1 : // String based streams -*- C++ -*-
2 :
3 : // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 : // 2006, 2008 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 2, 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 : // You should have received a copy of the GNU General Public License
18 : // along with this library; see the file COPYING. If not, write to
19 : // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 : // Boston, MA 02110-1301, USA.
21 :
22 : // As a special exception, you may use this file as part of a free software
23 : // library without restriction. Specifically, if other files instantiate
24 : // templates or use macros or inline functions from this file, or you compile
25 : // this file and link it with other files to produce an executable, this
26 : // file does not by itself cause the resulting executable to be covered by
27 : // the GNU General Public License. This exception does not however
28 : // invalidate any other reasons why the executable file might be covered by
29 : // the GNU General Public License.
30 :
31 : /** @file sstream
32 : * This is a Standard C++ Library header.
33 : */
34 :
35 : //
36 : // ISO C++ 14882: 27.7 String-based streams
37 : //
38 :
39 : #ifndef _GLIBCXX_SSTREAM
40 : #define _GLIBCXX_SSTREAM 1
41 :
42 : #pragma GCC system_header
43 :
44 : #include <istream>
45 : #include <ostream>
46 :
47 : _GLIBCXX_BEGIN_NAMESPACE(std)
48 :
49 : // [27.7.1] template class basic_stringbuf
50 : /**
51 : * @brief The actual work of input and output (for std::string).
52 : *
53 : * This class associates either or both of its input and output sequences
54 : * with a sequence of characters, which can be initialized from, or made
55 : * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
56 : *
57 : * For this class, open modes (of type @c ios_base::openmode) have
58 : * @c in set if the input sequence can be read, and @c out set if the
59 : * output sequence can be written.
60 : */
61 : template<typename _CharT, typename _Traits, typename _Alloc>
62 : class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
63 : {
64 : public:
65 : // Types:
66 : typedef _CharT char_type;
67 : typedef _Traits traits_type;
68 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
69 : // 251. basic_stringbuf missing allocator_type
70 : typedef _Alloc allocator_type;
71 : typedef typename traits_type::int_type int_type;
72 : typedef typename traits_type::pos_type pos_type;
73 : typedef typename traits_type::off_type off_type;
74 :
75 : typedef basic_streambuf<char_type, traits_type> __streambuf_type;
76 : typedef basic_string<char_type, _Traits, _Alloc> __string_type;
77 : typedef typename __string_type::size_type __size_type;
78 :
79 : protected:
80 : /// Place to stash in || out || in | out settings for current stringbuf.
81 : ios_base::openmode _M_mode;
82 :
83 : // Data Members:
84 : __string_type _M_string;
85 :
86 : public:
87 : // Constructors:
88 : /**
89 : * @brief Starts with an empty string buffer.
90 : * @param mode Whether the buffer can read, or write, or both.
91 : *
92 : * The default constructor initializes the parent class using its
93 : * own default ctor.
94 : */
95 : explicit
96 0 : basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
97 0 : : __streambuf_type(), _M_mode(__mode), _M_string()
98 0 : { }
99 :
100 : /**
101 : * @brief Starts with an existing string buffer.
102 : * @param str A string to copy as a starting buffer.
103 : * @param mode Whether the buffer can read, or write, or both.
104 : *
105 : * This constructor initializes the parent class using its
106 : * own default ctor.
107 : */
108 : explicit
109 : basic_stringbuf(const __string_type& __str,
110 0 : ios_base::openmode __mode = ios_base::in | ios_base::out)
111 0 : : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())
112 0 : { _M_stringbuf_init(__mode); }
113 :
114 : // Get and set:
115 : /**
116 : * @brief Copying out the string buffer.
117 : * @return A copy of one of the underlying sequences.
118 : *
119 : * "If the buffer is only created in input mode, the underlying
120 : * character sequence is equal to the input sequence; otherwise, it
121 : * is equal to the output sequence." [27.7.1.2]/1
122 : */
123 : __string_type
124 0 : str() const
125 : {
126 0 : __string_type __ret;
127 0 : if (this->pptr())
128 : {
129 : // The current egptr() may not be the actual string end.
130 0 : if (this->pptr() > this->egptr())
131 0 : __ret = __string_type(this->pbase(), this->pptr());
132 : else
133 0 : __ret = __string_type(this->pbase(), this->egptr());
134 : }
135 : else
136 0 : __ret = _M_string;
137 0 : return __ret;
138 : }
139 :
140 : /**
141 : * @brief Setting a new buffer.
142 : * @param s The string to use as a new sequence.
143 : *
144 : * Deallocates any previous stored sequence, then copies @a s to
145 : * use as a new one.
146 : */
147 : void
148 : str(const __string_type& __s)
149 : {
150 : // Cannot use _M_string = __s, since v3 strings are COW.
