1 // Components for manipulating sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 1997-2014 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file bits/basic_string.tcc
26  *  This is an internal header file, included by other library headers.
27  *  Do not attempt to use it directly. @headername{string}
28  */
29 
30 //
31 // ISO C++ 14882: 21  Strings library
32 //
33 
34 // Written by Jason Merrill based upon the specification by Takanori Adachi
35 // in ANSI X3J16/94-0013R2.  Rewritten by Nathan Myers to ISO-14882.
36 
37 #ifndef _BASIC_STRING_TCC
38 #define _BASIC_STRING_TCC 1
39 
40 #pragma GCC system_header
41 
42 #include <bits/cxxabi_forced.h>
43 
44 namespace std _GLIBCXX_VISIBILITY(default)
45 {
46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 
48   template<typename _CharT, typename _Traits, typename _Alloc>
49     const typename basic_string<_CharT, _Traits, _Alloc>::size_type
50     basic_string<_CharT, _Traits, _Alloc>::
51     _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;
52 
53   template<typename _CharT, typename _Traits, typename _Alloc>
54     const _CharT
55     basic_string<_CharT, _Traits, _Alloc>::
56     _Rep::_S_terminal = _CharT();
57 
58   template<typename _CharT, typename _Traits, typename _Alloc>
59     const typename basic_string<_CharT, _Traits, _Alloc>::size_type
60     basic_string<_CharT, _Traits, _Alloc>::npos;
61 
62   // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
63   // at static init time (before static ctors are run).
64   template<typename _CharT, typename _Traits, typename _Alloc>
65     typename basic_string<_CharT, _Traits, _Alloc>::size_type
66     basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
67     (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
68       sizeof(size_type)];
69 
70   // NB: This is the special case for Input Iterators, used in
71   // istreambuf_iterators, etc.
72   // Input Iterators have a cost structure very different from
73   // pointers, calling for a different coding style.
74   template<typename _CharT, typename _Traits, typename _Alloc>
75     template<typename _InIterator>
76       _CharT*
77       basic_string<_CharT, _Traits, _Alloc>::
_S_construct(_InIterator __beg,_InIterator __end,const _Alloc & __a,input_iterator_tag)78       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
79 		   input_iterator_tag)
80       {
81 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
82 	if (__beg == __end && __a == _Alloc())
83 	  return _S_empty_rep()._M_refdata();
84 #endif
85 	// Avoid reallocation for common case.
86 	_CharT __buf[128];
87 	size_type __len = 0;
88 	while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
89 	  {
90 	    __buf[__len++] = *__beg;
91 	    ++__beg;
92 	  }
93 	_Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
94 	_M_copy(__r->_M_refdata(), __buf, __len);
95 	__try
96 	  {
97 	    while (__beg != __end)
98 	      {
99 		if (__len == __r->_M_capacity)
100 		  {
101 		    // Allocate more space.
102 		    _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
103 		    _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
104 		    __r->_M_destroy(__a);
105 		    __r = __another;
106 		  }
107 		__r->_M_refdata()[__len++] = *__beg;
108 		++__beg;
109 	      }
110 	  }
111 	__catch(...)
112 	  {
113 	    __r->_M_destroy(__a);
114 	    __throw_exception_again;
115 	  }
116 	__r->_M_set_length_and_sharable(__len);
117 	return __r->_M_refdata();
118       }
119 
120   template<typename _CharT, typename _Traits, typename _Alloc>
121     template <typename _InIterator>
122       _CharT*
123       basic_string<_CharT, _Traits, _Alloc>::
_S_construct(_InIterator __beg,_InIterator __end,const _Alloc & __a,forward_iterator_tag)124       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
125 		   forward_iterator_tag)
126       {
127 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
128 	if (__beg == __end && __a == _Alloc())
129 	  return _S_empty_rep()._M_refdata();
130 #endif
131 	// NB: Not required, but considered best practice.
132 	if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end)
133 	  __throw_logic_error(__N("basic_string::_S_construct null not valid"));
134 
135 	const size_type __dnew = static_cast<size_type>(std::distance(__beg,
136 								      __end));
137 	// Check for out_of_range and length_error exceptions.
138 	_Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
139 	__try
140 	  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
141 	__catch(...)
142 	  {
143 	    __r->_M_destroy(__a);
144 	    __throw_exception_again;
145 	  }
146 	__r->_M_set_length_and_sharable(__dnew);
147 	return __r->_M_refdata();
148       }
149 
150   template<typename _CharT, typename _Traits, typename _Alloc>
151     _CharT*
152     basic_string<_CharT, _Traits, _Alloc>::
153     _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
154     {
155 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
156       if (__n == 0 && __a == _Alloc())
157 	return _S_empty_rep()._M_refdata();
158 #endif
159       // Check for out_of_range and length_error exceptions.
