1// Components for manipulating sequences of characters -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31/** @file basic_string.tcc
32 *  This is an internal header file, included by other library headers.
33 *  You should not attempt to use it directly.
34 */
35
36//
37// ISO C++ 14882: 21  Strings library
38//
39
40// Written by Jason Merrill based upon the specification by Takanori Adachi
41// in ANSI X3J16/94-0013R2.  Rewritten by Nathan Myers to ISO-14882.
42
43#ifndef _BASIC_STRING_TCC
44#define _BASIC_STRING_TCC 1
45
46#pragma GCC system_header
47
48namespace std
49{
50  template<typename _Type>
51    inline bool
52    __is_null_pointer(_Type* __ptr)
53    { return __ptr == 0; }
54
55  template<typename _Type>
56    inline bool
57    __is_null_pointer(_Type)
58    { return false; }
59
60  template<typename _CharT, typename _Traits, typename _Alloc>
61    const typename basic_string<_CharT, _Traits, _Alloc>::size_type
62    basic_string<_CharT, _Traits, _Alloc>::
63    _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;
64
65  template<typename _CharT, typename _Traits, typename _Alloc>
66    const _CharT
67    basic_string<_CharT, _Traits, _Alloc>::
68    _Rep::_S_terminal = _CharT();
69
70  template<typename _CharT, typename _Traits, typename _Alloc>
71    const typename basic_string<_CharT, _Traits, _Alloc>::size_type
72    basic_string<_CharT, _Traits, _Alloc>::npos;
73
74  // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
75  // at static init time (before static ctors are run).
76  template<typename _CharT, typename _Traits, typename _Alloc>
77    typename basic_string<_CharT, _Traits, _Alloc>::size_type
78    basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
79    (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
80      sizeof(size_type)];
81
82  // NB: This is the special case for Input Iterators, used in
83  // istreambuf_iterators, etc.
84  // Input Iterators have a cost structure very different from
85  // pointers, calling for a different coding style.
86  template<typename _CharT, typename _Traits, typename _Alloc>
87    template<typename _InIterator>
88      _CharT*
89      basic_string<_CharT, _Traits, _Alloc>::
90      _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
91		   input_iterator_tag)
92      {
93#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
94	if (__beg == __end && __a == _Alloc())
95	  return _S_empty_rep()._M_refdata();
96#endif
97	// Avoid reallocation for common case.
98	_CharT __buf[128];
99	size_type __len = 0;
100	while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
101	  {
102	    __buf[__len++] = *__beg;
103	    ++__beg;
104	  }
105	_Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
106	_M_copy(__r->_M_refdata(), __buf, __len);
107	try
108	  {
109	    while (__beg != __end)
110	      {
111		if (__len == __r->_M_capacity)
112		  {
113		    // Allocate more space.
114		    _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
115		    _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
116		    __r->_M_destroy(__a);
117		    __r = __another;
118		  }
119		__r->_M_refdata()[__len++] = *__beg;
120		++__beg;
121	      }
122	  }
123	catch(...)
124	  {
125	    __r->_M_destroy(__a);
126	    __throw_exception_again;
127	  }
128	__r->_M_set_length_and_sharable(__len);
129	return __r->_M_refdata();
130      }
131
132  template<typename _CharT, typename _Traits, typename _Alloc>
133    template <typename _InIterator>
134      _CharT*
135      basic_string<_CharT, _Traits, _Alloc>::
136      _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
137		   forward_iterator_tag)
138      {
139#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
140	if (__beg == __end && __a == _Alloc())
141	  return _S_empty_rep()._M_refdata();
142#endif
143	// NB: Not required, but considered best practice.
144	if (__builtin_expect(__is_null_pointer(__beg) && __beg != __end, 0))
145	  __throw_logic_error(__N("basic_string::_S_construct NULL not valid"));
146
147	const size_type __dnew = static_cast<size_type>(std::distance(__beg,
148								      __end));
149	// Check for out_of_range and length_error exceptions.
150	_Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
151	try
152	  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
153	catch(...)
154	  {
155	    __r->_M_destroy(__a);
156	    __throw_exception_again;
157	  }
158	__r->_M_set_length_and_sharable(__dnew);
159	return __r->_M_refdata();
160      }
161
162  template<typename _CharT, typename _Traits, typename _Alloc>
163    _CharT*
164    basic_string<_CharT, _Traits, _Alloc>::
165    _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
166    {
167#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
168      if (__n == 0 && __a == _Alloc())
169	return _S_empty_rep()._M_refdata();
170#endif
171      // Check for out_of_range and length_error exceptions.
