Line data Source code
1 : // String based streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997-2014 Free Software Foundation, Inc.
4 : //
5 : // This file is part of the GNU ISO C++ Library. This library is free
6 : // software; you can redistribute it and/or modify it under the
7 : // terms of the GNU General Public License as published by the
8 : // Free Software Foundation; either version 3, or (at your option)
9 : // any later version.
10 :
11 : // This library is distributed in the hope that it will be useful,
12 : // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : // GNU General Public License for more details.
15 :
16 : // Under Section 7 of GPL version 3, you are granted additional
17 : // permissions described in the GCC Runtime Library Exception, version
18 : // 3.1, as published by the Free Software Foundation.
19 :
20 : // You should have received a copy of the GNU General Public License and
21 : // a copy of the GCC Runtime Library Exception along with this program;
22 : // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 : // <http://www.gnu.org/licenses/>.
24 :
25 : /** @file include/sstream
26 : * This is a Standard C++ Library header.
27 : */
28 :
29 : //
30 : // ISO C++ 14882: 27.7 String-based streams
31 : //
32 :
33 : #ifndef _GLIBCXX_SSTREAM
34 : #define _GLIBCXX_SSTREAM 1
35 :
36 : #pragma GCC system_header
37 :
38 : #include <istream>
39 : #include <ostream>
40 :
41 : namespace std _GLIBCXX_VISIBILITY(default)
42 : {
43 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 :
45 : // [27.7.1] template class basic_stringbuf
46 : /**
47 : * @brief The actual work of input and output (for std::string).
48 : * @ingroup io
49 : *
50 : * @tparam _CharT Type of character stream.
51 : * @tparam _Traits Traits for character type, defaults to
52 : * char_traits<_CharT>.
53 : * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
54 : *
55 : * This class associates either or both of its input and output sequences
56 : * with a sequence of characters, which can be initialized from, or made
57 : * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
58 : *
59 : * For this class, open modes (of type @c ios_base::openmode) have
60 : * @c in set if the input sequence can be read, and @c out set if the
61 : * output sequence can be written.
62 : */
63 : template<typename _CharT, typename _Traits, typename _Alloc>
64 0 : class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
65 : {
66 : public:
67 : // Types:
68 : typedef _CharT char_type;
69 : typedef _Traits traits_type;
70 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
71 : // 251. basic_stringbuf missing allocator_type
72 : typedef _Alloc allocator_type;
73 : typedef typename traits_type::int_type int_type;
74 : typedef typename traits_type::pos_type pos_type;
75 : typedef typename traits_type::off_type off_type;
76 :
77 : typedef basic_streambuf<char_type, traits_type> __streambuf_type;
78 : typedef basic_string<char_type, _Traits, _Alloc> __string_type;
79 : typedef typename __string_type::size_type __size_type;
80 :
81 : protected:
82 : /// Place to stash in || out || in | out settings for current stringbuf.
83 : ios_base::openmode _M_mode;
84 :
85 : // Data Members:
86 : __string_type _M_string;
87 :
88 : public:
89 : // Constructors:
90 : /**
91 : * @brief Starts with an empty string buffer.
92 : * @param __mode Whether the buffer can read, or write, or both.
93 : *
94 : * The default constructor initializes the parent class using its
95 : * own default ctor.
96 : */
97 : explicit
98 0 : basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
99 0 : : __streambuf_type(), _M_mode(__mode), _M_string()
100 0 : { }
101 :
102 : /**
103 : * @brief Starts with an existing string buffer.
104 : * @param __str A string to copy as a starting buffer.
105 : * @param __mode Whether the buffer can read, or write, or both.
106 : *
107 : * This constructor initializes the parent class using its
108 : * own default ctor.
109 : */
110 : explicit
111 0 : basic_stringbuf(const __string_type& __str,
112 : ios_base::openmode __mode = ios_base::in | ios_base::out)
113 0 : : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())
114 0 : { _M_stringbuf_init(__mode); }
115 :
116 : // Get and set:
117 : /**
118 : * @brief Copying out the string buffer.
