1 // SGI's rope class implementation -*- C++ -*-
2 
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
20 
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24 // <http://www.gnu.org/licenses/>.
25 
26 /*
27  * Copyright (c) 1997
28  * Silicon Graphics Computer Systems, Inc.
29  *
30  * Permission to use, copy, modify, distribute and sell this software
31  * and its documentation for any purpose is hereby granted without fee,
32  * provided that the above copyright notice appear in all copies and
33  * that both that copyright notice and this permission notice appear
34  * in supporting documentation.  Silicon Graphics makes no
35  * representations about the suitability of this software for any
36  * purpose.  It is provided "as is" without express or implied warranty.
37  */
38 
39 /** @file ropeimpl.h
40  *  This is an internal header file, included by other library headers.
41  *  Do not attempt to use it directly. @headername{ext/rope}
42  */
43 
44 #include <cstdio>
45 #include <ostream>
46 #include <bits/functexcept.h>
47 
48 #include <ext/algorithm> // For copy_n and lexicographical_compare_3way
49 #include <ext/memory> // For uninitialized_copy_n
50 #include <ext/numeric> // For power
51 
52 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
53 {
54 _GLIBCXX_BEGIN_NAMESPACE_VERSION
55 
56   using std::size_t;
57   using std::printf;
58   using std::basic_ostream;
59   using std::__throw_length_error;
60   using std::_Destroy;
61   using std::uninitialized_fill_n;
62 
63   // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf
64   // if necessary.  Assumes _M_path_end[leaf_index] and leaf_pos are correct.
65   // Results in a valid buf_ptr if the iterator can be legitimately
66   // dereferenced.
67   template <class _CharT, class _Alloc>
68     void
69     _Rope_iterator_base<_CharT, _Alloc>::
70     _S_setbuf(_Rope_iterator_base<_CharT, _Alloc>& __x)
71     {
72       const _RopeRep* __leaf = __x._M_path_end[__x._M_leaf_index];
73       size_t __leaf_pos = __x._M_leaf_pos;
74       size_t __pos = __x._M_current_pos;
75 
76       switch(__leaf->_M_tag)
77 	{
78 	case __detail::_S_leaf:
79 	  __x._M_buf_start = ((_Rope_RopeLeaf<_CharT, _Alloc>*)__leaf)->_M_data;
80 	  __x._M_buf_ptr = __x._M_buf_start + (__pos - __leaf_pos);
81 	  __x._M_buf_end = __x._M_buf_start + __leaf->_M_size;
82 	  break;
83 	case __detail::_S_function:
84 	case __detail::_S_substringfn:
85 	  {
86 	    size_t __len = _S_iterator_buf_len;
87 	    size_t __buf_start_pos = __leaf_pos;
88 	    size_t __leaf_end = __leaf_pos + __leaf->_M_size;
89 	    char_producer<_CharT>* __fn = ((_Rope_RopeFunction<_CharT,
90 					    _Alloc>*)__leaf)->_M_fn;
91 	    if (__buf_start_pos + __len <= __pos)
92 	      {
93 		__buf_start_pos = __pos - __len / 4;
94 		if (__buf_start_pos + __len > __leaf_end)
95 		  __buf_start_pos = __leaf_end - __len;
96 	      }
97 	    if (__buf_start_pos + __len > __leaf_end)
98 	      __len = __leaf_end - __buf_start_pos;
99 	    (*__fn)(__buf_start_pos - __leaf_pos, __len, __x._M_tmp_buf);
100 	    __x._M_buf_ptr = __x._M_tmp_buf + (__pos - __buf_start_pos);
101 	    __x._M_buf_start = __x._M_tmp_buf;
102 	    __x._M_buf_end = __x._M_tmp_buf + __len;
103 	  }
104 	  break;
105 	default:
106 	  break;
107 	}
108     }
109 
110   // Set path and buffer inside a rope iterator.  We assume that
111   // pos and root are already set.
112   template <class _CharT, class _Alloc>
113     void
114     _Rope_iterator_base<_CharT, _Alloc>::
115     _S_setcache(_Rope_iterator_base<_CharT, _Alloc>& __x)
116     {
117       const _RopeRep* __path[int(__detail::_S_max_rope_depth) + 1];
118       const _RopeRep* __curr_rope;
119       int __curr_depth = -1;  /* index into path    */
120       size_t __curr_start_pos = 0;
121       size_t __pos = __x._M_current_pos;
122       unsigned char __dirns = 0; // Bit vector marking right turns in the path
123 
124       if (__pos >= __x._M_root->_M_size)
125 	{
126 	  __x._M_buf_ptr = 0;
127 	  return;
128 	}
129       __curr_rope = __x._M_root;
130       if (0 != __curr_rope->_M_c_string)
131 	{
132 	  /* Treat the root as a leaf. */
133 	  __x._M_buf_start = __curr_rope->_M_c_string;
134 	  __x._M_buf_end = __curr_rope->_M_c_string + __curr_rope->_M_size;
135 	  __x._M_buf_ptr = __curr_rope->_M_c_string + __pos;
136 	  __x._M_path_end[0] = __curr_rope;
137 	  __x._M_leaf_index = 0;
138 	  __x._M_leaf_pos = 0;
139 	  return;
140 	}
141       for(;;)
142 	{
143 	  ++__curr_depth;
144 	  __path[__curr_depth] = __curr_rope;
145 	  switch(__curr_rope->_M_tag)
146 	    {
147 	    case __detail::_S_leaf:
148 	    case __detail::_S_function:
149 	    case __detail::_S_substringfn:
150 	      __x._M_leaf_pos = __curr_start_pos;
151 	      goto done;
152 	    case __detail::_S_concat:
153 	      {
154 		_Rope_RopeConcatenation<_CharT, _Alloc>* __c =
155 		  (_Rope_RopeConcatenation<_CharT, _Alloc>*)__curr_rope;
156 		_RopeRep* __left = __c->_M_left;
157 		size_t __left_len = __left->_M_size;
158 
159 		__dirns <<= 1;
160 		if (__pos >= __curr_start_pos + __left_len)
161 		  {
162 		    __dirns |= 1;
163 		    __curr_rope = __c->_M_right;
164 		    __curr_start_pos += __left_len;
165 		  }
166 		else
167 		  __curr_rope = __left;
168 	      }
169 	      break;
170 	    }
171 	}
172     done:
173       // Copy last section of path into _M_path_end.
