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1 : // Output streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2007, 2008, 2009
5 : // Free Software Foundation, Inc.
6 : //
7 : // This file is part of the GNU ISO C++ Library. This library is free
8 : // software; you can redistribute it and/or modify it under the
9 : // terms of the GNU General Public License as published by the
10 : // Free Software Foundation; either version 3, or (at your option)
11 : // any later version.
12 :
13 : // This library is distributed in the hope that it will be useful,
14 : // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 : // GNU General Public License for more details.
17 :
18 : // Under Section 7 of GPL version 3, you are granted additional
19 : // permissions described in the GCC Runtime Library Exception, version
20 : // 3.1, as published by the Free Software Foundation.
21 :
22 : // You should have received a copy of the GNU General Public License and
23 : // a copy of the GCC Runtime Library Exception along with this program;
24 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
25 : // <http://www.gnu.org/licenses/>.
26 :
27 : /** @file ostream
28 : * This is a Standard C++ Library header.
29 : */
30 :
31 : //
32 : // ISO C++ 14882: 27.6.2 Output streams
33 : //
34 :
35 : #ifndef _GLIBCXX_OSTREAM
36 : #define _GLIBCXX_OSTREAM 1
37 :
38 : #pragma GCC system_header
39 :
40 : #include <ios>
41 : #include <bits/ostream_insert.h>
42 :
43 : _GLIBCXX_BEGIN_NAMESPACE(std)
44 :
45 : // [27.6.2.1] Template class basic_ostream
46 : /**
47 : * @brief Controlling output.
48 : * @ingroup io
49 : *
50 : * This is the base class for all output streams. It provides text
51 : * formatting of all builtin types, and communicates with any class
52 : * derived from basic_streambuf to do the actual output.
53 : */
54 : template<typename _CharT, typename _Traits>
55 : class basic_ostream : virtual public basic_ios<_CharT, _Traits>
56 : {
57 : public:
58 : // Types (inherited from basic_ios (27.4.4)):
59 : typedef _CharT char_type;
60 : typedef typename _Traits::int_type int_type;
61 : typedef typename _Traits::pos_type pos_type;
62 : typedef typename _Traits::off_type off_type;
63 : typedef _Traits traits_type;
64 :
65 : // Non-standard Types:
66 : typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
67 : typedef basic_ios<_CharT, _Traits> __ios_type;
68 : typedef basic_ostream<_CharT, _Traits> __ostream_type;
69 : typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> >
70 : __num_put_type;
71 : typedef ctype<_CharT> __ctype_type;
72 :
73 : // [27.6.2.2] constructor/destructor
74 : /**
75 : * @brief Base constructor.
76 : *
77 : * This ctor is almost never called by the user directly, rather from
78 : * derived classes' initialization lists, which pass a pointer to
79 : * their own stream buffer.
80 : */
81 : explicit
82 : basic_ostream(__streambuf_type* __sb)
83 : { this->init(__sb); }
84 :
85 : /**
86 : * @brief Base destructor.
87 : *
88 : * This does very little apart from providing a virtual base dtor.
89 : */
90 : virtual
91 : ~basic_ostream() { }
92 :
93 : // [27.6.2.3] prefix/suffix
94 : class sentry;
95 : friend class sentry;
96 :
97 : // [27.6.2.5] formatted output
98 : // [27.6.2.5.3] basic_ostream::operator<<
99 : //@{
100 : /**
101 : * @brief Interface for manipulators.
102 : *
103 : * Manipulators such as @c std::endl and @c std::hex use these
104 : * functions in constructs like "std::cout << std::endl". For more
105 : * information, see the iomanip header.
106 : */
107 : __ostream_type&
108 0 : operator<<(__ostream_type& (*__pf)(__ostream_type&))
109 : {
110 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
111 : // DR 60. What is a formatted input function?
112 : // The inserters for manipulators are *not* formatted output functions.
113 0 : return __pf(*this);
114 : }
115 :
116 : __ostream_type&
117 : operator<<(__ios_type& (*__pf)(__ios_type&))
118 : {
119 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
120 : // DR 60. What is a formatted input function?
121 : // The inserters for manipulators are *not* formatted output functions.
122 : __pf(*this);
123 : return *this;
124 : }
125 :
126 : __ostream_type&
127 : operator<<(ios_base& (*__pf) (ios_base&))
128 : {
129 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
130 : // DR 60. What is a formatted input function?
131 : // The inserters for manipulators are *not* formatted output functions.
132 : __pf(*this);
133 : return *this;
134 : }
135 : //@}
136 :
137 : // [27.6.2.5.2] arithmetic inserters
138 : /**
139 : * @name Arithmetic Inserters
140 : *
141 : * All the @c operator<< functions (aka <em>formatted output
142 : * functions</em>) have some common behavior. Each starts by
143 : * constructing a temporary object of type std::basic_ostream::sentry.
