1 // String based streams -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 // 2006, 2008 Free Software Foundation, Inc.
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)
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.
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.
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.
32 * This is a Standard C++ Library header.
36 // ISO C++ 14882: 27.7 String-based streams
39 #ifndef _GLIBCXX_SSTREAM
40 #define _GLIBCXX_SSTREAM 1
42 #pragma GCC system_header
47 _GLIBCXX_BEGIN_NAMESPACE(std)
49 // [27.7.1] template class basic_stringbuf
51 * @brief The actual work of input and output (for std::string).
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.)
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.
61 template<typename _CharT, typename _Traits, typename _Alloc>
62 class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
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;
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;
80 /// Place to stash in || out || in | out settings for current stringbuf.
81 ios_base::openmode _M_mode;
84 __string_type _M_string;
89 * @brief Starts with an empty string buffer.
90 * @param mode Whether the buffer can read, or write, or both.
92 * The default constructor initializes the parent class using its
96 basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
97 : __streambuf_type(), _M_mode(__mode), _M_string()
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.
105 * This constructor initializes the parent class using its
109 basic_stringbuf(const __string_type& __str,
110 ios_base::openmode __mode = ios_base::in | ios_base::out)
111 : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())
112 { _M_stringbuf_init(__mode); }
116 * @brief Copying out the string buffer.
117 * @return A copy of one of the underlying sequences.
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
129 // The current egptr() may not be the actual string end.
130 if (this->pptr() > this->egptr())
131 __ret = __string_type(this->pbase(), this->pptr());
133 __ret = __string_type(this->pbase(), this->egptr());
141 * @brief Setting a new buffer.
142 * @param s The string to use as a new sequence.
144 * Deallocates any previous stored sequence, then copies @a s to
148 str(const __string_type& __s)
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);
156 // Common initialization code goes here.
158 _M_stringbuf_init(ios_base::openmode __mode)
161 __size_type __len = 0;
162 if (_M_mode & (ios_base::ate | ios_base::app))
163 __len = _M_string.size();
164 _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
170 streamsize __ret = -1;
171 if (_M_mode & ios_base::in)
174 __ret = this->egptr() - this->gptr();
183 pbackfail(int_type __c = traits_type::eof());
186 overflow(int_type __c = traits_type::eof());
189 * @brief Manipulates the buffer.
190 * @param s Pointer to a buffer area.
191 * @param n Size of @a s.
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++/manual/bk01pt11ch25s02.html
199 virtual __streambuf_type*
200 setbuf(char_type* __s, streamsize __n)
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.
209 // Step 1: Destroy the current internal array.
212 // Step 2: Use the external array.
213 _M_sync(__s, __n, 0);
219 seekoff(off_type __off, ios_base::seekdir __way,
220 ios_base::openmode __mode = ios_base::in | ios_base::out);
223 seekpos(pos_type __sp,
224 ios_base::openmode __mode = ios_base::in | ios_base::out);
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.
230 _M_sync(char_type* __base, __size_type __i, __size_type __o);
232 // Internal function for correctly updating egptr() to the actual
237 const bool __testin = _M_mode & ios_base::in;
238 if (this->pptr() && this->pptr() > this->egptr())
240 this->setg(this->eback(), this->gptr(), this->pptr());
242 this->setg(this->pptr(), this->pptr(), this->pptr());
247 // [27.7.2] Template class basic_istringstream
249 * @brief Controlling input for std::string.
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.
256 template<typename _CharT, typename _Traits, typename _Alloc>
257 class basic_istringstream : public basic_istream<_CharT, _Traits>
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;
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;
276 __stringbuf_type _M_stringbuf;
281 * @brief Default constructor starts with an empty string buffer.
282 * @param mode Whether the buffer can read, or write, or both.
284 * @c ios_base::in is automatically included in @a mode.
286 * Initializes @c sb using @c mode|in, and passes @c &sb to the base
287 * class initializer. Does not allocate any buffer.
289 * That's a lie. We initialize the base class with NULL, because the
290 * string class does its own memory management.
293 basic_istringstream(ios_base::openmode __mode = ios_base::in)
294 : __istream_type(), _M_stringbuf(__mode | ios_base::in)
295 { this->init(&_M_stringbuf); }
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.
302 * @c ios_base::in is automatically included in @a mode.
304 * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
305 * to the base class initializer.
307 * That's a lie. We initialize the base class with NULL, because the
308 * string class does its own memory management.
311 basic_istringstream(const __string_type& __str,
312 ios_base::openmode __mode = ios_base::in)
313 : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
314 { this->init(&_M_stringbuf); }
317 * @brief The destructor does nothing.