174       {
175 	int __i = -1;
176 	int __j = __curr_depth + 1 - int(_S_path_cache_len);
177 
178 	if (__j < 0) __j = 0;
179 	while (__j <= __curr_depth)
180 	  __x._M_path_end[++__i] = __path[__j++];
181 	__x._M_leaf_index = __i;
182       }
183       __x._M_path_directions = __dirns;
184       _S_setbuf(__x);
185     }
186 
187   // Specialized version of the above.  Assumes that
188   // the path cache is valid for the previous position.
189   template <class _CharT, class _Alloc>
190     void
191     _Rope_iterator_base<_CharT, _Alloc>::
192     _S_setcache_for_incr(_Rope_iterator_base<_CharT, _Alloc>& __x)
193     {
194       int __current_index = __x._M_leaf_index;
195       const _RopeRep* __current_node = __x._M_path_end[__current_index];
196       size_t __len = __current_node->_M_size;
197       size_t __node_start_pos = __x._M_leaf_pos;
198       unsigned char __dirns = __x._M_path_directions;
199       _Rope_RopeConcatenation<_CharT, _Alloc>* __c;
200 
201       if (__x._M_current_pos - __node_start_pos < __len)
202 	{
203 	  /* More stuff in this leaf, we just didn't cache it. */
204 	  _S_setbuf(__x);
205 	  return;
206 	}
207       //  node_start_pos is starting position of last_node.
208       while (--__current_index >= 0)
209 	{
210 	  if (!(__dirns & 1) /* Path turned left */)
211 	    break;
212 	  __current_node = __x._M_path_end[__current_index];
213 	  __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
214 	  // Otherwise we were in the right child.  Thus we should pop
215 	  // the concatenation node.
216 	  __node_start_pos -= __c->_M_left->_M_size;
217 	  __dirns >>= 1;
218 	}
219       if (__current_index < 0)
220 	{
221 	  // We underflowed the cache. Punt.
222 	  _S_setcache(__x);
223 	  return;
224 	}
225       __current_node = __x._M_path_end[__current_index];
226       __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
227       // current_node is a concatenation node.  We are positioned on the first
228       // character in its right child.
229       // node_start_pos is starting position of current_node.
230       __node_start_pos += __c->_M_left->_M_size;
231       __current_node = __c->_M_right;
232       __x._M_path_end[++__current_index] = __current_node;
233       __dirns |= 1;
234       while (__detail::_S_concat == __current_node->_M_tag)
235 	{
236 	  ++__current_index;
237 	  if (int(_S_path_cache_len) == __current_index)
238 	    {
239 	      int __i;
240 	      for (__i = 0; __i < int(_S_path_cache_len) - 1; __i++)
241 		__x._M_path_end[__i] = __x._M_path_end[__i+1];
242 	      --__current_index;
243 	    }
244 	  __current_node =
245 	    ((_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node)->_M_left;
246 	  __x._M_path_end[__current_index] = __current_node;
247 	  __dirns <<= 1;
248 	  // node_start_pos is unchanged.
249 	}
250       __x._M_leaf_index = __current_index;
251       __x._M_leaf_pos = __node_start_pos;
252       __x._M_path_directions = __dirns;
253       _S_setbuf(__x);
254     }
255 
256   template <class _CharT, class _Alloc>
257     void
258     _Rope_iterator_base<_CharT, _Alloc>::
259     _M_incr(size_t __n)
260     {
261       _M_current_pos += __n;
262       if (0 != _M_buf_ptr)
263 	{
264 	  size_t __chars_left = _M_buf_end - _M_buf_ptr;
265 	  if (__chars_left > __n)
266 	    _M_buf_ptr += __n;
267 	  else if (__chars_left == __n)
268 	    {
269 	      _M_buf_ptr += __n;
270 	      _S_setcache_for_incr(*this);
271 	    }
272 	  else
273 	    _M_buf_ptr = 0;
274 	}
275     }
276 
277   template <class _CharT, class _Alloc>
278     void
279     _Rope_iterator_base<_CharT, _Alloc>::
280     _M_decr(size_t __n)
281     {
282       if (0 != _M_buf_ptr)
283 	{
284 	  size_t __chars_left = _M_buf_ptr - _M_buf_start;
285 	  if (__chars_left >= __n)
286 	    _M_buf_ptr -= __n;
287 	  else
288 	    _M_buf_ptr = 0;
289 	}
290       _M_current_pos -= __n;
291     }
292 
293   template <class _CharT, class _Alloc>
294     void
295     _Rope_iterator<_CharT, _Alloc>::
296     _M_check()
297     {
298       if (_M_root_rope->_M_tree_ptr != this->_M_root)
299 	{
300 	  // _Rope was modified.  Get things fixed up.