119 : * @return A copy of one of the underlying sequences.
120 : *
121 : * <em>If the buffer is only created in input mode, the underlying
122 : * character sequence is equal to the input sequence; otherwise, it
123 : * is equal to the output sequence.</em> [27.7.1.2]/1
124 : */
125 : __string_type
126 0 : str() const
127 : {
128 0 : __string_type __ret;
129 0 : if (this->pptr())
130 : {
131 : // The current egptr() may not be the actual string end.
132 0 : if (this->pptr() > this->egptr())
133 0 : __ret = __string_type(this->pbase(), this->pptr());
134 : else
135 0 : __ret = __string_type(this->pbase(), this->egptr());
136 : }
137 : else
138 0 : __ret = _M_string;
139 0 : return __ret;
140 : }
141 :
142 : /**
143 : * @brief Setting a new buffer.
144 : * @param __s The string to use as a new sequence.
145 : *
146 : * Deallocates any previous stored sequence, then copies @a s to
147 : * use as a new one.
148 : */
149 : void
150 : str(const __string_type& __s)
151 : {
152 : // Cannot use _M_string = __s, since v3 strings are COW.
153 : _M_string.assign(__s.data(), __s.size());
154 : _M_stringbuf_init(_M_mode);
155 : }
156 :
157 : protected:
158 : // Common initialization code goes here.
159 : void
160 0 : _M_stringbuf_init(ios_base::openmode __mode)
161 : {
162 0 : _M_mode = __mode;
163 0 : __size_type __len = 0;
164 0 : if (_M_mode & (ios_base::ate | ios_base::app))
165 0 : __len = _M_string.size();
166 0 : _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
167 0 : }
168 :
169 : virtual streamsize
170 : showmanyc()
171 : {
172 : streamsize __ret = -1;
173 : if (_M_mode & ios_base::in)
174 : {
175 : _M_update_egptr();
176 : __ret = this->egptr() - this->gptr();
177 : }
178 : return __ret;
179 : }
180 :
181 : virtual int_type
182 : underflow();
183 :
184 : virtual int_type
185 : pbackfail(int_type __c = traits_type::eof());
186 :
187 : virtual int_type
188 : overflow(int_type __c = traits_type::eof());
189 :
190 : /**
191 : * @brief Manipulates the buffer.
192 : * @param __s Pointer to a buffer area.
193 : * @param __n Size of @a __s.
194 : * @return @c this
195 : *
196 : * If no buffer has already been created, and both @a __s and @a __n are
197 : * non-zero, then @c __s is used as a buffer; see
198 : * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html
199 : * for more.
200 : */
201 : virtual __streambuf_type*
202 : setbuf(char_type* __s, streamsize __n)
203 : {
204 : if (__s && __n >= 0)
205 : {
206 : // This is implementation-defined behavior, and assumes
207 : // that an external char_type array of length __n exists
208 : // and has been pre-allocated. If this is not the case,
209 : // things will quickly blow up.
210 :
211 : // Step 1: Destroy the current internal array.
212 : _M_string.clear();
213 :
214 : // Step 2: Use the external array.
215 : _M_sync(__s, __n, 0);
216 : }
217 : return this;
218 : }
219 :
220 : virtual pos_type
221 : seekoff(off_type __off, ios_base::seekdir __way,
222 : ios_base::openmode __mode = ios_base::in | ios_base::out);
223 :
224 : virtual pos_type
225 : seekpos(pos_type __sp,
226 : ios_base::openmode __mode = ios_base::in | ios_base::out);
227 :
228 : // Internal function for correctly updating the internal buffer
229 : // for a particular _M_string, due to initialization or re-sizing
230 : // of an existing _M_string.
231 : void
232 : _M_sync(char_type* __base, __size_type __i, __size_type __o);
233 :
234 : // Internal function for correctly updating egptr() to the actual
235 : // string end.
