixed, ios_base::floatfield).
910 fixed(ios_base
& __base
)
912 __base
.setf(ios_base::fixed
, ios_base::floatfield
);
916 /// Calls base.setf(ios_base::scientific, ios_base::floatfield).
918 scientific(ios_base
& __base
)
920 __base
.setf(ios_base::scientific
, ios_base::floatfield
);
925 #endif /* _IOS_BASE_H */