libstdc++
sstream
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1 // String based streams -*- C++ -*-
2 
3 // Copyright (C) 1997-2022 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 #include <bits/alloc_traits.h> // allocator_traits, __allocator_like
41 
42 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
43 # define _GLIBCXX_LVAL_REF_QUAL &
44 # define _GLIBCXX_SSTREAM_ALWAYS_INLINE
45 #else
46 # define _GLIBCXX_LVAL_REF_QUAL
47 // For symbols that are not exported from libstdc++.so for the COW string ABI.
48 # define _GLIBCXX_SSTREAM_ALWAYS_INLINE [[__gnu__::__always_inline__]]
49 #endif
50 
51 
52 
53 namespace std _GLIBCXX_VISIBILITY(default)
54 {
55 _GLIBCXX_BEGIN_NAMESPACE_VERSION
56 _GLIBCXX_BEGIN_NAMESPACE_CXX11
57 
58  // [27.7.1] template class basic_stringbuf
59  /**
60  * @brief The actual work of input and output (for std::string).
61  * @ingroup io
62  *
63  * @tparam _CharT Type of character stream.
64  * @tparam _Traits Traits for character type, defaults to
65  * char_traits<_CharT>.
66  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
67  *
68  * This class associates either or both of its input and output sequences
69  * with a sequence of characters, which can be initialized from, or made
70  * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
71  *
72  * For this class, open modes (of type @c ios_base::openmode) have
73  * @c in set if the input sequence can be read, and @c out set if the
74  * output sequence can be written.
75  */
76  template<typename _CharT, typename _Traits, typename _Alloc>
77  class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
78  {
79  struct __xfer_bufptrs;
80 
81 #if __cplusplus >= 201103L
82  using allocator_traits = std::allocator_traits<_Alloc>;
83  using _Noexcept_swap
84  = __or_<typename allocator_traits::propagate_on_container_swap,
85  typename allocator_traits::is_always_equal>;
86 #endif
87 
88  public:
89  // Types:
90  typedef _CharT char_type;
91  typedef _Traits traits_type;
92  // _GLIBCXX_RESOLVE_LIB_DEFECTS
93  // 251. basic_stringbuf missing allocator_type
94  typedef _Alloc allocator_type;
95  typedef typename traits_type::int_type int_type;
96  typedef typename traits_type::pos_type pos_type;
97  typedef typename traits_type::off_type off_type;
98 
99  typedef basic_streambuf<char_type, traits_type> __streambuf_type;
100  typedef basic_string<char_type, _Traits, _Alloc> __string_type;
101  typedef typename __string_type::size_type __size_type;
102 
103  protected:
104  /// Place to stash in || out || in | out settings for current stringbuf.
105  ios_base::openmode _M_mode;
106 
107  // Data Members:
108  __string_type _M_string;
109 
110  public:
111  // Constructors:
112 
113  /**
114  * @brief Starts with an empty string buffer.
115  *
116  * The default constructor initializes the parent class using its
117  * own default ctor.
118  */
119  basic_stringbuf()
120  : __streambuf_type(), _M_mode(ios_base::in | ios_base::out), _M_string()
121  { }
122 
123  /**
124  * @brief Starts with an empty string buffer.
125  * @param __mode Whether the buffer can read, or write, or both.
126  *
127  * The default constructor initializes the parent class using its
128  * own default ctor.
129  */
130  explicit
131  basic_stringbuf(ios_base::openmode __mode)
132  : __streambuf_type(), _M_mode(__mode), _M_string()
133  { }
134 
135  /**
136  * @brief Starts with an existing string buffer.
137  * @param __str A string to copy as a starting buffer.
138  * @param __mode Whether the buffer can read, or write, or both.
139  *
140  * This constructor initializes the parent class using its
141  * own default ctor.
