1 : // String based streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
5 : //
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 3, or (at your option)
10 : // any later version.
11 :
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.
16 :
17 : // Under Section 7 of GPL version 3, you are granted additional
18 : // permissions described in the GCC Runtime Library Exception, version
19 : // 3.1, as published by the Free Software Foundation.
20 :
21 : // You should have received a copy of the GNU General Public License and
22 : // a copy of the GCC Runtime Library Exception along with this program;
23 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 : // <http://www.gnu.org/licenses/>.
25 :
26 : /** @file include/sstream
27 : * This is a Standard C++ Library header.
28 : */
29 :
30 : //
31 : // ISO C++ 14882: 27.7 String-based streams
32 : //
33 :
34 : #ifndef _GLIBCXX_SSTREAM
35 : #define _GLIBCXX_SSTREAM 1
36 :
37 : #pragma GCC system_header
38 :
39 : #include <istream>
40 : #include <ostream>
41 :
42 : namespace std _GLIBCXX_VISIBILITY(default)
43 : {
44 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
45 :
46 : // [27.7.1] template class basic_stringbuf
47 : /**
48 : * @brief The actual work of input and output (for std::string).
49 : * @ingroup io
50 : *
51 : * This class associates either or both of its input and output sequences
52 : * with a sequence of characters, which can be initialized from, or made
53 : * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
54 : *
55 : * For this class, open modes (of type @c ios_base::openmode) have
56 : * @c in set if the input sequence can be read, and @c out set if the
57 : * output sequence can be written.
58 : */
59 : template<typename _CharT, typename _Traits, typename _Alloc>
60 0 : class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
61 : {
62 : public:
63 : // Types:
64 : typedef _CharT char_type;
65 : typedef _Traits traits_type;
66 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
67 : // 251. basic_stringbuf missing allocator_type
68 : typedef _Alloc allocator_type;
69 : typedef typename traits_type::int_type int_type;
70 : typedef typename traits_type::pos_type pos_type;
71 : typedef typename traits_type::off_type off_type;
72 :
73 : typedef basic_streambuf<char_type, traits_type> __streambuf_type;
74 : typedef basic_string<char_type, _Traits, _Alloc> __string_type;
75 : typedef typename __string_type::size_type __size_type;
76 :
77 : protected:
78 : /// Place to stash in || out || in | out settings for current stringbuf.
79 : ios_base::openmode _M_mode;
80 :
81 : // Data Members:
82 : __string_type _M_string;
83 :
84 : public:
85 : // Constructors:
86 : /**
87 : * @brief Starts with an empty string buffer.
88 : * @param mode Whether the buffer can read, or write, or both.
89 : *
90 : * The default constructor initializes the parent class using its
91 : * own default ctor.
92 : */
93 : explicit
94 0 : basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
95 0 : : __streambuf_type(), _M_mode(__mode), _M_string()
96 0 : { }
97 :
98 : /**
99 : * @brief Starts with an existing string buffer.
100 : * @param str A string to copy as a starting buffer.
101 : * @param mode Whether the buffer can read, or write, or both.
102 : *
103 : * This constructor initializes the parent class using its
104 : * own default ctor.
105 : */
106 : explicit
107 : basic_stringbuf(const __string_type& __str,
108 : ios_base::openmode __mode = ios_base::in | ios_base::out)
109 : : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())
110 : { _M_stringbuf_init(__mode); }
111 :
112 : // Get and set:
113 : /**
114 : * @brief Copying out the string buffer.
115 : * @return A copy of one of the underlying sequences.
116 : *
117 : * <em>If the buffer is only created in input mode, the underlying
118 : * character sequence is equal to the input sequence; otherwise, it
119 : * is equal to the output sequence.</em> [27.7.1.2]/1
120 : */
121 : __string_type
122 0 : str() const
123 : {
124 0 : __string_type __ret;
125 0 : if (this->pptr())
126 : {
127 : // The current egptr() may not be the actual string end.
128 0 : if (this->pptr() > this->egptr())
129 0 : __ret = __string_type(this->pbase(), this->pptr());
130 : else
131 0 : __ret = __string_type(this->pbase(), this->egptr());
132 : }
133 : else
134 0 : __ret = _M_string;
135 0 : return __ret;
136 : }
137 :
138 : /**
139 : * @brief Setting a new buffer.
140 : * @param s The string to use as a new sequence.
141 : *
142 : * Deallocates any previous stored sequence, then copies @a s to
143 : * use as a new one.
144 : */
145 : void
146 : str(const __string_type& __s)
147 : {
148 : // Cannot use _M_string = __s, since v3 strings are COW.
149 : _M_string.assign(__s.data(), __s.size());
150 : _M_stringbuf_init(_M_mode);
151 : }
152 :
153 : protected:
154 : // Common initialization code goes here.
