1 // Components for manipulating sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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 //
32 // ISO C++ 14882: 21  Strings library
33 //
34 
35 // This file is included by <string>.  It is not meant to be included
36 // separately.
37 
38 // Written by Jason Merrill based upon the specification by Takanori Adachi
39 // in ANSI X3J16/94-0013R2.  Rewritten by Nathan Myers to ISO-14882.
40 
41 #ifndef _CPP_BITS_STRING_TCC
42 #define _CPP_BITS_STRING_TCC 1
43 
44 #pragma GCC system_header
45 
46 namespace std
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))/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>::_S_empty_rep_storage[
67     (sizeof(_Rep) + sizeof(_CharT) + sizeof(size_type) - 1)/sizeof(size_type)];
68 
69   // NB: This is the special case for Input Iterators, used in
70   // istreambuf_iterators, etc.
71   // Input Iterators have a cost structure very different from
72   // pointers, calling for a different coding style.
73   template<typename _CharT, typename _Traits, typename _Alloc>
74     template<typename _InIter>
75       _CharT*
76       basic_string<_CharT, _Traits, _Alloc>::
77       _S_construct(_InIter __beg, _InIter __end, const _Alloc& __a,
78 		   input_iterator_tag)
79       {
80 	if (__beg == __end && __a == _Alloc())
81 	  return _S_empty_rep()._M_refcopy();
82 	// Avoid reallocation for common case.
83 	_CharT __buf[100];
84 	size_type __i = 0;
85 	while (__beg != __end && __i < sizeof(__buf) / sizeof(_CharT))
86 	  {
87 	    __buf[__i++] = *__beg;
88 	    ++__beg;
89 	  }
90 	_Rep* __r = _Rep::_S_create(__i, __a);
91 	traits_type::copy(__r->_M_refdata(), __buf, __i);
92 	__r->_M_length = __i;
93 	try
94 	  {
95 	    // NB: this loop looks precisely this way because
96 	    // it avoids comparing __beg != __end any more
97 	    // than strictly necessary; != might be expensive!
98 	    for (;;)
99 	      {
100 		_CharT* __p = __r->_M_refdata() + __r->_M_length;
101 		_CharT* __last = __r->_M_refdata() + __r->_M_capacity;
102 		for (;;)
103 		  {
104 		    if (__beg == __end)
105 		      {
106 			__r->_M_length = __p - __r->_M_refdata();
107 			*__p = _Rep::_S_terminal;       // grrr.
108 			return __r->_M_refdata();
109 		      }
110 		    if (__p == __last)
111 		      break;
112 		    *__p++ = *__beg;
113 		    ++__beg;
114 		  }
115 		// Allocate more space.
116 		size_type __len = __p - __r->_M_refdata();
117 		_Rep* __another = _Rep::_S_create(__len + 1, __a);
118 		traits_type::copy(__another->_M_refdata(),
119 				  __r->_M_refdata(), __len);
120 		__r->_M_destroy(__a);
121 		__r = __another;
122 		__r->_M_length = __len;
123 	      }
124 	  }
125 	catch(...)
126 	  {
127 	    __r->_M_destroy(__a);
128 	    __throw_exception_again;
129 	  }
130 	return 0;
131       }
132 
133   template<typename _CharT, typename _Traits, typename _Alloc>
134     template <class _InIter>
135       _CharT*
136       basic_string<_CharT, _Traits, _Alloc>::
137       _S_construct(_InIter __beg, _InIter __end, const _Alloc& __a,
138 		   forward_iterator_tag)
139       {
140 	size_type __dnew = static_cast<size_type>(distance(__beg, __end));
141 
142 	// NB: Not required, but considered best practice.
143 	if (__builtin_expect(__beg == _InIter(), 0))
144 	  __throw_logic_error("attempt to create string with null pointer");
145 
146 	if (__beg == __end && __a == _Alloc())
147 	  return _S_empty_rep()._M_refcopy();
148 
149 	// Check for out_of_range and length_error exceptions.
150 	_Rep* __r = _Rep::_S_create(__dnew, __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_length = __dnew;
159 
160 	__r->_M_refdata()[__dnew] = _Rep::_S_terminal;  // grrr.
161 	return __r->_M_refdata();
162       }
163 
164   template<typename _CharT, typename _Traits, typename _Alloc>
165     _CharT*
166     basic_string<_CharT, _Traits, _Alloc>::
167     _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
168     {
169       if (__n == 0 && __a == _Alloc())
170 	return _S_empty_rep()._M_refcopy();
171 
172       // Check for out_of_range and length_error exceptions.