142  */
143  explicit
144  basic_stringbuf(const __string_type& __str,
145  ios_base::openmode __mode = ios_base::in | ios_base::out)
146  : __streambuf_type(), _M_mode(),
147  _M_string(__str.data(), __str.size(), __str.get_allocator())
148  { _M_stringbuf_init(__mode); }
149 
150 #if __cplusplus >= 201103L
151  basic_stringbuf(const basic_stringbuf&) = delete;
152 
153  basic_stringbuf(basic_stringbuf&& __rhs)
154  : basic_stringbuf(std::move(__rhs), __xfer_bufptrs(__rhs, this))
155  { __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
156 
157 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
158  explicit
159  basic_stringbuf(const allocator_type& __a)
160  : basic_stringbuf(ios_base::in | std::ios_base::out, __a)
161  { }
162 
163  basic_stringbuf(ios_base::openmode __mode,
164  const allocator_type& __a)
165  : __streambuf_type(), _M_mode(__mode), _M_string(__a)
166  { }
167 
168  explicit
169  basic_stringbuf(__string_type&& __s,
170  ios_base::openmode __mode = ios_base::in
171  | ios_base::out)
172  : __streambuf_type(), _M_mode(__mode), _M_string(std::move(__s))
173  { _M_stringbuf_init(__mode); }
174 
175  template<typename _SAlloc>
176  basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
177  const allocator_type& __a)
178  : basic_stringbuf(__s, ios_base::in | std::ios_base::out, __a)
179  { }
180 
181  template<typename _SAlloc>
182  basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
183  ios_base::openmode __mode,
184  const allocator_type& __a)
185  : __streambuf_type(), _M_mode(__mode),
186  _M_string(__s.data(), __s.size(), __a)
187  { _M_stringbuf_init(__mode); }
188 
189  template<typename _SAlloc>
190  explicit
191  basic_stringbuf(const basic_string<_CharT, _Traits, _SAlloc>& __s,
192  ios_base::openmode __mode = ios_base::in
193  | ios_base::out)
194  : basic_stringbuf(__s, __mode, allocator_type{})
195  { }
196 
197  basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type& __a)
198  : basic_stringbuf(std::move(__rhs), __a, __xfer_bufptrs(__rhs, this))
199  { __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
200 
201  allocator_type get_allocator() const noexcept
202  { return _M_string.get_allocator(); }
203 #endif // C++20
204 
205  // 27.8.2.2 Assign and swap:
206 
207  basic_stringbuf&
208  operator=(const basic_stringbuf&) = delete;
209 
210  basic_stringbuf&
211  operator=(basic_stringbuf&& __rhs)
212  {
213  __xfer_bufptrs __st{__rhs, this};
214  const __streambuf_type& __base = __rhs;
215  __streambuf_type::operator=(__base);
216  this->pubimbue(__rhs.getloc());
217  _M_mode = __rhs._M_mode;
218  _M_string = std::move(__rhs._M_string);
219  __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0);
220  return *this;
221  }
222 
223  void
224  swap(basic_stringbuf& __rhs) noexcept(_Noexcept_swap::value)
225  {
226  __xfer_bufptrs __l_st{*this, std::__addressof(__rhs)};
227  __xfer_bufptrs __r_st{__rhs, this};
228  __streambuf_type& __base = __rhs;
229  __streambuf_type::swap(__base);
230  __rhs.pubimbue(this->pubimbue(__rhs.getloc()));
231  std::swap(_M_mode, __rhs._M_mode);
232  std::swap(_M_string, __rhs._M_string); // XXX not exception safe
233  }
234 #endif // C++11
235 
236  // Getters and setters:
237 
238  /**
239  * @brief Copying out the string buffer.
240  * @return A copy of one of the underlying sequences.
241  *
242  * <em>If the buffer is only created in input mode, the underlying
243  * character sequence is equal to the input sequence; otherwise, it
244  * is equal to the output sequence.</em> [27.7.1.2]/1
245  */
246  __string_type
247  str() const _GLIBCXX_LVAL_REF_QUAL
248  {
249  __string_type __ret(_M_string.get_allocator());
250  if (char_type* __hi = _M_high_mark())
251  __ret.assign(this->pbase(), __hi);
252  else
253  __ret = _M_string;
254  return __ret;
255  }
256 
257 #if __cplusplus > 201703L
258 #if _GLIBCXX_USE_CXX11_ABI
259 #if __cpp_concepts
260  template<__allocator_like _SAlloc>
261  basic_string<_CharT, _Traits, _SAlloc>
262  str(const _SAlloc& __sa) const
263  {
264  auto __sv = view();
265  return { __sv.data(), __sv.size(), __sa };
266  }
267 #endif
268 
269  __string_type
270  str() &&
271  {
272  if (char_type* __hi = _M_high_mark())
273  {
274  // Set length to end of character sequence and add null terminator.
275  _M_string._M_set_length(_M_high_mark() - this->pbase());
276  }
277  auto __str = std::move(_M_string);
278  _M_string.clear();
279  _M_sync(_M_string.data(), 0, 0);
280  return __str;
281  }
282 #endif // cxx11 ABI
283 
284  _GLIBCXX_SSTREAM_ALWAYS_INLINE
285  basic_string_view<char_type, traits_type>
286  view() const noexcept
287  {
288  if (char_type* __hi = _M_high_mark())
289  return { this->pbase(), __hi };
290  else
291  return _M_string;
292  }
293 #endif // C++20
294 
295  /**
296  * @brief Setting a new buffer.
297  * @param __s The string to use as a new sequence.
298  *
299  * Deallocates any previous stored sequence, then copies @a s to
300  * use as a new one.
301  */
302  void
303  str(const __string_type& __s)
304  {
305  // Cannot use _M_string = __s, since v3 strings are COW
306  // (not always true now but assign() always works).
307  _M_string.assign(__s.data(), __s.size());
308  _M_stringbuf_init(_M_mode);
309  }
310 
311 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
312 #if __cpp_concepts
313  template<__allocator_like _SAlloc>
314  requires (!is_same_v<_SAlloc, _Alloc>)
315  void
316  str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
317  {
318  _M_string.assign(__s.data(), __s.size());
319  _M_stringbuf_init(_M_mode);
320  }
321 #endif
322 
323  void
324  str(__string_type&& __s)
325  {
326  _M_string = std::move(__s);
327  _M_stringbuf_init(_M_mode);
328  }
329 #endif
330 
331  protected:
332  // Common initialization code goes here.
