libstdc++
sstream
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1 // String based streams -*- C++ -*-
2 
3 // Copyright (C) 1997-2015 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 _GLIBCXX_BEGIN_NAMESPACE_CXX11
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  * @tparam _CharT Type of character stream.
52  * @tparam _Traits Traits for character type, defaults to
53  * char_traits<_CharT>.
54  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
55  *
56  * This class associates either or both of its input and output sequences
57  * with a sequence of characters, which can be initialized from, or made
58  * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
59  *
60  * For this class, open modes (of type @c ios_base::openmode) have
61  * @c in set if the input sequence can be read, and @c out set if the
62  * output sequence can be written.
63  */
64  template<typename _CharT, typename _Traits, typename _Alloc>
65  class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
66  {
67  struct __xfer_bufptrs;
68  public:
69  // Types:
70  typedef _CharT char_type;
71  typedef _Traits traits_type;
72  // _GLIBCXX_RESOLVE_LIB_DEFECTS
73  // 251. basic_stringbuf missing allocator_type
74  typedef _Alloc allocator_type;
75  typedef typename traits_type::int_type int_type;
76  typedef typename traits_type::pos_type pos_type;
77  typedef typename traits_type::off_type off_type;
78 
79  typedef basic_streambuf<char_type, traits_type> __streambuf_type;
80  typedef basic_string<char_type, _Traits, _Alloc> __string_type;
81  typedef typename __string_type::size_type __size_type;
82 
83  protected:
84  /// Place to stash in || out || in | out settings for current stringbuf.
85  ios_base::openmode _M_mode;
86 
87  // Data Members:
88  __string_type _M_string;
89 
90  public:
91  // Constructors:
92  /**
93  * @brief Starts with an empty string buffer.
94  * @param __mode Whether the buffer can read, or write, or both.
95  *
96  * The default constructor initializes the parent class using its
97  * own default ctor.
98  */
99  explicit
100  basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
101  : __streambuf_type(), _M_mode(__mode), _M_string()
102  { }
103 
104  /**
105  * @brief Starts with an existing string buffer.
106  * @param __str A string to copy as a starting buffer.
107  * @param __mode Whether the buffer can read, or write, or both.
108  *
109  * This constructor initializes the parent class using its
110  * own default ctor.
111  */
112  explicit
113  basic_stringbuf(const __string_type& __str,
114  ios_base::openmode __mode = ios_base::in | ios_base::out)
115  : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())
116  { _M_stringbuf_init(__mode); }
117 
118 #if __cplusplus >= 201103L
119  basic_stringbuf(const basic_stringbuf&) = delete;
120 
121  basic_stringbuf(basic_stringbuf&& __rhs)
122  : basic_stringbuf(std::move(__rhs), __xfer_bufptrs(__rhs, this))
123  { __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
124 
125  // 27.8.2.2 Assign and swap:
126 
127  basic_stringbuf&
128  operator=(const basic_stringbuf&) = delete;
129 
130  basic_stringbuf&
131  operator=(basic_stringbuf&& __rhs)
132  {
133  __xfer_bufptrs __st{__rhs, this};
134  const __streambuf_type& __base = __rhs;
135  __streambuf_type::operator=(__base);
136  this->pubimbue(__rhs.getloc());
137  _M_mode = __rhs._M_mode;
138  _M_string = std::move(__rhs._M_string);
139  __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0);
140  return *this;
141  }
142 
143  void
144  swap(basic_stringbuf& __rhs)
145  {
146  __xfer_bufptrs __l_st{*this, std::__addressof(__rhs)};
147  __xfer_bufptrs __r_st{__rhs, this};
148  __streambuf_type& __base = __rhs;
149  __streambuf_type::swap(__base);
150  __rhs.pubimbue(this->pubimbue(__rhs.getloc()));
151  std::swap(_M_mode, __rhs._M_mode);
152  std::swap(_M_string, __rhs._M_string);
153  }
154 #endif
155 
156  // Get and set:
157  /**
158  * @brief Copying out the string buffer.
159  * @return A copy of one of the underlying sequences.