301 	  _RopeRep::_S_unref(this->_M_root);
302 	  this->_M_root = _M_root_rope->_M_tree_ptr;
303 	  _RopeRep::_S_ref(this->_M_root);
304 	  this->_M_buf_ptr = 0;
305 	}
306     }
307 
308   template <class _CharT, class _Alloc>
309     inline
310     _Rope_const_iterator<_CharT, _Alloc>::
311     _Rope_const_iterator(const _Rope_iterator<_CharT, _Alloc>& __x)
312     : _Rope_iterator_base<_CharT, _Alloc>(__x)
313     { }
314 
315   template <class _CharT, class _Alloc>
316     inline
317     _Rope_iterator<_CharT, _Alloc>::
318     _Rope_iterator(rope<_CharT, _Alloc>& __r, size_t __pos)
319     : _Rope_iterator_base<_CharT,_Alloc>(__r._M_tree_ptr, __pos),
320       _M_root_rope(&__r)
321     { _RopeRep::_S_ref(this->_M_root); }
322 
323   template <class _CharT, class _Alloc>
324     inline size_t
325     rope<_CharT, _Alloc>::
326     _S_char_ptr_len(const _CharT* __s)
327     {
328       const _CharT* __p = __s;
329 
330       while (!_S_is0(*__p))
331 	++__p;
332       return (__p - __s);
333     }
334 
335 
336 #ifndef __GC
337 
338   template <class _CharT, class _Alloc>
339     inline void
340     _Rope_RopeRep<_CharT, _Alloc>::
341     _M_free_c_string()
342     {
343       _CharT* __cstr = _M_c_string;
344       if (0 != __cstr)
345 	{
346 	  size_t __size = this->_M_size + 1;
347 	  _Destroy(__cstr, __cstr + __size, _M_get_allocator());
348 	  this->_Data_deallocate(__cstr, __size);
349 	}
350     }
351 
352   template <class _CharT, class _Alloc>
353     inline void
354     _Rope_RopeRep<_CharT, _Alloc>::
355     _S_free_string(_CharT* __s, size_t __n, allocator_type& __a)
356     {
357       if (!_S_is_basic_char_type((_CharT*)0))
358 	_Destroy(__s, __s + __n, __a);
359 
360       //  This has to be a static member, so this gets a bit messy
361       __a.deallocate(__s,
362 		     _Rope_RopeLeaf<_CharT, _Alloc>::_S_rounded_up_size(__n));
363     }
364 
365   //  There are several reasons for not doing this with virtual destructors
366   //  and a class specific delete operator:
367   //  - A class specific delete operator can't easily get access to
368   //    allocator instances if we need them.
369   //  - Any virtual function would need a 4 or byte vtable pointer;
370   //    this only requires a one byte tag per object.
371   template <class _CharT, class _Alloc>
372     void
373     _Rope_RopeRep<_CharT, _Alloc>::
374     _M_free_tree()
375     {
376       switch(_M_tag)
377 	{
378 	case __detail::_S_leaf:
379 	  {
380 	    _Rope_RopeLeaf<_CharT, _Alloc>* __l
381 	      = (_Rope_RopeLeaf<_CharT, _Alloc>*)this;
382 	    __l->_Rope_RopeLeaf<_CharT, _Alloc>::~_Rope_RopeLeaf();
383 	    this->_L_deallocate(__l, 1);
384 	    break;
385 	  }
386 	case __detail::_S_concat:
387 	  {
388 	    _Rope_RopeConcatenation<_CharT,_Alloc>* __c
389 	      = (_Rope_RopeConcatenation<_CharT, _Alloc>*)this;
390 	    __c->_Rope_RopeConcatenation<_CharT, _Alloc>::
391 	      ~_Rope_RopeConcatenation();
392 	    this->_C_deallocate(__c, 1);
393 	    break;
394 	  }
395 	case __detail::_S_function:
396 	  {
397 	    _Rope_RopeFunction<_CharT, _Alloc>* __f
398 	      = (_Rope_RopeFunction<_CharT, _Alloc>*)this;
399 	    __f->_Rope_RopeFunction<_CharT, _Alloc>::~_Rope_RopeFunction();
400 	    this->_F_deallocate(__f, 1);
401 	    break;
402 	  }
403 	case __detail::_S_substringfn:
404 	  {
405 	    _Rope_RopeSubstring<_CharT, _Alloc>* __ss =
406 	      (_Rope_RopeSubstring<_CharT, _Alloc>*)this;
407 	    __ss->_Rope_RopeSubstring<_CharT, _Alloc>::
408 	      ~_Rope_RopeSubstring();
409 	    this->_S_deallocate(__ss, 1);
410 	    break;
411 	  }
412 	}
413     }
414 #else
415 
416   template <class _CharT, class _Alloc>
417     inline void
418     _Rope_RopeRep<_CharT, _Alloc>::
419     _S_free_string(const _CharT*, size_t, allocator_type)
420     { }
421 
422 #endif
423 
424   // Concatenate a C string onto a leaf rope by copying the rope data.
425   // Used for short ropes.