319 * The buffer is deallocated by the stringbuf object, not the
322 ~basic_istringstream()
327 * @brief Accessing the underlying buffer.
328 * @return The current basic_stringbuf buffer.
330 * This hides both signatures of std::basic_ios::rdbuf().
334 { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
337 * @brief Copying out the string buffer.
338 * @return @c rdbuf()->str()
342 { return _M_stringbuf.str(); }
345 * @brief Setting a new buffer.
346 * @param s The string to use as a new sequence.
348 * Calls @c rdbuf()->str(s).
351 str(const __string_type& __s)
352 { _M_stringbuf.str(__s); }
356 // [27.7.3] Template class basic_ostringstream
358 * @brief Controlling output for std::string.
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.
365 template <typename _CharT, typename _Traits, typename _Alloc>
366 class basic_ostringstream : public basic_ostream<_CharT, _Traits>
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;
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;
385 __stringbuf_type _M_stringbuf;
388 // Constructors/destructor:
390 * @brief Default constructor starts with an empty string buffer.
391 * @param mode Whether the buffer can read, or write, or both.
393 * @c ios_base::out is automatically included in @a mode.
395 * Initializes @c sb using @c mode|out, and passes @c &sb to the base
396 * class initializer. Does not allocate any buffer.
398 * That's a lie. We initialize the base class with NULL, because the
399 * string class does its own memory management.
402 basic_ostringstream(ios_base::openmode __mode = ios_base::out)
403 : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
404 { this->init(&_M_stringbuf); }
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.
411 * @c ios_base::out is automatically included in @a mode.
413 * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
414 * to the base class initializer.
416 * That's a lie. We initialize the base class with NULL, because the
417 * string class does its own memory management.
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); }
426 * @brief The destructor does nothing.
428 * The buffer is deallocated by the stringbuf object, not the
431 ~basic_ostringstream()
436 * @brief Accessing the underlying buffer.
437 * @return The current basic_stringbuf buffer.
439 * This hides both signatures of std::basic_ios::rdbuf().
443 { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
446 * @brief Copying out the string buffer.
447 * @return @c rdbuf()->str()
451 { return _M_stringbuf.str(); }
454 * @brief Setting a new buffer.
455 * @param s The string to use as a new sequence.
457 * Calls @c rdbuf()->str(s).
460 str(const __string_type& __s)
461 { _M_stringbuf.str(__s); }
465 // [27.7.4] Template class basic_stringstream
467 * @brief Controlling input and output for std::string.
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.
474 template <typename _CharT, typename _Traits, typename _Alloc>
475 class basic_stringstream : public basic_iostream<_CharT, _Traits>
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;
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;
494 __stringbuf_type _M_stringbuf;
497 // Constructors/destructors
499 * @brief Default constructor starts with an empty string buffer.
500 * @param mode Whether the buffer can read, or write, or both.
502 * Initializes @c sb using @c mode, and passes @c &sb to the base
503 * class initializer. Does not allocate any buffer.
505 * That's a lie. We initialize the base class with NULL, because the
506 * string class does its own memory management.
509 basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
510 : __iostream_type(), _M_stringbuf(__m)
511 { this->init(&_M_stringbuf); }
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.
518 * Initializes @c sb using @a str and @c mode, and passes @c &sb
519 * to the base class initializer.
521 * That's a lie. We initialize the base class with NULL, because the
522 * string class does its own memory management.
525 basic_stringstream(const __string_type& __str,
526 ios_base::openmode __m = ios_base::out | ios_base::in)
527 : __iostream_type(), _M_stringbuf(__str, __m)
528 { this->init(&_M_stringbuf); }
531 * @brief The destructor does nothing.
533 * The buffer is deallocated by the stringbuf object, not the
536 ~basic_stringstream()
541 * @brief Accessing the underlying buffer.
542 * @return The current basic_stringbuf buffer.
544 * This hides both signatures of std::basic_ios::rdbuf().
548 { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
551 * @brief Copying out the string buffer.
552 * @return @c rdbuf()->str()
556 { return _M_stringbuf.str(); }
559 * @brief Setting a new buffer.
560 * @param s The string to use as a new sequence.
562 * Calls @c rdbuf()->str(s).
565 str(const __string_type& __s)
566 { _M_stringbuf.str(__s); }
569 _GLIBCXX_END_NAMESPACE
571 #ifndef _GLIBCXX_EXPORT_TEMPLATE
572 # include <bits/sstream.tcc>
575 #endif /* _GLIBCXX_SSTREAM */