173       _Rep* __r = _Rep::_S_create(__n, __a);
174       try
175 	{
176 	  if (__n)
177 	    traits_type::assign(__r->_M_refdata(), __n, __c);
178 	}
179       catch(...)
180 	{
181 	  __r->_M_destroy(__a);
182 	  __throw_exception_again;
183 	}
184       __r->_M_length = __n;
185       __r->_M_refdata()[__n] = _Rep::_S_terminal;  // grrr
186       return __r->_M_refdata();
187     }
188 
189   template<typename _CharT, typename _Traits, typename _Alloc>
190     basic_string<_CharT, _Traits, _Alloc>::
191     basic_string(const basic_string& __str)
192     : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(), __str.get_allocator()),
193 		 __str.get_allocator())
194     { }
195 
196   template<typename _CharT, typename _Traits, typename _Alloc>
197     basic_string<_CharT, _Traits, _Alloc>::
198     basic_string(const _Alloc& __a)
199     : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
200     { }
201 
202   template<typename _CharT, typename _Traits, typename _Alloc>
203     basic_string<_CharT, _Traits, _Alloc>::
204     basic_string(const basic_string& __str, size_type __pos, size_type __n)
205     : _M_dataplus(_S_construct(__str._M_check(__pos),
206 			       __str._M_fold(__pos, __n), _Alloc()), _Alloc())
207     { }
208 
209   template<typename _CharT, typename _Traits, typename _Alloc>
210     basic_string<_CharT, _Traits, _Alloc>::
211     basic_string(const basic_string& __str, size_type __pos,
212 		 size_type __n, const _Alloc& __a)
213     : _M_dataplus(_S_construct(__str._M_check(__pos),
214 			       __str._M_fold(__pos, __n), __a), __a)
215     { }
216 
217   template<typename _CharT, typename _Traits, typename _Alloc>
218     basic_string<_CharT, _Traits, _Alloc>::
219     basic_string(const _CharT* __s, size_type __n, const _Alloc& __a)
220     : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
221     { }
222 
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) : 0,
227 			       __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   template<typename _CharT, typename _Traits, typename _Alloc>
237     template<typename _InputIter>
238     basic_string<_CharT, _Traits, _Alloc>::
239     basic_string(_InputIter __beg, _InputIter __end, const _Alloc& __a)
240     : _M_dataplus(_S_construct(__beg, __end, __a), __a)
241     { }
242 
243   template<typename _CharT, typename _Traits, typename _Alloc>
244     basic_string<_CharT, _Traits, _Alloc>&
245     basic_string<_CharT, _Traits, _Alloc>::assign(const basic_string& __str)
246     {
247       if (_M_rep() != __str._M_rep())
248 	{
249 	  // XXX MT
250 	  allocator_type __a = this->get_allocator();
251 	  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
252 	  _M_rep()->_M_dispose(__a);
253 	  _M_data(__tmp);
254 	}
255       return *this;
256     }
257 
258   template<typename _CharT, typename _Traits, typename _Alloc>
259     void
260     basic_string<_CharT, _Traits, _Alloc>::_Rep::
261     _M_destroy(const _Alloc& __a) throw ()
262     {
263       size_type __size = sizeof(_Rep) + (_M_capacity + 1) * sizeof(_CharT);
264       _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
265     }
266 
267   template<typename _CharT, typename _Traits, typename _Alloc>
268     void
269     basic_string<_CharT, _Traits, _Alloc>::_M_leak_hard()
270     {
271       if (_M_rep()->_M_is_shared())
272 	_M_mutate(0, 0, 0);
273       _M_rep()->_M_set_leaked();
274     }
275 
276   // _M_mutate and, below, _M_clone, include, in the same form, an exponential
277   // growth policy, necessary to meet amortized linear time requirements of
278   // the library: see http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
279   // The policy is active for allocations requiring an amount of memory above
280   // system pagesize. This is consistent with the requirements of the standard:
281   // see, f.i., http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
282   template<typename _CharT, typename _Traits, typename _Alloc>
283     void
284     basic_string<_CharT, _Traits, _Alloc>::
285     _M_mutate(size_type __pos, size_type __len1, size_type __len2)
286     {
287       size_type       __old_size = this->size();
288       const size_type __new_size = __old_size + __len2 - __len1;
289       const _CharT*        __src = _M_data()  + __pos + __len1;
290       const size_type __how_much = __old_size - __pos - __len1;
291 
292       if (_M_rep()->_M_is_shared() || __new_size > capacity())
293 	{
294 	  // Must reallocate.