172      _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
173      if (__n)
174	_M_assign(__r->_M_refdata(), __n, __c);
175
176      __r->_M_set_length_and_sharable(__n);
177      return __r->_M_refdata();
178    }
179
180  template<typename _CharT, typename _Traits, typename _Alloc>
181    basic_string<_CharT, _Traits, _Alloc>::
182    basic_string(const basic_string& __str)
183    : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()),
184					  __str.get_allocator()),
185		  __str.get_allocator())
186    { }
187
188  template<typename _CharT, typename _Traits, typename _Alloc>
189    basic_string<_CharT, _Traits, _Alloc>::
190    basic_string(const _Alloc& __a)
191    : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
192    { }
193
194  template<typename _CharT, typename _Traits, typename _Alloc>
195    basic_string<_CharT, _Traits, _Alloc>::
196    basic_string(const basic_string& __str, size_type __pos, size_type __n)
197    : _M_dataplus(_S_construct(__str._M_data()
198			       + __str._M_check(__pos,
199						"basic_string::basic_string"),
200			       __str._M_data() + __str._M_limit(__pos, __n)
201			       + __pos, _Alloc()), _Alloc())
202    { }
203
204  template<typename _CharT, typename _Traits, typename _Alloc>
205    basic_string<_CharT, _Traits, _Alloc>::
206    basic_string(const basic_string& __str, size_type __pos,
207		 size_type __n, const _Alloc& __a)
208    : _M_dataplus(_S_construct(__str._M_data()
209			       + __str._M_check(__pos,
210						"basic_string::basic_string"),
211			       __str._M_data() + __str._M_limit(__pos, __n)
212			       + __pos, __a), __a)
213    { }
214
215  // TBD: DPG annotate
216  template<typename _CharT, typename _Traits, typename _Alloc>
217    basic_string<_CharT, _Traits, _Alloc>::
218    basic_string(const _CharT* __s, size_type __n, const _Alloc& __a)
219    : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
220    { }
221
222  // TBD: DPG annotate
223  template<typename _CharT, typename _Traits, typename _Alloc>
224    basic_string<_CharT, _Traits, _Alloc>::
225    basic_string(const _CharT* __s, const _Alloc& __a)
226    : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) :
227			       __s + npos, __a), __a)
228    { }
229
230  template<typename _CharT, typename _Traits, typename _Alloc>
231    basic_string<_CharT, _Traits, _Alloc>::
232    basic_string(size_type __n, _CharT __c, const _Alloc& __a)
233    : _M_dataplus(_S_construct(__n, __c, __a), __a)
234    { }
235
236  // TBD: DPG annotate
237  template<typename _CharT, typename _Traits, typename _Alloc>
238    template<typename _InputIterator>
239    basic_string<_CharT, _Traits, _Alloc>::
240    basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc& __a)
241    : _M_dataplus(_S_construct(__beg, __end, __a), __a)
242    { }
243
244  template<typename _CharT, typename _Traits, typename _Alloc>
245    basic_string<_CharT, _Traits, _Alloc>&
246    basic_string<_CharT, _Traits, _Alloc>::
247    assign(const basic_string& __str)
248    {
249      if (_M_rep() != __str._M_rep())
250	{
251	  // XXX MT
252	  const allocator_type __a = this->get_allocator();
253	  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
254	  _M_rep()->_M_dispose(__a);
255	  _M_data(__tmp);
256	}
257      return *this;
258    }
259
260  template<typename _CharT, typename _Traits, typename _Alloc>
261    basic_string<_CharT, _Traits, _Alloc>&
262    basic_string<_CharT, _Traits, _Alloc>::
263    assign(const _CharT* __s, size_type __n)
264    {
265      __glibcxx_requires_string_len(__s, __n);
266      _M_check_length(this->size(), __n, "basic_string::assign");
267      if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
268	return _M_replace_safe(size_type(0), this->size(), __s, __n);
269      else
270	{
271	  // Work in-place.