144 : * This can have several effects, concluding with the setting of a
145 : * status flag; see the sentry documentation for more.
146 : *
147 : * If the sentry status is good, the function tries to generate
148 : * whatever data is appropriate for the type of the argument.
149 : *
150 : * If an exception is thrown during insertion, ios_base::badbit
151 : * will be turned on in the stream's error state without causing an
152 : * ios_base::failure to be thrown. The original exception will then
153 : * be rethrown.
154 : */
155 : //@{
156 : /**
157 : * @brief Basic arithmetic inserters
158 : * @param A variable of builtin type.
159 : * @return @c *this if successful
160 : *
161 : * These functions use the stream's current locale (specifically, the
162 : * @c num_get facet) to perform numeric formatting.
163 : */
164 : __ostream_type&
165 : operator<<(long __n)
166 : { return _M_insert(__n); }
167 :
168 : __ostream_type&
169 : operator<<(unsigned long __n)
170 : { return _M_insert(__n); }
171 :
172 : __ostream_type&
173 : operator<<(bool __n)
174 : { return _M_insert(__n); }
175 :
176 : __ostream_type&
177 : operator<<(short __n);
178 :
179 : __ostream_type&
180 : operator<<(unsigned short __n)
181 : {
182 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
183 : // 117. basic_ostream uses nonexistent num_put member functions.
184 : return _M_insert(static_cast<unsigned long>(__n));
185 : }
186 :
187 : __ostream_type&
188 : operator<<(int __n);
189 :
190 : __ostream_type&
191 : operator<<(unsigned int __n)
192 : {
193 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
194 : // 117. basic_ostream uses nonexistent num_put member functions.
195 : return _M_insert(static_cast<unsigned long>(__n));
196 : }
197 :
198 : #ifdef _GLIBCXX_USE_LONG_LONG
199 : __ostream_type&
200 : operator<<(long long __n)
201 : { return _M_insert(__n); }
202 :
203 : __ostream_type&
204 : operator<<(unsigned long long __n)
205 : { return _M_insert(__n); }
206 : #endif
207 :
208 : __ostream_type&
209 0 : operator<<(double __f)
210 0 : { return _M_insert(__f); }
211 :
212 : __ostream_type&
213 : operator<<(float __f)
214 : {
215 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
216 : // 117. basic_ostream uses nonexistent num_put member functions.
217 : return _M_insert(static_cast<double>(__f));
218 : }
219 :
220 : __ostream_type&
221 : operator<<(long double __f)
222 : { return _M_insert(__f); }
223 :
224 : __ostream_type&
225 : operator<<(const void* __p)
226 : { return _M_insert(__p); }
227 :
228 : /**
229 : * @brief Extracting from another streambuf.
230 : * @param sb A pointer to a streambuf
231 : *
232 : * This function behaves like one of the basic arithmetic extractors,
233 : * in that it also constructs a sentry object and has the same error
234 : * handling behavior.
235 : *
236 : * If @a sb is NULL, the stream will set failbit in its error state.
237 : *
238 : * Characters are extracted from @a sb and inserted into @c *this
239 : * until one of the following occurs:
240 : *
241 : * - the input stream reaches end-of-file,
242 : * - insertion into the output sequence fails (in this case, the
243 : * character that would have been inserted is not extracted), or
244 : * - an exception occurs while getting a character from @a sb, which
245 : * sets failbit in the error state
246 : *
247 : * If the function inserts no characters, failbit is set.
248 : */
249 : __ostream_type&
250 : operator<<(__streambuf_type* __sb);
251 : //@}
252 :
253 : // [27.6.2.6] unformatted output functions
254 : /**
255 : * @name Unformatted Output Functions
256 : *
257 : * All the unformatted output functions have some common behavior.
258 : * Each starts by constructing a temporary object of type
259 : * std::basic_ostream::sentry. This has several effects, concluding
260 : * with the setting of a status flag; see the sentry documentation
261 : * for more.
262 : *
263 : * If the sentry status is good, the function tries to generate
264 : * whatever data is appropriate for the type of the argument.
265 : *
266 : * If an exception is thrown during insertion, ios_base::badbit
267 : * will be turned on in the stream's error state. If badbit is on in
268 : * the stream's exceptions mask, the exception will be rethrown
269 : * without completing its actions.
270 : */
271 : //@{
272 : /**
273 : * @brief Simple insertion.
274 : * @param c The character to insert.
275 : * @return *this
276 : *
277 : * Tries to insert @a c.
278 : *
279 : * @note This function is not overloaded on signed char and
280 : * unsigned char.
281 : */
282 : __ostream_type&
283 : put(char_type __c);
284 :
285 : // Core write functionality, without sentry.