155 : void
156 : _M_stringbuf_init(ios_base::openmode __mode)
157 : {
158 : _M_mode = __mode;
159 : __size_type __len = 0;
160 : if (_M_mode & (ios_base::ate | ios_base::app))
161 : __len = _M_string.size();
162 : _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
163 : }
164 :
165 : virtual streamsize
166 : showmanyc()
167 : {
168 : streamsize __ret = -1;
169 : if (_M_mode & ios_base::in)
170 : {
171 : _M_update_egptr();
172 : __ret = this->egptr() - this->gptr();
173 : }
174 : return __ret;
175 : }
176 :
177 : virtual int_type
178 : underflow();
179 :
180 : virtual int_type
181 : pbackfail(int_type __c = traits_type::eof());
182 :
183 : virtual int_type
184 : overflow(int_type __c = traits_type::eof());
185 :
186 : /**
187 : * @brief Manipulates the buffer.
188 : * @param s Pointer to a buffer area.
189 : * @param n Size of @a s.
190 : * @return @c this
191 : *
192 : * If no buffer has already been created, and both @a s and @a n are
193 : * non-zero, then @c s is used as a buffer; see
194 : * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
195 : * for more.
196 : */
197 : virtual __streambuf_type*
198 : setbuf(char_type* __s, streamsize __n)
199 : {
200 : if (__s && __n >= 0)
201 : {
202 : // This is implementation-defined behavior, and assumes
203 : // that an external char_type array of length __n exists
204 : // and has been pre-allocated. If this is not the case,
205 : // things will quickly blow up.
206 :
207 : // Step 1: Destroy the current internal array.
208 : _M_string.clear();
209 :
210 : // Step 2: Use the external array.
211 : _M_sync(__s, __n, 0);
212 : }
213 : return this;
214 : }
215 :
216 : virtual pos_type
217 : seekoff(off_type __off, ios_base::seekdir __way,
218 : ios_base::openmode __mode = ios_base::in | ios_base::out);
219 :
220 : virtual pos_type
221 : seekpos(pos_type __sp,
222 : ios_base::openmode __mode = ios_base::in | ios_base::out);
223 :
224 : // Internal function for correctly updating the internal buffer
225 : // for a particular _M_string, due to initialization or re-sizing
226 : // of an existing _M_string.
227 : void
228 : _M_sync(char_type* __base, __size_type __i, __size_type __o);
229 :
230 : // Internal function for correctly updating egptr() to the actual
231 : // string end.
232 : void
233 : _M_update_egptr()
234 : {
235 : const bool __testin = _M_mode & ios_base::in;
236 : if (this->pptr() && this->pptr() > this->egptr())
237 : {
238 : if (__testin)
239 : this->setg(this->eback(), this->gptr(), this->pptr());
240 : else
241 : this->setg(this->pptr(), this->pptr(), this->pptr());
242 : }
243 : }
244 :
245 : // Works around the issue with pbump, part of the protected
246 : // interface of basic_streambuf, taking just an int.
247 : void
248 : _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off);
249 : };
250 :
251 :
252 : // [27.7.2] Template class basic_istringstream
253 : /**
254 : * @brief Controlling input for std::string.
255 : * @ingroup io
256 : *
257 : * This class supports reading from objects of type std::basic_string,
258 : * using the inherited functions from std::basic_istream. To control
259 : * the associated sequence, an instance of std::basic_stringbuf is used,
260 : * which this page refers to as @c sb.
261 : */
262 : template<typename _CharT, typename _Traits, typename _Alloc>
263 : class basic_istringstream : public basic_istream<_CharT, _Traits>
264 : {
265 : public:
266 : // Types:
267 : typedef _CharT char_type;
268 : typedef _Traits traits_type;
269 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
270 : // 251. basic_stringbuf missing allocator_type
271 : typedef _Alloc allocator_type;
272 : typedef typename traits_type::int_type int_type;
273 : typedef typename traits_type::pos_type pos_type;
274 : typedef typename traits_type::off_type off_type;
275 :
276 : // Non-standard types:
277 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
278 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
279 : typedef basic_istream<char_type, traits_type> __istream_type;
280 :
281 : private:
282 : __stringbuf_type _M_stringbuf;
283 :
284 : public:
285 : // Constructors:
286 : /**
287 : * @brief Default constructor starts with an empty string buffer.
288 : * @param mode Whether the buffer can read, or write, or both.
289 : *
290 : * @c ios_base::in is automatically included in @a mode.
291 : *
292 : * Initializes @c sb using @c mode|in, and passes @c &sb to the base
293 : * class initializer. Does not allocate any buffer.
294 : *
295 : * That's a lie. We initialize the base class with NULL, because the
296 : * string class does its own memory management.