333  void
334  _M_stringbuf_init(ios_base::openmode __mode)
335  {
336  _M_mode = __mode;
337  __size_type __len = 0;
338  if (_M_mode & (ios_base::ate | ios_base::app))
339  __len = _M_string.size();
340  _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
341  }
342 
343  virtual streamsize
344  showmanyc()
345  {
346  streamsize __ret = -1;
347  if (_M_mode & ios_base::in)
348  {
349  _M_update_egptr();
350  __ret = this->egptr() - this->gptr();
351  }
352  return __ret;
353  }
354 
355  virtual int_type
356  underflow();
357 
358  virtual int_type
359  pbackfail(int_type __c = traits_type::eof());
360 
361  virtual int_type
362  overflow(int_type __c = traits_type::eof());
363 
364  /**
365  * @brief Manipulates the buffer.
366  * @param __s Pointer to a buffer area.
367  * @param __n Size of @a __s.
368  * @return @c this
369  *
370  * If no buffer has already been created, and both @a __s and @a __n are
371  * non-zero, then @c __s is used as a buffer; see
372  * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
373  * for more.
374  */
375  virtual __streambuf_type*
376  setbuf(char_type* __s, streamsize __n)
377  {
378  if (__s && __n >= 0)
379  {
380  // This is implementation-defined behavior, and assumes
381  // that an external char_type array of length __n exists
382  // and has been pre-allocated. If this is not the case,
383  // things will quickly blow up.
384 
385  // Step 1: Destroy the current internal array.
386  _M_string.clear();
387 
388  // Step 2: Use the external array.
389  _M_sync(__s, __n, 0);
390  }
391  return this;
392  }
393 
394  virtual pos_type
395  seekoff(off_type __off, ios_base::seekdir __way,
396  ios_base::openmode __mode = ios_base::in | ios_base::out);
397 
398  virtual pos_type
399  seekpos(pos_type __sp,
400  ios_base::openmode __mode = ios_base::in | ios_base::out);
401 
402  // Internal function for correctly updating the internal buffer
403  // for a particular _M_string, due to initialization or re-sizing
404  // of an existing _M_string.
405  void
406  _M_sync(char_type* __base, __size_type __i, __size_type __o);
407 
408  // Internal function for correctly updating egptr() to the actual
409  // string end.
410  void
411  _M_update_egptr()
412  {
413  if (char_type* __pptr = this->pptr())
414  {
415  char_type* __egptr = this->egptr();
416  if (!__egptr || __pptr > __egptr)
417  {
418  if (_M_mode & ios_base::in)
419  this->setg(this->eback(), this->gptr(), __pptr);
420  else
421  this->setg(__pptr, __pptr, __pptr);
422  }
423  }
424  }
425 
426  // Works around the issue with pbump, part of the protected
427  // interface of basic_streambuf, taking just an int.
428  void
429  _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off);
430 
431  private:
432  // Return a pointer to the end of the underlying character sequence.
433  // This might not be the same character as _M_string.end() because
434  // basic_stringbuf::overflow might have written to unused capacity
435  // in _M_string without updating its length.
436  __attribute__((__always_inline__))
437  char_type*
438  _M_high_mark() const _GLIBCXX_NOEXCEPT
439  {
440  if (char_type* __pptr = this->pptr())
441  {
442  char_type* __egptr = this->egptr();
443  if (!__egptr || __pptr > __egptr)
444  return __pptr; // Underlying sequence is [pbase, pptr).
445  else
446  return __egptr; // Underlying sequence is [pbase, egptr).
447  }
448  return 0; // Underlying character sequence is just _M_string.
449  }
450 
451 #if __cplusplus >= 201103L
452 #if _GLIBCXX_USE_CXX11_ABI
453  // This type captures the state of the gptr / pptr pointers as offsets
454  // so they can be restored in another object after moving the string.
455  struct __xfer_bufptrs
456  {
457  __xfer_bufptrs(const basic_stringbuf& __from, basic_stringbuf* __to)
458  : _M_to{__to}, _M_goff{-1, -1, -1}, _M_poff{-1, -1, -1}
459  {
460  const _CharT* const __str = __from._M_string.data();
461  const _CharT* __end = nullptr;
462  if (__from.eback())
463  {
464  _M_goff[0] = __from.eback() - __str;
465  _M_goff[1] = __from.gptr() - __str;
466  _M_goff[2] = __from.egptr() - __str;
467  __end = __from.egptr();
468  }
469  if (__from.pbase())
470  {
471  _M_poff[0] = __from.pbase() - __str;
472  _M_poff[1] = __from.pptr() - __from.pbase();
473  _M_poff[2] = __from.epptr() - __str;
474  if (!__end || __from.pptr() > __end)
475  __end = __from.pptr();
476  }
477 
478  // Set _M_string length to the greater of the get and put areas.
479  if (__end)
480  {
481  // The const_cast avoids changing this constructor's signature,
482  // because it is exported from the dynamic library.