286 : void
287 : _M_write(const char_type* __s, streamsize __n)
288 : {
289 : const streamsize __put = this->rdbuf()->sputn(__s, __n);
290 : if (__put != __n)
291 : this->setstate(ios_base::badbit);
292 : }
293 :
294 : /**
295 : * @brief Character string insertion.
296 : * @param s The array to insert.
297 : * @param n Maximum number of characters to insert.
298 : * @return *this
299 : *
300 : * Characters are copied from @a s and inserted into the stream until
301 : * one of the following happens:
302 : *
303 : * - @a n characters are inserted
304 : * - inserting into the output sequence fails (in this case, badbit
305 : * will be set in the stream's error state)
306 : *
307 : * @note This function is not overloaded on signed char and
308 : * unsigned char.
309 : */
310 : __ostream_type&
311 : write(const char_type* __s, streamsize __n);
312 : //@}
313 :
314 : /**
315 : * @brief Synchronizing the stream buffer.
316 : * @return *this
317 : *
318 : * If @c rdbuf() is a null pointer, changes nothing.
319 : *
320 : * Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
321 : * sets badbit.
322 : */
323 : __ostream_type&
324 : flush();
325 :
326 : // [27.6.2.4] seek members
327 : /**
328 : * @brief Getting the current write position.
329 : * @return A file position object.
330 : *
331 : * If @c fail() is not false, returns @c pos_type(-1) to indicate
332 : * failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
333 : */
334 : pos_type
335 : tellp();
336 :
337 : /**
338 : * @brief Changing the current write position.
339 : * @param pos A file position object.
340 : * @return *this
341 : *
342 : * If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
343 : * that function fails, sets failbit.
344 : */
345 : __ostream_type&
346 : seekp(pos_type);
347 :
348 : /**
349 : * @brief Changing the current write position.
350 : * @param off A file offset object.
351 : * @param dir The direction in which to seek.
352 : * @return *this
353 : *
354 : * If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
355 : * If that function fails, sets failbit.
356 : */
357 : __ostream_type&
358 : seekp(off_type, ios_base::seekdir);
359 :
360 : protected:
361 : basic_ostream()
362 : { this->init(0); }
363 :
364 : template<typename _ValueT>
365 : __ostream_type&
366 : _M_insert(_ValueT __v);
367 : };
368 :
369 : /**
370 : * @brief Performs setup work for output streams.
371 : *
372 : * Objects of this class are created before all of the standard
373 : * inserters are run. It is responsible for "exception-safe prefix and
374 : * suffix operations."
375 : */
376 : template <typename _CharT, typename _Traits>
377 : class basic_ostream<_CharT, _Traits>::sentry
378 : {
379 : // Data Members:
380 : bool _M_ok;
381 : basic_ostream<_CharT, _Traits>& _M_os;
382 :
383 : public:
384 : /**
385 : * @brief The constructor performs preparatory work.
386 : * @param os The output stream to guard.
387 : *
388 : * If the stream state is good (@a os.good() is true), then if the
389 : * stream is tied to another output stream, @c is.tie()->flush()
390 : * is called to synchronize the output sequences.
391 : *
392 : * If the stream state is still good, then the sentry state becomes
393 : * true ("okay").
394 : */
395 : explicit
396 : sentry(basic_ostream<_CharT, _Traits>& __os);
397 :
398 : /**
399 : * @brief Possibly flushes the stream.
400 : *
401 : * If @c ios_base::unitbuf is set in @c os.flags(), and
402 : * @c std::uncaught_exception() is true, the sentry destructor calls
403 : * @c flush() on the output stream.
404 : */
405 : ~sentry()
406 : {
407 : // XXX MT
408 : if (bool(_M_os.flags() & ios_base::unitbuf) && !uncaught_exception())
409 : {
410 : // Can't call flush directly or else will get into recursive lock.
411 : if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
412 : _M_os.setstate(ios_base::badbit);
413 : }
414 : }
415 :
416 : /**
417 : * @brief Quick status checking.
418 : * @return The sentry state.
419 : *
420 : * For ease of use, sentries may be converted to booleans. The
421 : * return value is that of the sentry state (true == okay).
422 : */
423 : operator bool() const
424 : { return _M_ok; }
425 : };
426 :
427 : // [27.6.2.5.4] character insertion templates
428 : //@{
429 : /**
430 : * @brief Character inserters
431 : * @param out An output stream.
432 : * @param c A character.
433 : * @return out
434 : *
435 : * Behaves like one of the formatted arithmetic inserters described in
436 : * std::basic_ostream. After constructing a sentry object with good
437 : * status, this function inserts a single character and any required
438 : * padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
439 : * called.