295 	  allocator_type __a = get_allocator();
296 	  // See below (_S_create) for the meaning and value of these
297 	  // constants.
298 	  const size_type __pagesize = 4096;
299 	  const size_type __malloc_header_size = 4 * sizeof (void*);
300 	  // The biggest string which fits in a memory page
301 	  const size_type __page_capacity = (__pagesize - __malloc_header_size
302 					     - sizeof(_Rep) - sizeof(_CharT))
303 	    				     / sizeof(_CharT);
304 	  _Rep* __r;
305 	  if (__new_size > capacity() && __new_size > __page_capacity)
306 	    // Growing exponentially.
307 	    __r = _Rep::_S_create(__new_size > 2*capacity() ?
308 				  __new_size : 2*capacity(), __a);
309 	  else
310 	    __r = _Rep::_S_create(__new_size, __a);
311 	  try
312 	    {
313 	      if (__pos)
314 		traits_type::copy(__r->_M_refdata(), _M_data(), __pos);
315 	      if (__how_much)
316 		traits_type::copy(__r->_M_refdata() + __pos + __len2,
317 				  __src, __how_much);
318 	    }
319 	  catch(...)
320 	    {
321 	      __r->_M_dispose(get_allocator());
322 	      __throw_exception_again;
323 	    }
324 	  _M_rep()->_M_dispose(__a);
325 	  _M_data(__r->_M_refdata());
326       }
327       else if (__how_much && __len1 != __len2)
328 	{
329 	  // Work in-place
330 	  traits_type::move(_M_data() + __pos + __len2, __src, __how_much);
331 	}
332       _M_rep()->_M_set_sharable();
333       _M_rep()->_M_length = __new_size;
334       _M_data()[__new_size] = _Rep::_S_terminal; // grrr. (per 21.3.4)
335     // You cannot leave those LWG people alone for a second.
336     }
337 
338   template<typename _CharT, typename _Traits, typename _Alloc>
339     void
340     basic_string<_CharT, _Traits, _Alloc>::reserve(size_type __res)
341     {
342       if (__res > this->capacity() || _M_rep()->_M_is_shared())
343         {
344 	  if (__res > this->max_size())
345 	    __throw_length_error("basic_string::reserve");
346 	  // Make sure we don't shrink below the current size
347 	  if (__res < this->size())
348 	    __res = this->size();
349 	  allocator_type __a = get_allocator();
350 	  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
351 	  _M_rep()->_M_dispose(__a);
352 	  _M_data(__tmp);
353         }
354     }
355 
356   template<typename _CharT, typename _Traits, typename _Alloc>
357     void basic_string<_CharT, _Traits, _Alloc>::swap(basic_string& __s)
358     {
359       if (_M_rep()->_M_is_leaked())
360 	_M_rep()->_M_set_sharable();
361       if (__s._M_rep()->_M_is_leaked())
362 	__s._M_rep()->_M_set_sharable();
363       if (this->get_allocator() == __s.get_allocator())
364 	{
365 	  _CharT* __tmp = _M_data();
366 	  _M_data(__s._M_data());
367 	  __s._M_data(__tmp);
368 	}
369       // The code below can usually be optimized away.
370       else
371 	{
372 	  basic_string __tmp1(_M_ibegin(), _M_iend(), __s.get_allocator());
373 	  basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
374 			      this->get_allocator());
375 	  *this = __tmp2;
376 	  __s = __tmp1;
377 	}
378     }
379 
380   template<typename _CharT, typename _Traits, typename _Alloc>
381     typename basic_string<_CharT, _Traits, _Alloc>::_Rep*
382     basic_string<_CharT, _Traits, _Alloc>::_Rep::
383     _S_create(size_t __capacity, const _Alloc& __alloc)
384     {
385       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
386 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
387       // 83.  String::npos vs. string::max_size()
388       if (__capacity > _S_max_size)
389 #else
390       if (__capacity == npos)
391 #endif
392 	__throw_length_error("basic_string::_S_create");
393 
394       // NB: Need an array of char_type[__capacity], plus a
395       // terminating null char_type() element, plus enough for the
396       // _Rep data structure. Whew. Seemingly so needy, yet so elemental.
