1 : // Output streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2007, 2008, 2009, 2010, 2011
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 include/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 : namespace std _GLIBCXX_VISIBILITY(default)
44 : {
45 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
46 :
47 : // [27.6.2.1] Template class basic_ostream
48 : /**
49 : * @brief Controlling output.
50 : * @ingroup io
51 : *
52 : * This is the base class for all output streams. It provides text
53 : * formatting of all builtin types, and communicates with any class
54 : * derived from basic_streambuf to do the actual output.
55 : */
56 : template<typename _CharT, typename _Traits>
57 : class basic_ostream : virtual public basic_ios<_CharT, _Traits>
58 : {
59 : public:
60 : // Types (inherited from basic_ios (27.4.4)):
61 : typedef _CharT char_type;
62 : typedef typename _Traits::int_type int_type;
63 : typedef typename _Traits::pos_type pos_type;
64 : typedef typename _Traits::off_type off_type;
65 : typedef _Traits traits_type;
66 :
67 : // Non-standard Types:
68 : typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
69 : typedef basic_ios<_CharT, _Traits> __ios_type;
70 : typedef basic_ostream<_CharT, _Traits> __ostream_type;
71 : typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> >
72 : __num_put_type;
73 : typedef ctype<_CharT> __ctype_type;
74 :
75 : // [27.6.2.2] constructor/destructor
76 : /**
77 : * @brief Base constructor.
78 : *
79 : * This ctor is almost never called by the user directly, rather from
80 : * derived classes' initialization lists, which pass a pointer to
81 : * their own stream buffer.
82 : */
83 : explicit
84 : basic_ostream(__streambuf_type* __sb)
85 : { this->init(__sb); }
86 :
87 : /**
88 : * @brief Base destructor.
89 : *
90 : * This does very little apart from providing a virtual base dtor.
91 : */
92 : virtual
93 0 : ~basic_ostream() { }
94 :
95 : // [27.6.2.3] prefix/suffix
96 : class sentry;
97 : friend class sentry;
98 :
99 : // [27.6.2.5] formatted output
100 : // [27.6.2.5.3] basic_ostream::operator<<
101 : //@{
102 : /**
103 : * @brief Interface for manipulators.
104 : *
105 : * Manipulators such as @c std::endl and @c std::hex use these
106 : * functions in constructs like "std::cout << std::endl". For more
107 : * information, see the iomanip header.
108 : */
109 : __ostream_type&
110 0 : operator<<(__ostream_type& (*__pf)(__ostream_type&))
111 : {
112 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
113 : // DR 60. What is a formatted input function?
114 : // The inserters for manipulators are *not* formatted output functions.
115 0 : return __pf(*this);
116 : }
117 :
118 : __ostream_type&
119 : operator<<(__ios_type& (*__pf)(__ios_type&))
120 : {
121 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
122 : // DR 60. What is a formatted input function?
123 : // The inserters for manipulators are *not* formatted output functions.
124 : __pf(*this);
125 : return *this;
126 : }
127 :
128 : __ostream_type&
129 0 : operator<<(ios_base& (*__pf) (ios_base&))
130 : {
131 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
132 : // DR 60. What is a formatted input function?
133 : // The inserters for manipulators are *not* formatted output functions.
134 0 : __pf(*this);
135 0 : return *this;
136 : }
137 : //@}
138 :
139 : // [27.6.2.5.2] arithmetic inserters
140 : /**
141 : * @name Arithmetic Inserters
142 : *
143 : * All the @c operator<< functions (aka <em>formatted output
144 : * functions</em>) have some common behavior. Each starts by
145 : * constructing a temporary object of type std::basic_ostream::sentry.
146 : * This can have several effects, concluding with the setting of a
147 : * status flag; see the sentry documentation for more.
148 : *
149 : * If the sentry status is good, the function tries to generate
150 : * whatever data is appropriate for the type of the argument.
151 : *
152 : * If an exception is thrown during insertion, ios_base::badbit
153 : * will be turned on in the stream's error state without causing an
154 : * ios_base::failure to be thrown. The original exception will then
155 : * be rethrown.
156 : */
157 : //@{
158 : /**
159 : * @brief Basic arithmetic inserters
160 : * @param A variable of builtin type.
161 : * @return @c *this if successful
162 : *
163 : * These functions use the stream's current locale (specifically, the
164 : * @c num_get facet) to perform numeric formatting.
165 : */
166 : __ostream_type&
167 : operator<<(long __n)
168 : { return _M_insert(__n); }
169 :
170 : __ostream_type&
171 : operator<<(unsigned long __n)
172 : { return _M_insert(__n); }
173 :
174 : __ostream_type&
175 : operator<<(bool __n)
176 : { return _M_insert(__n); }
177 :
178 : __ostream_type&
179 : operator<<(short __n);
180 :
181 : __ostream_type&
182 0 : operator<<(unsigned short __n)
183 : {
184 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
185 : // 117. basic_ostream uses nonexistent num_put member functions.