272	  const size_type __pos = __s - _M_data();
273	  if (__pos >= __n)
274	    _M_copy(_M_data(), __s, __n);
275	  else if (__pos)
276	    _M_move(_M_data(), __s, __n);
277	  _M_rep()->_M_set_length_and_sharable(__n);
278	  return *this;
279	}
280     }
281
282  template<typename _CharT, typename _Traits, typename _Alloc>
283    basic_string<_CharT, _Traits, _Alloc>&
284    basic_string<_CharT, _Traits, _Alloc>::
285    append(size_type __n, _CharT __c)
286    {
287      if (__n)
288	{
289	  _M_check_length(size_type(0), __n, "basic_string::append");	  
290	  const size_type __len = __n + this->size();
291	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
292	    this->reserve(__len);
293	  _M_assign(_M_data() + this->size(), __n, __c);
294	  _M_rep()->_M_set_length_and_sharable(__len);
295	}
296      return *this;
297    }
298
299  template<typename _CharT, typename _Traits, typename _Alloc>
300    basic_string<_CharT, _Traits, _Alloc>&
301    basic_string<_CharT, _Traits, _Alloc>::
302    append(const _CharT* __s, size_type __n)
303    {
304      __glibcxx_requires_string_len(__s, __n);
305      if (__n)
306	{
307	  _M_check_length(size_type(0), __n, "basic_string::append");
308	  const size_type __len = __n + this->size();
309	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
310	    {
311	      if (_M_disjunct(__s))
312		this->reserve(__len);
313	      else
314		{
315		  const size_type __off = __s - _M_data();
316		  this->reserve(__len);
317		  __s = _M_data() + __off;
318		}
319	    }
320	  _M_copy(_M_data() + this->size(), __s, __n);
321	  _M_rep()->_M_set_length_and_sharable(__len);
322	}
323      return *this;
324    }
325
326  template<typename _CharT, typename _Traits, typename _Alloc>
327    basic_string<_CharT, _Traits, _Alloc>&
328    basic_string<_CharT, _Traits, _Alloc>::
329    append(const basic_string& __str)
330    {
331      const size_type __size = __str.size();
332      if (__size)
333	{
334	  const size_type __len = __size + this->size();
335	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
336	    this->reserve(__len);
337	  _M_copy(_M_data() + this->size(), __str._M_data(), __size);
338	  _M_rep()->_M_set_length_and_sharable(__len);
339	}
340      return *this;
341    }    
342
343  template<typename _CharT, typename _Traits, typename _Alloc>
344    basic_string<_CharT, _Traits, _Alloc>&
345    basic_string<_CharT, _Traits, _Alloc>::
346    append(const basic_string& __str, size_type __pos, size_type __n)
347    {
348      __str._M_check(__pos, "basic_string::append");
349      __n = __str._M_limit(__pos, __n);
350      if (__n)
351	{
352	  const size_type __len = __n + this->size();
353	  if (__len > this->capacity() || _M_rep()->_M_is_shared())
354	    this->reserve(__len);
355	  _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
356	  _M_rep()->_M_set_length_and_sharable(__len);	  
357	}
358      return *this;
359    }
360
361   template<typename _CharT, typename _Traits, typename _Alloc>
362     basic_string<_CharT, _Traits, _Alloc>&
363     basic_string<_CharT, _Traits, _Alloc>::
364     insert(size_type __pos, const _CharT* __s, size_type __n)
365     {
366       __glibcxx_requires_string_len(__s, __n);
367       _M_check(__pos, "basic_string::insert");
368       _M_check_length(size_type(0), __n, "basic_string::insert");
369       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
370         return _M_replace_safe(__pos, size_type(0), __s, __n);
371       else
372         {
373           // Work in-place.
374           const size_type __off = __s - _M_data();
375           _M_mutate(__pos, 0, __n);
376           __s = _M_data() + __off;
377           _CharT* __p = _M_data() + __pos;
378           if (__s  + __n <= __p)
379             _M_copy(__p, __s, __n);
380           else if (__s >= __p)
381             _M_copy(__p, __s + __n, __n);
382           else
383             {
384	       const size_type __nleft = __p - __s;
385               _M_copy(__p, __s, __nleft);
386               _M_copy(__p + __nleft, __p + __n, __n - __nleft);
387             }
388           return *this;
389         }
390     }
391
392   template<typename _CharT, typename _Traits, typename _Alloc>
393     basic_string<_CharT, _Traits, _Alloc>&
394     basic_string<_CharT, _Traits, _Alloc>::
395     replace(size_type __pos, size_type __n1, const _CharT* __s,
396	     size_type __n2)
397     {
398       __glibcxx_requires_string_len(__s, __n2);
399       _M_check(__pos, "basic_string::replace");
400       __n1 = _M_limit(__pos, __n1);
401       _M_check_length(__n1, __n2, "basic_string::replace");
402       bool __left;
403       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
404         return _M_replace_safe(__pos, __n1, __s, __n2);
405       else if ((__left = __s + __n2 <= _M_data() + __pos)
406		|| _M_data() + __pos + __n1 <= __s)
407	 {
408	   // Work in-place: non-overlapping case.
