1 : // Output streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2007
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 2, 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 : // You should have received a copy of the GNU General Public License along
19 : // with this library; see the file COPYING. If not, write to the Free
20 : // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
21 : // USA.
22 :
23 : // As a special exception, you may use this file as part of a free software
24 : // library without restriction. Specifically, if other files instantiate
25 : // templates or use macros or inline functions from this file, or you compile
26 : // this file and link it with other files to produce an executable, this
27 : // file does not by itself cause the resulting executable to be covered by
28 : // the GNU General Public License. This exception does not however
29 : // invalidate any other reasons why the executable file might be covered by
30 : // the GNU General Public License.
31 :
32 : /** @file ostream
33 : * This is a Standard C++ Library header.
34 : */
35 :
36 : //
37 : // ISO C++ 14882: 27.6.2 Output streams
38 : //
39 :
40 : #ifndef _GLIBCXX_OSTREAM
41 : #define _GLIBCXX_OSTREAM 1
42 :
43 : #pragma GCC system_header
44 :
45 : #include <ios>
46 : #include <bits/ostream_insert.h>
47 :
48 : _GLIBCXX_BEGIN_NAMESPACE(std)
49 :
50 : // [27.6.2.1] Template class basic_ostream
51 : /**
52 : * @brief Controlling output.
53 : *
54 : * This is the base class for all output streams. It provides text
55 : * formatting of all builtin types, and communicates with any class
56 : * derived from basic_streambuf to do the actual output.
57 : */
58 : template<typename _CharT, typename _Traits>
59 : class basic_ostream : virtual public basic_ios<_CharT, _Traits>
60 : {
61 : public:
62 : // Types (inherited from basic_ios (27.4.4)):
63 : typedef _CharT char_type;
64 : typedef typename _Traits::int_type int_type;
65 : typedef typename _Traits::pos_type pos_type;
66 : typedef typename _Traits::off_type off_type;
67 : typedef _Traits traits_type;
68 :
69 : // Non-standard Types:
70 : typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
71 : typedef basic_ios<_CharT, _Traits> __ios_type;
72 : typedef basic_ostream<_CharT, _Traits> __ostream_type;
73 : typedef num_put<_CharT, ostreambuf_iterator<_CharT, _Traits> >
74 : __num_put_type;
75 : typedef ctype<_CharT> __ctype_type;
76 :
77 : // [27.6.2.2] constructor/destructor
78 : /**
79 : * @brief Base constructor.
80 : *
81 : * This ctor is almost never called by the user directly, rather from
82 : * derived classes' initialization lists, which pass a pointer to
83 : * their own stream buffer.
84 : */
85 : explicit
86 : basic_ostream(__streambuf_type* __sb)
87 : { this->init(__sb); }
88 :
89 : /**
90 : * @brief Base destructor.
91 : *
92 : * This does very little apart from providing a virtual base dtor.
93 : */
94 : virtual
95 0 : ~basic_ostream() { }
96 :
97 : // [27.6.2.3] prefix/suffix
98 : class sentry;
99 : friend class sentry;
100 :
101 : // [27.6.2.5] formatted output
102 : // [27.6.2.5.3] basic_ostream::operator<<
103 : //@{
104 : /**
105 : * @brief Interface for manipulators.
106 : *
107 : * Manuipulators such as @c std::endl and @c std::hex use these
108 : * functions in constructs like "std::cout << std::endl". For more
109 : * information, see the iomanip header.
110 : */
111 : __ostream_type&
112 0 : operator<<(__ostream_type& (*__pf)(__ostream_type&))
113 : {
114 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
115 : // DR 60. What is a formatted input function?
116 : // The inserters for manipulators are *not* formatted output functions.
117 0 : return __pf(*this);
118 : }
119 :
120 : __ostream_type&
121 : operator<<(__ios_type& (*__pf)(__ios_type&))
122 : {
123 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
124 : // DR 60. What is a formatted input function?
125 : // The inserters for manipulators are *not* formatted output functions.
126 : __pf(*this);
127 : return *this;
128 : }
129 :
130 : __ostream_type&
131 0 : operator<<(ios_base& (*__pf) (ios_base&))
132 : {
133 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
134 : // DR 60. What is a formatted input function?
135 : // The inserters for manipulators are *not* formatted output functions.
136 0 : __pf(*this);
137 0 : return *this;
138 : }
139 : //@}
140 :
141 : // [27.6.2.5.2] arithmetic inserters
142 : /**
143 : * @name Arithmetic Inserters
144 : *
145 : * All the @c operator<< functions (aka <em>formatted output
146 : * functions</em>) have some common behavior. Each starts by
147 : * constructing a temporary object of type std::basic_ostream::sentry.
148 : * This can have several effects, concluding with the setting of a
149 : * status flag; see the sentry documentation for more.