236 : void
237 : _M_update_egptr()
238 : {
239 : const bool __testin = _M_mode & ios_base::in;
240 : if (this->pptr() && this->pptr() > this->egptr())
241 : {
242 : if (__testin)
243 : this->setg(this->eback(), this->gptr(), this->pptr());
244 : else
245 : this->setg(this->pptr(), this->pptr(), this->pptr());
246 : }
247 : }
248 :
249 : // Works around the issue with pbump, part of the protected
250 : // interface of basic_streambuf, taking just an int.
251 : void
252 : _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off);
253 : };
254 :
255 :
256 : // [27.7.2] Template class basic_istringstream
257 : /**
258 : * @brief Controlling input for std::string.
259 : * @ingroup io
260 : *
261 : * @tparam _CharT Type of character stream.
262 : * @tparam _Traits Traits for character type, defaults to
263 : * char_traits<_CharT>.
264 : * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
265 : *
266 : * This class supports reading from objects of type std::basic_string,
267 : * using the inherited functions from std::basic_istream. To control
268 : * the associated sequence, an instance of std::basic_stringbuf is used,
269 : * which this page refers to as @c sb.
270 : */
271 : template<typename _CharT, typename _Traits, typename _Alloc>
272 : class basic_istringstream : public basic_istream<_CharT, _Traits>
273 : {
274 : public:
275 : // Types:
276 : typedef _CharT char_type;
277 : typedef _Traits traits_type;
278 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
279 : // 251. basic_stringbuf missing allocator_type
280 : typedef _Alloc allocator_type;
281 : typedef typename traits_type::int_type int_type;
282 : typedef typename traits_type::pos_type pos_type;
283 : typedef typename traits_type::off_type off_type;
284 :
285 : // Non-standard types:
286 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
287 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
288 : typedef basic_istream<char_type, traits_type> __istream_type;
289 :
290 : private:
291 : __stringbuf_type _M_stringbuf;
292 :
293 : public:
294 : // Constructors:
295 : /**
296 : * @brief Default constructor starts with an empty string buffer.
297 : * @param __mode Whether the buffer can read, or write, or both.
298 : *
299 : * @c ios_base::in is automatically included in @a __mode.
300 : *
301 : * Initializes @c sb using @c __mode|in, and passes @c &sb to the base
302 : * class initializer. Does not allocate any buffer.
303 : *
304 : * That's a lie. We initialize the base class with NULL, because the
305 : * string class does its own memory management.
306 : */
307 : explicit
308 : basic_istringstream(ios_base::openmode __mode = ios_base::in)
309 : : __istream_type(), _M_stringbuf(__mode | ios_base::in)
310 : { this->init(&_M_stringbuf); }
311 :
312 : /**
313 : * @brief Starts with an existing string buffer.
314 : * @param __str A string to copy as a starting buffer.
315 : * @param __mode Whether the buffer can read, or write, or both.
316 : *
317 : * @c ios_base::in is automatically included in @a mode.
318 : *
319 : * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
320 : * to the base class initializer.
321 : *
322 : * That's a lie. We initialize the base class with NULL, because the
323 : * string class does its own memory management.
324 : */
325 : explicit
326 : basic_istringstream(const __string_type& __str,
327 : ios_base::openmode __mode = ios_base::in)
328 : : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
329 : { this->init(&_M_stringbuf); }
330 :
331 : /**
332 : * @brief The destructor does nothing.
333 : *
334 : * The buffer is deallocated by the stringbuf object, not the
335 : * formatting stream.
336 : */
337 : ~basic_istringstream()
338 : { }
339 :
340 : // Members:
341 : /**
342 : * @brief Accessing the underlying buffer.
343 : * @return The current basic_stringbuf buffer.
344 : *
345 : * This hides both signatures of std::basic_ios::rdbuf().
346 : */
347 : __stringbuf_type*
348 : rdbuf() const
349 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
350 :
351 : /**
352 : * @brief Copying out the string buffer.
353 : * @return @c rdbuf()->str()
354 : */
355 : __string_type
356 : str() const
357 : { return _M_stringbuf.str(); }
358 :
359 : /**
360 : * @brief Setting a new buffer.
361 : * @param __s The string to use as a new sequence.