483  auto& __mut_from = const_cast<basic_stringbuf&>(__from);
484  __mut_from._M_string._M_length(__end - __str);
485  }
486  }
487 
488  ~__xfer_bufptrs()
489  {
490  char_type* __str = const_cast<char_type*>(_M_to->_M_string.data());
491  if (_M_goff[0] != -1)
492  _M_to->setg(__str+_M_goff[0], __str+_M_goff[1], __str+_M_goff[2]);
493  if (_M_poff[0] != -1)
494  _M_to->_M_pbump(__str+_M_poff[0], __str+_M_poff[2], _M_poff[1]);
495  }
496 
497  basic_stringbuf* _M_to;
498  off_type _M_goff[3];
499  off_type _M_poff[3];
500  };
501 #else
502  // This type does nothing when using Copy-On-Write strings.
503  struct __xfer_bufptrs
504  {
505  __xfer_bufptrs(const basic_stringbuf&, basic_stringbuf*) { }
506  };
507 #endif
508 
509  // The move constructor initializes an __xfer_bufptrs temporary then
510  // delegates to this constructor to performs moves during its lifetime.
511  basic_stringbuf(basic_stringbuf&& __rhs, __xfer_bufptrs&&)
512  : __streambuf_type(static_cast<const __streambuf_type&>(__rhs)),
513  _M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string))
514  { }
515 
516 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
517  // The move constructor initializes an __xfer_bufptrs temporary then
518  // delegates to this constructor to performs moves during its lifetime.
519  basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type& __a,
520  __xfer_bufptrs&&)
521  : __streambuf_type(static_cast<const __streambuf_type&>(__rhs)),
522  _M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string), __a)
523  { }
524 #endif
525 #endif // C++11
526  };
527 
528 
529  // [27.7.2] Template class basic_istringstream
530  /**
531  * @brief Controlling input for std::string.
532  * @ingroup io
533  *
534  * @tparam _CharT Type of character stream.
535  * @tparam _Traits Traits for character type, defaults to
536  * char_traits<_CharT>.
537  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
538  *
539  * This class supports reading from objects of type std::basic_string,
540  * using the inherited functions from std::basic_istream. To control
541  * the associated sequence, an instance of std::basic_stringbuf is used,
542  * which this page refers to as @c sb.
543  */
544  template<typename _CharT, typename _Traits, typename _Alloc>
545  class basic_istringstream : public basic_istream<_CharT, _Traits>
546  {
547  public:
548  // Types:
549  typedef _CharT char_type;
550  typedef _Traits traits_type;
551  // _GLIBCXX_RESOLVE_LIB_DEFECTS
552  // 251. basic_stringbuf missing allocator_type
553  typedef _Alloc allocator_type;
554  typedef typename traits_type::int_type int_type;
555  typedef typename traits_type::pos_type pos_type;
556  typedef typename traits_type::off_type off_type;
557 
558  // Non-standard types:
559  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
560  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
561  typedef basic_istream<char_type, traits_type> __istream_type;
562 
563  private:
564  __stringbuf_type _M_stringbuf;
565 
566  public:
567  // Constructors:
568 
569  /**
570  * @brief Default constructor starts with an empty string buffer.
571  *
572  * Initializes @c sb using @c in, and passes @c &sb to the base
573  * class initializer. Does not allocate any buffer.
574  *
575  * That's a lie. We initialize the base class with NULL, because the
576  * string class does its own memory management.
577  */
578  basic_istringstream()
579  : __istream_type(), _M_stringbuf(ios_base::in)
580  { this->init(&_M_stringbuf); }
581 
582  /**
583  * @brief Starts with an empty string buffer.
584  * @param __mode Whether the buffer can read, or write, or both.
585  *
586  * @c ios_base::in is automatically included in @a __mode.
587  *
588  * Initializes @c sb using @c __mode|in, and passes @c &sb to the base
589  * class initializer. Does not allocate any buffer.
590  *
591  * That's a lie. We initialize the base class with NULL, because the
592  * string class does its own memory management.
593  */
594  explicit
595  basic_istringstream(ios_base::openmode __mode)
596  : __istream_type(), _M_stringbuf(__mode | ios_base::in)
597  { this->init(&_M_stringbuf); }
598 
599  /**
600  * @brief Starts with an existing string buffer.
601  * @param __str A string to copy as a starting buffer.
602  * @param __mode Whether the buffer can read, or write, or both.
603  *
604  * @c ios_base::in is automatically included in @a mode.
605  *
606  * Initializes @c sb using @a str and @c mode|in, and passes @c &sb
607  * to the base class initializer.
608  *
609  * That's a lie. We initialize the base class with NULL, because the
610  * string class does its own memory management.
611  */
612  explicit
613  basic_istringstream(const __string_type& __str,
614  ios_base::openmode __mode = ios_base::in)
615  : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
616  { this->init(&_M_stringbuf); }
617 
618  /**
619  * @brief The destructor does nothing.
620  *
621  * The buffer is deallocated by the stringbuf object, not the
622  * formatting stream.