397       size_t __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
398 
399       // The standard places no restriction on allocating more memory
400       // than is strictly needed within this layer at the moment or as
401       // requested by an explicit application call to reserve().  Many
402       // malloc implementations perform quite poorly when an
403       // application attempts to allocate memory in a stepwise fashion
404       // growing each allocation size by only 1 char.  Additionally,
405       // it makes little sense to allocate less linear memory than the
406       // natural blocking size of the malloc implementation.
407       // Unfortunately, we would need a somewhat low-level calculation
408       // with tuned parameters to get this perfect for any particular
409       // malloc implementation.  Fortunately, generalizations about
410       // common features seen among implementations seems to suffice.
411 
412       // __pagesize need not match the actual VM page size for good
413       // results in practice, thus we pick a common value on the low
414       // side.  __malloc_header_size is an estimate of the amount of
415       // overhead per memory allocation (in practice seen N * sizeof
416       // (void*) where N is 0, 2 or 4).  According to folklore,
417       // picking this value on the high side is better than
418       // low-balling it (especially when this algorithm is used with
419       // malloc implementations that allocate memory blocks rounded up
420       // to a size which is a power of 2).
421       const size_t __pagesize = 4096; // must be 2^i * __subpagesize
422       const size_t __subpagesize = 128; // should be >> __malloc_header_size
423       const size_t __malloc_header_size = 4 * sizeof (void*);
424       if ((__size + __malloc_header_size) > __pagesize)
425 	{
426 	  size_t __extra =
427 	    (__pagesize - ((__size + __malloc_header_size) % __pagesize))
428 	    % __pagesize;
429 	  __capacity += __extra / sizeof(_CharT);
430 	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
431 	}
432       else if (__size > __subpagesize)
433 	{
434 	  size_t __extra =
435 	    (__subpagesize - ((__size + __malloc_header_size) % __subpagesize))
436 	    % __subpagesize;
437 	  __capacity += __extra / sizeof(_CharT);
438 	  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
439 	}
440 
441       // NB: Might throw, but no worries about a leak, mate: _Rep()
442       // does not throw.
443       void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
444       _Rep *__p = new (__place) _Rep;
445       __p->_M_capacity = __capacity;
446       __p->_M_set_sharable();  // One reference.
447       __p->_M_length = 0;
448       return __p;
449     }
450 
451   template<typename _CharT, typename _Traits, typename _Alloc>
452     _CharT*
453     basic_string<_CharT, _Traits, _Alloc>::_Rep::
454     _M_clone(const _Alloc& __alloc, size_type __res)
455     {
456       // Requested capacity of the clone.
457       const size_type __requested_cap = _M_length + __res;
458       // See above (_S_create) for the meaning and value of these constants.
459       const size_type __pagesize = 4096;
460       const size_type __malloc_header_size = 4 * sizeof (void*);
461       // The biggest string which fits in a memory page.
462       const size_type __page_capacity =
463         (__pagesize - __malloc_header_size - sizeof(_Rep) - sizeof(_CharT))
464         / sizeof(_CharT);
465       _Rep* __r;
466       if (__requested_cap > _M_capacity && __requested_cap > __page_capacity)
467         // Growing exponentially.
468         __r = _Rep::_S_create(__requested_cap > 2*_M_capacity ?
469                               __requested_cap : 2*_M_capacity, __alloc);
470       else
471         __r = _Rep::_S_create(__requested_cap, __alloc);
472 
473       if (_M_length)
474 	{
475 	  try
476 	    { traits_type::copy(__r->_M_refdata(), _M_refdata(), _M_length); }
477 	  catch(...)
478 	    {
479 	      __r->_M_destroy(__alloc);
480 	      __throw_exception_again;
481 	    }
482 	}
483       __r->_M_length = _M_length;
484       return __r->_M_refdata();
485     }
486 
487   template<typename _CharT, typename _Traits, typename _Alloc>
488     void
489     basic_string<_CharT, _Traits, _Alloc>::resize(size_type __n, _CharT __c)
490     {
491       if (__n > max_size())
492 	__throw_length_error("basic_string::resize");
493       size_type __size = this->size();
494       if (__size < __n)
495 	this->append(__n - __size, __c);
496       else if (__n < __size)
497 	this->erase(__n);
498       // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
499     }
500 
501 
502   // This is the general replace helper, which currently gets instantiated both
503   // for input iterators and reverse iterators. It buffers internally and then
504   // calls _M_replace_safe.