409	   size_type __off = __s - _M_data();
410	   __left ? __off : (__off += __n2 - __n1);
411	   _M_mutate(__pos, __n1, __n2);
412	   _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
413	   return *this;
414	 }
415       else
416	 {
417	   // Todo: overlapping case.
418	   const basic_string __tmp(__s, __n2);
419	   return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
420	 }
421     }
422
423  template<typename _CharT, typename _Traits, typename _Alloc>
424    void
425    basic_string<_CharT, _Traits, _Alloc>::_Rep::
426    _M_destroy(const _Alloc& __a) throw ()
427    {
428      const size_type __size = sizeof(_Rep_base) +
429	                       (this->_M_capacity + 1) * sizeof(_CharT);
430      _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
431    }
432
433  template<typename _CharT, typename _Traits, typename _Alloc>
434    void
435    basic_string<_CharT, _Traits, _Alloc>::
436    _M_leak_hard()
437    {
438#ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
439      if (_M_rep() == &_S_empty_rep())
440	return;
441#endif
442      if (_M_rep()->_M_is_shared())
443	_M_mutate(0, 0, 0);
444      _M_rep()->_M_set_leaked();
445    }
446
447  template<typename _CharT, typename _Traits, typename _Alloc>
448    void
449    basic_string<_CharT, _Traits, _Alloc>::
450    _M_mutate(size_type __pos, size_type __len1, size_type __len2)
451    {
452      const size_type __old_size = this->size();
453      const size_type __new_size = __old_size + __len2 - __len1;
454      const size_type __how_much = __old_size - __pos - __len1;
455
456      if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
457	{
458	  // Must reallocate.
459	  const allocator_type __a = get_allocator();
460	  _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);
461
462	  if (__pos)
463	    _M_copy(__r->_M_refdata(), _M_data(), __pos);
464	  if (__how_much)
465	    _M_copy(__r->_M_refdata() + __pos + __len2,
466		    _M_data() + __pos + __len1, __how_much);
467
468	  _M_rep()->_M_dispose(__a);
469	  _M_data(__r->_M_refdata());
470	}
471      else if (__how_much && __len1 != __len2)
472	{
473	  // Work in-place.
474	  _M_move(_M_data() + __pos + __len2,
475		  _M_data() + __pos + __len1, __how_much);
476	}
477      _M_rep()->_M_set_length_and_sharable(__new_size);
478    }
479
480  template<typename _CharT, typename _Traits, typename _Alloc>
481    void
482    basic_string<_CharT, _Traits, _Alloc>::
483    reserve(size_type __res)
484    {
485      if (__res != this->capacity() || _M_rep()->_M_is_shared())
486        {
487	  // Make sure we don't shrink below the current size
488	  if (__res < this->size())
489	    __res = this->size();
490	  const allocator_type __a = get_allocator();
491	  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
492	  _M_rep()->_M_dispose(__a);
493	  _M_data(__tmp);
494        }
495    }
496
497  template<typename _CharT, typename _Traits, typename _Alloc>
498    void
499    basic_string<_CharT, _Traits, _Alloc>::
500    swap(basic_string& __s)
501    {
502      if (_M_rep()->_M_is_leaked())
503	_M_rep()->_M_set_sharable();
504      if (__s._M_rep()->_M_is_leaked())
505	__s._M_rep()->_M_set_sharable();
506      if (this->get_allocator() == __s.get_allocator())
507	{
508	  _CharT* __tmp = _M_data();
509	  _M_data(__s._M_data());
510	  __s._M_data(__tmp);
511	}
512      // The code below can usually be optimized away.