160       _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
161       if (__n)
162 	_M_assign(__r->_M_refdata(), __n, __c);
163 
164       __r->_M_set_length_and_sharable(__n);
165       return __r->_M_refdata();
166     }
167 
168   template<typename _CharT, typename _Traits, typename _Alloc>
169     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const basic_string & __str)170     basic_string(const basic_string& __str)
171     : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()),
172 					  __str.get_allocator()),
173 		  __str.get_allocator())
174     { }
175 
176   template<typename _CharT, typename _Traits, typename _Alloc>
177     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const _Alloc & __a)178     basic_string(const _Alloc& __a)
179     : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
180     { }
181 
182   template<typename _CharT, typename _Traits, typename _Alloc>
183     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const basic_string & __str,size_type __pos,size_type __n)184     basic_string(const basic_string& __str, size_type __pos, size_type __n)
185     : _M_dataplus(_S_construct(__str._M_data()
186 			       + __str._M_check(__pos,
187 						"basic_string::basic_string"),
188 			       __str._M_data() + __str._M_limit(__pos, __n)
189 			       + __pos, _Alloc()), _Alloc())
190     { }
191 
192   template<typename _CharT, typename _Traits, typename _Alloc>
193     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const basic_string & __str,size_type __pos,size_type __n,const _Alloc & __a)194     basic_string(const basic_string& __str, size_type __pos,
195 		 size_type __n, const _Alloc& __a)
196     : _M_dataplus(_S_construct(__str._M_data()
197 			       + __str._M_check(__pos,
198 						"basic_string::basic_string"),
199 			       __str._M_data() + __str._M_limit(__pos, __n)
200 			       + __pos, __a), __a)
201     { }
202 
203   // TBD: DPG annotate
204   template<typename _CharT, typename _Traits, typename _Alloc>
205     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const _CharT * __s,size_type __n,const _Alloc & __a)206     basic_string(const _CharT* __s, size_type __n, const _Alloc& __a)
207     : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
208     { }
209 
210   // TBD: DPG annotate
211   template<typename _CharT, typename _Traits, typename _Alloc>
212     basic_string<_CharT, _Traits, _Alloc>::
basic_string(const _CharT * __s,const _Alloc & __a)213     basic_string(const _CharT* __s, const _Alloc& __a)
214     : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) :
215 			       __s + npos, __a), __a)
216     { }
217 
218   template<typename _CharT, typename _Traits, typename _Alloc>
219     basic_string<_CharT, _Traits, _Alloc>::
basic_string(size_type __n,_CharT __c,const _Alloc & __a)220     basic_string(size_type __n, _CharT __c, const _Alloc& __a)
221     : _M_dataplus(_S_construct(__n, __c, __a), __a)
222     { }
223 
224   // TBD: DPG annotate
225   template<typename _CharT, typename _Traits, typename _Alloc>
226     template<typename _InputIterator>
227     basic_string<_CharT, _Traits, _Alloc>::
basic_string(_InputIterator __beg,_InputIterator __end,const _Alloc & __a)228     basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc& __a)
229     : _M_dataplus(_S_construct(__beg, __end, __a), __a)
230     { }
231 
232 #if __cplusplus >= 201103L
233   template<typename _CharT, typename _Traits, typename _Alloc>
234     basic_string<_CharT, _Traits, _Alloc>::
basic_string(initializer_list<_CharT> __l,const _Alloc & __a)235     basic_string(initializer_list<_CharT> __l, const _Alloc& __a)
236     : _M_dataplus(_S_construct(__l.begin(), __l.end(), __a), __a)
237     { }
238 #endif
239 
240   template<typename _CharT, typename _Traits, typename _Alloc>
241     basic_string<_CharT, _Traits, _Alloc>&
242     basic_string<_CharT, _Traits, _Alloc>::
assign(const basic_string & __str)243     assign(const basic_string& __str)
244     {
245       if (_M_rep() != __str._M_rep())
246 	{
247 	  // XXX MT
248 	  const allocator_type __a = this->get_allocator();
249 	  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
250 	  _M_rep()->_M_dispose(__a);
251 	  _M_data(__tmp);
252 	}
253       return *this;
254     }
255 
256   template<typename _CharT, typename _Traits, typename _Alloc>
257     basic_string<_CharT, _Traits, _Alloc>&
258     basic_string<_CharT, _Traits, _Alloc>::
assign(const _CharT * __s,size_type __n)259     assign(const _CharT* __s, size_type __n)
260     {
261       __glibcxx_requires_string_len(__s, __n);
262       _M_check_length(this->size(), __n, "basic_string::assign");
263       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
264 	return _M_replace_safe(size_type(0), this->size(), __s, __n);
265       else
266 	{
267 	  // Work in-place.
268 	  const size_type __pos = __s - _M_data();
269 	  if (__pos >= __n)
270 	    _M_copy(_M_data(), __s, __n);
271 	  else if (__pos)
272 	    _M_move(_M_data(), __s, __n);
273 	  _M_rep()->_M_set_length_and_sharable(__n);
274 	  return *this;
275 	}
276      }
277 
278   template<typename _CharT, typename _Traits, typename _Alloc>
279     basic_string<_CharT, _Traits, _Alloc>&
280     basic_string<_CharT, _Traits, _Alloc>::
append(size_type __n,_CharT __c)281     append(size_type __n, _CharT __c)
282     {
283       if (__n)
284 	{
285 	  _M_check_length(size_type(0), __n, "basic_string::append");
286 	  const size_type __len = __n + this->size();
287 	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
288 	    this->reserve(__len);
289 	  _M_assign(_M_data() + this->size(), __n, __c);
290 	  _M_rep()->_M_set_length_and_sharable(__len);
291 	}
292       return *this;
293     }
294 
295   template<typename _CharT, typename _Traits, typename _Alloc>
296     basic_string<_CharT, _Traits, _Alloc>&
297     basic_string<_CharT, _Traits, _Alloc>::
append(const _CharT * __s,size_type __n)298     append(const _CharT* __s, size_type __n)
299     {
300       __glibcxx_requires_string_len(__s, __n);
301       if (__n)
302 	{
303 	  _M_check_length(size_type(0), __n, "basic_string::append");
304 	  const size_type __len = __n + this->size();
305 	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
306 	    {
307 	      if (_M_disjunct(__s))
308 		this->reserve(__len);
309 	      else
310 		{
311 		  const size_type __off = __s - _M_data();
312 		  this->reserve(__len);
313 		  __s = _M_data() + __off;