623  */
624  ~basic_istringstream()
625  { }
626 
627 #if __cplusplus >= 201103L
628  basic_istringstream(const basic_istringstream&) = delete;
629 
630  basic_istringstream(basic_istringstream&& __rhs)
631  : __istream_type(std::move(__rhs)),
632  _M_stringbuf(std::move(__rhs._M_stringbuf))
633  { __istream_type::set_rdbuf(&_M_stringbuf); }
634 
635 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
636  basic_istringstream(ios_base::openmode __mode, const allocator_type& __a)
637  : __istream_type(), _M_stringbuf(__mode | ios_base::in, __a)
638  { this->init(std::__addressof(_M_stringbuf)); }
639 
640  explicit
641  basic_istringstream(__string_type&& __str,
642  ios_base::openmode __mode = ios_base::in)
643  : __istream_type(), _M_stringbuf(std::move(__str), __mode | ios_base::in)
644  { this->init(std::__addressof(_M_stringbuf)); }
645 
646  template<typename _SAlloc>
647  basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
648  const allocator_type& __a)
649  : basic_istringstream(__str, ios_base::in, __a)
650  { }
651 
652  template<typename _SAlloc>
653  basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
654  ios_base::openmode __mode,
655  const allocator_type& __a)
656  : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in, __a)
657  { this->init(std::__addressof(_M_stringbuf)); }
658 
659  template<typename _SAlloc>
660  explicit
661  basic_istringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
662  ios_base::openmode __mode = ios_base::in)
663  : basic_istringstream(__str, __mode, allocator_type())
664  { }
665 #endif // C++20
666 
667  // 27.8.3.2 Assign and swap:
668 
669  basic_istringstream&
670  operator=(const basic_istringstream&) = delete;
671 
672  basic_istringstream&
673  operator=(basic_istringstream&& __rhs)
674  {
675  __istream_type::operator=(std::move(__rhs));
676  _M_stringbuf = std::move(__rhs._M_stringbuf);
677  return *this;
678  }
679 
680  void
681  swap(basic_istringstream& __rhs)
682  {
683  __istream_type::swap(__rhs);
684  _M_stringbuf.swap(__rhs._M_stringbuf);
685  }
686 #endif // C++11
687 
688  // Members:
689  /**
690  * @brief Accessing the underlying buffer.
691  * @return The current basic_stringbuf buffer.
692  *
693  * This hides both signatures of std::basic_ios::rdbuf().
694  */
695  __stringbuf_type*
696  rdbuf() const
697  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
698 
699  /**
700  * @brief Copying out the string buffer.
701  * @return @c rdbuf()->str()
702  */
703  __string_type
704  str() const _GLIBCXX_LVAL_REF_QUAL
705  { return _M_stringbuf.str(); }
706 
707 #if __cplusplus > 201703L
708 #if _GLIBCXX_USE_CXX11_ABI
709 #if __cpp_concepts
710  template<__allocator_like _SAlloc>
711  basic_string<_CharT, _Traits, _SAlloc>
712  str(const _SAlloc& __sa) const
713  { return _M_stringbuf.str(__sa); }
714 #endif
715 
716  __string_type
717  str() &&
718  { return std::move(_M_stringbuf).str(); }
719 #endif // cxx11 ABI
720 
721  _GLIBCXX_SSTREAM_ALWAYS_INLINE
722  basic_string_view<char_type, traits_type>
723  view() const noexcept
724  { return _M_stringbuf.view(); }
725 #endif // C++20
726 
727  /**
728  * @brief Setting a new buffer.
729  * @param __s The string to use as a new sequence.
730  *
731  * Calls @c rdbuf()->str(s).
732  */
733  void
734  str(const __string_type& __s)
735  { _M_stringbuf.str(__s); }
736 
737 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
738 #if __cpp_concepts
739  template<__allocator_like _SAlloc>
740  requires (!is_same_v<_SAlloc, _Alloc>)
741  void
742  str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
743  { _M_stringbuf.str(__s); }
744 #endif
745 
746  void
747  str(__string_type&& __s)
748  { _M_stringbuf.str(std::move(__s)); }
749 #endif
750  };
751 
752 
753  // [27.7.3] Template class basic_ostringstream
754  /**
755  * @brief Controlling output for std::string.
756  * @ingroup io
757  *
758  * @tparam _CharT Type of character stream.
759  * @tparam _Traits Traits for character type, defaults to
760  * char_traits<_CharT>.
761  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
762  *
763  * This class supports writing to objects of type std::basic_string,
764  * using the inherited functions from std::basic_ostream. To control
765  * the associated sequence, an instance of std::basic_stringbuf is used,
766  * which this page refers to as @c sb.
767  */
768  template <typename _CharT, typename _Traits, typename _Alloc>
769  class basic_ostringstream : public basic_ostream<_CharT, _Traits>
770  {
771  public:
772  // Types:
773  typedef _CharT char_type;
774  typedef _Traits traits_type;
775  // _GLIBCXX_RESOLVE_LIB_DEFECTS
776  // 251. basic_stringbuf missing allocator_type
777  typedef _Alloc allocator_type;
778  typedef typename traits_type::int_type int_type;
779  typedef typename traits_type::pos_type pos_type;
780  typedef typename traits_type::off_type off_type;
781 
782  // Non-standard types:
783  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
784  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
785  typedef basic_ostream<char_type, traits_type> __ostream_type;
786 
787  private:
788  __stringbuf_type _M_stringbuf;
789 
790  public:
791  // Constructors/destructor:
792 
793  /**
794  * @brief Default constructor starts with an empty string buffer.
795  *
796  * Initializes @c sb using @c mode|out, and passes @c &sb to the base
797  * class initializer. Does not allocate any buffer.