151 : _M_string.assign(__s.data(), __s.size());
152 : _M_stringbuf_init(_M_mode);
153 : }
154 :
155 : protected:
156 : // Common initialization code goes here.
157 : void
158 0 : _M_stringbuf_init(ios_base::openmode __mode)
159 : {
160 0 : _M_mode = __mode;
161 0 : __size_type __len = 0;
162 0 : if (_M_mode & (ios_base::ate | ios_base::app))
163 0 : __len = _M_string.size();
164 0 : _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
165 0 : }
166 :
167 : virtual streamsize
168 : showmanyc()
169 : {
170 : streamsize __ret = -1;
171 : if (_M_mode & ios_base::in)
172 : {
173 : _M_update_egptr();
174 : __ret = this->egptr() - this->gptr();
175 : }
176 : return __ret;
177 : }
178 :
179 : virtual int_type
180 : underflow();
181 :
182 : virtual int_type
183 : pbackfail(int_type __c = traits_type::eof());
184 :
185 : virtual int_type
186 : overflow(int_type __c = traits_type::eof());
187 :
188 : /**
189 : * @brief Manipulates the buffer.
190 : * @param s Pointer to a buffer area.
191 : * @param n Size of @a s.
192 : * @return @c this
193 : *
194 : * If no buffer has already been created, and both @a s and @a n are
195 : * non-zero, then @c s is used as a buffer; see
196 : * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2
197 : * for more.
198 : */
199 : virtual __streambuf_type*
200 : setbuf(char_type* __s, streamsize __n)
201 : {
202 : if (__s && __n >= 0)
203 : {
204 : // This is implementation-defined behavior, and assumes
205 : // that an external char_type array of length __n exists
206 : // and has been pre-allocated. If this is not the case,
207 : // things will quickly blow up.
208 :
209 : // Step 1: Destroy the current internal array.
210 : _M_string.clear();
211 :
212 : // Step 2: Use the external array.
213 : _M_sync(__s, __n, 0);
214 : }
215 : return this;
216 : }
217 :
218 : virtual pos_type
219 : seekoff(off_type __off, ios_base::seekdir __way,
220 : ios_base::openmode __mode = ios_base::in | ios_base::out);
221 :
222 : virtual pos_type
223 : seekpos(pos_type __sp,
224 : ios_base::openmode __mode = ios_base::in | ios_base::out);
225 :
226 : // Internal function for correctly updating the internal buffer
227 : // for a particular _M_string, due to initialization or re-sizing
228 : // of an existing _M_string.
229 : void
230 : _M_sync(char_type* __base, __size_type __i, __size_type __o);
231 :
232 : // Internal function for correctly updating egptr() to the actual
233 : // string end.
234 : void
235 : _M_update_egptr()
236 : {
237 : const bool __testin = _M_mode & ios_base::in;
238 : if (this->pptr() && this->pptr() > this->egptr())
239 : if (__testin)
240 : this->setg(this->eback(), this->gptr(), this->pptr());
241 : else
242 : this->setg(this->pptr(), this->pptr(), this->pptr());
243 : }
244 : };
245 :
246 :
247 : // [27.7.2] Template class basic_istringstream
248 : /**
249 : * @brief Controlling input for std::string.
250 : *
251 : * This class supports reading from objects of type std::basic_string,
252 : * using the inherited functions from std::basic_istream. To control
253 : * the associated sequence, an instance of std::basic_stringbuf is used,
254 : * which this page refers to as @c sb.
255 : */
256 : template<typename _CharT, typename _Traits, typename _Alloc>
257 : class basic_istringstream : public basic_istream<_CharT, _Traits>
258 : {
259 : public:
260 : // Types:
261 : typedef _CharT char_type;
262 : typedef _Traits traits_type;
263 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
264 : // 251. basic_stringbuf missing allocator_type
265 : typedef _Alloc allocator_type;
266 : typedef typename traits_type::int_type int_type;
267 : typedef typename traits_type::pos_type pos_type;
268 : typedef typename traits_type::off_type off_type;
269 :
270 : // Non-standard types:
271 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
272 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
273 : typedef basic_istream<char_type, traits_type> __istream_type;
274 :
275 : private:
276 : __stringbuf_type _M_stringbuf;
277 :
278 : public:
279 : // Constructors:
280 : /**
281 : * @brief Default constructor starts with an empty string buffer.
282 : * @param mode Whether the buffer can read, or write, or both.
283 : *
284 : * @c ios_base::in is automatically included in @a mode.
285 : *
286 : * Initializes @c sb using @c mode|in, and passes @c &sb to the base
287 : * class initializer. Does not allocate any buffer.
288 : *
289 : * That's a lie. We initialize the base class with NULL, because the
290 : * string class does its own memory management.