314 		}
315 	    }
316 	  _M_copy(_M_data() + this->size(), __s, __n);
317 	  _M_rep()->_M_set_length_and_sharable(__len);
318 	}
319       return *this;
320     }
321 
322   template<typename _CharT, typename _Traits, typename _Alloc>
323     basic_string<_CharT, _Traits, _Alloc>&
324     basic_string<_CharT, _Traits, _Alloc>::
append(const basic_string & __str)325     append(const basic_string& __str)
326     {
327       const size_type __size = __str.size();
328       if (__size)
329 	{
330 	  const size_type __len = __size + this->size();
331 	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
332 	    this->reserve(__len);
333 	  _M_copy(_M_data() + this->size(), __str._M_data(), __size);
334 	  _M_rep()->_M_set_length_and_sharable(__len);
335 	}
336       return *this;
337     }
338 
339   template<typename _CharT, typename _Traits, typename _Alloc>
340     basic_string<_CharT, _Traits, _Alloc>&
341     basic_string<_CharT, _Traits, _Alloc>::
append(const basic_string & __str,size_type __pos,size_type __n)342     append(const basic_string& __str, size_type __pos, size_type __n)
343     {
344       __str._M_check(__pos, "basic_string::append");
345       __n = __str._M_limit(__pos, __n);
346       if (__n)
347 	{
348 	  const size_type __len = __n + this->size();
349 	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
350 	    this->reserve(__len);
351 	  _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
352 	  _M_rep()->_M_set_length_and_sharable(__len);
353 	}
354       return *this;
355     }
356 
357    template<typename _CharT, typename _Traits, typename _Alloc>
358      basic_string<_CharT, _Traits, _Alloc>&
359      basic_string<_CharT, _Traits, _Alloc>::
insert(size_type __pos,const _CharT * __s,size_type __n)360      insert(size_type __pos, const _CharT* __s, size_type __n)
361      {
362        __glibcxx_requires_string_len(__s, __n);
363        _M_check(__pos, "basic_string::insert");
364        _M_check_length(size_type(0), __n, "basic_string::insert");
365        if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
366          return _M_replace_safe(__pos, size_type(0), __s, __n);
367        else
368          {
369            // Work in-place.
370            const size_type __off = __s - _M_data();
371            _M_mutate(__pos, 0, __n);
372            __s = _M_data() + __off;
373            _CharT* __p = _M_data() + __pos;
374            if (__s  + __n <= __p)
375              _M_copy(__p, __s, __n);
376            else if (__s >= __p)
377              _M_copy(__p, __s + __n, __n);
378            else
379              {
380 	       const size_type __nleft = __p - __s;
381                _M_copy(__p, __s, __nleft);
382                _M_copy(__p + __nleft, __p + __n, __n - __nleft);
383              }
384            return *this;
385          }
386      }
387 
388    template<typename _CharT, typename _Traits, typename _Alloc>
389      typename basic_string<_CharT, _Traits, _Alloc>::iterator
390      basic_string<_CharT, _Traits, _Alloc>::
erase(iterator __first,iterator __last)391      erase(iterator __first, iterator __last)
392      {
393        _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last
394 				&& __last <= _M_iend());
395 
396        // NB: This isn't just an optimization (bail out early when
397        // there is nothing to do, really), it's also a correctness
398        // issue vs MT, see libstdc++/40518.
399        const size_type __size = __last - __first;
400        if (__size)
401 	 {
402 	   const size_type __pos = __first - _M_ibegin();
403 	   _M_mutate(__pos, __size, size_type(0));
404 	   _M_rep()->_M_set_leaked();
405 	   return iterator(_M_data() + __pos);
406 	 }
407        else
408 	 return __first;
409      }
410 
411    template<typename _CharT, typename _Traits, typename _Alloc>
412      basic_string<_CharT, _Traits, _Alloc>&
413      basic_string<_CharT, _Traits, _Alloc>::
replace(size_type __pos,size_type __n1,const _CharT * __s,size_type __n2)414      replace(size_type __pos, size_type __n1, const _CharT* __s,
415 	     size_type __n2)
416      {
417        __glibcxx_requires_string_len(__s, __n2);
418        _M_check(__pos, "basic_string::replace");
419        __n1 = _M_limit(__pos, __n1);
420        _M_check_length(__n1, __n2, "basic_string::replace");
421        bool __left;
422        if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
423          return _M_replace_safe(__pos, __n1, __s, __n2);
424        else if ((__left = __s + __n2 <= _M_data() + __pos)
425 		|| _M_data() + __pos + __n1 <= __s)
426 	 {
427 	   // Work in-place: non-overlapping case.
428 	   size_type __off = __s - _M_data();
429 	   __left ? __off : (__off += __n2 - __n1);
430 	   _M_mutate(__pos, __n1, __n2);
431 	   _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
432 	   return *this;
433 	 }
434        else
435 	 {
436 	   // Todo: overlapping case.
437 	   const basic_string __tmp(__s, __n2);
438 	   return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
439 	 }
440      }
441 
442   template<typename _CharT, typename _Traits, typename _Alloc>
443     void
444     basic_string<_CharT, _Traits, _Alloc>::_Rep::
_M_destroy(const _Alloc & __a)445     _M_destroy(const _Alloc& __a) throw ()
446     {
447       const size_type __size = sizeof(_Rep_base) +
448 	                       (this->_M_capacity + 1) * sizeof(_CharT);
449       _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
450     }
451 
452   template<typename _CharT, typename _Traits, typename _Alloc>
453     void
454     basic_string<_CharT, _Traits, _Alloc>::
_M_leak_hard()455     _M_leak_hard()
456     {
457 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
458       if (_M_rep() == &_S_empty_rep())
459 	return;
460 #endif
461       if (_M_rep()->_M_is_shared())
462 	_M_mutate(0, 0, 0);
463       _M_rep()->_M_set_leaked();
464     }
465 
466   template<typename _CharT, typename _Traits, typename _Alloc>
467     void
468     basic_string<_CharT, _Traits, _Alloc>::
_M_mutate(size_type __pos,size_type __len1,size_type __len2)469     _M_mutate(size_type __pos, size_type __len1, size_type __len2)
470     {
471       const size_type __old_size = this->size();
472       const size_type __new_size = __old_size + __len2 - __len1;
473       const size_type __how_much = __old_size - __pos - __len1;
474 
475       if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
476 	{
477 	  // Must reallocate.