513      else
514	{
515	  const basic_string __tmp1(_M_ibegin(), _M_iend(),
516				    __s.get_allocator());
517	  const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
518				    this->get_allocator());
519	  *this = __tmp2;
520	  __s = __tmp1;
521	}
522    }
523
524  template<typename _CharT, typename _Traits, typename _Alloc>
525    typename basic_string<_CharT, _Traits, _Alloc>::_Rep*
526    basic_string<_CharT, _Traits, _Alloc>::_Rep::
527    _S_create(size_type __capacity, size_type __old_capacity,
528	      const _Alloc& __alloc)
529    {
530      // _GLIBCXX_RESOLVE_LIB_DEFECTS
531      // 83.  String::npos vs. string::max_size()
532      if (__capacity > _S_max_size)
533	__throw_length_error(__N("basic_string::_S_create"));
534
535      // The standard places no restriction on allocating more memory
536      // than is strictly needed within this layer at the moment or as
537      // requested by an explicit application call to reserve().
538
539      // Many malloc implementations perform quite poorly when an
540      // application attempts to allocate memory in a stepwise fashion
541      // growing each allocation size by only 1 char.  Additionally,
542      // it makes little sense to allocate less linear memory than the
543      // natural blocking size of the malloc implementation.
544      // Unfortunately, we would need a somewhat low-level calculation
545      // with tuned parameters to get this perfect for any particular
546      // malloc implementation.  Fortunately, generalizations about
547      // common features seen among implementations seems to suffice.
548
549      // __pagesize need not match the actual VM page size for good
550      // results in practice, thus we pick a common value on the low
551      // side.  __malloc_header_size is an estimate of the amount of
552      // overhead per memory allocation (in practice seen N * sizeof
553      // (void*) where N is 0, 2 or 4).  According to folklore,
554      // picking this value on the high side is better than
555      // low-balling it (especially when this algorithm is used with
556      // malloc implementations that allocate memory blocks rounded up
557      // to a size which is a power of 2).
558      const size_type __pagesize = 4096;
559      const size_type __malloc_header_size = 4 * sizeof(void*);
560
561      // The below implements an exponential growth policy, necessary to
562      // meet amortized linear time requirements of the library: see
563      // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
564      // It's active for allocations requiring an amount of memory above
565      // system pagesize. This is consistent with the requirements of the
566      // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
567      if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
568	__capacity = 2 * __old_capacity;
569
570      // NB: Need an array of char_type[__capacity], plus a terminating
571      // null char_type() element, plus enough for the _Rep data structure.
572      // Whew. Seemingly so needy, yet so elemental.
573      size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
574
575      const size_type __adj_size = __size + __malloc_header_size;
576      if (__adj_size > __pagesize && __capacity > __old_capacity)
577	{
578	  const size_type __extra = __pagesize - __adj_size % __pagesize;
579	  __capacity += __extra / sizeof(_CharT);
580	  // Never allocate a string bigger than _S_max_size.
581	  if (__capacity > _S_max_size)
582	    __capacity = _S_max_size;
583	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
584	}
585
586      // NB: Might throw, but no worries about a leak, mate: _Rep()
587      // does not throw.
588      void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
589      _Rep *__p = new (__place) _Rep;
590      __p->_M_capacity = __capacity;
591      // ABI compatibility - 3.4.x set in _S_create both
592      // _M_refcount and _M_length.  All callers of _S_create
593      // in basic_string.tcc then set just _M_length.
594      // In 4.0.x and later both _M_refcount and _M_length
595      // are initialized in the callers, unfortunately we can
596      // have 3.4.x compiled code with _S_create callers inlined
597      // calling 4.0.x+ _S_create.
598      __p->_M_set_sharable();
599      return __p;
600    }
601
602  template<typename _CharT, typename _Traits, typename _Alloc>
603    _CharT*
604    basic_string<_CharT, _Traits, _Alloc>::_Rep::
605    _M_clone(const _Alloc& __alloc, size_type __res)
606    {
607      // Requested capacity of the clone.