426   template <class _CharT, class _Alloc>
427     typename rope<_CharT, _Alloc>::_RopeLeaf*
428     rope<_CharT, _Alloc>::
429     _S_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter, size_t __len)
430     {
431       size_t __old_len = __r->_M_size;
432       _CharT* __new_data = (_CharT*)
433 	rope::_Data_allocate(_S_rounded_up_size(__old_len + __len));
434       _RopeLeaf* __result;
435 
436       uninitialized_copy_n(__r->_M_data, __old_len, __new_data);
437       uninitialized_copy_n(__iter, __len, __new_data + __old_len);
438       _S_cond_store_eos(__new_data[__old_len + __len]);
439       __try
440 	{
441 	  __result = _S_new_RopeLeaf(__new_data, __old_len + __len,
442 				     __r->_M_get_allocator());
443 	}
444       __catch(...)
445 	{
446 	  _RopeRep::__STL_FREE_STRING(__new_data, __old_len + __len,
447 				      __r->_M_get_allocator());
448 	  __throw_exception_again;
449 	}
450       return __result;
451     }
452 
453 #ifndef __GC
454   // As above, but it's OK to clobber original if refcount is 1
455   template <class _CharT, class _Alloc>
456     typename rope<_CharT,_Alloc>::_RopeLeaf*
457     rope<_CharT, _Alloc>::
458     _S_destr_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter,
459 				   size_t __len)
460     {
461       if (__r->_M_ref_count > 1)
462 	return _S_leaf_concat_char_iter(__r, __iter, __len);
463       size_t __old_len = __r->_M_size;
464       if (_S_allocated_capacity(__old_len) >= __old_len + __len)
465 	{
466 	  // The space has been partially initialized for the standard
467 	  // character types.  But that doesn't matter for those types.
468 	  uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);
469 	  if (_S_is_basic_char_type((_CharT*)0))
470 	    _S_cond_store_eos(__r->_M_data[__old_len + __len]);
471 	  else if (__r->_M_c_string != __r->_M_data && 0 != __r->_M_c_string)
472 	    {
473 	      __r->_M_free_c_string();
474 	      __r->_M_c_string = 0;
475 	    }
476 	  __r->_M_size = __old_len + __len;
477 	  __r->_M_ref_count = 2;
478 	  return __r;
479 	}
480       else
481 	{
482 	  _RopeLeaf* __result = _S_leaf_concat_char_iter(__r, __iter, __len);
483 	  return __result;
484 	}
485     }
486 #endif
487 
488   // Assumes left and right are not 0.
489   // Does not increment (nor decrement on exception) child reference counts.
490   // Result has ref count 1.
491   template <class _CharT, class _Alloc>
492     typename rope<_CharT, _Alloc>::_RopeRep*
493     rope<_CharT, _Alloc>::
494     _S_tree_concat(_RopeRep* __left, _RopeRep* __right)
495     {
496       _RopeConcatenation* __result = _S_new_RopeConcatenation(__left, __right,
497 							      __left->
498 							      _M_get_allocator());
499       size_t __depth = __result->_M_depth;
500 
501       if (__depth > 20
502 	  && (__result->_M_size < 1000
503 	      || __depth > size_t(__detail::_S_max_rope_depth)))
504 	{
505 	  _RopeRep* __balanced;
506 
507 	  __try
508 	    {
509 	      __balanced = _S_balance(__result);
510 	      __result->_M_unref_nonnil();
511 	    }
512 	  __catch(...)
513 	    {
514 	      rope::_C_deallocate(__result,1);
515 	      __throw_exception_again;
516 	    }
517 	  // In case of exception, we need to deallocate
518 	  // otherwise dangling result node.  But caller
519 	  // still owns its children.  Thus unref is
520 	  // inappropriate.
521 	  return __balanced;
522 	}
523       else
524 	return __result;
525     }
526 
527   template <class _CharT, class _Alloc>
528     typename rope<_CharT, _Alloc>::_RopeRep*
529     rope<_CharT, _Alloc>::
530     _S_concat_char_iter(_RopeRep* __r, const _CharT*__s, size_t __slen)
531     {
532       _RopeRep* __result;
533       if (0 == __slen)
534 	{
535 	  _S_ref(__r);
536 	  return __r;
537 	}
538       if (0 == __r)
539 	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
540 						__r->_M_get_allocator());
541       if (__r->_M_tag == __detail::_S_leaf
542 	  && __r->_M_size + __slen <= size_t(_S_copy_max))
543 	{
544 	  __result = _S_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);
545 	  return __result;
546 	}
547       if (__detail::_S_concat == __r->_M_tag
548 	  && __detail::_S_leaf == ((_RopeConcatenation*) __r)->_M_right->_M_tag)
549 	{
550 	  _RopeLeaf* __right =
551 	    (_RopeLeaf* )(((_RopeConcatenation* )__r)->_M_right);
552 	  if (__right->_M_size + __slen <= size_t(_S_copy_max))
553 	    {
554 	      _RopeRep* __left = ((_RopeConcatenation*)__r)->_M_left;
555 	      _RopeRep* __nright =
556 		_S_leaf_concat_char_iter((_RopeLeaf*)__right, __s, __slen);
557 	      __left->_M_ref_nonnil();
558 	      __try
559 		{ __result = _S_tree_concat(__left, __nright); }
560 	      __catch(...)
561 		{
562 		  _S_unref(__left);
563 		  _S_unref(__nright);
564 		  __throw_exception_again;
565 		}
566 	      return __result;
567 	    }
568 	}
569       _RopeRep* __nright =
570 	__STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
571       __try
572 	{
573 	  __r->_M_ref_nonnil();
574 	  __result = _S_tree_concat(__r, __nright);
575 	}
576       __catch(...)