362 : *
363 : * Calls @c rdbuf()->str(s).
364 : */
365 : void
366 : str(const __string_type& __s)
367 : { _M_stringbuf.str(__s); }
368 : };
369 :
370 :
371 : // [27.7.3] Template class basic_ostringstream
372 : /**
373 : * @brief Controlling output for std::string.
374 : * @ingroup io
375 : *
376 : * @tparam _CharT Type of character stream.
377 : * @tparam _Traits Traits for character type, defaults to
378 : * char_traits<_CharT>.
379 : * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
380 : *
381 : * This class supports writing to objects of type std::basic_string,
382 : * using the inherited functions from std::basic_ostream. To control
383 : * the associated sequence, an instance of std::basic_stringbuf is used,
384 : * which this page refers to as @c sb.
385 : */
386 : template <typename _CharT, typename _Traits, typename _Alloc>
387 : class basic_ostringstream : public basic_ostream<_CharT, _Traits>
388 : {
389 : public:
390 : // Types:
391 : typedef _CharT char_type;
392 : typedef _Traits traits_type;
393 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
394 : // 251. basic_stringbuf missing allocator_type
395 : typedef _Alloc allocator_type;
396 : typedef typename traits_type::int_type int_type;
397 : typedef typename traits_type::pos_type pos_type;
398 : typedef typename traits_type::off_type off_type;
399 :
400 : // Non-standard types:
401 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
402 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
403 : typedef basic_ostream<char_type, traits_type> __ostream_type;
404 :
405 : private:
406 : __stringbuf_type _M_stringbuf;
407 :
408 : public:
409 : // Constructors/destructor:
410 : /**
411 : * @brief Default constructor starts with an empty string buffer.
412 : * @param __mode Whether the buffer can read, or write, or both.
413 : *
414 : * @c ios_base::out is automatically included in @a mode.
415 : *
416 : * Initializes @c sb using @c mode|out, and passes @c &sb to the base
417 : * class initializer. Does not allocate any buffer.
418 : *
419 : * That's a lie. We initialize the base class with NULL, because the
420 : * string class does its own memory management.
421 : */
422 : explicit
423 : basic_ostringstream(ios_base::openmode __mode = ios_base::out)
424 : : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
425 : { this->init(&_M_stringbuf); }
426 :
427 : /**
428 : * @brief Starts with an existing string buffer.
429 : * @param __str A string to copy as a starting buffer.
430 : * @param __mode Whether the buffer can read, or write, or both.
431 : *
432 : * @c ios_base::out is automatically included in @a mode.
433 : *
434 : * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
435 : * to the base class initializer.
436 : *
437 : * That's a lie. We initialize the base class with NULL, because the
438 : * string class does its own memory management.
439 : */
440 : explicit
441 : basic_ostringstream(const __string_type& __str,
442 : ios_base::openmode __mode = ios_base::out)
443 : : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
444 : { this->init(&_M_stringbuf); }
445 :
446 : /**
447 : * @brief The destructor does nothing.
448 : *
449 : * The buffer is deallocated by the stringbuf object, not the
450 : * formatting stream.
451 : */
452 : ~basic_ostringstream()
453 : { }
454 :
455 : // Members:
456 : /**
457 : * @brief Accessing the underlying buffer.
458 : * @return The current basic_stringbuf buffer.
459 : *
460 : * This hides both signatures of std::basic_ios::rdbuf().
461 : */
462 : __stringbuf_type*
463 : rdbuf() const
464 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
465 :
466 : /**
467 : * @brief Copying out the string buffer.
468 : * @return @c rdbuf()->str()
469 : */
470 : __string_type
471 : str() const
472 : { return _M_stringbuf.str(); }
473 :
474 : /**
475 : * @brief Setting a new buffer.
476 : * @param __s The string to use as a new sequence.
477 : *
478 : * Calls @c rdbuf()->str(s).
479 : */
480 : void
481 : str(const __string_type& __s)
482 : { _M_stringbuf.str(__s); }
483 : };
484 :
485 :
486 : // [27.7.4] Template class basic_stringstream
487 : /**
488 : * @brief Controlling input and output for std::string.
