1 // Output streams -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
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: 27.6.2 Output streams
36 * This is a Standard C++ Library header. You should @c #include this header
37 * in your programs, rather than any of the "st[dl]_*.h" implementation files.
41 #define _CPP_OSTREAM 1
43 #pragma GCC system_header
49 // [27.6.2.1] Template class basic_ostream
51 * @brief Controlling output.
53 * This is the base class for all output streams. It provides text
54 * formatting of all builtin types, and communicates with any class
55 * derived from basic_streambuf to do the actual output.
57 template<typename _CharT
, typename _Traits
>
58 class basic_ostream
: virtual public basic_ios
<_CharT
, _Traits
>
61 // Types (inherited from basic_ios (27.4.4)):
62 typedef _CharT char_type
;
63 typedef typename
_Traits::int_type int_type
;
64 typedef typename
_Traits::pos_type pos_type
;
65 typedef typename
_Traits::off_type off_type
;
66 typedef _Traits traits_type
;
68 // Non-standard Types:
69 typedef basic_streambuf
<_CharT
, _Traits
> __streambuf_type
;
70 typedef basic_ios
<_CharT
, _Traits
> __ios_type
;
71 typedef basic_ostream
<_CharT
, _Traits
> __ostream_type
;
72 typedef ostreambuf_iterator
<_CharT
, _Traits
> __ostreambuf_iter
;
73 typedef num_put
<_CharT
, __ostreambuf_iter
> __numput_type
;
74 typedef ctype
<_CharT
> __ctype_type
;
76 // [27.6.2.2] constructor/destructor
78 * @brief Base constructor.
80 * This ctor is almost never called by the user directly, rather from
81 * derived classes' initialization lists, which pass a pointer to
82 * their own stream buffer.
85 basic_ostream(__streambuf_type
* __sb
)
89 * @brief Base destructor.
91 * This does very little apart from providing a virtual base dtor.
96 // [27.6.2.3] prefix/suffix
100 // [27.6.2.5] formatted output
101 // [27.6.2.5.3] basic_ostream::operator<<
104 * @brief Interface for manipulators.
106 * Manuipulators such as @c std::endl and @c std::hex use these
107 * functions in constructs like "std::cout << std::endl". For more
108 * information, see the iomanip header.
111 operator<<(__ostream_type
& (*__pf
)(__ostream_type
&));
114 operator<<(__ios_type
& (*__pf
)(__ios_type
&));
117 operator<<(ios_base
& (*__pf
) (ios_base
&));
120 // [27.6.2.5.2] arithmetic inserters
122 * @name Arithmetic Inserters
124 * All the @c operator<< functions (aka <em>formatted output
125 * functions</em>) have some common behavior. Each starts by
126 * constructing a temporary object of type std::basic_ostream::sentry.
127 * This can have several effects, concluding with the setting of a
128 * status flag; see the sentry documentation for more.
130 * If the sentry status is good, the function tries to generate
131 * whatever data is appropriate for the type of the argument.
133 * If an exception is thrown during insertion, ios_base::badbit
134 * will be turned on in the stream's error state without causing an
135 * ios_base::failure to be thrown. The original exception will then
140 * @brief Basic arithmetic inserters
141 * @param A variable of builtin type.
142 * @return @c *this if successful
144 * These functions use the stream's current locale (specifically, the
145 * @c num_get facet) to perform numeric formatting.
148 operator<<(long __n
);
151 operator<<(unsigned long __n
);
154 operator<<(bool __n
);
157 operator<<(short __n
)
159 ios_base::fmtflags __fmt
= this->flags() & ios_base::basefield
;
160 if (__fmt
& ios_base::oct
|| __fmt
& ios_base::hex
)
161 return this->operator<<(static_cast<unsigned long>
162 (static_cast<unsigned short>(__n
)));
164 return this->operator<<(static_cast<long>(__n
));
168 operator<<(unsigned short __n
)
169 { return this->operator<<(static_cast<unsigned long>(__n
)); }
174 ios_base::fmtflags __fmt
= this->flags() & ios_base::basefield
;
175 if (__fmt
& ios_base::oct
|| __fmt
& ios_base::hex
)
176 return this->operator<<(static_cast<unsigned long>
177 (static_cast<unsigned int>(__n
)));
179 return this->operator<<(static_cast<long>(__n
));
183 operator<<(unsigned int __n
)
184 { return this->operator<<(static_cast<unsigned long>(__n
)); }
186 #ifdef _GLIBCPP_USE_LONG_LONG
188 operator<<(long long __n
);
191 operator<<(unsigned long long __n
);
195 operator<<(double __f
);
198 operator<<(float __f
)
199 { return this->operator<<(static_cast<double>(__f
)); }
202 operator<<(long double __f
);
205 operator<<(const void* __p
);
208 * @brief Extracting from another streambuf.