478 	  const allocator_type __a = get_allocator();
479 	  _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);
480 
481 	  if (__pos)
482 	    _M_copy(__r->_M_refdata(), _M_data(), __pos);
483 	  if (__how_much)
484 	    _M_copy(__r->_M_refdata() + __pos + __len2,
485 		    _M_data() + __pos + __len1, __how_much);
486 
487 	  _M_rep()->_M_dispose(__a);
488 	  _M_data(__r->_M_refdata());
489 	}
490       else if (__how_much && __len1 != __len2)
491 	{
492 	  // Work in-place.
493 	  _M_move(_M_data() + __pos + __len2,
494 		  _M_data() + __pos + __len1, __how_much);
495 	}
496       _M_rep()->_M_set_length_and_sharable(__new_size);
497     }
498 
499   template<typename _CharT, typename _Traits, typename _Alloc>
500     void
501     basic_string<_CharT, _Traits, _Alloc>::
reserve(size_type __res)502     reserve(size_type __res)
503     {
504       if (__res != this->capacity() || _M_rep()->_M_is_shared())
505         {
506 	  // Make sure we don't shrink below the current size
507 	  if (__res < this->size())
508 	    __res = this->size();
509 	  const allocator_type __a = get_allocator();
510 	  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
511 	  _M_rep()->_M_dispose(__a);
512 	  _M_data(__tmp);
513         }
514     }
515 
516   template<typename _CharT, typename _Traits, typename _Alloc>
517     void
518     basic_string<_CharT, _Traits, _Alloc>::
swap(basic_string & __s)519     swap(basic_string& __s)
520     {
521       if (_M_rep()->_M_is_leaked())
522 	_M_rep()->_M_set_sharable();
523       if (__s._M_rep()->_M_is_leaked())
524 	__s._M_rep()->_M_set_sharable();
525       if (this->get_allocator() == __s.get_allocator())
526 	{
527 	  _CharT* __tmp = _M_data();
528 	  _M_data(__s._M_data());
529 	  __s._M_data(__tmp);
530 	}
531       // The code below can usually be optimized away.
532       else
533 	{
534 	  const basic_string __tmp1(_M_ibegin(), _M_iend(),
535 				    __s.get_allocator());
536 	  const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
537 				    this->get_allocator());
538 	  *this = __tmp2;
539 	  __s = __tmp1;
540 	}
541     }
542 
543   template<typename _CharT, typename _Traits, typename _Alloc>
544     typename basic_string<_CharT, _Traits, _Alloc>::_Rep*
545     basic_string<_CharT, _Traits, _Alloc>::_Rep::
_S_create(size_type __capacity,size_type __old_capacity,const _Alloc & __alloc)546     _S_create(size_type __capacity, size_type __old_capacity,
547 	      const _Alloc& __alloc)
548     {
549       // _GLIBCXX_RESOLVE_LIB_DEFECTS
550       // 83.  String::npos vs. string::max_size()
551       if (__capacity > _S_max_size)
552 	__throw_length_error(__N("basic_string::_S_create"));
553 
554       // The standard places no restriction on allocating more memory
555       // than is strictly needed within this layer at the moment or as
556       // requested by an explicit application call to reserve().
557 
558       // Many malloc implementations perform quite poorly when an
559       // application attempts to allocate memory in a stepwise fashion
560       // growing each allocation size by only 1 char.  Additionally,
561       // it makes little sense to allocate less linear memory than the
562       // natural blocking size of the malloc implementation.
563       // Unfortunately, we would need a somewhat low-level calculation
564       // with tuned parameters to get this perfect for any particular
565       // malloc implementation.  Fortunately, generalizations about
566       // common features seen among implementations seems to suffice.
567 
568       // __pagesize need not match the actual VM page size for good
569       // results in practice, thus we pick a common value on the low
570       // side.  __malloc_header_size is an estimate of the amount of
571       // overhead per memory allocation (in practice seen N * sizeof
572       // (void*) where N is 0, 2 or 4).  According to folklore,
573       // picking this value on the high side is better than
574       // low-balling it (especially when this algorithm is used with
575       // malloc implementations that allocate memory blocks rounded up
576       // to a size which is a power of 2).
577       const size_type __pagesize = 4096;
578       const size_type __malloc_header_size = 4 * sizeof(void*);
579 
580       // The below implements an exponential growth policy, necessary to
581       // meet amortized linear time requirements of the library: see
582       // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
583       // It's active for allocations requiring an amount of memory above
584       // system pagesize. This is consistent with the requirements of the
585       // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
586       if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
587 	__capacity = 2 * __old_capacity;
588 
589       // NB: Need an array of char_type[__capacity], plus a terminating
590       // null char_type() element, plus enough for the _Rep data structure.
591       // Whew. Seemingly so needy, yet so elemental.
592       size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
593 
594       const size_type __adj_size = __size + __malloc_header_size;
595       if (__adj_size > __pagesize && __capacity > __old_capacity)
596 	{
597 	  const size_type __extra = __pagesize - __adj_size % __pagesize;
598 	  __capacity += __extra / sizeof(_CharT);
599 	  // Never allocate a string bigger than _S_max_size.