160  *
161  * <em>If the buffer is only created in input mode, the underlying
162  * character sequence is equal to the input sequence; otherwise, it
163  * is equal to the output sequence.</em> [27.7.1.2]/1
164  */
165  __string_type
166  str() const
167  {
168  __string_type __ret;
169  if (this->pptr())
170  {
171  // The current egptr() may not be the actual string end.
172  if (this->pptr() > this->egptr())
173  __ret = __string_type(this->pbase(), this->pptr());
174  else
175  __ret = __string_type(this->pbase(), this->egptr());
176  }
177  else
178  __ret = _M_string;
179  return __ret;
180  }
181 
182  /**
183  * @brief Setting a new buffer.
184  * @param __s The string to use as a new sequence.
185  *
186  * Deallocates any previous stored sequence, then copies @a s to
187  * use as a new one.
188  */
189  void
190  str(const __string_type& __s)
191  {
192  // Cannot use _M_string = __s, since v3 strings are COW
193  // (not always true now but assign() always works).
194  _M_string.assign(__s.data(), __s.size());
195  _M_stringbuf_init(_M_mode);
196  }
197 
198  protected:
199  // Common initialization code goes here.
200  void
201  _M_stringbuf_init(ios_base::openmode __mode)
202  {
203  _M_mode = __mode;
204  __size_type __len = 0;
205  if (_M_mode & (ios_base::ate | ios_base::app))
206  __len = _M_string.size();
207  _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
208  }
209 
210  virtual streamsize
211  showmanyc()
212  {
213  streamsize __ret = -1;
214  if (_M_mode & ios_base::in)
215  {
216  _M_update_egptr();
217  __ret = this->egptr() - this->gptr();
218  }
219  return __ret;
220  }
221 
222  virtual int_type
223  underflow();
224 
225  virtual int_type
226  pbackfail(int_type __c = traits_type::eof());
227 
228  virtual int_type
229  overflow(int_type __c = traits_type::eof());
230 
231  /**
232  * @brief Manipulates the buffer.
233  * @param __s Pointer to a buffer area.
234  * @param __n Size of @a __s.
235  * @return @c this
236  *
237  * If no buffer has already been created, and both @a __s and @a __n are
238  * non-zero, then @c __s is used as a buffer; see
239  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
240  * for more.
241  */
242  virtual __streambuf_type*
243  setbuf(char_type* __s, streamsize __n)
244  {
245  if (__s && __n >= 0)
246  {
247  // This is implementation-defined behavior, and assumes
248  // that an external char_type array of length __n exists
249  // and has been pre-allocated. If this is not the case,
250  // things will quickly blow up.
251 
252  // Step 1: Destroy the current internal array.
253  _M_string.clear();
254 
255  // Step 2: Use the external array.
256  _M_sync(__s, __n, 0);
257  }
258  return this;
259  }
260 
261  virtual pos_type
262  seekoff(off_type __off, ios_base::seekdir __way,
263  ios_base::openmode __mode = ios_base::in | ios_base::out);
264 
265  virtual pos_type
266  seekpos(pos_type __sp,
267  ios_base::openmode __mode = ios_base::in | ios_base::out);
268 
269  // Internal function for correctly updating the internal buffer
270  // for a particular _M_string, due to initialization or re-sizing
271  // of an existing _M_string.
272  void
273  _M_sync(char_type* __base, __size_type __i, __size_type __o);
274 
275  // Internal function for correctly updating egptr() to the actual
276  // string end.
277  void
278  _M_update_egptr()
279  {
280  const bool __testin = _M_mode & ios_base::in;
281  if (this->pptr() && this->pptr() > this->egptr())
282  {
283  if (__testin)
284  this->setg(this->eback(), this->gptr(), this->pptr());
285  else
286  this->setg(this->pptr(), this->pptr(), this->pptr());
287  }
288  }
289 
290  // Works around the issue with pbump, part of the protected
291  // interface of basic_streambuf, taking just an int.
292  void
293  _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off);
294 
295  private:
296 #if __cplusplus >= 201103L
297 #if _GLIBCXX_USE_CXX11_ABI
298  // This type captures the state of the gptr / pptr pointers as offsets
299  // so they can be restored in another object after moving the string.