608      const size_type __requested_cap = this->_M_length + __res;
609      _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
610				  __alloc);
611      if (this->_M_length)
612	_M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
613
614      __r->_M_set_length_and_sharable(this->_M_length);
615      return __r->_M_refdata();
616    }
617
618  template<typename _CharT, typename _Traits, typename _Alloc>
619    void
620    basic_string<_CharT, _Traits, _Alloc>::
621    resize(size_type __n, _CharT __c)
622    {
623      const size_type __size = this->size();
624      _M_check_length(__size, __n, "basic_string::resize");
625      if (__size < __n)
626	this->append(__n - __size, __c);
627      else if (__n < __size)
628	this->erase(__n);
629      // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
630    }
631
632  template<typename _CharT, typename _Traits, typename _Alloc>
633    template<typename _InputIterator>
634      basic_string<_CharT, _Traits, _Alloc>&
635      basic_string<_CharT, _Traits, _Alloc>::
636      _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
637			  _InputIterator __k2, __false_type)
638      {
639	const basic_string __s(__k1, __k2);
640	const size_type __n1 = __i2 - __i1;
641	_M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
642	return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
643			       __s.size());
644      }
645
646  template<typename _CharT, typename _Traits, typename _Alloc>
647    basic_string<_CharT, _Traits, _Alloc>&
648    basic_string<_CharT, _Traits, _Alloc>::
649    _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
650		   _CharT __c)
651    {
652      _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
653      _M_mutate(__pos1, __n1, __n2);
654      if (__n2)
655	_M_assign(_M_data() + __pos1, __n2, __c);
656      return *this;
657    }
658
659  template<typename _CharT, typename _Traits, typename _Alloc>
660    basic_string<_CharT, _Traits, _Alloc>&
661    basic_string<_CharT, _Traits, _Alloc>::
662    _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
663		    size_type __n2)
664    {
665      _M_mutate(__pos1, __n1, __n2);
666      if (__n2)
667	_M_copy(_M_data() + __pos1, __s, __n2);
668      return *this;
669    }
670   
671  template<typename _CharT, typename _Traits, typename _Alloc>
672    basic_string<_CharT, _Traits, _Alloc>
673    operator+(const _CharT* __lhs,
674	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
675    {
676      __glibcxx_requires_string(__lhs);
677      typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
678      typedef typename __string_type::size_type	  __size_type;
679      const __size_type __len = _Traits::length(__lhs);
680      __string_type __str;
681      __str.reserve(__len + __rhs.size());
682      __str.append(__lhs, __len);
683      __str.append(__rhs);
684      return __str;
685    }
686
687  template<typename _CharT, typename _Traits, typename _Alloc>
688    basic_string<_CharT, _Traits, _Alloc>
689    operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
690    {
691      typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
692      typedef typename __string_type::size_type	  __size_type;
693      __string_type __str;
694      const __size_type __len = __rhs.size();
695      __str.reserve(__len + 1);
696      __str.append(__size_type(1), __lhs);
697      __str.append(__rhs);
698      return __str;
699    }
700
701  template<typename _CharT, typename _Traits, typename _Alloc>
702    typename basic_string<_CharT, _Traits, _Alloc>::size_type
703    basic_string<_CharT, _Traits, _Alloc>::
704    copy(_CharT* __s, size_type __n, size_type __pos) const
705    {
706      _M_check(__pos, "basic_string::copy");
707      __n = _M_limit(__pos, __n);
708      __glibcxx_requires_string_len(__s, __n);
709      if (__n)
710	_M_copy(__s, _M_data() + __pos, __n);
711      // 21.3.5.7 par 3: do not append null.  (good.)