186 0 : return _M_insert(static_cast<unsigned long>(__n));
187 : }
188 :
189 : __ostream_type&
190 : operator<<(int __n);
191 :
192 : __ostream_type&
193 0 : operator<<(unsigned int __n)
194 : {
195 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
196 : // 117. basic_ostream uses nonexistent num_put member functions.
197 0 : return _M_insert(static_cast<unsigned long>(__n));
198 : }
199 :
200 : #ifdef _GLIBCXX_USE_LONG_LONG
201 : __ostream_type&
202 0 : operator<<(long long __n)
203 0 : { return _M_insert(__n); }
204 :
205 : __ostream_type&
206 0 : operator<<(unsigned long long __n)
207 0 : { return _M_insert(__n); }
208 : #endif
209 :
210 : __ostream_type&
211 0 : operator<<(double __f)
212 0 : { return _M_insert(__f); }
213 :
214 : __ostream_type&
215 : operator<<(float __f)
216 : {
217 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
218 : // 117. basic_ostream uses nonexistent num_put member functions.
219 : return _M_insert(static_cast<double>(__f));
220 : }
221 :
222 : __ostream_type&
223 : operator<<(long double __f)
224 : { return _M_insert(__f); }
225 :
226 : __ostream_type&
227 0 : operator<<(const void* __p)
228 0 : { return _M_insert(__p); }
229 :
230 : /**
231 : * @brief Extracting from another streambuf.
232 : * @param sb A pointer to a streambuf
233 : *
234 : * This function behaves like one of the basic arithmetic extractors,
235 : * in that it also constructs a sentry object and has the same error
236 : * handling behavior.
237 : *
238 : * If @a sb is NULL, the stream will set failbit in its error state.
239 : *
240 : * Characters are extracted from @a sb and inserted into @c *this
241 : * until one of the following occurs:
242 : *
243 : * - the input stream reaches end-of-file,
244 : * - insertion into the output sequence fails (in this case, the
245 : * character that would have been inserted is not extracted), or
246 : * - an exception occurs while getting a character from @a sb, which
247 : * sets failbit in the error state
248 : *
249 : * If the function inserts no characters, failbit is set.
250 : */
251 : __ostream_type&
252 : operator<<(__streambuf_type* __sb);
253 : //@}
254 :
255 : // [27.6.2.6] unformatted output functions
256 : /**
257 : * @name Unformatted Output Functions
258 : *
259 : * All the unformatted output functions have some common behavior.
260 : * Each starts by constructing a temporary object of type
261 : * std::basic_ostream::sentry. This has several effects, concluding
262 : * with the setting of a status flag; see the sentry documentation
263 : * for more.
264 : *
265 : * If the sentry status is good, the function tries to generate
266 : * whatever data is appropriate for the type of the argument.
267 : *
268 : * If an exception is thrown during insertion, ios_base::badbit
269 : * will be turned on in the stream's error state. If badbit is on in
270 : * the stream's exceptions mask, the exception will be rethrown
271 : * without completing its actions.
272 : */
273 : //@{
274 : /**
275 : * @brief Simple insertion.
276 : * @param c The character to insert.
277 : * @return *this
278 : *
279 : * Tries to insert @a c.
280 : *
281 : * @note This function is not overloaded on signed char and
282 : * unsigned char.
283 : */
284 : __ostream_type&
285 : put(char_type __c);
286 :
287 : // Core write functionality, without sentry.
288 : void
289 : _M_write(const char_type* __s, streamsize __n)
290 : {
291 : const streamsize __put = this->rdbuf()->sputn(__s, __n);
292 : if (__put != __n)
293 : this->setstate(ios_base::badbit);
294 : }
295 :
296 : /**
297 : * @brief Character string insertion.
298 : * @param s The array to insert.
299 : * @param n Maximum number of characters to insert.
300 : * @return *this
301 : *
302 : * Characters are copied from @a s and inserted into the stream until
303 : * one of the following happens:
304 : *
305 : * - @a n characters are inserted
306 : * - inserting into the output sequence fails (in this case, badbit
307 : * will be set in the stream's error state)
308 : *
309 : * @note This function is not overloaded on signed char and
310 : * unsigned char.
311 : */
312 : __ostream_type&
313 : write(const char_type* __s, streamsize __n);
314 : //@}
315 :
316 : /**
317 : * @brief Synchronizing the stream buffer.