798  *
799  * That's a lie. We initialize the base class with NULL, because the
800  * string class does its own memory management.
801  */
802  basic_ostringstream()
803  : __ostream_type(), _M_stringbuf(ios_base::out)
804  { this->init(&_M_stringbuf); }
805 
806  /**
807  * @brief Starts with an empty string buffer.
808  * @param __mode Whether the buffer can read, or write, or both.
809  *
810  * @c ios_base::out is automatically included in @a mode.
811  *
812  * Initializes @c sb using @c mode|out, and passes @c &sb to the base
813  * class initializer. Does not allocate any buffer.
814  *
815  * That's a lie. We initialize the base class with NULL, because the
816  * string class does its own memory management.
817  */
818  explicit
819  basic_ostringstream(ios_base::openmode __mode)
820  : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
821  { this->init(&_M_stringbuf); }
822 
823  /**
824  * @brief Starts with an existing string buffer.
825  * @param __str A string to copy as a starting buffer.
826  * @param __mode Whether the buffer can read, or write, or both.
827  *
828  * @c ios_base::out is automatically included in @a mode.
829  *
830  * Initializes @c sb using @a str and @c mode|out, and passes @c &sb
831  * to the base class initializer.
832  *
833  * That's a lie. We initialize the base class with NULL, because the
834  * string class does its own memory management.
835  */
836  explicit
837  basic_ostringstream(const __string_type& __str,
838  ios_base::openmode __mode = ios_base::out)
839  : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
840  { this->init(&_M_stringbuf); }
841 
842  /**
843  * @brief The destructor does nothing.
844  *
845  * The buffer is deallocated by the stringbuf object, not the
846  * formatting stream.
847  */
848  ~basic_ostringstream()
849  { }
850 
851 #if __cplusplus >= 201103L
852  basic_ostringstream(const basic_ostringstream&) = delete;
853 
854  basic_ostringstream(basic_ostringstream&& __rhs)
855  : __ostream_type(std::move(__rhs)),
856  _M_stringbuf(std::move(__rhs._M_stringbuf))
857  { __ostream_type::set_rdbuf(&_M_stringbuf); }
858 
859 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
860  basic_ostringstream(ios_base::openmode __mode, const allocator_type& __a)
861  : __ostream_type(), _M_stringbuf(__mode | ios_base::out, __a)
862  { this->init(std::__addressof(_M_stringbuf)); }
863 
864  explicit
865  basic_ostringstream(__string_type&& __str,
866  ios_base::openmode __mode = ios_base::out)
867  : __ostream_type(), _M_stringbuf(std::move(__str), __mode | ios_base::out)
868  { this->init(std::__addressof(_M_stringbuf)); }
869 
870  template<typename _SAlloc>
871  basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
872  const allocator_type& __a)
873  : basic_ostringstream(__str, ios_base::out, __a)
874  { }
875 
876  template<typename _SAlloc>
877  basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
878  ios_base::openmode __mode,
879  const allocator_type& __a)
880  : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out, __a)
881  { this->init(std::__addressof(_M_stringbuf)); }
882 
883  template<typename _SAlloc>
884  explicit
885  basic_ostringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
886  ios_base::openmode __mode = ios_base::out)
887  : basic_ostringstream(__str, __mode, allocator_type())
888  { }
889 #endif // C++20
890 
891  // 27.8.3.2 Assign and swap:
892 
893  basic_ostringstream&
894  operator=(const basic_ostringstream&) = delete;
895 
896  basic_ostringstream&
897  operator=(basic_ostringstream&& __rhs)
898  {
899  __ostream_type::operator=(std::move(__rhs));
900  _M_stringbuf = std::move(__rhs._M_stringbuf);
901  return *this;
902  }
903 
904  void
905  swap(basic_ostringstream& __rhs)
906  {
907  __ostream_type::swap(__rhs);
908  _M_stringbuf.swap(__rhs._M_stringbuf);
909  }
910 #endif // C++11
911 
912  // Members:
913  /**
914  * @brief Accessing the underlying buffer.
915  * @return The current basic_stringbuf buffer.
916  *
917  * This hides both signatures of std::basic_ios::rdbuf().
918  */
919  __stringbuf_type*
920  rdbuf() const
921  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
922 
923  /**
924  * @brief Copying out the string buffer.
925  * @return @c rdbuf()->str()
926  */
927  __string_type
928  str() const _GLIBCXX_LVAL_REF_QUAL
929  { return _M_stringbuf.str(); }
930 
931 #if __cplusplus > 201703L
932 #if _GLIBCXX_USE_CXX11_ABI
933 #if __cpp_concepts
934  template<__allocator_like _SAlloc>
935  basic_string<_CharT, _Traits, _SAlloc>
936  str(const _SAlloc& __sa) const
937  { return _M_stringbuf.str(__sa); }
938 #endif
939 
940  __string_type
941  str() &&
942  { return std::move(_M_stringbuf).str(); }
943 #endif // cxx11 ABI
944 
945  _GLIBCXX_SSTREAM_ALWAYS_INLINE
946  basic_string_view<char_type, traits_type>
947  view() const noexcept
948  { return _M_stringbuf.view(); }
949 #endif // C++20
950 
951  /**
952  * @brief Setting a new buffer.