297 : */
298 : explicit
299 : basic_istringstream(ios_base::openmode __mode = ios_base::in)
300 : : __istream_type(), _M_stringbuf(__mode | ios_base::in)
301 : { this->init(&_M_stringbuf); }
302 :
303 : /**
304 : * @brief Starts with an existing string buffer.
305 : * @param str A string to copy as a starting buffer.
306 : * @param mode Whether the buffer can read, or write, or both.
307 : *
308 : * @c ios_base::in is automatically included in @a mode.
309 : *
310 : * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
311 : * to the base class initializer.
312 : *
313 : * That's a lie. We initialize the base class with NULL, because the
314 : * string class does its own memory management.
315 : */
316 : explicit
317 : basic_istringstream(const __string_type& __str,
318 : ios_base::openmode __mode = ios_base::in)
319 : : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
320 : { this->init(&_M_stringbuf); }
321 :
322 : /**
323 : * @brief The destructor does nothing.
324 : *
325 : * The buffer is deallocated by the stringbuf object, not the
326 : * formatting stream.
327 : */
328 : ~basic_istringstream()
329 : { }
330 :
331 : // Members:
332 : /**
333 : * @brief Accessing the underlying buffer.
334 : * @return The current basic_stringbuf buffer.
335 : *
336 : * This hides both signatures of std::basic_ios::rdbuf().
337 : */
338 : __stringbuf_type*
339 : rdbuf() const
340 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
341 :
342 : /**
343 : * @brief Copying out the string buffer.
344 : * @return @c rdbuf()->str()
345 : */
346 : __string_type
347 : str() const
348 : { return _M_stringbuf.str(); }
349 :
350 : /**
351 : * @brief Setting a new buffer.
352 : * @param s The string to use as a new sequence.
353 : *
354 : * Calls @c rdbuf()->str(s).
355 : */
356 : void
357 : str(const __string_type& __s)
358 : { _M_stringbuf.str(__s); }
359 : };
360 :
361 :
362 : // [27.7.3] Template class basic_ostringstream
363 : /**
364 : * @brief Controlling output for std::string.
365 : * @ingroup io
366 : *
367 : * This class supports writing to objects of type std::basic_string,
368 : * using the inherited functions from std::basic_ostream. To control
369 : * the associated sequence, an instance of std::basic_stringbuf is used,
370 : * which this page refers to as @c sb.
371 : */
372 : template <typename _CharT, typename _Traits, typename _Alloc>
373 : class basic_ostringstream : public basic_ostream<_CharT, _Traits>
374 : {
375 : public:
376 : // Types:
377 : typedef _CharT char_type;
378 : typedef _Traits traits_type;
379 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
380 : // 251. basic_stringbuf missing allocator_type
381 : typedef _Alloc allocator_type;
382 : typedef typename traits_type::int_type int_type;
383 : typedef typename traits_type::pos_type pos_type;
384 : typedef typename traits_type::off_type off_type;
385 :
386 : // Non-standard types:
387 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
388 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
389 : typedef basic_ostream<char_type, traits_type> __ostream_type;
390 :
391 : private:
392 : __stringbuf_type _M_stringbuf;
393 :
394 : public:
395 : // Constructors/destructor:
396 : /**
397 : * @brief Default constructor starts with an empty string buffer.
398 : * @param mode Whether the buffer can read, or write, or both.
399 : *
400 : * @c ios_base::out is automatically included in @a mode.
401 : *
402 : * Initializes @c sb using @c mode|out, and passes @c &sb to the base
403 : * class initializer. Does not allocate any buffer.
404 : *
405 : * That's a lie. We initialize the base class with NULL, because the
406 : * string class does its own memory management.
407 : */
408 : explicit
409 0 : basic_ostringstream(ios_base::openmode __mode = ios_base::out)
410 0 : : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
411 0 : { this->init(&_M_stringbuf); }
412 :
413 : /**
414 : * @brief Starts with an existing string buffer.
415 : * @param str A string to copy as a starting buffer.
416 : * @param mode Whether the buffer can read, or write, or both.
417 : *
418 : * @c ios_base::out is automatically included in @a mode.
419 : *
420 : * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
421 : * to the base class initializer.
422 : *
423 : * That's a lie. We initialize the base class with NULL, because the
424 : * string class does its own memory management.
425 : */
426 : explicit
427 : basic_ostringstream(const __string_type& __str,
428 : ios_base::openmode __mode = ios_base::out)
429 : : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
430 : { this->init(&_M_stringbuf); }
431 :
432 : /**
433 : * @brief The destructor does nothing.
434 : *
435 : * The buffer is deallocated by the stringbuf object, not the
436 : * formatting stream.