577 	{
578 	  _S_unref(__r);
579 	  _S_unref(__nright);
580 	  __throw_exception_again;
581 	}
582       return __result;
583     }
584 
585 #ifndef __GC
586   template <class _CharT, class _Alloc>
587     typename rope<_CharT,_Alloc>::_RopeRep*
588     rope<_CharT,_Alloc>::
589     _S_destr_concat_char_iter(_RopeRep* __r, const _CharT* __s, size_t __slen)
590     {
591       _RopeRep* __result;
592       if (0 == __r)
593 	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,
594 						__r->_M_get_allocator());
595       size_t __count = __r->_M_ref_count;
596       size_t __orig_size = __r->_M_size;
597       if (__count > 1)
598 	return _S_concat_char_iter(__r, __s, __slen);
599       if (0 == __slen)
600 	{
601 	  __r->_M_ref_count = 2;      // One more than before
602 	  return __r;
603 	}
604       if (__orig_size + __slen <= size_t(_S_copy_max)
605 	  && __detail::_S_leaf == __r->_M_tag)
606 	{
607 	  __result = _S_destr_leaf_concat_char_iter((_RopeLeaf*)__r, __s,
608 						    __slen);
609 	  return __result;
610 	}
611       if (__detail::_S_concat == __r->_M_tag)
612 	{
613 	  _RopeLeaf* __right = (_RopeLeaf*)(((_RopeConcatenation*)
614 					     __r)->_M_right);
615 	  if (__detail::_S_leaf == __right->_M_tag
616 	      && __right->_M_size + __slen <= size_t(_S_copy_max))
617 	    {
618 	      _RopeRep* __new_right =
619 		_S_destr_leaf_concat_char_iter(__right, __s, __slen);
620 	      if (__right == __new_right)
621 		__new_right->_M_ref_count = 1;
622 	      else
623 		__right->_M_unref_nonnil();
624 	      __r->_M_ref_count = 2;    // One more than before.
625 	      ((_RopeConcatenation*)__r)->_M_right = __new_right;
626 	      __r->_M_size = __orig_size + __slen;
627 	      if (0 != __r->_M_c_string)
628 		{
629 		  __r->_M_free_c_string();
630 		  __r->_M_c_string = 0;
631 		}
632 	      return __r;
633 	    }
634 	}
635       _RopeRep* __right =
636 	__STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->_M_get_allocator());
637       __r->_M_ref_nonnil();
638       __try
639 	{ __result = _S_tree_concat(__r, __right); }
640       __catch(...)
641 	{
642 	  _S_unref(__r);
643 	  _S_unref(__right);
644 	  __throw_exception_again;
645 	}
646       return __result;
647     }
648 #endif /* !__GC */
649 
650   template <class _CharT, class _Alloc>
651     typename rope<_CharT, _Alloc>::_RopeRep*
652     rope<_CharT, _Alloc>::
653     _S_concat(_RopeRep* __left, _RopeRep* __right)
654     {
655       if (0 == __left)
656 	{
657 	  _S_ref(__right);
658 	  return __right;
659 	}
660       if (0 == __right)
661 	{
662 	  __left->_M_ref_nonnil();
663 	  return __left;
664 	}
665       if (__detail::_S_leaf == __right->_M_tag)
666 	{
667 	  if (__detail::_S_leaf == __left->_M_tag)
668 	    {
669 	      if (__right->_M_size + __left->_M_size <= size_t(_S_copy_max))
670 		return _S_leaf_concat_char_iter((_RopeLeaf*)__left,
671 						((_RopeLeaf*)__right)->_M_data,
672 						__right->_M_size);
673 	    }
674 	  else if (__detail::_S_concat == __left->_M_tag
675 		   && __detail::_S_leaf == ((_RopeConcatenation*)
676 						   __left)->_M_right->_M_tag)
677 	    {
678 	      _RopeLeaf* __leftright =
679 		(_RopeLeaf*)(((_RopeConcatenation*)__left)->_M_right);
680 	      if (__leftright->_M_size
681 		  + __right->_M_size <= size_t(_S_copy_max))
682 		{
683 		  _RopeRep* __leftleft = ((_RopeConcatenation*)__left)->_M_left;
684 		  _RopeRep* __rest = _S_leaf_concat_char_iter(__leftright,
685 							      ((_RopeLeaf*)
686 							       __right)->
687 							      _M_data,
688 							      __right->_M_size);
689 		  __leftleft->_M_ref_nonnil();
690 		  __try
691 		    { return(_S_tree_concat(__leftleft, __rest)); }
692 		  __catch(...)
693 		    {
694 		      _S_unref(__leftleft);
695 		      _S_unref(__rest);
696 		      __throw_exception_again;
697 		    }
698 		}
699 	    }
700 	}
701       __left->_M_ref_nonnil();
702       __right->_M_ref_nonnil();
703       __try
704 	{ return(_S_tree_concat(__left, __right)); }
705       __catch(...)