150 : *
151 : * If the sentry status is good, the function tries to generate
152 : * whatever data is appropriate for the type of the argument.
153 : *
154 : * If an exception is thrown during insertion, ios_base::badbit
155 : * will be turned on in the stream's error state without causing an
156 : * ios_base::failure to be thrown. The original exception will then
157 : * be rethrown.
158 : */
159 : //@{
160 : /**
161 : * @brief Basic arithmetic inserters
162 : * @param A variable of builtin type.
163 : * @return @c *this if successful
164 : *
165 : * These functions use the stream's current locale (specifically, the
166 : * @c num_get facet) to perform numeric formatting.
167 : */
168 : __ostream_type&
169 0 : operator<<(long __n)
170 0 : { return _M_insert(__n); }
171 :
172 : __ostream_type&
173 0 : operator<<(unsigned long __n)
174 0 : { return _M_insert(__n); }
175 :
176 : __ostream_type&
177 : operator<<(bool __n)
178 : { return _M_insert(__n); }
179 :
180 : __ostream_type&
181 : operator<<(short __n);
182 :
183 : __ostream_type&
184 : operator<<(unsigned short __n)
185 : {
186 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
187 : // 117. basic_ostream uses nonexistent num_put member functions.
188 : return _M_insert(static_cast<unsigned long>(__n));
189 : }
190 :
191 : __ostream_type&
192 : operator<<(int __n);
193 :
194 : __ostream_type&
195 0 : operator<<(unsigned int __n)
196 : {
197 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
198 : // 117. basic_ostream uses nonexistent num_put member functions.
199 0 : return _M_insert(static_cast<unsigned long>(__n));
200 : }
201 :
202 : #ifdef _GLIBCXX_USE_LONG_LONG
203 : __ostream_type&
204 0 : operator<<(long long __n)
205 0 : { return _M_insert(__n); }
206 :
207 : __ostream_type&
208 : operator<<(unsigned long long __n)
209 : { return _M_insert(__n); }
210 : #endif
211 :
212 : __ostream_type&
213 0 : operator<<(double __f)
214 0 : { return _M_insert(__f); }
215 :
216 : __ostream_type&
217 0 : operator<<(float __f)
218 : {
219 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
220 : // 117. basic_ostream uses nonexistent num_put member functions.
221 0 : return _M_insert(static_cast<double>(__f));
222 : }
223 :
224 : __ostream_type&
225 : operator<<(long double __f)
226 : { return _M_insert(__f); }
227 :
228 : __ostream_type&
229 0 : operator<<(const void* __p)
230 0 : { return _M_insert(__p); }
231 :
232 : /**
233 : * @brief Extracting from another streambuf.
234 : * @param sb A pointer to a streambuf
235 : *
236 : * This function behaves like one of the basic arithmetic extractors,
237 : * in that it also constructs a sentry object and has the same error
238 : * handling behavior.
239 : *
240 : * If @a sb is NULL, the stream will set failbit in its error state.
241 : *
242 : * Characters are extracted from @a sb and inserted into @c *this
243 : * until one of the following occurs:
244 : *
245 : * - the input stream reaches end-of-file,
246 : * - insertion into the output sequence fails (in this case, the
247 : * character that would have been inserted is not extracted), or
248 : * - an exception occurs while getting a character from @a sb, which
249 : * sets failbit in the error state
250 : *
251 : * If the function inserts no characters, failbit is set.
252 : */
253 : __ostream_type&
254 : operator<<(__streambuf_type* __sb);
255 : //@}
256 :
257 : // [27.6.2.6] unformatted output functions
258 : /**
259 : * @name Unformatted Output Functions
260 : *
261 : * All the unformatted output functions have some common behavior.
262 : * Each starts by constructing a temporary object of type
263 : * std::basic_ostream::sentry. This has several effects, concluding
264 : * with the setting of a status flag; see the sentry documentation
265 : * for more.
266 : *
267 : * If the sentry status is good, the function tries to generate
268 : * whatever data is appropriate for the type of the argument.
269 : *
270 : * If an exception is thrown during insertion, ios_base::badbit
271 : * will be turned on in the stream's error state. If badbit is on in
272 : * the stream's exceptions mask, the exception will be rethrown
273 : * without completing its actions.
274 : */
275 : //@{
276 : /**
277 : * @brief Simple insertion.
278 : * @param c The character to insert.
279 : * @return *this
280 : *
281 : * Tries to insert @a c.
282 : *
283 : * @note This function is not overloaded on signed char and
284 : * unsigned char.
285 : */
286 : __ostream_type&
287 : put(char_type __c);
288 :
289 : // Core write functionality, without sentry.