505   template<typename _CharT, typename _Traits, typename _Alloc>
506     template<typename _InputIter>
507       basic_string<_CharT, _Traits, _Alloc>&
508       basic_string<_CharT, _Traits, _Alloc>::
509       _M_replace(iterator __i1, iterator __i2, _InputIter __k1,
510 		 _InputIter __k2, input_iterator_tag)
511       {
512 	// Save concerned source string data in a temporary.
513 	basic_string __s(__k1, __k2);
514 	return _M_replace_safe(__i1, __i2, __s._M_ibegin(), __s._M_iend());
515       }
516 
517   // This is a special replace helper, which does not buffer internally
518   // and can be used in "safe" situations involving forward iterators,
519   // i.e., when source and destination ranges are known to not overlap.
520   template<typename _CharT, typename _Traits, typename _Alloc>
521     template<typename _ForwardIter>
522       basic_string<_CharT, _Traits, _Alloc>&
523       basic_string<_CharT, _Traits, _Alloc>::
524       _M_replace_safe(iterator __i1, iterator __i2, _ForwardIter __k1,
525 		      _ForwardIter __k2)
526       {
527 	size_type __dnew = static_cast<size_type>(distance(__k1, __k2));
528 	size_type __dold = __i2 - __i1;
529 	size_type __dmax = this->max_size();
530 
531 	if (__dmax <= __dnew)
532 	  __throw_length_error("basic_string::_M_replace");
533 	size_type __off = __i1 - _M_ibegin();
534 	_M_mutate(__off, __dold, __dnew);
535 
536 	// Invalidated __i1, __i2
537         if (__dnew)
538 	  _S_copy_chars(_M_data() + __off, __k1, __k2);
539 
540 	return *this;
541       }
542 
543   template<typename _CharT, typename _Traits, typename _Alloc>
544     basic_string<_CharT, _Traits, _Alloc>&
545     basic_string<_CharT, _Traits, _Alloc>::
546     replace(size_type __pos1, size_type __n1, const basic_string& __str,
547 	    size_type __pos2, size_type __n2)
548     {
549       const size_type __strsize = __str.size();
550       if (__pos2 > __strsize)
551 	__throw_out_of_range("basic_string::replace");
552       const bool __testn2 = __n2 < __strsize - __pos2;
553       const size_type __foldn2 = __testn2 ? __n2 : __strsize - __pos2;
554       return this->replace(__pos1, __n1,
555 			   __str._M_data() + __pos2, __foldn2);
556     }
557 
558   template<typename _CharT, typename _Traits, typename _Alloc>
559     basic_string<_CharT, _Traits, _Alloc>&
560     basic_string<_CharT, _Traits, _Alloc>::
561     append(const basic_string& __str)
562     {
563       // Iff appending itself, string needs to pre-reserve the
564       // correct size so that _M_mutate does not clobber the
565       // iterators formed here.
566       size_type __size = __str.size();
567       size_type __len = __size + this->size();
568       if (__len > this->capacity())
569 	this->reserve(__len);
570       return _M_replace_safe(_M_iend(), _M_iend(), __str._M_ibegin(),
571 			     __str._M_iend());
572     }
573 
574   template<typename _CharT, typename _Traits, typename _Alloc>
575     basic_string<_CharT, _Traits, _Alloc>&
576     basic_string<_CharT, _Traits, _Alloc>::
577     append(const basic_string& __str, size_type __pos, size_type __n)
578     {
579       // Iff appending itself, string needs to pre-reserve the
580       // correct size so that _M_mutate does not clobber the
581       // iterators formed here.