706 	{
707 	  _S_unref(__left);
708 	  _S_unref(__right);
709 	  __throw_exception_again;
710 	}
711     }
712 
713   template <class _CharT, class _Alloc>
714     typename rope<_CharT, _Alloc>::_RopeRep*
715     rope<_CharT, _Alloc>::
716     _S_substring(_RopeRep* __base, size_t __start, size_t __endp1)
717     {
718       if (0 == __base)
719 	return 0;
720       size_t __len = __base->_M_size;
721       size_t __adj_endp1;
722       const size_t __lazy_threshold = 128;
723 
724       if (__endp1 >= __len)
725 	{
726 	  if (0 == __start)
727 	    {
728 	      __base->_M_ref_nonnil();
729 	      return __base;
730 	    }
731 	  else
732 	    __adj_endp1 = __len;
733 
734 	}
735       else
736 	__adj_endp1 = __endp1;
737 
738       switch(__base->_M_tag)
739 	{
740 	case __detail::_S_concat:
741 	    {
742 	      _RopeConcatenation* __c = (_RopeConcatenation*)__base;
743 	      _RopeRep* __left = __c->_M_left;
744 	      _RopeRep* __right = __c->_M_right;
745 	      size_t __left_len = __left->_M_size;
746 	      _RopeRep* __result;
747 
748 	      if (__adj_endp1 <= __left_len)
749 		return _S_substring(__left, __start, __endp1);
750 	      else if (__start >= __left_len)
751 		return _S_substring(__right, __start - __left_len,
752 				    __adj_endp1 - __left_len);
753 	      _Self_destruct_ptr __left_result(_S_substring(__left,
754 							    __start,
755 							    __left_len));
756 	      _Self_destruct_ptr __right_result(_S_substring(__right, 0,
757 							     __endp1
758 							     - __left_len));
759 	      __result = _S_concat(__left_result, __right_result);
760 	      return __result;
761 	    }
762 	case __detail::_S_leaf:
763 	  {
764 	    _RopeLeaf* __l = (_RopeLeaf*)__base;
765 	    _RopeLeaf* __result;
766 	    size_t __result_len;
767 	    if (__start >= __adj_endp1)
768 	      return 0;
769 	    __result_len = __adj_endp1 - __start;
770 	    if (__result_len > __lazy_threshold)
771 	      goto lazy;
772 #ifdef __GC
773 	    const _CharT* __section = __l->_M_data + __start;
774 	    __result = _S_new_RopeLeaf(__section, __result_len,
775 				       __base->_M_get_allocator());
776 	    __result->_M_c_string = 0;  // Not eos terminated.
777 #else
778 	    // We should sometimes create substring node instead.
779 	    __result = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__l->_M_data + __start,
780 							__result_len,
781 							__base->
782 							_M_get_allocator());
783 #endif
784 	    return __result;
785 	  }
786 	case __detail::_S_substringfn:
787 	  // Avoid introducing multiple layers of substring nodes.
788 	  {
789 	    _RopeSubstring* __old = (_RopeSubstring*)__base;
790 	    size_t __result_len;
791 	    if (__start >= __adj_endp1)
792 	      return 0;
793 	    __result_len = __adj_endp1 - __start;
794 	    if (__result_len > __lazy_threshold)
795 	      {
796 		_RopeSubstring* __result =
797 		  _S_new_RopeSubstring(__old->_M_base,
798 				       __start + __old->_M_start,
799 				       __adj_endp1 - __start,
800 				       __base->_M_get_allocator());
801 		return __result;
802 
803 	      } // *** else fall through: ***
804 	  }
805 	case __detail::_S_function:
806 	  {
807 	    _RopeFunction* __f = (_RopeFunction*)__base;
808 	    _CharT* __section;
809 	    size_t __result_len;
810 	    if (__start >= __adj_endp1)
811 	      return 0;
812 	    __result_len = __adj_endp1 - __start;
813 
814 	    if (__result_len > __lazy_threshold)
815 	      goto lazy;
816 	    __section = (_CharT*)
817 	      rope::_Data_allocate(_S_rounded_up_size(__result_len));
818 	    __try
819 	      {	(*(__f->_M_fn))(__start, __result_len, __section); }
820 	    __catch(...)
821 	      {
822 		_RopeRep::__STL_FREE_STRING(__section, __result_len,
823 					    __base->_M_get_allocator());
824 		__throw_exception_again;
825 	      }
826 	    _S_cond_store_eos(__section[__result_len]);
827 	    return _S_new_RopeLeaf(__section, __result_len,
828 				   __base->_M_get_allocator());
829 	  }
830 	}
831     lazy:
832       {
833 	// Create substring node.
834 	return _S_new_RopeSubstring(__base, __start, __adj_endp1 - __start,
835 				    __base->_M_get_allocator());
836       }
837     }
838 
839   template<class _CharT>
840     class _Rope_flatten_char_consumer
841     : public _Rope_char_consumer<_CharT>
842     {
843     private:
844       _CharT* _M_buf_ptr;
845     public:
846 
847       _Rope_flatten_char_consumer(_CharT* __buffer)
848       { _M_buf_ptr = __buffer; };
849 
850       ~_Rope_flatten_char_consumer() {}
851 
852       bool
853       operator()(const _CharT* __leaf, size_t __n)
854       {
855 	uninitialized_copy_n(__leaf, __n, _M_buf_ptr);
856 	_M_buf_ptr += __n;
857 	return true;
858       }
859     };
860 
861   template<class _CharT>
862     class _Rope_find_char_char_consumer
863     : public _Rope_char_consumer<_CharT>
864     {
865     private:
866       _CharT _M_pattern;
867     public:
868       size_t _M_count;  // Number of nonmatching characters
869 
870       _Rope_find_char_char_consumer(_CharT __p)
871       : _M_pattern(__p), _M_count(0) {}
872 
873       ~_Rope_find_char_char_consumer() {}
874 
875       bool
876       operator()(const _CharT* __leaf, size_t __n)
877       {
878 	size_t __i;
879 	for (__i = 0; __i < __n; __i++)
880 	  {
881 	    if (__leaf[__i] == _M_pattern)
882 	      {
883 		_M_count += __i;
884 		return false;
885 	      }
886 	  }
887 	_M_count += __n; return true;
888       }
889     };
890 
891   template<class _CharT, class _Traits>
892   // Here _CharT is both the stream and rope character type.