290 : void
291 : _M_write(const char_type* __s, streamsize __n)
292 : {
293 : const streamsize __put = this->rdbuf()->sputn(__s, __n);
294 : if (__put != __n)
295 : this->setstate(ios_base::badbit);
296 : }
297 :
298 : /**
299 : * @brief Character string insertion.
300 : * @param s The array to insert.
301 : * @param n Maximum number of characters to insert.
302 : * @return *this
303 : *
304 : * Characters are copied from @a s and inserted into the stream until
305 : * one of the following happens:
306 : *
307 : * - @a n characters are inserted
308 : * - inserting into the output sequence fails (in this case, badbit
309 : * will be set in the stream's error state)
310 : *
311 : * @note This function is not overloaded on signed char and
312 : * unsigned char.
313 : */
314 : __ostream_type&
315 : write(const char_type* __s, streamsize __n);
316 : //@}
317 :
318 : /**
319 : * @brief Synchronizing the stream buffer.
320 : * @return *this
321 : *
322 : * If @c rdbuf() is a null pointer, changes nothing.
323 : *
324 : * Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
325 : * sets badbit.
326 : */
327 : __ostream_type&
328 : flush();
329 :
330 : // [27.6.2.4] seek members
331 : /**
332 : * @brief Getting the current write position.
333 : * @return A file position object.
334 : *
335 : * If @c fail() is not false, returns @c pos_type(-1) to indicate
336 : * failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
337 : */
338 : pos_type
339 : tellp();
340 :
341 : /**
342 : * @brief Changing the current write position.
343 : * @param pos A file position object.
344 : * @return *this
345 : *
346 : * If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
347 : * that function fails, sets failbit.
348 : */
349 : __ostream_type&
350 : seekp(pos_type);
351 :
352 : /**
353 : * @brief Changing the current write position.
354 : * @param off A file offset object.
355 : * @param dir The direction in which to seek.
356 : * @return *this
357 : *
358 : * If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
359 : * If that function fails, sets failbit.
360 : */
361 : __ostream_type&
362 : seekp(off_type, ios_base::seekdir);
363 :
364 : protected:
365 : explicit
366 0 : basic_ostream() { }
367 :
368 : template<typename _ValueT>
369 : __ostream_type&
370 : _M_insert(_ValueT __v);
371 : };
372 :
373 : /**
374 : * @brief Performs setup work for output streams.
375 : *
376 : * Objects of this class are created before all of the standard
377 : * inserters are run. It is responsible for "exception-safe prefix and
378 : * suffix operations." Additional actions may be added by the
379 : * implementation, and we list them in
380 : * http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5
381 : * under [27.6] notes.
382 : */
383 : template <typename _CharT, typename _Traits>
384 : class basic_ostream<_CharT, _Traits>::sentry
385 : {
386 : // Data Members:
387 : bool _M_ok;
388 : basic_ostream<_CharT, _Traits>& _M_os;
389 :
390 : public:
391 : /**
392 : * @brief The constructor performs preparatory work.
393 : * @param os The output stream to guard.
394 : *
395 : * If the stream state is good (@a os.good() is true), then if the
396 : * stream is tied to another output stream, @c is.tie()->flush()
397 : * is called to synchronize the output sequences.
398 : *
399 : * If the stream state is still good, then the sentry state becomes
400 : * true ("okay").
401 : */
402 : explicit
403 : sentry(basic_ostream<_CharT, _Traits>& __os);
404 :
405 : /**
406 : * @brief Possibly flushes the stream.
407 : *
408 : * If @c ios_base::unitbuf is set in @c os.flags(), and
409 : * @c std::uncaught_exception() is true, the sentry destructor calls
410 : * @c flush() on the output stream.
411 : */
412 : ~sentry()
413 : {
414 : // XXX MT
415 : if (_M_os.flags() & ios_base::unitbuf && !uncaught_exception())
416 : {
417 : // Can't call flush directly or else will get into recursive lock.
418 : if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
419 : _M_os.setstate(ios_base::badbit);
420 : }
421 : }
422 :
423 : /**
424 : * @brief Quick status checking.
425 : * @return The sentry state.
426 : *
427 : * For ease of use, sentries may be converted to booleans. The
428 : * return value is that of the sentry state (true == okay).
429 : */
430 : operator bool() const
431 : { return _M_ok; }
432 : };
433 :
434 : // [27.6.2.5.4] character insertion templates
435 : //@{
436 : /**
437 : * @brief Character inserters
438 : * @param out An output stream.
439 : * @param c A character.
440 : * @return out
441 : *
442 : * Behaves like one of the formatted arithmetic inserters described in
443 : * std::basic_ostream. After constructing a sentry object with good
444 : * status, this function inserts a single character and any required
445 : * padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
446 : * called.