489 : * @ingroup io
490 : *
491 : * @tparam _CharT Type of character stream.
492 : * @tparam _Traits Traits for character type, defaults to
493 : * char_traits<_CharT>.
494 : * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
495 : *
496 : * This class supports reading from and writing to objects of type
497 : * std::basic_string, using the inherited functions from
498 : * std::basic_iostream. To control the associated sequence, an instance
499 : * of std::basic_stringbuf is used, which this page refers to as @c sb.
500 : */
501 : template <typename _CharT, typename _Traits, typename _Alloc>
502 : class basic_stringstream : public basic_iostream<_CharT, _Traits>
503 : {
504 : public:
505 : // Types:
506 : typedef _CharT char_type;
507 : typedef _Traits traits_type;
508 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
509 : // 251. basic_stringbuf missing allocator_type
510 : typedef _Alloc allocator_type;
511 : typedef typename traits_type::int_type int_type;
512 : typedef typename traits_type::pos_type pos_type;
513 : typedef typename traits_type::off_type off_type;
514 :
515 : // Non-standard Types:
516 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
517 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
518 : typedef basic_iostream<char_type, traits_type> __iostream_type;
519 :
520 : private:
521 : __stringbuf_type _M_stringbuf;
522 :
523 : public:
524 : // Constructors/destructors
525 : /**
526 : * @brief Default constructor starts with an empty string buffer.
527 : * @param __m Whether the buffer can read, or write, or both.
528 : *
529 : * Initializes @c sb using the mode from @c __m, and passes @c
530 : * &sb to the base class initializer. Does not allocate any
531 : * buffer.
532 : *
533 : * That's a lie. We initialize the base class with NULL, because the
534 : * string class does its own memory management.
535 : */
536 : explicit
537 0 : basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
538 0 : : __iostream_type(), _M_stringbuf(__m)
539 0 : { this->init(&_M_stringbuf); }
540 :
541 : /**
542 : * @brief Starts with an existing string buffer.
543 : * @param __str A string to copy as a starting buffer.
544 : * @param __m Whether the buffer can read, or write, or both.
545 : *
546 : * Initializes @c sb using @a __str and @c __m, and passes @c &sb
547 : * to the base class initializer.
548 : *
549 : * That's a lie. We initialize the base class with NULL, because the
550 : * string class does its own memory management.
551 : */
552 : explicit
553 0 : basic_stringstream(const __string_type& __str,
554 : ios_base::openmode __m = ios_base::out | ios_base::in)
555 0 : : __iostream_type(), _M_stringbuf(__str, __m)
556 0 : { this->init(&_M_stringbuf); }
557 :
558 : /**
559 : * @brief The destructor does nothing.
560 : *
561 : * The buffer is deallocated by the stringbuf object, not the
562 : * formatting stream.
563 : */
564 0 : ~basic_stringstream()
565 0 : { }
566 :
567 : // Members:
568 : /**
569 : * @brief Accessing the underlying buffer.
570 : * @return The current basic_stringbuf buffer.
571 : *
572 : * This hides both signatures of std::basic_ios::rdbuf().
573 : */
574 : __stringbuf_type*
575 : rdbuf() const
576 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
577 :
578 : /**
579 : * @brief Copying out the string buffer.
580 : * @return @c rdbuf()->str()
581 : */
582 : __string_type
583 0 : str() const
584 0 : { return _M_stringbuf.str(); }
585 :
586 : /**
587 : * @brief Setting a new buffer.
588 : * @param __s The string to use as a new sequence.
589 : *
590 : * Calls @c rdbuf()->str(s).
591 : */
592 : void
593 : str(const __string_type& __s)
594 : { _M_stringbuf.str(__s); }
595 : };
596 :
597 : _GLIBCXX_END_NAMESPACE_VERSION
598 : } // namespace
599 :
600 : #include <bits/sstream.tcc>
601 :
602 : #endif /* _GLIBCXX_SSTREAM */
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