893     class _Rope_insert_char_consumer
894     : public _Rope_char_consumer<_CharT>
895     {
896     private:
897       typedef basic_ostream<_CharT,_Traits> _Insert_ostream;
898       _Insert_ostream& _M_o;
899     public:
900       _Rope_insert_char_consumer(_Insert_ostream& __writer)
901 	: _M_o(__writer) {};
902       ~_Rope_insert_char_consumer() { };
903       // Caller is presumed to own the ostream
904       bool operator() (const _CharT* __leaf, size_t __n);
905       // Returns true to continue traversal.
906     };
907 
908   template<class _CharT, class _Traits>
909     bool
910     _Rope_insert_char_consumer<_CharT, _Traits>::
911     operator()(const _CharT* __leaf, size_t __n)
912     {
913       size_t __i;
914       //  We assume that formatting is set up correctly for each element.
915       for (__i = 0; __i < __n; __i++)
916 	_M_o.put(__leaf[__i]);
917       return true;
918     }
919 
920   template <class _CharT, class _Alloc>
921     bool
922     rope<_CharT, _Alloc>::
923     _S_apply_to_pieces(_Rope_char_consumer<_CharT>& __c,
924 		       const _RopeRep* __r, size_t __begin, size_t __end)
925     {
926       if (0 == __r)
927 	return true;
928       switch(__r->_M_tag)
929 	{
930 	case __detail::_S_concat:
931 	  {
932 	    _RopeConcatenation* __conc = (_RopeConcatenation*)__r;
933 	    _RopeRep* __left =  __conc->_M_left;
934 	    size_t __left_len = __left->_M_size;
935 	    if (__begin < __left_len)
936 	      {
937 		size_t __left_end = std::min(__left_len, __end);
938 		if (!_S_apply_to_pieces(__c, __left, __begin, __left_end))
939 		  return false;
940 	      }
941 	    if (__end > __left_len)
942 	      {
943 		_RopeRep* __right =  __conc->_M_right;
944 		size_t __right_start = std::max(__left_len, __begin);
945 		if (!_S_apply_to_pieces(__c, __right,
946 					__right_start - __left_len,
947 					__end - __left_len))
948 		  return false;
949 	      }
950 	  }
951 	  return true;
952 	case __detail::_S_leaf:
953 	  {
954 	    _RopeLeaf* __l = (_RopeLeaf*)__r;
955 	    return __c(__l->_M_data + __begin, __end - __begin);
956 	  }
957 	case __detail::_S_function:
958 	case __detail::_S_substringfn:
959 	    {
960 	      _RopeFunction* __f = (_RopeFunction*)__r;
961 	      size_t __len = __end - __begin;
962 	      bool __result;
963 	      _CharT* __buffer =
964 		(_CharT*)_Alloc().allocate(__len * sizeof(_CharT));
965 	      __try
966 		{
967 		  (*(__f->_M_fn))(__begin, __len, __buffer);
968 		  __result = __c(__buffer, __len);
969                   _Alloc().deallocate(__buffer, __len * sizeof(_CharT));
970                 }
971 	      __catch(...)
972 		{
973 		  _Alloc().deallocate(__buffer, __len * sizeof(_CharT));
974 		  __throw_exception_again;
975 		}
976 	      return __result;
977 	    }
978 	default:
979 	  return false;
980 	}
981     }
982 
983   template<class _CharT, class _Traits>
984     inline void
985     _Rope_fill(basic_ostream<_CharT, _Traits>& __o, size_t __n)
986     {
987       char __f = __o.fill();
988       size_t __i;
989 
990       for (__i = 0; __i < __n; __i++)
991 	__o.put(__f);
992     }
993 
994 
995   template <class _CharT>
996     inline bool
997     _Rope_is_simple(_CharT*)
998     { return false; }
999 
1000   inline bool
1001   _Rope_is_simple(char*)
1002   { return true; }
1003 
1004   inline bool
1005   _Rope_is_simple(wchar_t*)
1006   { return true; }
1007 
1008   template<class _CharT, class _Traits, class _Alloc>
1009     basic_ostream<_CharT, _Traits>&
1010     operator<<(basic_ostream<_CharT, _Traits>& __o,
1011 	       const rope<_CharT, _Alloc>& __r)
1012     {
1013       size_t __w = __o.width();
1014       bool __left = bool(__o.flags() & std::ios::left);
1015       size_t __pad_len;
1016       size_t __rope_len = __r.size();
1017       _Rope_insert_char_consumer<_CharT, _Traits> __c(__o);
1018       bool __is_simple = _Rope_is_simple((_CharT*)0);
1019 
1020       if (__rope_len < __w)
1021 	__pad_len = __w - __rope_len;
1022       else
1023 	__pad_len = 0;
1024 
1025       if (!__is_simple)
1026 	__o.width(__w / __rope_len);
1027       __try
1028 	{
1029 	  if (__is_simple && !__left && __pad_len > 0)
1030 	    _Rope_fill(__o, __pad_len);
1031 	  __r.apply_to_pieces(0, __r.size(), __c);
1032 	  if (__is_simple && __left && __pad_len > 0)
1033 	    _Rope_fill(__o, __pad_len);
1034 	  if (!__is_simple)
1035 	    __o.width(__w);
1036 	}
1037       __catch(...)