600 	  if (__capacity > _S_max_size)
601 	    __capacity = _S_max_size;
602 	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
603 	}
604 
605       // NB: Might throw, but no worries about a leak, mate: _Rep()
606       // does not throw.
607       void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
608       _Rep *__p = new (__place) _Rep;
609       __p->_M_capacity = __capacity;
610       // ABI compatibility - 3.4.x set in _S_create both
611       // _M_refcount and _M_length.  All callers of _S_create
612       // in basic_string.tcc then set just _M_length.
613       // In 4.0.x and later both _M_refcount and _M_length
614       // are initialized in the callers, unfortunately we can
615       // have 3.4.x compiled code with _S_create callers inlined
616       // calling 4.0.x+ _S_create.
617       __p->_M_set_sharable();
618       return __p;
619     }
620 
621   template<typename _CharT, typename _Traits, typename _Alloc>
622     _CharT*
623     basic_string<_CharT, _Traits, _Alloc>::_Rep::
624     _M_clone(const _Alloc& __alloc, size_type __res)
625     {
626       // Requested capacity of the clone.
627       const size_type __requested_cap = this->_M_length + __res;
628       _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
629 				  __alloc);
630       if (this->_M_length)
631 	_M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
632 
633       __r->_M_set_length_and_sharable(this->_M_length);
634       return __r->_M_refdata();
635     }
636 
637   template<typename _CharT, typename _Traits, typename _Alloc>
638     void
639     basic_string<_CharT, _Traits, _Alloc>::
resize(size_type __n,_CharT __c)640     resize(size_type __n, _CharT __c)
641     {
642       const size_type __size = this->size();
643       _M_check_length(__size, __n, "basic_string::resize");
644       if (__size < __n)
645 	this->append(__n - __size, __c);
646       else if (__n < __size)
647 	this->erase(__n);
648       // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
649     }
650 
651   template<typename _CharT, typename _Traits, typename _Alloc>
652     template<typename _InputIterator>
653       basic_string<_CharT, _Traits, _Alloc>&
654       basic_string<_CharT, _Traits, _Alloc>::
_M_replace_dispatch(iterator __i1,iterator __i2,_InputIterator __k1,_InputIterator __k2,__false_type)655       _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
656 			  _InputIterator __k2, __false_type)
657       {
658 	const basic_string __s(__k1, __k2);
659 	const size_type __n1 = __i2 - __i1;
660 	_M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
661 	return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
662 			       __s.size());
663       }
664 
665   template<typename _CharT, typename _Traits, typename _Alloc>
666     basic_string<_CharT, _Traits, _Alloc>&
667     basic_string<_CharT, _Traits, _Alloc>::
_M_replace_aux(size_type __pos1,size_type __n1,size_type __n2,_CharT __c)668     _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
669 		   _CharT __c)
670     {
671       _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
672       _M_mutate(__pos1, __n1, __n2);
673       if (__n2)
674 	_M_assign(_M_data() + __pos1, __n2, __c);
675       return *this;
676     }
677 
678   template<typename _CharT, typename _Traits, typename _Alloc>
679     basic_string<_CharT, _Traits, _Alloc>&
680     basic_string<_CharT, _Traits, _Alloc>::
_M_replace_safe(size_type __pos1,size_type __n1,const _CharT * __s,size_type __n2)681     _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
682 		    size_type __n2)
683     {
684       _M_mutate(__pos1, __n1, __n2);
685       if (__n2)
686 	_M_copy(_M_data() + __pos1, __s, __n2);
687       return *this;
688     }
689 
690   template<typename _CharT, typename _Traits, typename _Alloc>
691     basic_string<_CharT, _Traits, _Alloc>
operator +(const _CharT * __lhs,const basic_string<_CharT,_Traits,_Alloc> & __rhs)692     operator+(const _CharT* __lhs,
693 	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
694     {
695       __glibcxx_requires_string(__lhs);
696       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
697       typedef typename __string_type::size_type	  __size_type;
698       const __size_type __len = _Traits::length(__lhs);
699       __string_type __str;
700       __str.reserve(__len + __rhs.size());
701       __str.append(__lhs, __len);
702       __str.append(__rhs);
703       return __str;
704     }
705 
706   template<typename _CharT, typename _Traits, typename _Alloc>
707     basic_string<_CharT, _Traits, _Alloc>
operator +(_CharT __lhs,const basic_string<_CharT,_Traits,_Alloc> & __rhs)708     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
709     {
710       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
711       typedef typename __string_type::size_type	  __size_type;
712       __string_type __str;
713       const __size_type __len = __rhs.size();
714       __str.reserve(__len + 1);
715       __str.append(__size_type(1), __lhs);
716       __str.append(__rhs);
717       return __str;
718     }
719 
720   template<typename _CharT, typename _Traits, typename _Alloc>
721     typename basic_string<_CharT, _Traits, _Alloc>::size_type
722     basic_string<_CharT, _Traits, _Alloc>::
copy(_CharT * __s,size_type __n,size_type __pos) const723     copy(_CharT* __s, size_type __n, size_type __pos) const
724     {
725       _M_check(__pos, "basic_string::copy");
726       __n = _M_limit(__pos, __n);
727       __glibcxx_requires_string_len(__s, __n);
728       if (__n)
729 	_M_copy(__s, _M_data() + __pos, __n);
730       // 21.3.5.7 par 3: do not append null.  (good.)