300  struct __xfer_bufptrs
301  {
302  __xfer_bufptrs(const basic_stringbuf& __from, basic_stringbuf* __to)
303  : _M_to{__to}, _M_goff{-1, -1, -1}, _M_poff{-1, -1, -1}
304  {
305  const _CharT* __str = __from._M_string.data();
306  if (__from.eback())
307  {
308  _M_goff[0] = __from.eback() - __str;
309  _M_goff[1] = __from.gptr() - __str;
310  _M_goff[2] = __from.egptr() - __str;
311  }
312  if (__from.pbase())
313  {
314  _M_poff[0] = __from.pbase() - __str;
315  _M_poff[1] = __from.pptr() - __from.pbase();
316  _M_poff[2] = __from.epptr() - __str;
317  }
318  }
319 
320  ~__xfer_bufptrs()
321  {
322  char_type* __str = const_cast<char_type*>(_M_to->_M_string.data());
323  if (_M_goff[0] != -1)
324  _M_to->setg(__str+_M_goff[0], __str+_M_goff[1], __str+_M_goff[2]);
325  if (_M_poff[0] != -1)
326  _M_to->_M_pbump(__str+_M_poff[0], __str+_M_poff[2], _M_poff[1]);
327  }
328 
329  basic_stringbuf* _M_to;
330  off_type _M_goff[3];
331  off_type _M_poff[3];
332  };
333 #else
334  // This type does nothing when using Copy-On-Write strings.
335  struct __xfer_bufptrs
336  {
337  __xfer_bufptrs(const basic_stringbuf&, basic_stringbuf*) { }
338  };
339 #endif
340 
341  // The move constructor initializes an __xfer_bufptrs temporary then
342  // delegates to this constructor to performs moves during its lifetime.
343  basic_stringbuf(basic_stringbuf&& __rhs, __xfer_bufptrs&&)
344  : __streambuf_type(static_cast<const __streambuf_type&>(__rhs)),
345  _M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string))
346  { }
347 #endif
348  };
349 
350 
351  // [27.7.2] Template class basic_istringstream
352  /**
353  * @brief Controlling input for std::string.
354  * @ingroup io
355  *
356  * @tparam _CharT Type of character stream.
357  * @tparam _Traits Traits for character type, defaults to
358  * char_traits<_CharT>.
359  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
360  *
361  * This class supports reading from objects of type std::basic_string,
362  * using the inherited functions from std::basic_istream. To control
363  * the associated sequence, an instance of std::basic_stringbuf is used,
364  * which this page refers to as @c sb.
365  */
366  template<typename _CharT, typename _Traits, typename _Alloc>
367  class basic_istringstream : public basic_istream<_CharT, _Traits>
368  {
369  public:
370  // Types:
371  typedef _CharT char_type;
372  typedef _Traits traits_type;
373  // _GLIBCXX_RESOLVE_LIB_DEFECTS
374  // 251. basic_stringbuf missing allocator_type
375  typedef _Alloc allocator_type;
376  typedef typename traits_type::int_type int_type;
377  typedef typename traits_type::pos_type pos_type;
378  typedef typename traits_type::off_type off_type;
379 
380  // Non-standard types:
381  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
382  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
383  typedef basic_istream<char_type, traits_type> __istream_type;
384 
385  private:
386  __stringbuf_type _M_stringbuf;
387 
388  public:
389  // Constructors:
390  /**
391  * @brief Default constructor starts with an empty string buffer.
392  * @param __mode Whether the buffer can read, or write, or both.
393  *
394  * @c ios_base::in is automatically included in @a __mode.
395  *
396  * Initializes @c sb using @c __mode|in, and passes @c &sb to the base
397  * class initializer. Does not allocate any buffer.
398  *
399  * That's a lie. We initialize the base class with NULL, because the
400  * string class does its own memory management.
401  */
402  explicit
403  basic_istringstream(ios_base::openmode __mode = ios_base::in)
404  : __istream_type(), _M_stringbuf(__mode | ios_base::in)
405  { this->init(&_M_stringbuf); }
406 
407  /**
408  * @brief Starts with an existing string buffer.
409  * @param __str A string to copy as a starting buffer.
410  * @param __mode Whether the buffer can read, or write, or both.
411  *
412  * @c ios_base::in is automatically included in @a mode.
413  *
414  * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
415  * to the base class initializer.
416  *
417  * That's a lie. We initialize the base class with NULL, because the
418  * string class does its own memory management.
