1 : // Output streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2007, 2008, 2009, 2010
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 0 : ~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 0 : 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 0 : __pf(*this);
133 0 : 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 0 : operator<<(long __n)
166 0 : { 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 0 : operator<<(unsigned int __n)
192 : {
193 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
194 : // 117. basic_ostream uses nonexistent num_put member functions.
195 0 : 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 0 : operator<<(unsigned long long __n)
205 0 : { return _M_insert(__n); }
206 : #endif
207 :
208 : __ostream_type&
209 : operator<<(double __f)
210 : { return _M_insert(__f); }
211 :
212 : __ostream_type&
213 0 : operator<<(float __f)
214 : {
215 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
216 : // 117. basic_ostream uses nonexistent num_put member functions.
217 0 : 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 0 : operator<<(const void* __p)
226 0 : { 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 0 : basic_ostream()
362 0 : { 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 <em>exception-safe prefix and
374 : * suffix operations</em>.
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 (@a 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 0 : ~sentry()
406 : {
407 : // XXX MT
408 0 : 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 0 : if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
412 0 : _M_os.setstate(ios_base::badbit);
413 : }
414 0 : }
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 : #ifdef __GXX_EXPERIMENTAL_CXX0X__
424 : explicit
425 : #endif
426 0 : operator bool() const
427 0 : { return _M_ok; }
428 : };
429 :
430 : // [27.6.2.5.4] character insertion templates
431 : //@{
432 : /**
433 : * @brief Character inserters
434 : * @param out An output stream.
435 : * @param c A character.
436 : * @return out
437 : *
438 : * Behaves like one of the formatted arithmetic inserters described in
439 : * std::basic_ostream. After constructing a sentry object with good
440 : * status, this function inserts a single character and any required
441 : * padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
442 : * called.
443 : *
444 : * If @a c is of type @c char and the character type of the stream is not
445 : * @c char, the character is widened before insertion.
446 : */
447 : template<typename _CharT, typename _Traits>
448 : inline basic_ostream<_CharT, _Traits>&
449 : operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
450 : { return __ostream_insert(__out, &__c, 1); }
451 :
452 : template<typename _CharT, typename _Traits>
453 : inline basic_ostream<_CharT, _Traits>&
454 : operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
455 : { return (__out << __out.widen(__c)); }
456 :
457 : // Specialization
458 : template <class _Traits>
459 : inline basic_ostream<char, _Traits>&
460 0 : operator<<(basic_ostream<char, _Traits>& __out, char __c)
461 0 : { return __ostream_insert(__out, &__c, 1); }
462 :
463 : // Signed and unsigned
464 : template<class _Traits>
465 : inline basic_ostream<char, _Traits>&
466 : operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
467 : { return (__out << static_cast<char>(__c)); }
468 :
469 : template<class _Traits>
470 : inline basic_ostream<char, _Traits>&
471 : operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
472 : { return (__out << static_cast<char>(__c)); }
473 : //@}
474 :
475 : //@{
476 : /**
477 : * @brief String inserters
478 : * @param out An output stream.
479 : * @param s A character string.
480 : * @return out
481 : * @pre @a s must be a non-NULL pointer
482 : *
483 : * Behaves like one of the formatted arithmetic inserters described in
484 : * std::basic_ostream. After constructing a sentry object with good
485 : * status, this function inserts @c traits::length(s) characters starting
486 : * at @a s, widened if necessary, followed by any required padding (as
487 : * determined by [22.2.2.2.2]). @c out.width(0) is then called.
488 : */
489 : template<typename _CharT, typename _Traits>
490 : inline basic_ostream<_CharT, _Traits>&
491 : operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
492 : {
493 : if (!__s)
494 : __out.setstate(ios_base::badbit);
495 : else
496 : __ostream_insert(__out, __s,
497 : static_cast<streamsize>(_Traits::length(__s)));
498 : return __out;
499 : }
500 :
501 : template<typename _CharT, typename _Traits>
502 : basic_ostream<_CharT, _Traits> &
503 : operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
504 :
505 : // Partial specializations
506 : template<class _Traits>
507 : inline basic_ostream<char, _Traits>&
508 0 : operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
509 : {
510 0 : if (!__s)
511 0 : __out.setstate(ios_base::badbit);
512 : else
513 0 : __ostream_insert(__out, __s,
514 : static_cast<streamsize>(_Traits::length(__s)));
515 0 : return __out;
516 : }
517 :
518 : // Signed and unsigned
519 : template<class _Traits>
520 : inline basic_ostream<char, _Traits>&
521 : operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
522 : { return (__out << reinterpret_cast<const char*>(__s)); }
523 :
524 : template<class _Traits>
525 : inline basic_ostream<char, _Traits> &
526 : operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
527 : { return (__out << reinterpret_cast<const char*>(__s)); }
528 : //@}
529 :
530 : // [27.6.2.7] standard basic_ostream manipulators
531 : /**
532 : * @brief Write a newline and flush the stream.
533 : *
534 : * This manipulator is often mistakenly used when a simple newline is
535 : * desired, leading to poor buffering performance. See
536 : * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
537 : * for more on this subject.
538 : */
539 : template<typename _CharT, typename _Traits>
540 : inline basic_ostream<_CharT, _Traits>&
541 0 : endl(basic_ostream<_CharT, _Traits>& __os)
542 0 : { return flush(__os.put(__os.widen('\n'))); }
543 :
544 : /**
545 : * @brief Write a null character into the output sequence.
546 : *
547 : * <em>Null character</em> is @c CharT() by definition. For CharT of @c char,
548 : * this correctly writes the ASCII @c NUL character string terminator.
549 : */
550 : template<typename _CharT, typename _Traits>
551 : inline basic_ostream<_CharT, _Traits>&
552 : ends(basic_ostream<_CharT, _Traits>& __os)
553 : { return __os.put(_CharT()); }
554 :
555 : /**
556 : * @brief Flushes the output stream.
557 : *
558 : * This manipulator simply calls the stream's @c flush() member function.
559 : */
560 : template<typename _CharT, typename _Traits>
561 : inline basic_ostream<_CharT, _Traits>&
562 0 : flush(basic_ostream<_CharT, _Traits>& __os)
563 0 : { return __os.flush(); }
564 :
565 : #ifdef __GXX_EXPERIMENTAL_CXX0X__
566 : // [27.7.2.9] Rvalue stream insertion
567 : /**
568 : * @brief Generic inserter for rvalue stream
569 : * @param os An input stream.
570 : * @param x A reference to the object being inserted.
571 : * @return os
572 : *
573 : * This is just a forwarding function to allow insertion to
574 : * rvalue streams since they won't bind to the inserter functions
575 : * that take an lvalue reference.
576 : */
577 : template<typename _CharT, typename _Traits, typename _Tp>
578 : inline basic_ostream<_CharT, _Traits>&
579 : operator<<(basic_ostream<_CharT, _Traits>&& __os, const _Tp& __x)
580 : { return (__os << __x); }
581 : #endif // __GXX_EXPERIMENTAL_CXX0X__
582 :
583 : _GLIBCXX_END_NAMESPACE
584 :
585 : #ifndef _GLIBCXX_EXPORT_TEMPLATE
586 : # include <bits/ostream.tcc>
587 : #endif
588 :
589 : #endif /* _GLIBCXX_OSTREAM */
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