953  * @param __s The string to use as a new sequence.
954  *
955  * Calls @c rdbuf()->str(s).
956  */
957  void
958  str(const __string_type& __s)
959  { _M_stringbuf.str(__s); }
960 
961 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
962 #if __cpp_concepts
963  template<__allocator_like _SAlloc>
964  requires (!is_same_v<_SAlloc, _Alloc>)
965  void
966  str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
967  { _M_stringbuf.str(__s); }
968 #endif
969 
970  void
971  str(__string_type&& __s)
972  { _M_stringbuf.str(std::move(__s)); }
973 #endif
974  };
975 
976 
977  // [27.7.4] Template class basic_stringstream
978  /**
979  * @brief Controlling input and output for std::string.
980  * @ingroup io
981  *
982  * @tparam _CharT Type of character stream.
983  * @tparam _Traits Traits for character type, defaults to
984  * char_traits<_CharT>.
985  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
986  *
987  * This class supports reading from and writing to objects of type
988  * std::basic_string, using the inherited functions from
989  * std::basic_iostream. To control the associated sequence, an instance
990  * of std::basic_stringbuf is used, which this page refers to as @c sb.
991  */
992  template <typename _CharT, typename _Traits, typename _Alloc>
993  class basic_stringstream : public basic_iostream<_CharT, _Traits>
994  {
995  public:
996  // Types:
997  typedef _CharT char_type;
998  typedef _Traits traits_type;
999  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1000  // 251. basic_stringbuf missing allocator_type
1001  typedef _Alloc allocator_type;
1002  typedef typename traits_type::int_type int_type;
1003  typedef typename traits_type::pos_type pos_type;
1004  typedef typename traits_type::off_type off_type;
1005 
1006  // Non-standard Types:
1007  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
1008  typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
1009  typedef basic_iostream<char_type, traits_type> __iostream_type;
1010 
1011  private:
1012  __stringbuf_type _M_stringbuf;
1013 
1014  public:
1015  // Constructors/destructors
1016 
1017  /**
1018  * @brief Default constructor starts with an empty string buffer.
1019  *
1020  * Initializes @c sb using the mode @c in|out, and passes @c &sb
1021  * to the base class initializer. Does not allocate any buffer.
1022  *
1023  * That's a lie. We initialize the base class with NULL, because the
1024  * string class does its own memory management.
1025  */
1026  basic_stringstream()
1027  : __iostream_type(), _M_stringbuf(ios_base::out | ios_base::in)
1028  { this->init(&_M_stringbuf); }
1029 
1030  /**
1031  * @brief Starts with an empty string buffer.
1032  * @param __m Whether the buffer can read, or write, or both.
1033  *
1034  * Initializes @c sb using the mode from @c __m, and passes @c &sb
1035  * to the base class initializer. Does not allocate any buffer.
1036  *
1037  * That's a lie. We initialize the base class with NULL, because the
1038  * string class does its own memory management.
1039  */
1040  explicit
1041  basic_stringstream(ios_base::openmode __m)
1042  : __iostream_type(), _M_stringbuf(__m)
1043  { this->init(&_M_stringbuf); }
1044 
1045  /**
1046  * @brief Starts with an existing string buffer.
1047  * @param __str A string to copy as a starting buffer.
1048  * @param __m Whether the buffer can read, or write, or both.
1049  *
1050  * Initializes @c sb using @a __str and @c __m, and passes @c &sb
1051  * to the base class initializer.
1052  *
1053  * That's a lie. We initialize the base class with NULL, because the
1054  * string class does its own memory management.
1055  */
1056  explicit
1057  basic_stringstream(const __string_type& __str,
1058  ios_base::openmode __m = ios_base::out | ios_base::in)
1059  : __iostream_type(), _M_stringbuf(__str, __m)
1060  { this->init(&_M_stringbuf); }
1061 
1062  /**
1063  * @brief The destructor does nothing.
1064  *
1065  * The buffer is deallocated by the stringbuf object, not the
1066  * formatting stream.