712      return __n;
713    }
714
715  template<typename _CharT, typename _Traits, typename _Alloc>
716    typename basic_string<_CharT, _Traits, _Alloc>::size_type
717    basic_string<_CharT, _Traits, _Alloc>::
718    find(const _CharT* __s, size_type __pos, size_type __n) const
719    {
720      __glibcxx_requires_string_len(__s, __n);
721      size_type __ret = npos;
722      const size_type __size = this->size();
723      if (__pos + __n <= __size)
724	{
725	  const _CharT* __data = _M_data();
726	  const _CharT* __p = std::search(__data + __pos, __data + __size,
727					  __s, __s + __n, traits_type::eq);
728	  if (__p != __data + __size || __n == 0)
729	    __ret = __p - __data;
730	}
731      return __ret;
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>::
737    find(_CharT __c, size_type __pos) const
738    {
739      size_type __ret = npos;
740      const size_type __size = this->size();
741      if (__pos < __size)
742	{
743	  const _CharT* __data = _M_data();
744	  const size_type __n = __size - __pos;
745	  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
746	  if (__p)
747	    __ret = __p - __data;
748	}
749      return __ret;
750    }
751
752  template<typename _CharT, typename _Traits, typename _Alloc>
753    typename basic_string<_CharT, _Traits, _Alloc>::size_type
754    basic_string<_CharT, _Traits, _Alloc>::
755    rfind(const _CharT* __s, size_type __pos, size_type __n) const
756    {
757      __glibcxx_requires_string_len(__s, __n);
758      const size_type __size = this->size();
759      if (__n <= __size)
760	{
761	  __pos = std::min(size_type(__size - __n), __pos);
762	  const _CharT* __data = _M_data();
763	  do
764	    {
765	      if (traits_type::compare(__data + __pos, __s, __n) == 0)
766		return __pos;
767	    }
768	  while (__pos-- > 0);
769	}
770      return npos;
771    }
772
773  template<typename _CharT, typename _Traits, typename _Alloc>
774    typename basic_string<_CharT, _Traits, _Alloc>::size_type
775    basic_string<_CharT, _Traits, _Alloc>::
776    rfind(_CharT __c, size_type __pos) const
777    {
778      size_type __size = this->size();
779      if (__size)
780	{
781	  if (--__size > __pos)
782	    __size = __pos;
783	  for (++__size; __size-- > 0; )
784	    if (traits_type::eq(_M_data()[__size], __c))
785	      return __size;
786	}
787      return npos;
788    }
789
790  template<typename _CharT, typename _Traits, typename _Alloc>
791    typename basic_string<_CharT, _Traits, _Alloc>::size_type
792    basic_string<_CharT, _Traits, _Alloc>::
793    find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
794    {
795      __glibcxx_requires_string_len(__s, __n);
796      for (; __n && __pos < this->size(); ++__pos)
797	{
798	  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
799	  if (__p)
800	    return __pos;
801	}
802      return npos;
803    }
804
805  template<typename _CharT, typename _Traits, typename _Alloc>
806    typename basic_string<_CharT, _Traits, _Alloc>::size_type
807    basic_string<_CharT, _Traits, _Alloc>::
808    find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
809    {
810      __glibcxx_requires_string_len(__s, __n);
811      size_type __size = this->size();
812      if (__size && __n)
813	{
814	  if (--__size > __pos)
815	    __size = __pos;
816	  do
817	    {
818	      if (traits_type::find(__s, __n, _M_data()[__size]))
819		return __size;
820	    }
821	  while (__size-- != 0);
822	}
823      return npos;
824    }
825
826  template<typename _CharT, typename _Traits, typename _Alloc>
827    typename basic_string<_CharT, _Traits, _Alloc>::size_type
828    basic_string<_CharT, _Traits, _Alloc>::
829    find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
830    {
831      __glibcxx_requires_string_len(__s, __n);
832      for (; __pos < this->size(); ++__pos)
833	if (!traits_type::find(__s, __n, _M_data()[__pos]))
834	  return __pos;
835      return npos;
836    }
837
838  template<typename _CharT, typename _Traits, typename _Alloc>
839    typename basic_string<_CharT, _Traits, _Alloc>::size_type
840    basic_string<_CharT, _Traits, _Alloc>::
841    find_first_not_of(_CharT __c, size_type __pos) const
842    {
843      for (; __pos < this->size(); ++__pos)
844	if (!traits_type::eq(_M_data()[__pos], __c))
845	  return __pos;
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>::
852    find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
853    {
854      __glibcxx_requires_string_len(__s, __n);
855      size_type __size = this->size();
856      if (__size)
857	{
858	  if (--__size > __pos)
859	    __size = __pos;
860	  do
861	    {
862	      if (!traits_type::find(__s, __n, _M_data()[__size]))
863		return __size;
864	    }
865	  while (__size--);
866	}
867      return npos;