318 : * @return *this
319 : *
320 : * If @c rdbuf() is a null pointer, changes nothing.
321 : *
322 : * Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
323 : * sets badbit.
324 : */
325 : __ostream_type&
326 : flush();
327 :
328 : // [27.6.2.4] seek members
329 : /**
330 : * @brief Getting the current write position.
331 : * @return A file position object.
332 : *
333 : * If @c fail() is not false, returns @c pos_type(-1) to indicate
334 : * failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
335 : */
336 : pos_type
337 : tellp();
338 :
339 : /**
340 : * @brief Changing the current write position.
341 : * @param pos A file position object.
342 : * @return *this
343 : *
344 : * If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
345 : * that function fails, sets failbit.
346 : */
347 : __ostream_type&
348 : seekp(pos_type);
349 :
350 : /**
351 : * @brief Changing the current write position.
352 : * @param off A file offset object.
353 : * @param dir The direction in which to seek.
354 : * @return *this
355 : *
356 : * If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
357 : * If that function fails, sets failbit.
358 : */
359 : __ostream_type&
360 : seekp(off_type, ios_base::seekdir);
361 :
362 : protected:
363 0 : basic_ostream()
364 0 : { this->init(0); }
365 :
366 : template<typename _ValueT>
367 : __ostream_type&
368 : _M_insert(_ValueT __v);
369 : };
370 :
371 : /**
372 : * @brief Performs setup work for output streams.
373 : *
374 : * Objects of this class are created before all of the standard
375 : * inserters are run. It is responsible for <em>exception-safe prefix and
376 : * suffix operations</em>.
377 : */
378 : template <typename _CharT, typename _Traits>
379 : class basic_ostream<_CharT, _Traits>::sentry
380 : {
381 : // Data Members.
382 : bool _M_ok;
383 : basic_ostream<_CharT, _Traits>& _M_os;
384 :
385 : public:
386 : /**
387 : * @brief The constructor performs preparatory work.
388 : * @param os The output stream to guard.
389 : *
390 : * If the stream state is good (@a os.good() is true), then if the
391 : * stream is tied to another output stream, @c is.tie()->flush()
392 : * is called to synchronize the output sequences.
393 : *
394 : * If the stream state is still good, then the sentry state becomes
395 : * true (@a okay).
396 : */
397 : explicit
398 : sentry(basic_ostream<_CharT, _Traits>& __os);
399 :
400 : /**
401 : * @brief Possibly flushes the stream.
402 : *
403 : * If @c ios_base::unitbuf is set in @c os.flags(), and
404 : * @c std::uncaught_exception() is true, the sentry destructor calls
405 : * @c flush() on the output stream.
406 : */
407 : ~sentry()
408 : {
409 : // XXX MT
410 : if (bool(_M_os.flags() & ios_base::unitbuf) && !uncaught_exception())
411 : {
412 : // Can't call flush directly or else will get into recursive lock.
413 : if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
414 : _M_os.setstate(ios_base::badbit);
415 : }
416 : }
417 :
418 : /**
419 : * @brief Quick status checking.
420 : * @return The sentry state.
421 : *
422 : * For ease of use, sentries may be converted to booleans. The
423 : * return value is that of the sentry state (true == okay).
424 : */
425 : #ifdef __GXX_EXPERIMENTAL_CXX0X__
426 : explicit
427 : #endif
428 : operator bool() const
429 : { return _M_ok; }
430 : };
431 :
432 : // [27.6.2.5.4] character insertion templates
433 : //@{
434 : /**
435 : * @brief Character inserters
436 : * @param out An output stream.
437 : * @param c A character.
438 : * @return out
439 : *
440 : * Behaves like one of the formatted arithmetic inserters described in
441 : * std::basic_ostream. After constructing a sentry object with good
442 : * status, this function inserts a single character and any required
443 : * padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
444 : * called.
445 : *
446 : * If @a c is of type @c char and the character type of the stream is not
447 : * @c char, the character is widened before insertion.
448 : */
449 : template<typename _CharT, typename _Traits>
450 : inline basic_ostream<_CharT, _Traits>&
451 : operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
452 : { return __ostream_insert(__out, &__c, 1); }
453 :
454 : template<typename _CharT, typename _Traits>
455 : inline basic_ostream<_CharT, _Traits>&
456 : operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
457 : { return (__out << __out.widen(__c)); }
458 :
459 : // Specialization
460 : template <class _Traits>
461 : inline basic_ostream<char, _Traits>&
462 0 : operator<<(basic_ostream<char, _Traits>& __out, char __c)
463 0 : { return __ostream_insert(__out, &__c, 1); }
464 :
465 : // Signed and unsigned
466 : template<class _Traits>
467 : inline basic_ostream<char, _Traits>&
468 : operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
469 : { return (__out << static_cast<char>(__c)); }
470 :
471 : template<class _Traits>
472 : inline basic_ostream<char, _Traits>&
473 0 : operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
474 0 : { return (__out << static_cast<char>(__c)); }
475 : //@}
476 :
477 : //@{
478 : /**
479 : * @brief String inserters
480 : * @param out An output stream.