419  */
420  explicit
421  basic_istringstream(const __string_type& __str,
422  ios_base::openmode __mode = ios_base::in)
423  : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
424  { this->init(&_M_stringbuf); }
425 
426  /**
427  * @brief The destructor does nothing.
428  *
429  * The buffer is deallocated by the stringbuf object, not the
430  * formatting stream.
431  */
432  ~basic_istringstream()
433  { }
434 
435 #if __cplusplus >= 201103L
436  basic_istringstream(const basic_istringstream&) = delete;
437 
438  basic_istringstream(basic_istringstream&& __rhs)
439  : __istream_type(std::move(__rhs)),
440  _M_stringbuf(std::move(__rhs._M_stringbuf))
441  { __istream_type::set_rdbuf(&_M_stringbuf); }
442 
443  // 27.8.3.2 Assign and swap:
444 
445  basic_istringstream&
446  operator=(const basic_istringstream&) = delete;
447 
448  basic_istringstream&
449  operator=(basic_istringstream&& __rhs)
450  {
451  __istream_type::operator=(std::move(__rhs));
452  _M_stringbuf = std::move(__rhs._M_stringbuf);
453  return *this;
454  }
455 
456  void
457  swap(basic_istringstream& __rhs)
458  {
459  __istream_type::swap(__rhs);
460  _M_stringbuf.swap(__rhs._M_stringbuf);
461  }
462 #endif
463 
464  // Members:
465  /**
466  * @brief Accessing the underlying buffer.
467  * @return The current basic_stringbuf buffer.
468  *
469  * This hides both signatures of std::basic_ios::rdbuf().
470  */
471  __stringbuf_type*
472  rdbuf() const
473  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
474 
475  /**
476  * @brief Copying out the string buffer.
477  * @return @c rdbuf()->str()
478  */
479  __string_type
480  str() const
481  { return _M_stringbuf.str(); }
482 
483  /**
484  * @brief Setting a new buffer.
485  * @param __s The string to use as a new sequence.
486  *
487  * Calls @c rdbuf()->str(s).
488  */
489  void
490  str(const __string_type& __s)
491  { _M_stringbuf.str(__s); }
492  };
493 
494 
495  // [27.7.3] Template class basic_ostringstream
496  /**
497  * @brief Controlling output for std::string.
498  * @ingroup io
499  *
500  * @tparam _CharT Type of character stream.
501  * @tparam _Traits Traits for character type, defaults to
502  * char_traits<_CharT>.
503  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
504  *
505  * This class supports writing to objects of type std::basic_string,
506  * using the inherited functions from std::basic_ostream. To control
507  * the associated sequence, an instance of std::basic_stringbuf is used,
508  * which this page refers to as @c sb.
509  */
510  template <typename _CharT, typename _Traits, typename _Alloc>
511  class basic_ostringstream : public basic_ostream<_CharT, _Traits>
512  {
513  public:
514  // Types:
515  typedef _CharT char_type;
516  typedef _Traits traits_type;
517  // _GLIBCXX_RESOLVE_LIB_DEFECTS
518  // 251. basic_stringbuf missing allocator_type
519  typedef _Alloc allocator_type;
520  typedef typename traits_type::int_type int_type;
521  typedef typename traits_type::pos_type pos_type;
522  typedef typename traits_type::off_type off_type;
523 
524  // Non-standard types:
525  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
526  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
527  typedef basic_ostream<char_type, traits_type> __ostream_type;
528 
529  private:
530  __stringbuf_type _M_stringbuf;
531 
532  public:
533  // Constructors/destructor:
534  /**
535  * @brief Default constructor starts with an empty string buffer.
536  * @param __mode Whether the buffer can read, or write, or both.
537  *
538  * @c ios_base::out is automatically included in @a mode.
539  *
540  * Initializes @c sb using @c mode|out, and passes @c &sb to the base
541  * class initializer. Does not allocate any buffer.
542  *
543  * That's a lie. We initialize the base class with NULL, because the
544  * string class does its own memory management.
545  */
546  explicit
547  basic_ostringstream(ios_base::openmode __mode = ios_base::out)
548  : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
549  { this->init(&_M_stringbuf); }
550 
551  /**
552  * @brief Starts with an existing string buffer.