868    }
869
870  template<typename _CharT, typename _Traits, typename _Alloc>
871    typename basic_string<_CharT, _Traits, _Alloc>::size_type
872    basic_string<_CharT, _Traits, _Alloc>::
873    find_last_not_of(_CharT __c, size_type __pos) const
874    {
875      size_type __size = this->size();
876      if (__size)
877	{
878	  if (--__size > __pos)
879	    __size = __pos;
880	  do
881	    {
882	      if (!traits_type::eq(_M_data()[__size], __c))
883		return __size;
884	    }
885	  while (__size--);
886	}
887      return npos;
888    }
889
890  template<typename _CharT, typename _Traits, typename _Alloc>
891    int
892    basic_string<_CharT, _Traits, _Alloc>::
893    compare(size_type __pos, size_type __n, const basic_string& __str) const
894    {
895      _M_check(__pos, "basic_string::compare");
896      __n = _M_limit(__pos, __n);
897      const size_type __osize = __str.size();
898      const size_type __len = std::min(__n, __osize);
899      int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
900      if (!__r)
901	__r = __n - __osize;
902      return __r;
903    }
904
905  template<typename _CharT, typename _Traits, typename _Alloc>
906    int
907    basic_string<_CharT, _Traits, _Alloc>::
908    compare(size_type __pos1, size_type __n1, const basic_string& __str,
909	    size_type __pos2, size_type __n2) const
910    {
911      _M_check(__pos1, "basic_string::compare");
912      __str._M_check(__pos2, "basic_string::compare");
913      __n1 = _M_limit(__pos1, __n1);
914      __n2 = __str._M_limit(__pos2, __n2);
915      const size_type __len = std::min(__n1, __n2);
916      int __r = traits_type::compare(_M_data() + __pos1,
917				     __str.data() + __pos2, __len);
918      if (!__r)
919	__r = __n1 - __n2;
920      return __r;
921    }
922
923  template<typename _CharT, typename _Traits, typename _Alloc>
924    int
925    basic_string<_CharT, _Traits, _Alloc>::
926    compare(const _CharT* __s) const
927    {
928      __glibcxx_requires_string(__s);
929      const size_type __size = this->size();
930      const size_type __osize = traits_type::length(__s);
931      const size_type __len = std::min(__size, __osize);
932      int __r = traits_type::compare(_M_data(), __s, __len);
933      if (!__r)
934	__r = __size - __osize;
935      return __r;
936    }
937
938  template<typename _CharT, typename _Traits, typename _Alloc>
939    int
940    basic_string <_CharT, _Traits, _Alloc>::
941    compare(size_type __pos, size_type __n1, const _CharT* __s) const
942    {
943      __glibcxx_requires_string(__s);
944      _M_check(__pos, "basic_string::compare");
945      __n1 = _M_limit(__pos, __n1);
946      const size_type __osize = traits_type::length(__s);
947      const size_type __len = std::min(__n1, __osize);
948      int __r = traits_type::compare(_M_data() + __pos, __s, __len);
949      if (!__r)
950	__r = __n1 - __osize;
951      return __r;
952    }
953
954  template<typename _CharT, typename _Traits, typename _Alloc>
955    int
956    basic_string <_CharT, _Traits, _Alloc>::
957    compare(size_type __pos, size_type __n1, const _CharT* __s,
958	    size_type __n2) const
959    {
960      __glibcxx_requires_string_len(__s, __n2);
961      _M_check(__pos, "basic_string::compare");
962      __n1 = _M_limit(__pos, __n1);
963      const size_type __len = std::min(__n1, __n2);
964      int __r = traits_type::compare(_M_data() + __pos, __s, __len);
965      if (!__r)
966	__r = __n1 - __n2;
967      return __r;
968    }
969
970  // Inhibit implicit instantiations for required instantiations,
971  // which are defined via explicit instantiations elsewhere.
972  // NB: This syntax is a GNU extension.
973#if _GLIBCXX_EXTERN_TEMPLATE
974  extern template class basic_string<char>;
975  extern template
976    basic_istream<char>&
977    operator>>(basic_istream<char>&, string&);
978  extern template
979    basic_ostream<char>&
980    operator<<(basic_ostream<char>&, const string&);
981  extern template
982    basic_istream<char>&
983    getline(basic_istream<char>&, string&, char);
984  extern template
985    basic_istream<char>&
986    getline(basic_istream<char>&, string&);
987
988#ifdef _GLIBCXX_USE_WCHAR_T
989  extern template class basic_string<wchar_t>;
990  extern template
991    basic_istream<wchar_t>&
992    operator>>(basic_istream<wchar_t>&, wstring&);
993  extern template
994    basic_ostream<wchar_t>&
995    operator<<(basic_ostream<wchar_t>&, const wstring&);
996  extern template
997    basic_istream<wchar_t>&
998    getline(basic_istream<wchar_t>&, wstring&, wchar_t);
999  extern template
1000    basic_istream<wchar_t>&
1001    getline(basic_istream<wchar_t>&, wstring&);
1002#endif
1003#endif
1004} // namespace std
1005
1006#endif
1007