582       size_type __len = min(__str.size() - __pos, __n) + this->size();
583       if (__len > this->capacity())
584 	this->reserve(__len);
585       return _M_replace_safe(_M_iend(), _M_iend(), __str._M_check(__pos),
586 			     __str._M_fold(__pos, __n));
587     }
588 
589   template<typename _CharT, typename _Traits, typename _Alloc>
590     basic_string<_CharT, _Traits, _Alloc>&
591     basic_string<_CharT, _Traits, _Alloc>::
592     append(const _CharT* __s, size_type __n)
593     {
594       size_type __len = __n + this->size();
595       if (__len > this->capacity())
596 	this->reserve(__len);
597       return _M_replace_safe(_M_iend(), _M_iend(), __s, __s + __n);
598     }
599 
600   template<typename _CharT, typename _Traits, typename _Alloc>
601     basic_string<_CharT, _Traits, _Alloc>&
602     basic_string<_CharT, _Traits, _Alloc>::
603     append(size_type __n, _CharT __c)
604     {
605       size_type __len = __n + this->size();
606       if (__len > this->capacity())
607 	this->reserve(__len);
608        return this->replace(_M_iend(), _M_iend(), __n, __c);
609     }
610 
611   template<typename _CharT, typename _Traits, typename _Alloc>
612     basic_string<_CharT, _Traits, _Alloc>
613     operator+(const _CharT* __lhs,
614 	      const basic_string<_CharT, _Traits, _Alloc>& __rhs)
615     {
616       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
617       typedef typename __string_type::size_type	  __size_type;
618       __size_type __len = _Traits::length(__lhs);
619       __string_type __str;
620       __str.reserve(__len + __rhs.size());
621       __str.append(__lhs, __lhs + __len);
622       __str.append(__rhs);
623       return __str;
624     }
625 
626   template<typename _CharT, typename _Traits, typename _Alloc>
627     basic_string<_CharT, _Traits, _Alloc>
628     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
629     {
630       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
631       typedef typename __string_type::size_type	  __size_type;
632       __string_type __str;
633       __size_type __len = __rhs.size();
634       __str.reserve(__len + 1);
635       __str.append(__size_type(1), __lhs);
636       __str.append(__rhs);
637       return __str;
638     }
639 
640   template<typename _CharT, typename _Traits, typename _Alloc>
641     basic_string<_CharT, _Traits, _Alloc>&
642     basic_string<_CharT, _Traits, _Alloc>::
643     replace(iterator __i1, iterator __i2, size_type __n2, _CharT __c)
644     {
645       size_type __n1 = __i2 - __i1;
646       size_type __off1 = __i1 - _M_ibegin();
647       if (max_size() - (this->size() - __n1) <= __n2)
648 	__throw_length_error("basic_string::replace");
649       _M_mutate (__off1, __n1, __n2);
650       // Invalidated __i1, __i2
651       if (__n2)
652 	traits_type::assign(_M_data() + __off1, __n2, __c);
653       return *this;
654     }
655 
656   template<typename _CharT, typename _Traits, typename _Alloc>
657     typename basic_string<_CharT, _Traits, _Alloc>::size_type
658     basic_string<_CharT, _Traits, _Alloc>::
659     copy(_CharT* __s, size_type __n, size_type __pos) const
660     {
661       if (__pos > this->size())
662 	__throw_out_of_range("basic_string::copy");
663 
664       if (__n > this->size() - __pos)
665 	__n = this->size() - __pos;
666 
667       traits_type::copy(__s, _M_data() + __pos, __n);
668       // 21.3.5.7 par 3: do not append null.  (good.)
669       return __n;
670     }
671 
672   template<typename _CharT, typename _Traits, typename _Alloc>
673     typename basic_string<_CharT, _Traits, _Alloc>::size_type
674     basic_string<_CharT, _Traits, _Alloc>::
675     find(const _CharT* __s, size_type __pos, size_type __n) const
676     {
677       size_type __size = this->size();
678       size_t __xpos = __pos;
679       const _CharT* __data = _M_data();
680       for (; __xpos + __n <= __size; ++__xpos)
681 	if (traits_type::compare(__data + __xpos, __s, __n) == 0)
682 	  return __xpos;
683       return npos;
684     }
685 
686   template<typename _CharT, typename _Traits, typename _Alloc>
687     typename basic_string<_CharT, _Traits, _Alloc>::size_type
688     basic_string<_CharT, _Traits, _Alloc>::
689     find(_CharT __c, size_type __pos) const
690     {
691       size_type __size = this->size();
692       size_type __ret = npos;
693       if (__pos < __size)
694 	{
695 	  const _CharT* __data = _M_data();
696 	  size_type __n = __size - __pos;
697 	  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
698 	  if (__p)