731       return __n;
732     }
733 
734   template<typename _CharT, typename _Traits, typename _Alloc>
735     typename basic_string<_CharT, _Traits, _Alloc>::size_type
736     basic_string<_CharT, _Traits, _Alloc>::
find(const _CharT * __s,size_type __pos,size_type __n) const737     find(const _CharT* __s, size_type __pos, size_type __n) const
738     {
739       __glibcxx_requires_string_len(__s, __n);
740       const size_type __size = this->size();
741       const _CharT* __data = _M_data();
742 
743       if (__n == 0)
744 	return __pos <= __size ? __pos : npos;
745 
746       if (__n <= __size)
747 	{
748 	  for (; __pos <= __size - __n; ++__pos)
749 	    if (traits_type::eq(__data[__pos], __s[0])
750 		&& traits_type::compare(__data + __pos + 1,
751 					__s + 1, __n - 1) == 0)
752 	      return __pos;
753 	}
754       return npos;
755     }
756 
757   template<typename _CharT, typename _Traits, typename _Alloc>
758     typename basic_string<_CharT, _Traits, _Alloc>::size_type
759     basic_string<_CharT, _Traits, _Alloc>::
find(_CharT __c,size_type __pos) const760     find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
761     {
762       size_type __ret = npos;
763       const size_type __size = this->size();
764       if (__pos < __size)
765 	{
766 	  const _CharT* __data = _M_data();
767 	  const size_type __n = __size - __pos;
768 	  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
769 	  if (__p)
770 	    __ret = __p - __data;
771 	}
772       return __ret;
773     }
774 
775   template<typename _CharT, typename _Traits, typename _Alloc>
776     typename basic_string<_CharT, _Traits, _Alloc>::size_type
777     basic_string<_CharT, _Traits, _Alloc>::
rfind(const _CharT * __s,size_type __pos,size_type __n) const778     rfind(const _CharT* __s, size_type __pos, size_type __n) const
779     {
780       __glibcxx_requires_string_len(__s, __n);
781       const size_type __size = this->size();
782       if (__n <= __size)
783 	{
784 	  __pos = std::min(size_type(__size - __n), __pos);
785 	  const _CharT* __data = _M_data();
786 	  do
787 	    {
788 	      if (traits_type::compare(__data + __pos, __s, __n) == 0)
789 		return __pos;
790 	    }
791 	  while (__pos-- > 0);
792 	}
793       return npos;
794     }
795 
796   template<typename _CharT, typename _Traits, typename _Alloc>
797     typename basic_string<_CharT, _Traits, _Alloc>::size_type
798     basic_string<_CharT, _Traits, _Alloc>::
rfind(_CharT __c,size_type __pos) const799     rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
800     {
801       size_type __size = this->size();
802       if (__size)
803 	{
804 	  if (--__size > __pos)
805 	    __size = __pos;
806 	  for (++__size; __size-- > 0; )
807 	    if (traits_type::eq(_M_data()[__size], __c))
808 	      return __size;
809 	}
810       return npos;
811     }
812 
813   template<typename _CharT, typename _Traits, typename _Alloc>
814     typename basic_string<_CharT, _Traits, _Alloc>::size_type
815     basic_string<_CharT, _Traits, _Alloc>::
find_first_of(const _CharT * __s,size_type __pos,size_type __n) const816     find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
817     {
818       __glibcxx_requires_string_len(__s, __n);
819       for (; __n && __pos < this->size(); ++__pos)
820 	{
821 	  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
822 	  if (__p)
823 	    return __pos;
824 	}
825       return npos;
826     }
827 
828   template<typename _CharT, typename _Traits, typename _Alloc>
829     typename basic_string<_CharT, _Traits, _Alloc>::size_type
830     basic_string<_CharT, _Traits, _Alloc>::
find_last_of(const _CharT * __s,size_type __pos,size_type __n) const831     find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
832     {
833       __glibcxx_requires_string_len(__s, __n);
834       size_type __size = this->size();
835       if (__size && __n)
836 	{
837 	  if (--__size > __pos)
838 	    __size = __pos;
839 	  do
840 	    {
841 	      if (traits_type::find(__s, __n, _M_data()[__size]))
842 		return __size;
843 	    }
844 	  while (__size-- != 0);
845 	}
846       return npos;
847     }
848 
849   template<typename _CharT, typename _Traits, typename _Alloc>
850     typename basic_string<_CharT, _Traits, _Alloc>::size_type
851     basic_string<_CharT, _Traits, _Alloc>::
find_first_not_of(const _CharT * __s,size_type __pos,size_type __n) const852     find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
853     {
854       __glibcxx_requires_string_len(__s, __n);
855       for (; __pos < this->size(); ++__pos)
856 	if (!traits_type::find(__s, __n, _M_data()[__pos]))
857 	  return __pos;
858       return npos;
859     }
860 
861   template<typename _CharT, typename _Traits, typename _Alloc>
862     typename basic_string<_CharT, _Traits, _Alloc>::size_type
863     basic_string<_CharT, _Traits, _Alloc>::
find_first_not_of(_CharT __c,size_type __pos) const864     find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
865     {
866       for (; __pos < this->size(); ++__pos)
867 	if (!traits_type::eq(_M_data()[__pos], __c))
868 	  return __pos;
869       return npos;
870     }
871 
872   template<typename _CharT, typename _Traits, typename _Alloc>
873     typename basic_string<_CharT, _Traits, _Alloc>::size_type
874     basic_string<_CharT, _Traits, _Alloc>::
find_last_not_of(const _CharT * __s,size_type __pos,size_type __n) const875     find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
876     {
877       __glibcxx_requires_string_len(__s, __n);