481 : * @param s A character string.
482 : * @return out
483 : * @pre @a s must be a non-NULL pointer
484 : *
485 : * Behaves like one of the formatted arithmetic inserters described in
486 : * std::basic_ostream. After constructing a sentry object with good
487 : * status, this function inserts @c traits::length(s) characters starting
488 : * at @a s, widened if necessary, followed by any required padding (as
489 : * determined by [22.2.2.2.2]). @c out.width(0) is then called.
490 : */
491 : template<typename _CharT, typename _Traits>
492 : inline basic_ostream<_CharT, _Traits>&
493 : operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
494 : {
495 : if (!__s)
496 : __out.setstate(ios_base::badbit);
497 : else
498 : __ostream_insert(__out, __s,
499 : static_cast<streamsize>(_Traits::length(__s)));
500 : return __out;
501 : }
502 :
503 : template<typename _CharT, typename _Traits>
504 : basic_ostream<_CharT, _Traits> &
505 : operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
506 :
507 : // Partial specializations
508 : template<class _Traits>
509 : inline basic_ostream<char, _Traits>&
510 0 : operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
511 : {
512 0 : if (!__s)
513 0 : __out.setstate(ios_base::badbit);
514 : else
515 0 : __ostream_insert(__out, __s,
516 : static_cast<streamsize>(_Traits::length(__s)));
517 0 : return __out;
518 : }
519 :
520 : // Signed and unsigned
521 : template<class _Traits>
522 : inline basic_ostream<char, _Traits>&
523 : operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
524 : { return (__out << reinterpret_cast<const char*>(__s)); }
525 :
526 : template<class _Traits>
527 : inline basic_ostream<char, _Traits> &
528 : operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
529 : { return (__out << reinterpret_cast<const char*>(__s)); }
530 : //@}
531 :
532 : // [27.6.2.7] standard basic_ostream manipulators
533 : /**
534 : * @brief Write a newline and flush the stream.
535 : *
536 : * This manipulator is often mistakenly used when a simple newline is
537 : * desired, leading to poor buffering performance. See
538 : * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
539 : * for more on this subject.
540 : */
541 : template<typename _CharT, typename _Traits>
542 : inline basic_ostream<_CharT, _Traits>&
543 0 : endl(basic_ostream<_CharT, _Traits>& __os)
544 0 : { return flush(__os.put(__os.widen('\n'))); }
545 :
546 : /**
547 : * @brief Write a null character into the output sequence.
548 : *
549 : * <em>Null character</em> is @c CharT() by definition. For CharT of @c char,
550 : * this correctly writes the ASCII @c NUL character string terminator.
551 : */
552 : template<typename _CharT, typename _Traits>
553 : inline basic_ostream<_CharT, _Traits>&
554 : ends(basic_ostream<_CharT, _Traits>& __os)
555 : { return __os.put(_CharT()); }
556 :
557 : /**
558 : * @brief Flushes the output stream.
559 : *
560 : * This manipulator simply calls the stream's @c flush() member function.
561 : */
562 : template<typename _CharT, typename _Traits>
563 : inline basic_ostream<_CharT, _Traits>&
564 0 : flush(basic_ostream<_CharT, _Traits>& __os)
565 0 : { return __os.flush(); }
566 :
567 : #ifdef __GXX_EXPERIMENTAL_CXX0X__
568 : // [27.7.2.9] Rvalue stream insertion
569 : /**
570 : * @brief Generic inserter for rvalue stream
571 : * @param os An input stream.
572 : * @param x A reference to the object being inserted.
573 : * @return os
574 : *
575 : * This is just a forwarding function to allow insertion to
576 : * rvalue streams since they won't bind to the inserter functions
577 : * that take an lvalue reference.
578 : */
579 : template<typename _CharT, typename _Traits, typename _Tp>
580 : inline basic_ostream<_CharT, _Traits>&
581 : operator<<(basic_ostream<_CharT, _Traits>&& __os, const _Tp& __x)
582 : { return (__os << __x); }
583 : #endif // __GXX_EXPERIMENTAL_CXX0X__
584 :
585 : _GLIBCXX_END_NAMESPACE_VERSION
586 : } // namespace
587 :
588 : #include <bits/ostream.tcc>
589 :
590 : #endif /* _GLIBCXX_OSTREAM */
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