699 	    __ret = __p - __data;
700 	}
701       return __ret;
702     }
703 
704 
705   template<typename _CharT, typename _Traits, typename _Alloc>
706     typename basic_string<_CharT, _Traits, _Alloc>::size_type
707     basic_string<_CharT, _Traits, _Alloc>::
708     rfind(const _CharT* __s, size_type __pos, size_type __n) const
709     {
710       size_type __size = this->size();
711       if (__n <= __size)
712 	{
713 	  __pos = std::min(__size - __n, __pos);
714 	  const _CharT* __data = _M_data();
715 	  do
716 	    {
717 	      if (traits_type::compare(__data + __pos, __s, __n) == 0)
718 		return __pos;
719 	    }
720 	  while (__pos-- > 0);
721 	}
722       return npos;
723     }
724 
725   template<typename _CharT, typename _Traits, typename _Alloc>
726     typename basic_string<_CharT, _Traits, _Alloc>::size_type
727     basic_string<_CharT, _Traits, _Alloc>::
728     rfind(_CharT __c, size_type __pos) const
729     {
730       size_type __size = this->size();
731       if (__size)
732 	{
733 	  size_t __xpos = __size - 1;
734 	  if (__xpos > __pos)
735 	    __xpos = __pos;
736 
737 	  for (++__xpos; __xpos-- > 0; )
738 	    if (traits_type::eq(_M_data()[__xpos], __c))
739 	      return __xpos;
740 	}
741       return npos;
742     }
743 
744   template<typename _CharT, typename _Traits, typename _Alloc>
745     typename basic_string<_CharT, _Traits, _Alloc>::size_type
746     basic_string<_CharT, _Traits, _Alloc>::
747     find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
748     {
749       for (; __n && __pos < this->size(); ++__pos)
750 	{
751 	  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
752 	  if (__p)
753 	    return __pos;
754 	}
755       return npos;
756     }
757 
758   template<typename _CharT, typename _Traits, typename _Alloc>
759     typename basic_string<_CharT, _Traits, _Alloc>::size_type
760     basic_string<_CharT, _Traits, _Alloc>::
761     find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
762     {
763       size_type __size = this->size();
764       if (__size && __n)
765 	{
766 	  if (--__size > __pos)
767 	    __size = __pos;
768 	  do
769 	    {
770 	      if (traits_type::find(__s, __n, _M_data()[__size]))
771 		return __size;
772 	    }
773 	  while (__size-- != 0);
774 	}
775       return npos;
776     }
777 
778   template<typename _CharT, typename _Traits, typename _Alloc>
779     typename basic_string<_CharT, _Traits, _Alloc>::size_type
780     basic_string<_CharT, _Traits, _Alloc>::
781     find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
782     {
783       size_t __xpos = __pos;
784       for (; __xpos < this->size(); ++__xpos)
785 	if (!traits_type::find(__s, __n, _M_data()[__xpos]))
786 	  return __xpos;
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_not_of(_CharT __c, size_type __pos) const
794     {
795       size_t __xpos = __pos;
796       for (; __xpos < this->size(); ++__xpos)
797 	if (!traits_type::eq(_M_data()[__xpos], __c))
798 	  return __xpos;
799       return npos;
800     }
801 
802   template<typename _CharT, typename _Traits, typename _Alloc>
803     typename basic_string<_CharT, _Traits, _Alloc>::size_type
804     basic_string<_CharT, _Traits, _Alloc>::
805     find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
806     {
807       size_type __size = this->size();
808       if (__size)
809 	{
810 	  if (--__size > __pos)
811 	    __size = __pos;
812 	  do
813 	    {
814 	      if (!traits_type::find(__s, __n, _M_data()[__size]))
815 		return __size;
816 	    }
817 	  while (__size--);
818 	}
819       return npos;
820     }
821 
822   template<typename _CharT, typename _Traits, typename _Alloc>
823     typename basic_string<_CharT, _Traits, _Alloc>::size_type
824     basic_string<_CharT, _Traits, _Alloc>::
825     find_last_not_of(_CharT __c, size_type __pos) const
826     {
827       size_type __size = this->size();
828       if (__size)
829 	{
830 	  if (--__size > __pos)
831 	    __size = __pos;
832 	  do
833 	    {
834 	      if (!traits_type::eq(_M_data()[__size], __c))
835 		return __size;
836 	    }
837 	  while (__size--);
838 	}
839       return npos;
840     }
841 
842   template<typename _CharT, typename _Traits, typename _Alloc>
843     int
844     basic_string<_CharT, _Traits, _Alloc>::
845     compare(size_type __pos, size_type __n, const basic_string& __str) const
846     {
847       size_type __size = this->size();
848       size_type __osize = __str.size();
849       if (__pos > __size)
850 	__throw_out_of_range("basic_string::compare");