209 * @param sb A pointer to a streambuf
211 * This function behaves like one of the basic arithmetic extractors,
212 * in that it also constructs a sentry onject and has the same error
215 * If @a sb is NULL, the stream will set failbit in its error state.
217 * Characters are extracted from @a sb and inserted into @c *this
218 * until one of the following occurs:
220 * - the input stream reaches end-of-file,
221 * - insertion into the output sequence fails (in this case, the
222 * character that would have been inserted is not extracted), or
223 * - an exception occurs while getting a character from @a sb, which
224 * sets failbit in the error state
226 * If the function inserts no characters, failbit is set.
229 operator<<(__streambuf_type
* __sb
);
232 // [27.6.2.6] unformatted output functions
234 * @name Unformatted Output Functions
236 * All the unformatted output functions have some common behavior.
237 * Each starts by constructing a temporary object of type
238 * std::basic_ostream::sentry. This has several effects, concluding
239 * with the setting of a status flag; see the sentry documentation
242 * If the sentry status is good, the function tries to generate
243 * whatever data is appropriate for the type of the argument.
245 * If an exception is thrown during insertion, ios_base::badbit
246 * will be turned on in the stream's error state. If badbit is on in
247 * the stream's exceptions mask, the exception will be rethrown
248 * without completing its actions.
252 * @brief Simple insertion.
253 * @param c The character to insert.
256 * Tries to insert @a c.
258 * @note This function is not overloaded on signed char and
265 * @brief Character string insertion.
266 * @param s The array to insert.
267 * @param n Maximum number of characters to insert.
270 * Characters are copied from @a s and inserted into the stream until
271 * one of the following happens:
273 * - @a n characters are inserted
274 * - inserting into the output sequence fails (in this case, badbit
275 * will be set in the stream's error state)
277 * @note This function is not overloaded on signed char and
281 write(const char_type
* __s
, streamsize __n
);
285 * @brief Synchronizing the stream buffer.
288 * If @c rdbuf() is a null pointer, changes nothing.
290 * Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
296 // [27.6.2.4] seek members
298 * @brief Getting the current write position.
299 * @return A file position object.
301 * If @c fail() is not false, returns @c pos_type(-1) to indicate
302 * failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
308 * @brief Changing the current write position.
309 * @param pos A file position object.
312 * If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
313 * that function fails, sets failbit.
319 * @brief Changing the current write position.
320 * @param off A file offset object.
321 * @param dir The direction in which to seek.
324 * If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
325 * If that function fails, sets failbit.
328 seekp(off_type
, ios_base::seekdir
);
332 * @brief Performs setup work for output streams.
334 * Objects of this class are created before all of the standard
335 * inserters are run. It is responsible for "exception-safe prefix and
336 * suffix operations." Additional actions may be added by the
337 * implementation, and we list them in
338 * http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5
339 * under [27.6] notes.
341 template <typename _CharT
, typename _Traits
>
342 class basic_ostream
<_CharT
, _Traits
>::sentry
346 basic_ostream
<_CharT
,_Traits
>& _M_os
;
350 * @brief The constructor performs preparatory work.
351 * @param os The output stream to guard.
353 * If the stream state is good (@a os.good() is true), then if the
354 * stream is tied to another output stream, @c is.tie()->flush()
355 * is called to synchronize the output sequences.
357 * If the stream state is still good, then the sentry state becomes
361 sentry(basic_ostream
<_CharT
,_Traits
>& __os
);
364 * @brief Possibly flushes the stream.
366 * If @c ios_base::unitbuf is set in @c os.flags(), and
367 * @c std::uncaught_exception() is true, the sentry destructor calls
368 * @c flush() on the output stream.
373 if (_M_os
.flags() & ios_base::unitbuf
&& !uncaught_exception())
375 // Can't call flush directly or else will get into recursive lock.
376 if (_M_os
.rdbuf() && _M_os
.rdbuf()->pubsync() == -1)
377 _M_os
.setstate(ios_base::badbit
);
382 * @brief Quick status checking.
383 * @return The sentry state.
385 * For ease of use, sentries may be converted to booleans. The
386 * return value is that of the sentry state (true == okay).
392 // [27.6.2.5.4] character insertion templates
395 * @brief Character inserters
396 * @param out An output stream.