553  * @param __str A string to copy as a starting buffer.
554  * @param __mode Whether the buffer can read, or write, or both.
555  *
556  * @c ios_base::out is automatically included in @a mode.
557  *
558  * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
559  * to the base class initializer.
560  *
561  * That's a lie. We initialize the base class with NULL, because the
562  * string class does its own memory management.
563  */
564  explicit
565  basic_ostringstream(const __string_type& __str,
566  ios_base::openmode __mode = ios_base::out)
567  : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
568  { this->init(&_M_stringbuf); }
569 
570  /**
571  * @brief The destructor does nothing.
572  *
573  * The buffer is deallocated by the stringbuf object, not the
574  * formatting stream.
575  */
576  ~basic_ostringstream()
577  { }
578 
579 #if __cplusplus >= 201103L
580  basic_ostringstream(const basic_ostringstream&) = delete;
581 
582  basic_ostringstream(basic_ostringstream&& __rhs)
583  : __ostream_type(std::move(__rhs)),
584  _M_stringbuf(std::move(__rhs._M_stringbuf))
585  { __ostream_type::set_rdbuf(&_M_stringbuf); }
586 
587  // 27.8.3.2 Assign and swap:
588 
589  basic_ostringstream&
590  operator=(const basic_ostringstream&) = delete;
591 
592  basic_ostringstream&
593  operator=(basic_ostringstream&& __rhs)
594  {
595  __ostream_type::operator=(std::move(__rhs));
596  _M_stringbuf = std::move(__rhs._M_stringbuf);
597  return *this;
598  }
599 
600  void
601  swap(basic_ostringstream& __rhs)
602  {
603  __ostream_type::swap(__rhs);
604  _M_stringbuf.swap(__rhs._M_stringbuf);
605  }
606 #endif
607 
608  // Members:
609  /**
610  * @brief Accessing the underlying buffer.
611  * @return The current basic_stringbuf buffer.
612  *
613  * This hides both signatures of std::basic_ios::rdbuf().
614  */
615  __stringbuf_type*
616  rdbuf() const
617  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
618 
619  /**
620  * @brief Copying out the string buffer.
621  * @return @c rdbuf()->str()
622  */
623  __string_type
624  str() const
625  { return _M_stringbuf.str(); }
626 
627  /**
628  * @brief Setting a new buffer.
629  * @param __s The string to use as a new sequence.
630  *
631  * Calls @c rdbuf()->str(s).
632  */
633  void
634  str(const __string_type& __s)
635  { _M_stringbuf.str(__s); }
636  };
637 
638 
639  // [27.7.4] Template class basic_stringstream
640  /**
641  * @brief Controlling input and output for std::string.
642  * @ingroup io
643  *
644  * @tparam _CharT Type of character stream.
645  * @tparam _Traits Traits for character type, defaults to
646  * char_traits<_CharT>.
647  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
648  *
649  * This class supports reading from and writing to objects of type
650  * std::basic_string, using the inherited functions from
651  * std::basic_iostream. To control the associated sequence, an instance
652  * of std::basic_stringbuf is used, which this page refers to as @c sb.
653  */
654  template <typename _CharT, typename _Traits, typename _Alloc>
655  class basic_stringstream : public basic_iostream<_CharT, _Traits>
656  {
657  public:
658  // Types:
659  typedef _CharT char_type;
660  typedef _Traits traits_type;
661  // _GLIBCXX_RESOLVE_LIB_DEFECTS
662  // 251. basic_stringbuf missing allocator_type
663  typedef _Alloc allocator_type;
664  typedef typename traits_type::int_type int_type;
665  typedef typename traits_type::pos_type pos_type;
666  typedef typename traits_type::off_type off_type;
667 
668  // Non-standard Types:
669  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
670  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
671  typedef basic_iostream<char_type, traits_type> __iostream_type;
672 
673  private:
674  __stringbuf_type _M_stringbuf;
675 
676  public:
677  // Constructors/destructors
678  /**
679  * @brief Default constructor starts with an empty string buffer.
680  * @param __m Whether the buffer can read, or write, or both.
681  *
682  * Initializes @c sb using the mode from @c __m, and passes @c
683  * &sb to the base class initializer. Does not allocate any
684  * buffer.