447 : *
448 : * If @a c is of type @c char and the character type of the stream is not
449 : * @c char, the character is widened before insertion.
450 : */
451 : template<typename _CharT, typename _Traits>
452 : inline basic_ostream<_CharT, _Traits>&
453 : operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
454 : { return __ostream_insert(__out, &__c, 1); }
455 :
456 : template<typename _CharT, typename _Traits>
457 : inline basic_ostream<_CharT, _Traits>&
458 : operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
459 : { return (__out << __out.widen(__c)); }
460 :
461 : // Specialization
462 : template <class _Traits>
463 : inline basic_ostream<char, _Traits>&
464 0 : operator<<(basic_ostream<char, _Traits>& __out, char __c)
465 0 : { return __ostream_insert(__out, &__c, 1); }
466 :
467 : // Signed and unsigned
468 : template<class _Traits>
469 : inline basic_ostream<char, _Traits>&
470 : operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
471 : { return (__out << static_cast<char>(__c)); }
472 :
473 : template<class _Traits>
474 : inline basic_ostream<char, _Traits>&
475 0 : operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
476 0 : { return (__out << static_cast<char>(__c)); }
477 : //@}
478 :
479 : //@{
480 : /**
481 : * @brief String inserters
482 : * @param out An output stream.
483 : * @param s A character string.
484 : * @return out
485 : * @pre @a s must be a non-NULL pointer
486 : *
487 : * Behaves like one of the formatted arithmetic inserters described in
488 : * std::basic_ostream. After constructing a sentry object with good
489 : * status, this function inserts @c traits::length(s) characters starting
490 : * at @a s, widened if necessary, followed by any required padding (as
491 : * determined by [22.2.2.2.2]). @c out.width(0) is then called.
492 : */
493 : template<typename _CharT, typename _Traits>
494 : inline basic_ostream<_CharT, _Traits>&
495 : operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
496 : {
497 : if (!__s)
498 : __out.setstate(ios_base::badbit);
499 : else
500 : __ostream_insert(__out, __s,
501 : static_cast<streamsize>(_Traits::length(__s)));
502 : return __out;
503 : }
504 :
505 : template<typename _CharT, typename _Traits>
506 : basic_ostream<_CharT, _Traits> &
507 : operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
508 :
509 : // Partial specializationss
510 : template<class _Traits>
511 : inline basic_ostream<char, _Traits>&
512 0 : operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
513 : {
514 0 : if (!__s)
515 0 : __out.setstate(ios_base::badbit);
516 : else
517 0 : __ostream_insert(__out, __s,
518 : static_cast<streamsize>(_Traits::length(__s)));
519 0 : return __out;
520 : }
521 :
522 : // Signed and unsigned
523 : template<class _Traits>
524 : inline basic_ostream<char, _Traits>&
525 : operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
526 : { return (__out << reinterpret_cast<const char*>(__s)); }
527 :
528 : template<class _Traits>
529 : inline basic_ostream<char, _Traits> &
530 : operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
531 : { return (__out << reinterpret_cast<const char*>(__s)); }
532 : //@}
533 :
534 : // [27.6.2.7] standard basic_ostream manipulators
535 : /**
536 : * @brief Write a newline and flush the stream.
537 : *
538 : * This manipulator is often mistakenly used when a simple newline is
539 : * desired, leading to poor buffering performance. See
540 : * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for more
541 : * on this subject.
542 : */
543 : template<typename _CharT, typename _Traits>
544 : inline basic_ostream<_CharT, _Traits>&
545 0 : endl(basic_ostream<_CharT, _Traits>& __os)
546 0 : { return flush(__os.put(__os.widen('\n'))); }
547 :
548 : /**
549 : * @brief Write a null character into the output sequence.
550 : *
551 : * "Null character" is @c CharT() by definition. For CharT of @c char,
552 : * this correctly writes the ASCII @c NUL character string terminator.
553 : */
554 : template<typename _CharT, typename _Traits>
555 : inline basic_ostream<_CharT, _Traits>&
556 : ends(basic_ostream<_CharT, _Traits>& __os)
557 : { return __os.put(_CharT()); }
558 :
559 : /**
560 : * @brief Flushes the output stream.
561 : *
562 : * This manipulator simply calls the stream's @c flush() member function.
563 : */
564 : template<typename _CharT, typename _Traits>
565 : inline basic_ostream<_CharT, _Traits>&
566 0 : flush(basic_ostream<_CharT, _Traits>& __os)
567 0 : { return __os.flush(); }
568 :
569 : _GLIBCXX_END_NAMESPACE
570 :
571 : #ifndef _GLIBCXX_EXPORT_TEMPLATE
572 : # include <bits/ostream.tcc>
573 : #endif
574 :
575 : #endif /* _GLIBCXX_OSTREAM */
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