291 : */
292 : explicit
293 : basic_istringstream(ios_base::openmode __mode = ios_base::in)
294 : : __istream_type(), _M_stringbuf(__mode | ios_base::in)
295 : { this->init(&_M_stringbuf); }
296 :
297 : /**
298 : * @brief Starts with an existing string buffer.
299 : * @param str A string to copy as a starting buffer.
300 : * @param mode Whether the buffer can read, or write, or both.
301 : *
302 : * @c ios_base::in is automatically included in @a mode.
303 : *
304 : * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
305 : * to the base class initializer.
306 : *
307 : * That's a lie. We initialize the base class with NULL, because the
308 : * string class does its own memory management.
309 : */
310 : explicit
311 : basic_istringstream(const __string_type& __str,
312 0 : ios_base::openmode __mode = ios_base::in)
313 0 : : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
314 0 : { this->init(&_M_stringbuf); }
315 :
316 : /**
317 : * @brief The destructor does nothing.
318 : *
319 : * The buffer is deallocated by the stringbuf object, not the
320 : * formatting stream.
321 : */
322 0 : ~basic_istringstream()
323 0 : { }
324 :
325 : // Members:
326 : /**
327 : * @brief Accessing the underlying buffer.
328 : * @return The current basic_stringbuf buffer.
329 : *
330 : * This hides both signatures of std::basic_ios::rdbuf().
331 : */
332 : __stringbuf_type*
333 : rdbuf() const
334 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
335 :
336 : /**
337 : * @brief Copying out the string buffer.
338 : * @return @c rdbuf()->str()
339 : */
340 : __string_type
341 : str() const
342 : { return _M_stringbuf.str(); }
343 :
344 : /**
345 : * @brief Setting a new buffer.
346 : * @param s The string to use as a new sequence.
347 : *
348 : * Calls @c rdbuf()->str(s).
349 : */
350 : void
351 : str(const __string_type& __s)
352 : { _M_stringbuf.str(__s); }
353 : };
354 :
355 :
356 : // [27.7.3] Template class basic_ostringstream
357 : /**
358 : * @brief Controlling output for std::string.
359 : *
360 : * This class supports writing to objects of type std::basic_string,
361 : * using the inherited functions from std::basic_ostream. To control
362 : * the associated sequence, an instance of std::basic_stringbuf is used,
363 : * which this page refers to as @c sb.
364 : */
365 : template <typename _CharT, typename _Traits, typename _Alloc>
366 : class basic_ostringstream : public basic_ostream<_CharT, _Traits>
367 : {
368 : public:
369 : // Types:
370 : typedef _CharT char_type;
371 : typedef _Traits traits_type;
372 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
373 : // 251. basic_stringbuf missing allocator_type
374 : typedef _Alloc allocator_type;
375 : typedef typename traits_type::int_type int_type;
376 : typedef typename traits_type::pos_type pos_type;
377 : typedef typename traits_type::off_type off_type;
378 :
379 : // Non-standard types:
380 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
381 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
382 : typedef basic_ostream<char_type, traits_type> __ostream_type;
383 :
384 : private:
385 : __stringbuf_type _M_stringbuf;
386 :
387 : public:
388 : // Constructors/destructor:
389 : /**
390 : * @brief Default constructor starts with an empty string buffer.
391 : * @param mode Whether the buffer can read, or write, or both.
392 : *
393 : * @c ios_base::out is automatically included in @a mode.
394 : *
395 : * Initializes @c sb using @c mode|out, and passes @c &sb to the base
396 : * class initializer. Does not allocate any buffer.
397 : *
398 : * That's a lie. We initialize the base class with NULL, because the
399 : * string class does its own memory management.
400 : */
401 : explicit
402 0 : basic_ostringstream(ios_base::openmode __mode = ios_base::out)
403 0 : : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
404 0 : { this->init(&_M_stringbuf); }
405 :
406 : /**
407 : * @brief Starts with an existing string buffer.
408 : * @param str A string to copy as a starting buffer.
409 : * @param mode Whether the buffer can read, or write, or both.
410 : *
411 : * @c ios_base::out is automatically included in @a mode.
412 : *
413 : * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
414 : * to the base class initializer.
415 : *
416 : * That's a lie. We initialize the base class with NULL, because the
417 : * string class does its own memory management.
418 : */
419 : explicit
420 : basic_ostringstream(const __string_type& __str,
421 : ios_base::openmode __mode = ios_base::out)
422 : : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
423 : { this->init(&_M_stringbuf); }
424 :
425 : /**
426 : * @brief The destructor does nothing.
427 : *
428 : * The buffer is deallocated by the stringbuf object, not the
429 : * formatting stream.