878       size_type __size = this->size();
879       if (__size)
880 	{
881 	  if (--__size > __pos)
882 	    __size = __pos;
883 	  do
884 	    {
885 	      if (!traits_type::find(__s, __n, _M_data()[__size]))
886 		return __size;
887 	    }
888 	  while (__size--);
889 	}
890       return npos;
891     }
892 
893   template<typename _CharT, typename _Traits, typename _Alloc>
894     typename basic_string<_CharT, _Traits, _Alloc>::size_type
895     basic_string<_CharT, _Traits, _Alloc>::
find_last_not_of(_CharT __c,size_type __pos) const896     find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
897     {
898       size_type __size = this->size();
899       if (__size)
900 	{
901 	  if (--__size > __pos)
902 	    __size = __pos;
903 	  do
904 	    {
905 	      if (!traits_type::eq(_M_data()[__size], __c))
906 		return __size;
907 	    }
908 	  while (__size--);
909 	}
910       return npos;
911     }
912 
913   template<typename _CharT, typename _Traits, typename _Alloc>
914     int
915     basic_string<_CharT, _Traits, _Alloc>::
compare(size_type __pos,size_type __n,const basic_string & __str) const916     compare(size_type __pos, size_type __n, const basic_string& __str) const
917     {
918       _M_check(__pos, "basic_string::compare");
919       __n = _M_limit(__pos, __n);
920       const size_type __osize = __str.size();
921       const size_type __len = std::min(__n, __osize);
922       int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
923       if (!__r)
924 	__r = _S_compare(__n, __osize);
925       return __r;
926     }
927 
928   template<typename _CharT, typename _Traits, typename _Alloc>
929     int
930     basic_string<_CharT, _Traits, _Alloc>::
compare(size_type __pos1,size_type __n1,const basic_string & __str,size_type __pos2,size_type __n2) const931     compare(size_type __pos1, size_type __n1, const basic_string& __str,
932 	    size_type __pos2, size_type __n2) const
933     {
934       _M_check(__pos1, "basic_string::compare");
935       __str._M_check(__pos2, "basic_string::compare");
936       __n1 = _M_limit(__pos1, __n1);
937       __n2 = __str._M_limit(__pos2, __n2);
938       const size_type __len = std::min(__n1, __n2);
939       int __r = traits_type::compare(_M_data() + __pos1,
940 				     __str.data() + __pos2, __len);
941       if (!__r)
942 	__r = _S_compare(__n1, __n2);
943       return __r;
944     }
945 
946   template<typename _CharT, typename _Traits, typename _Alloc>
947     int
948     basic_string<_CharT, _Traits, _Alloc>::
compare(const _CharT * __s) const949     compare(const _CharT* __s) const
950     {
951       __glibcxx_requires_string(__s);
952       const size_type __size = this->size();
953       const size_type __osize = traits_type::length(__s);
954       const size_type __len = std::min(__size, __osize);
955       int __r = traits_type::compare(_M_data(), __s, __len);
956       if (!__r)
957 	__r = _S_compare(__size, __osize);
958       return __r;
959     }
960 
961   template<typename _CharT, typename _Traits, typename _Alloc>
962     int
963     basic_string <_CharT, _Traits, _Alloc>::
compare(size_type __pos,size_type __n1,const _CharT * __s) const964     compare(size_type __pos, size_type __n1, const _CharT* __s) const
965     {
966       __glibcxx_requires_string(__s);
967       _M_check(__pos, "basic_string::compare");
968       __n1 = _M_limit(__pos, __n1);
969       const size_type __osize = traits_type::length(__s);
970       const size_type __len = std::min(__n1, __osize);
971       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
972       if (!__r)
973 	__r = _S_compare(__n1, __osize);
974       return __r;
975     }
976 
977   template<typename _CharT, typename _Traits, typename _Alloc>
978     int
979     basic_string <_CharT, _Traits, _Alloc>::
compare(size_type __pos,size_type __n1,const _CharT * __s,size_type __n2) const980     compare(size_type __pos, size_type __n1, const _CharT* __s,
981 	    size_type __n2) const
982     {
983       __glibcxx_requires_string_len(__s, __n2);
984       _M_check(__pos, "basic_string::compare");
985       __n1 = _M_limit(__pos, __n1);
986       const size_type __len = std::min(__n1, __n2);
987       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
988       if (!__r)
989 	__r = _S_compare(__n1, __n2);
990       return __r;
991     }
992 
993   // 21.3.7.9 basic_string::getline and operators
994   template<typename _CharT, typename _Traits, typename _Alloc>
995     basic_istream<_CharT, _Traits>&
operator >>(basic_istream<_CharT,_Traits> & __in,basic_string<_CharT,_Traits,_Alloc> & __str)996     operator>>(basic_istream<_CharT, _Traits>& __in,
997 	       basic_string<_CharT, _Traits, _Alloc>& __str)
998     {
999       typedef basic_istream<_CharT, _Traits>		__istream_type;
1000       typedef basic_string<_CharT, _Traits, _Alloc>	__string_type;
1001       typedef typename __istream_type::ios_base         __ios_base;
1002       typedef typename __istream_type::int_type		__int_type;
1003       typedef typename __string_type::size_type		__size_type;
1004       typedef ctype<_CharT>				__ctype_type;
1005       typedef typename __ctype_type::ctype_base         __ctype_base;
1006 
1007       __size_type __extracted = 0;
1008       typename __ios_base::iostate __err = __ios_base::goodbit;
1009       typename __istream_type::sentry __cerb(__in, false);
1010       if (__cerb)
1011 	{
1012 	  __try
1013 	    {
1014 	      // Avoid reallocation for common case.