1067  */
1068  ~basic_stringstream()
1069  { }
1070 
1071 #if __cplusplus >= 201103L
1072  basic_stringstream(const basic_stringstream&) = delete;
1073 
1074  basic_stringstream(basic_stringstream&& __rhs)
1075  : __iostream_type(std::move(__rhs)),
1076  _M_stringbuf(std::move(__rhs._M_stringbuf))
1077  { __iostream_type::set_rdbuf(&_M_stringbuf); }
1078 
1079 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
1080  basic_stringstream(ios_base::openmode __mode, const allocator_type& __a)
1081  : __iostream_type(), _M_stringbuf(__mode, __a)
1082  { this->init(&_M_stringbuf); }
1083 
1084  explicit
1085  basic_stringstream(__string_type&& __str,
1086  ios_base::openmode __mode = ios_base::in
1087  | ios_base::out)
1088  : __iostream_type(), _M_stringbuf(std::move(__str), __mode)
1089  { this->init(std::__addressof(_M_stringbuf)); }
1090 
1091  template<typename _SAlloc>
1092  basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
1093  const allocator_type& __a)
1094  : basic_stringstream(__str, ios_base::in | ios_base::out, __a)
1095  { }
1096 
1097  template<typename _SAlloc>
1098  basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
1099  ios_base::openmode __mode,
1100  const allocator_type& __a)
1101  : __iostream_type(), _M_stringbuf(__str, __mode, __a)
1102  { this->init(std::__addressof(_M_stringbuf)); }
1103 
1104  template<typename _SAlloc>
1105  explicit
1106  basic_stringstream(const basic_string<_CharT, _Traits, _SAlloc>& __str,
1107  ios_base::openmode __mode = ios_base::in
1108  | ios_base::out)
1109  : basic_stringstream(__str, __mode, allocator_type())
1110  { }
1111 #endif // C++20
1112 
1113  // 27.8.3.2 Assign and swap:
1114 
1115  basic_stringstream&
1116  operator=(const basic_stringstream&) = delete;
1117 
1118  basic_stringstream&
1119  operator=(basic_stringstream&& __rhs)
1120  {
1121  __iostream_type::operator=(std::move(__rhs));
1122  _M_stringbuf = std::move(__rhs._M_stringbuf);
1123  return *this;
1124  }
1125 
1126  void
1127  swap(basic_stringstream& __rhs)
1128  {
1129  __iostream_type::swap(__rhs);
1130  _M_stringbuf.swap(__rhs._M_stringbuf);
1131  }
1132 #endif // C++11
1133 
1134  // Members:
1135  /**
1136  * @brief Accessing the underlying buffer.
1137  * @return The current basic_stringbuf buffer.
1138  *
1139  * This hides both signatures of std::basic_ios::rdbuf().
1140  */
1141  __stringbuf_type*
1142  rdbuf() const
1143  { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
1144 
1145  /**
1146  * @brief Copying out the string buffer.
1147  * @return @c rdbuf()->str()
1148  */
1149  __string_type
1150  str() const _GLIBCXX_LVAL_REF_QUAL
1151  { return _M_stringbuf.str(); }
1152 
1153 #if __cplusplus > 201703L
1154 #if _GLIBCXX_USE_CXX11_ABI
1155 #if __cpp_concepts
1156  template<__allocator_like _SAlloc>
1157  basic_string<_CharT, _Traits, _SAlloc>
1158  str(const _SAlloc& __sa) const
1159  { return _M_stringbuf.str(__sa); }
1160 #endif
1161 
1162  __string_type
1163  str() &&
1164  { return std::move(_M_stringbuf).str(); }
1165 #endif // cxx11 ABI
1166 
1167  _GLIBCXX_SSTREAM_ALWAYS_INLINE
1168  basic_string_view<char_type, traits_type>
1169  view() const noexcept
1170  { return _M_stringbuf.view(); }
1171 #endif // C++20
1172 
1173  /**
1174  * @brief Setting a new buffer.
1175  * @param __s The string to use as a new sequence.
1176  *
1177  * Calls @c rdbuf()->str(s).
1178  */
1179  void
1180  str(const __string_type& __s)
1181  { _M_stringbuf.str(__s); }
1182 
1183 #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
1184 #if __cpp_concepts
1185  template<__allocator_like _SAlloc>
1186  requires (!is_same_v<_SAlloc, _Alloc>)
1187  void
1188  str(const basic_string<_CharT, _Traits, _SAlloc>& __s)
1189  { _M_stringbuf.str(__s); }
1190 #endif
1191 
1192  void
1193  str(__string_type&& __s)
1194  { _M_stringbuf.str(std::move(__s)); }
1195 #endif
1196  };
1197 
1198 #if __cplusplus >= 201103L
1199  /// Swap specialization for stringbufs.
1200  template <class _CharT, class _Traits, class _Allocator>
1201  inline void
1202  swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x,
1203  basic_stringbuf<_CharT, _Traits, _Allocator>& __y)
1204  noexcept(noexcept(__x.swap(__y)))
1205  { __x.swap(__y); }
1206 
1207  /// Swap specialization for istringstreams.
1208  template <class _CharT, class _Traits, class _Allocator>
1209  inline void
1210  swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x,
1211  basic_istringstream<_CharT, _Traits, _Allocator>& __y)
1212  { __x.swap(__y); }
1213 
1214  /// Swap specialization for ostringstreams.
1215  template <class _CharT, class _Traits, class _Allocator>
1216  inline void
1217  swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x,
1218  basic_ostringstream<_CharT, _Traits, _Allocator>& __y)
1219  { __x.swap(__y); }
1220 
1221  /// Swap specialization for stringstreams.
1222  template <class _CharT, class _Traits, class _Allocator>
1223  inline void
1224  swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x,
1225  basic_stringstream<_CharT, _Traits, _Allocator>& __y)
1226  { __x.swap(__y); }
1227 #endif // C++11
1228 
1229 _GLIBCXX_END_NAMESPACE_CXX11
1230 _GLIBCXX_END_NAMESPACE_VERSION
1231 } // namespace
1232 
1233 #undef _GLIBCXX_SSTREAM_ALWAYS_INLINE
1234 #undef _GLIBCXX_LVAL_REF_QUAL
1235 
1236 #include <bits/sstream.tcc>
1237 
1238 #endif /* _GLIBCXX_SSTREAM */