430 : */
431 0 : ~basic_ostringstream()
432 0 : { }
433 :
434 : // Members:
435 : /**
436 : * @brief Accessing the underlying buffer.
437 : * @return The current basic_stringbuf buffer.
438 : *
439 : * This hides both signatures of std::basic_ios::rdbuf().
440 : */
441 : __stringbuf_type*
442 : rdbuf() const
443 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
444 :
445 : /**
446 : * @brief Copying out the string buffer.
447 : * @return @c rdbuf()->str()
448 : */
449 : __string_type
450 0 : str() const
451 0 : { return _M_stringbuf.str(); }
452 :
453 : /**
454 : * @brief Setting a new buffer.
455 : * @param s The string to use as a new sequence.
456 : *
457 : * Calls @c rdbuf()->str(s).
458 : */
459 : void
460 : str(const __string_type& __s)
461 : { _M_stringbuf.str(__s); }
462 : };
463 :
464 :
465 : // [27.7.4] Template class basic_stringstream
466 : /**
467 : * @brief Controlling input and output for std::string.
468 : *
469 : * This class supports reading from and writing to objects of type
470 : * std::basic_string, using the inherited functions from
471 : * std::basic_iostream. To control the associated sequence, an instance
472 : * of std::basic_stringbuf is used, which this page refers to as @c sb.
473 : */
474 : template <typename _CharT, typename _Traits, typename _Alloc>
475 : class basic_stringstream : public basic_iostream<_CharT, _Traits>
476 : {
477 : public:
478 : // Types:
479 : typedef _CharT char_type;
480 : typedef _Traits traits_type;
481 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
482 : // 251. basic_stringbuf missing allocator_type
483 : typedef _Alloc allocator_type;
484 : typedef typename traits_type::int_type int_type;
485 : typedef typename traits_type::pos_type pos_type;
486 : typedef typename traits_type::off_type off_type;
487 :
488 : // Non-standard Types:
489 : typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
490 : typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
491 : typedef basic_iostream<char_type, traits_type> __iostream_type;
492 :
493 : private:
494 : __stringbuf_type _M_stringbuf;
495 :
496 : public:
497 : // Constructors/destructors
498 : /**
499 : * @brief Default constructor starts with an empty string buffer.
500 : * @param mode Whether the buffer can read, or write, or both.
501 : *
502 : * Initializes @c sb using @c mode, and passes @c &sb to the base
503 : * class initializer. Does not allocate any buffer.
504 : *
505 : * That's a lie. We initialize the base class with NULL, because the
506 : * string class does its own memory management.
507 : */
508 : explicit
509 0 : basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
510 0 : : __iostream_type(), _M_stringbuf(__m)
511 0 : { this->init(&_M_stringbuf); }
512 :
513 : /**
514 : * @brief Starts with an existing string buffer.
515 : * @param str A string to copy as a starting buffer.
516 : * @param mode Whether the buffer can read, or write, or both.
517 : *
518 : * Initializes @c sb using @a str and @c mode, and passes @c &sb
519 : * to the base class initializer.
520 : *
521 : * That's a lie. We initialize the base class with NULL, because the
522 : * string class does its own memory management.
523 : */
524 : explicit
525 : basic_stringstream(const __string_type& __str,
526 0 : ios_base::openmode __m = ios_base::out | ios_base::in)
527 0 : : __iostream_type(), _M_stringbuf(__str, __m)
528 0 : { this->init(&_M_stringbuf); }
529 :
530 : /**
531 : * @brief The destructor does nothing.
532 : *
533 : * The buffer is deallocated by the stringbuf object, not the
534 : * formatting stream.
535 : */
536 0 : ~basic_stringstream()
537 0 : { }
538 :
539 : // Members:
540 : /**
541 : * @brief Accessing the underlying buffer.
542 : * @return The current basic_stringbuf buffer.
543 : *
544 : * This hides both signatures of std::basic_ios::rdbuf().
545 : */
546 : __stringbuf_type*
547 : rdbuf() const
548 : { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
549 :
550 : /**
551 : * @brief Copying out the string buffer.
552 : * @return @c rdbuf()->str()
553 : */
554 : __string_type
555 0 : str() const
556 0 : { return _M_stringbuf.str(); }
557 :
558 : /**
559 : * @brief Setting a new buffer.
560 : * @param s The string to use as a new sequence.
561 : *
562 : * Calls @c rdbuf()->str(s).
563 : */
564 : void
565 : str(const __string_type& __s)
566 : { _M_stringbuf.str(__s); }
567 : };
568 :
569 : _GLIBCXX_END_NAMESPACE
570 :
571 : #ifndef _GLIBCXX_EXPORT_TEMPLATE
572 : # include <bits/sstream.tcc>
573 : #endif
574 :
575 : #endif /* _GLIBCXX_SSTREAM */
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