851 
852       size_type __rsize= min(__size - __pos, __n);
853       size_type __len = min(__rsize, __osize);
854       int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
855       if (!__r)
856 	__r = __rsize - __osize;
857       return __r;
858     }
859 
860   template<typename _CharT, typename _Traits, typename _Alloc>
861     int
862     basic_string<_CharT, _Traits, _Alloc>::
863     compare(size_type __pos1, size_type __n1, const basic_string& __str,
864 	    size_type __pos2, size_type __n2) const
865     {
866       size_type __size = this->size();
867       size_type __osize = __str.size();
868       if (__pos1 > __size || __pos2 > __osize)
869 	__throw_out_of_range("basic_string::compare");
870 
871       size_type __rsize = min(__size - __pos1, __n1);
872       size_type __rosize = min(__osize - __pos2, __n2);
873       size_type __len = min(__rsize, __rosize);
874       int __r = traits_type::compare(_M_data() + __pos1,
875 				     __str.data() + __pos2, __len);
876       if (!__r)
877 	__r = __rsize - __rosize;
878       return __r;
879     }
880 
881 
882   template<typename _CharT, typename _Traits, typename _Alloc>
883     int
884     basic_string<_CharT, _Traits, _Alloc>::
885     compare(const _CharT* __s) const
886     {
887       size_type __size = this->size();
888       int __r = traits_type::compare(_M_data(), __s, __size);
889       if (!__r)
890 	__r = __size - traits_type::length(__s);
891       return __r;
892     }
893 
894 
895   template<typename _CharT, typename _Traits, typename _Alloc>
896     int
897     basic_string <_CharT, _Traits, _Alloc>::
898     compare(size_type __pos, size_type __n1, const _CharT* __s) const
899     {
900       size_type __size = this->size();
901       if (__pos > __size)
902 	__throw_out_of_range("basic_string::compare");
903 
904       size_type __osize = traits_type::length(__s);
905       size_type __rsize = min(__size - __pos, __n1);
906       size_type __len = min(__rsize, __osize);
907       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
908       if (!__r)
909 	__r = __rsize - __osize;
910       return __r;
911     }
912 
913   template<typename _CharT, typename _Traits, typename _Alloc>
914     int
915     basic_string <_CharT, _Traits, _Alloc>::
916     compare(size_type __pos, size_type __n1, const _CharT* __s,
917 	    size_type __n2) const
918     {
919       size_type __size = this->size();
920       if (__pos > __size)
921 	__throw_out_of_range("basic_string::compare");
922 
923       size_type __osize = min(traits_type::length(__s), __n2);
924       size_type __rsize = min(__size - __pos, __n1);
925       size_type __len = min(__rsize, __osize);
926       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
927       if (!__r)
928 	__r = __rsize - __osize;
929       return __r;
930     }
931 
932   template <class _CharT, class _Traits, class _Alloc>
933     void
934     _S_string_copy(const basic_string<_CharT, _Traits, _Alloc>& __str,
935 		   _CharT* __buf, typename _Alloc::size_type __bufsiz)
936     {
937       typedef typename _Alloc::size_type size_type;
938       size_type __strsize = __str.size();
939       size_type __bytes = min(__strsize, __bufsiz - 1);
940       _Traits::copy(__buf, __str.data(), __bytes);
941       __buf[__bytes] = _CharT();
942     }
943 
944   // Inhibit implicit instantiations for required instantiations,
945   // which are defined via explicit instantiations elsewhere.
946   // NB: This syntax is a GNU extension.
947   extern template class basic_string<char>;
948   extern template
949     basic_istream<char>&
950     operator>>(basic_istream<char>&, string&);
951   extern template
952     basic_ostream<char>&
953     operator<<(basic_ostream<char>&, const string&);
954   extern template
955     basic_istream<char>&
956     getline(basic_istream<char>&, string&, char);
957   extern template
958     basic_istream<char>&
959     getline(basic_istream<char>&, string&);
960 
961   extern template class basic_string<wchar_t>;
962   extern template
963     basic_istream<wchar_t>&
964     operator>>(basic_istream<wchar_t>&, wstring&);
965   extern template
966     basic_ostream<wchar_t>&
967     operator<<(basic_ostream<wchar_t>&, const wstring&);
968   extern template
969     basic_istream<wchar_t>&
970     getline(basic_istream<wchar_t>&, wstring&, wchar_t);
971   extern template
972     basic_istream<wchar_t>&
973     getline(basic_istream<wchar_t>&, wstring&);
974 } // namespace std
975 
976 #endif
977