440 : *
441 : * If @a c is of type @c char and the character type of the stream is not
442 : * @c char, the character is widened before insertion.
443 : */
444 : template<typename _CharT, typename _Traits>
445 : inline basic_ostream<_CharT, _Traits>&
446 : operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
447 : { return __ostream_insert(__out, &__c, 1); }
448 :
449 : template<typename _CharT, typename _Traits>
450 : inline basic_ostream<_CharT, _Traits>&
451 : operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
452 : { return (__out << __out.widen(__c)); }
453 :
454 : // Specialization
455 : template <class _Traits>
456 : inline basic_ostream<char, _Traits>&
457 : operator<<(basic_ostream<char, _Traits>& __out, char __c)
458 : { return __ostream_insert(__out, &__c, 1); }
459 :
460 : // Signed and unsigned
461 : template<class _Traits>
462 : inline basic_ostream<char, _Traits>&
463 : operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
464 : { return (__out << static_cast<char>(__c)); }
465 :
466 : template<class _Traits>
467 : inline basic_ostream<char, _Traits>&
468 : operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
469 : { return (__out << static_cast<char>(__c)); }
470 : //@}
471 :
472 : //@{
473 : /**
474 : * @brief String inserters
475 : * @param out An output stream.
476 : * @param s A character string.
477 : * @return out
478 : * @pre @a s must be a non-NULL pointer
479 : *
480 : * Behaves like one of the formatted arithmetic inserters described in
481 : * std::basic_ostream. After constructing a sentry object with good
482 : * status, this function inserts @c traits::length(s) characters starting
483 : * at @a s, widened if necessary, followed by any required padding (as
484 : * determined by [22.2.2.2.2]). @c out.width(0) is then called.
485 : */
486 : template<typename _CharT, typename _Traits>
487 : inline basic_ostream<_CharT, _Traits>&
488 : operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
489 : {
490 : if (!__s)
491 : __out.setstate(ios_base::badbit);
492 : else
493 : __ostream_insert(__out, __s,
494 : static_cast<streamsize>(_Traits::length(__s)));
495 : return __out;
496 : }
497 :
498 : template<typename _CharT, typename _Traits>
499 : basic_ostream<_CharT, _Traits> &
500 : operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
501 :
502 : // Partial specializations
503 : template<class _Traits>
504 : inline basic_ostream<char, _Traits>&
505 0 : operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
506 : {
507 0 : if (!__s)
508 0 : __out.setstate(ios_base::badbit);
509 : else
510 0 : __ostream_insert(__out, __s,
511 : static_cast<streamsize>(_Traits::length(__s)));
512 0 : return __out;
513 : }
514 :
515 : // Signed and unsigned
516 : template<class _Traits>
517 : inline basic_ostream<char, _Traits>&
518 : operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
519 : { return (__out << reinterpret_cast<const char*>(__s)); }
520 :
521 : template<class _Traits>
522 : inline basic_ostream<char, _Traits> &
523 : operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
524 : { return (__out << reinterpret_cast<const char*>(__s)); }
525 : //@}
526 :
527 : // [27.6.2.7] standard basic_ostream manipulators
528 : /**
529 : * @brief Write a newline and flush the stream.
530 : *
531 : * This manipulator is often mistakenly used when a simple newline is
532 : * desired, leading to poor buffering performance. See
533 : * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for more
534 : * on this subject.
535 : */
536 : template<typename _CharT, typename _Traits>
537 : inline basic_ostream<_CharT, _Traits>&
538 0 : endl(basic_ostream<_CharT, _Traits>& __os)
539 0 : { return flush(__os.put(__os.widen('\n'))); }
540 :
541 : /**
542 : * @brief Write a null character into the output sequence.
543 : *
544 : * "Null character" is @c CharT() by definition. For CharT of @c char,
545 : * this correctly writes the ASCII @c NUL character string terminator.
546 : */
547 : template<typename _CharT, typename _Traits>
548 : inline basic_ostream<_CharT, _Traits>&
549 : ends(basic_ostream<_CharT, _Traits>& __os)
550 : { return __os.put(_CharT()); }
551 :
552 : /**
553 : * @brief Flushes the output stream.
554 : *
555 : * This manipulator simply calls the stream's @c flush() member function.
556 : */
557 : template<typename _CharT, typename _Traits>
558 : inline basic_ostream<_CharT, _Traits>&
559 0 : flush(basic_ostream<_CharT, _Traits>& __os)
560 0 : { return __os.flush(); }
561 :
562 : _GLIBCXX_END_NAMESPACE
563 :
564 : #ifndef _GLIBCXX_EXPORT_TEMPLATE
565 : # include <bits/ostream.tcc>
566 : #endif
567 :
568 : #endif /* _GLIBCXX_OSTREAM */
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