685  *
686  * That's a lie. We initialize the base class with NULL, because the
687  * string class does its own memory management.
688  */
689  explicit
690  basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
691  : __iostream_type(), _M_stringbuf(__m)
692  { this->init(&_M_stringbuf); }
693 
694  /**
695  * @brief Starts with an existing string buffer.
696  * @param __str A string to copy as a starting buffer.
697  * @param __m Whether the buffer can read, or write, or both.
698  *
699  * Initializes @c sb using @a __str and @c __m, and passes @c &sb
700  * to the base class initializer.
701  *
702  * That's a lie. We initialize the base class with NULL, because the
703  * string class does its own memory management.
704  */
705  explicit
706  basic_stringstream(const __string_type& __str,
707  ios_base::openmode __m = ios_base::out | ios_base::in)
708  : __iostream_type(), _M_stringbuf(__str, __m)
709  { this->init(&_M_stringbuf); }
710 
711  /**
712  * @brief The destructor does nothing.
713  *
714  * The buffer is deallocated by the stringbuf object, not the
715  * formatting stream.
716  */
717  ~basic_stringstream()
718  { }
719 
720 #if __cplusplus >= 201103L
721  basic_stringstream(const basic_stringstream&) = delete;
722 
723  basic_stringstream(basic_stringstream&& __rhs)
724  : __iostream_type(std::move(__rhs)),
725  _M_stringbuf(std::move(__rhs._M_stringbuf))
726  { __iostream_type::set_rdbuf(&_M_stringbuf); }
727 
728  // 27.8.3.2 Assign and swap:
729 
730  basic_stringstream&
731  operator=(const basic_stringstream&) = delete;
732 
733  basic_stringstream&
734  operator=(basic_stringstream&& __rhs)
735  {
736  __iostream_type::operator=(std::move(__rhs));
737  _M_stringbuf = std::move(__rhs._M_stringbuf);
738  return *this;
739  }
740 
741  void
742  swap(basic_stringstream& __rhs)
743  {
744  __iostream_type::swap(__rhs);
745  _M_stringbuf.swap(__rhs._M_stringbuf);
746  }
747 #endif
748 
749  // Members:
750  /**
751  * @brief Accessing the underlying buffer.
752  * @return The current basic_stringbuf buffer.
753  *
754  * This hides both signatures of std::basic_ios::rdbuf().
755  */
756  __stringbuf_type*
757  rdbuf() const
758  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
759 
760  /**
761  * @brief Copying out the string buffer.
762  * @return @c rdbuf()->str()
763  */
764  __string_type
765  str() const
766  { return _M_stringbuf.str(); }
767 
768  /**
769  * @brief Setting a new buffer.
770  * @param __s The string to use as a new sequence.
771  *
772  * Calls @c rdbuf()->str(s).
773  */
774  void
775  str(const __string_type& __s)
776  { _M_stringbuf.str(__s); }
777  };
778 
779 #if __cplusplus >= 201103L
780  /// Swap specialization for stringbufs.
781  template <class _CharT, class _Traits, class _Allocator>
782  inline void
783  swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x,
784  basic_stringbuf<_CharT, _Traits, _Allocator>& __y)
785  { __x.swap(__y); }
786 
787  /// Swap specialization for istringstreams.
788  template <class _CharT, class _Traits, class _Allocator>
789  inline void
790  swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x,
791  basic_istringstream<_CharT, _Traits, _Allocator>& __y)
792  { __x.swap(__y); }
793 
794  /// Swap specialization for ostringstreams.
795  template <class _CharT, class _Traits, class _Allocator>
796  inline void
797  swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x,
798  basic_ostringstream<_CharT, _Traits, _Allocator>& __y)
799  { __x.swap(__y); }
800 
801  /// Swap specialization for stringstreams.
802  template <class _CharT, class _Traits, class _Allocator>
803  inline void
804  swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x,
805  basic_stringstream<_CharT, _Traits, _Allocator>& __y)
806  { __x.swap(__y); }
807 #endif
808 
809 _GLIBCXX_END_NAMESPACE_CXX11
810 _GLIBCXX_END_NAMESPACE_VERSION
811 } // namespace
812 
813 #include <bits/sstream.tcc>
814 
815 #endif /* _GLIBCXX_SSTREAM */