437 : */
438 0 : ~basic_ostringstream()
439 0 : { }
440 :
441 : // Members:
442 : /**
443 : * @brief Accessing the underlying buffer.
444 : * @return The current basic_stringbuf buffer.
445 : *
446 : * This hides both signatures of std::basic_ios::rdbuf().
447 : */
448 : __stringbuf_type*
449 : rdbuf() const
450 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
451 :
452 : /**
453 : * @brief Copying out the string buffer.
454 : * @return @c rdbuf()->str()
455 : */
456 : __string_type
457 0 : str() const
458 0 : { return _M_stringbuf.str(); }
459 :
460 : /**
461 : * @brief Setting a new buffer.
462 : * @param s The string to use as a new sequence.
463 : *
464 : * Calls @c rdbuf()->str(s).
465 : */
466 : void
467 : str(const __string_type& __s)
468 : { _M_stringbuf.str(__s); }
469 : };
470 :
471 :
472 : // [27.7.4] Template class basic_stringstream
473 : /**
474 : * @brief Controlling input and output for std::string.
475 : * @ingroup io
476 : *
477 : * This class supports reading from and writing to objects of type
478 : * std::basic_string, using the inherited functions from
479 : * std::basic_iostream. To control the associated sequence, an instance
480 : * of std::basic_stringbuf is used, which this page refers to as @c sb.
481 : */
482 : template <typename _CharT, typename _Traits, typename _Alloc>
483 : class basic_stringstream : public basic_iostream<_CharT, _Traits>
484 : {
485 : public:
486 : // Types:
487 : typedef _CharT char_type;
488 : typedef _Traits traits_type;
489 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
490 : // 251. basic_stringbuf missing allocator_type
491 : typedef _Alloc allocator_type;
492 : typedef typename traits_type::int_type int_type;
493 : typedef typename traits_type::pos_type pos_type;
494 : typedef typename traits_type::off_type off_type;
495 :
496 : // Non-standard Types:
497 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
498 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
499 : typedef basic_iostream<char_type, traits_type> __iostream_type;
500 :
501 : private:
502 : __stringbuf_type _M_stringbuf;
503 :
504 : public:
505 : // Constructors/destructors
506 : /**
507 : * @brief Default constructor starts with an empty string buffer.
508 : * @param mode Whether the buffer can read, or write, or both.
509 : *
510 : * Initializes @c sb using @c mode, and passes @c &sb to the base
511 : * class initializer. Does not allocate any buffer.
512 : *
513 : * That's a lie. We initialize the base class with NULL, because the
514 : * string class does its own memory management.
515 : */
516 : explicit
517 0 : basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
518 0 : : __iostream_type(), _M_stringbuf(__m)
519 0 : { this->init(&_M_stringbuf); }
520 :
521 : /**
522 : * @brief Starts with an existing string buffer.
523 : * @param str A string to copy as a starting buffer.
524 : * @param mode Whether the buffer can read, or write, or both.
525 : *
526 : * Initializes @c sb using @a str and @c mode, and passes @c &sb
527 : * to the base class initializer.
528 : *
529 : * That's a lie. We initialize the base class with NULL, because the
530 : * string class does its own memory management.
531 : */
532 : explicit
533 : basic_stringstream(const __string_type& __str,
534 : ios_base::openmode __m = ios_base::out | ios_base::in)
535 : : __iostream_type(), _M_stringbuf(__str, __m)
536 : { this->init(&_M_stringbuf); }
537 :
538 : /**
539 : * @brief The destructor does nothing.
540 : *
541 : * The buffer is deallocated by the stringbuf object, not the
542 : * formatting stream.
543 : */
544 0 : ~basic_stringstream()
545 0 : { }
546 :
547 : // Members:
548 : /**
549 : * @brief Accessing the underlying buffer.
550 : * @return The current basic_stringbuf buffer.
551 : *
552 : * This hides both signatures of std::basic_ios::rdbuf().
553 : */
554 : __stringbuf_type*
555 : rdbuf() const
556 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
557 :
558 : /**
559 : * @brief Copying out the string buffer.
560 : * @return @c rdbuf()->str()
561 : */
562 : __string_type
563 0 : str() const
564 0 : { return _M_stringbuf.str(); }
565 :
566 : /**
567 : * @brief Setting a new buffer.
568 : * @param s The string to use as a new sequence.
569 : *
570 : * Calls @c rdbuf()->str(s).
571 : */
572 : void
573 : str(const __string_type& __s)
574 : { _M_stringbuf.str(__s); }
575 : };
576 :
577 : _GLIBCXX_END_NAMESPACE_VERSION
578 : } // namespace
579 :
580 : #include <bits/sstream.tcc>
581 :
582 : #endif /* _GLIBCXX_SSTREAM */
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