397 * @param c A character.
400 * Behaves like one of the formatted arithmetic inserters described in
401 * std::basic_ostream. After constructing a sentry object with good
402 * status, this function inserts a single character and any required
403 * padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
406 * If @a c is of type @c char and the character type of the stream is not
407 * @c char, the character is widened before insertion.
409 template<typename _CharT
, typename _Traits
>
410 basic_ostream
<_CharT
, _Traits
>&
411 operator<<(basic_ostream
<_CharT
, _Traits
>& __out
, _CharT __c
);
413 template<typename _CharT
, typename _Traits
>
414 basic_ostream
<_CharT
, _Traits
>&
415 operator<<(basic_ostream
<_CharT
, _Traits
>& __out
, char __c
)
416 { return (__out
<< __out
.widen(__c
)); }
419 template <class _Traits
>
420 basic_ostream
<char, _Traits
>&
421 operator<<(basic_ostream
<char, _Traits
>& __out
, char __c
);
423 // Signed and unsigned
424 template<class _Traits
>
425 basic_ostream
<char, _Traits
>&
426 operator<<(basic_ostream
<char, _Traits
>& __out
, signed char __c
)
427 { return (__out
<< static_cast<char>(__c
)); }
429 template<class _Traits
>
430 basic_ostream
<char, _Traits
>&
431 operator<<(basic_ostream
<char, _Traits
>& __out
, unsigned char __c
)
432 { return (__out
<< static_cast<char>(__c
)); }
437 * @brief String inserters
438 * @param out An output stream.
439 * @param s A character string.
441 * @pre @a s must be a non-NULL pointer
443 * Behaves like one of the formatted arithmetic inserters described in
444 * std::basic_ostream. After constructing a sentry object with good
445 * status, this function inserts @c traits::length(s) characters starting
446 * at @a s, widened if necessary, followed by any required padding (as
447 * determined by [22.2.2.2.2]). @c out.width(0) is then called.
449 template<typename _CharT
, typename _Traits
>
450 basic_ostream
<_CharT
, _Traits
>&
451 operator<<(basic_ostream
<_CharT
, _Traits
>& __out
, const _CharT
* __s
);
453 template<typename _CharT
, typename _Traits
>
454 basic_ostream
<_CharT
, _Traits
> &
455 operator<<(basic_ostream
<_CharT
, _Traits
>& __out
, const char* __s
);
457 // Partial specializationss
458 template<class _Traits
>
459 basic_ostream
<char, _Traits
>&
460 operator<<(basic_ostream
<char, _Traits
>& __out
, const char* __s
);
462 // Signed and unsigned
463 template<class _Traits
>
464 basic_ostream
<char, _Traits
>&
465 operator<<(basic_ostream
<char, _Traits
>& __out
, const signed char* __s
)
466 { return (__out
<< reinterpret_cast<const char*>(__s
)); }
468 template<class _Traits
>
469 basic_ostream
<char, _Traits
> &
470 operator<<(basic_ostream
<char, _Traits
>& __out
, const unsigned char* __s
)
471 { return (__out
<< reinterpret_cast<const char*>(__s
)); }
474 // [27.6.2.7] standard basic_ostream manipulators
476 * @brief Write a newline and flush the stream.
478 * This manipulator is often mistakenly used when a simple newline is
479 * desired, leading to poor buffering performance. See
480 * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for more
483 template<typename _CharT
, typename _Traits
>
484 basic_ostream
<_CharT
, _Traits
>&
485 endl(basic_ostream
<_CharT
, _Traits
>& __os
)
486 { return flush(__os
.put(__os
.widen('\n'))); }
489 * @brief Write a null character into the output sequence.
491 * "Null character" is @c CharT() by definition. For CharT of @c char,
492 * this correctly writes the ASCII @c NUL character string terminator.
494 template<typename _CharT
, typename _Traits
>
495 basic_ostream
<_CharT
, _Traits
>&
496 ends(basic_ostream
<_CharT
, _Traits
>& __os
)
497 { return __os
.put(_CharT()); }
500 * @brief Flushes the output stream.
502 * This manipulator simply calls the stream's @c flush() member function.
504 template<typename _CharT
, typename _Traits
>
505 basic_ostream
<_CharT
, _Traits
>&
506 flush(basic_ostream
<_CharT
, _Traits
>& __os
)
507 { return __os
.flush(); }
511 #ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
514 #ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS
515 # include <bits/ostream.tcc>
518 #endif /* _CPP_OSTREAM */