1015 	      __str.erase();
1016 	      _CharT __buf[128];
1017 	      __size_type __len = 0;
1018 	      const streamsize __w = __in.width();
1019 	      const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
1020 		                              : __str.max_size();
1021 	      const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
1022 	      const __int_type __eof = _Traits::eof();
1023 	      __int_type __c = __in.rdbuf()->sgetc();
1024 
1025 	      while (__extracted < __n
1026 		     && !_Traits::eq_int_type(__c, __eof)
1027 		     && !__ct.is(__ctype_base::space,
1028 				 _Traits::to_char_type(__c)))
1029 		{
1030 		  if (__len == sizeof(__buf) / sizeof(_CharT))
1031 		    {
1032 		      __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
1033 		      __len = 0;
1034 		    }
1035 		  __buf[__len++] = _Traits::to_char_type(__c);
1036 		  ++__extracted;
1037 		  __c = __in.rdbuf()->snextc();
1038 		}
1039 	      __str.append(__buf, __len);
1040 
1041 	      if (_Traits::eq_int_type(__c, __eof))
1042 		__err |= __ios_base::eofbit;
1043 	      __in.width(0);
1044 	    }
1045 	  __catch(__cxxabiv1::__forced_unwind&)
1046 	    {
1047 	      __in._M_setstate(__ios_base::badbit);
1048 	      __throw_exception_again;
1049 	    }
1050 	  __catch(...)
1051 	    {
1052 	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
1053 	      // 91. Description of operator>> and getline() for string<>
1054 	      // might cause endless loop
1055 	      __in._M_setstate(__ios_base::badbit);
1056 	    }
1057 	}
1058       // 211.  operator>>(istream&, string&) doesn't set failbit
1059       if (!__extracted)
1060 	__err |= __ios_base::failbit;
1061       if (__err)
1062 	__in.setstate(__err);
1063       return __in;
1064     }
1065 
1066   template<typename _CharT, typename _Traits, typename _Alloc>
1067     basic_istream<_CharT, _Traits>&
getline(basic_istream<_CharT,_Traits> & __in,basic_string<_CharT,_Traits,_Alloc> & __str,_CharT __delim)1068     getline(basic_istream<_CharT, _Traits>& __in,
1069 	    basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
1070     {
1071       typedef basic_istream<_CharT, _Traits>		__istream_type;
1072       typedef basic_string<_CharT, _Traits, _Alloc>	__string_type;
1073       typedef typename __istream_type::ios_base         __ios_base;
1074       typedef typename __istream_type::int_type		__int_type;
1075       typedef typename __string_type::size_type		__size_type;
1076 
1077       __size_type __extracted = 0;
1078       const __size_type __n = __str.max_size();
1079       typename __ios_base::iostate __err = __ios_base::goodbit;
1080       typename __istream_type::sentry __cerb(__in, true);
1081       if (__cerb)
1082 	{
1083 	  __try
1084 	    {
1085 	      __str.erase();
1086 	      const __int_type __idelim = _Traits::to_int_type(__delim);
1087 	      const __int_type __eof = _Traits::eof();
1088 	      __int_type __c = __in.rdbuf()->sgetc();
1089 
1090 	      while (__extracted < __n
1091 		     && !_Traits::eq_int_type(__c, __eof)
1092 		     && !_Traits::eq_int_type(__c, __idelim))
1093 		{
1094 		  __str += _Traits::to_char_type(__c);
1095 		  ++__extracted;
1096 		  __c = __in.rdbuf()->snextc();
1097 		}
1098 
1099 	      if (_Traits::eq_int_type(__c, __eof))
1100 		__err |= __ios_base::eofbit;
1101 	      else if (_Traits::eq_int_type(__c, __idelim))
1102 		{
1103 		  ++__extracted;
1104 		  __in.rdbuf()->sbumpc();
1105 		}
1106 	      else
1107 		__err |= __ios_base::failbit;
1108 	    }
1109 	  __catch(__cxxabiv1::__forced_unwind&)
1110 	    {
1111 	      __in._M_setstate(__ios_base::badbit);
1112 	      __throw_exception_again;
1113 	    }
1114 	  __catch(...)
1115 	    {
1116 	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
1117 	      // 91. Description of operator>> and getline() for string<>
1118 	      // might cause endless loop
1119 	      __in._M_setstate(__ios_base::badbit);
1120 	    }
1121 	}
1122       if (!__extracted)
1123 	__err |= __ios_base::failbit;
1124       if (__err)
1125 	__in.setstate(__err);
1126       return __in;
1127     }
1128 
1129   // Inhibit implicit instantiations for required instantiations,
1130   // which are defined via explicit instantiations elsewhere.
1131 #if _GLIBCXX_EXTERN_TEMPLATE > 0
1132   extern template class basic_string<char>;
1133   extern template
1134     basic_istream<char>&
1135     operator>>(basic_istream<char>&, string&);
1136   extern template
1137     basic_ostream<char>&
1138     operator<<(basic_ostream<char>&, const string&);
1139   extern template
1140     basic_istream<char>&
1141     getline(basic_istream<char>&, string&, char);
1142   extern template
1143     basic_istream<char>&
1144     getline(basic_istream<char>&, string&);
1145 
1146 #ifdef _GLIBCXX_USE_WCHAR_T
1147   extern template class basic_string<wchar_t>;
1148   extern template
1149     basic_istream<wchar_t>&
1150     operator>>(basic_istream<wchar_t>&, wstring&);
1151   extern template
1152     basic_ostream<wchar_t>&
1153     operator<<(basic_ostream<wchar_t>&, const wstring&);
1154   extern template
1155     basic_istream<wchar_t>&
1156     getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1157   extern template
1158     basic_istream<wchar_t>&
1159     getline(basic_istream<wchar_t>&, wstring&);
1160 #endif
1161 #endif
1162 
1163 _GLIBCXX_END_NAMESPACE_VERSION
1164 } // namespace std
1165 
1166 #endif
1167