1038 	{
1039 	  if (!__is_simple)
1040 	    __o.width(__w);
1041 	  __throw_exception_again;
1042 	}
1043       return __o;
1044     }
1045 
1046   template <class _CharT, class _Alloc>
1047     _CharT*
1048     rope<_CharT, _Alloc>::
1049     _S_flatten(_RopeRep* __r, size_t __start, size_t __len,
1050 	       _CharT* __buffer)
1051     {
1052       _Rope_flatten_char_consumer<_CharT> __c(__buffer);
1053       _S_apply_to_pieces(__c, __r, __start, __start + __len);
1054       return(__buffer + __len);
1055     }
1056 
1057   template <class _CharT, class _Alloc>
1058     size_t
1059     rope<_CharT, _Alloc>::
1060     find(_CharT __pattern, size_t __start) const
1061     {
1062       _Rope_find_char_char_consumer<_CharT> __c(__pattern);
1063       _S_apply_to_pieces(__c, this->_M_tree_ptr, __start, size());
1064       size_type __result_pos = __start + __c._M_count;
1065 #ifndef __STL_OLD_ROPE_SEMANTICS
1066       if (__result_pos == size())
1067 	__result_pos = npos;
1068 #endif
1069       return __result_pos;
1070     }
1071 
1072   template <class _CharT, class _Alloc>
1073     _CharT*
1074     rope<_CharT, _Alloc>::
1075     _S_flatten(_RopeRep* __r, _CharT* __buffer)
1076     {
1077       if (0 == __r)
1078 	return __buffer;
1079       switch(__r->_M_tag)
1080 	{
1081 	case __detail::_S_concat:
1082 	  {
1083 	    _RopeConcatenation* __c = (_RopeConcatenation*)__r;
1084 	    _RopeRep* __left = __c->_M_left;
1085 	    _RopeRep* __right = __c->_M_right;
1086 	    _CharT* __rest = _S_flatten(__left, __buffer);
1087 	    return _S_flatten(__right, __rest);
1088 	  }
1089 	case __detail::_S_leaf:
1090 	  {
1091 	    _RopeLeaf* __l = (_RopeLeaf*)__r;
1092 	    return copy_n(__l->_M_data, __l->_M_size, __buffer).second;
1093 	  }
1094 	case __detail::_S_function:
1095 	case __detail::_S_substringfn:
1096 	  // We don't yet do anything with substring nodes.
1097 	  // This needs to be fixed before ropefiles will work well.
1098 	  {
1099 	    _RopeFunction* __f = (_RopeFunction*)__r;
1100 	    (*(__f->_M_fn))(0, __f->_M_size, __buffer);
1101 	    return __buffer + __f->_M_size;
1102 	  }
1103 	default:
1104 	  return 0;
1105 	}
1106     }
1107 
1108   // This needs work for _CharT != char
1109   template <class _CharT, class _Alloc>
1110     void
1111     rope<_CharT, _Alloc>::
1112     _S_dump(_RopeRep* __r, int __indent)
1113     {
1114       for (int __i = 0; __i < __indent; __i++)
1115 	putchar(' ');
1116       if (0 == __r)
1117 	{
1118 	  printf("NULL\n");
1119 	  return;
1120 	}
1121       if (_S_concat == __r->_M_tag)
1122 	{
1123 	  _RopeConcatenation* __c = (_RopeConcatenation*)__r;
1124 	  _RopeRep* __left = __c->_M_left;
1125 	  _RopeRep* __right = __c->_M_right;
1126 
1127 #ifdef __GC
1128 	  printf("Concatenation %p (depth = %d, len = %ld, %s balanced)\n",
1129 		 __r, __r->_M_depth, __r->_M_size,
1130 		 __r->_M_is_balanced? "" : "not");
1131 #else
1132 	  printf("Concatenation %p (rc = %ld, depth = %d, "
1133 		 "len = %ld, %s balanced)\n",
1134 		 __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size,
1135 		 __r->_M_is_balanced? "" : "not");
1136 #endif
1137 	  _S_dump(__left, __indent + 2);
1138 	  _S_dump(__right, __indent + 2);
1139 	  return;
1140 	}
1141       else
1142 	{
1143 	  char* __kind;
1144 
1145 	  switch (__r->_M_tag)
1146 	    {
1147 	    case __detail::_S_leaf:
1148 	      __kind = "Leaf";
1149 	      break;
1150 	    case __detail::_S_function:
1151 	      __kind = "Function";
1152 	      break;
1153 	    case __detail::_S_substringfn:
1154 	      __kind = "Function representing substring";
1155 	      break;
1156 	    default:
1157 	      __kind = "(corrupted kind field!)";
1158 	    }
1159 #ifdef __GC
1160 	  printf("%s %p (depth = %d, len = %ld) ",
1161 		 __kind, __r, __r->_M_depth, __r->_M_size);
1162 #else
1163 	  printf("%s %p (rc = %ld, depth = %d, len = %ld) ",
1164 		 __kind, __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size);
1165 #endif
1166 	  if (_S_is_one_byte_char_type((_CharT*)0))
1167 	    {
1168 	      const int __max_len = 40;
1169 	      _Self_destruct_ptr __prefix(_S_substring(__r, 0, __max_len));
1170 	      _CharT __buffer[__max_len + 1];
1171 	      bool __too_big = __r->_M_size > __prefix->_M_size;
1172 
1173 	      _S_flatten(__prefix, __buffer);
1174 	      __buffer[__prefix->_M_size] = _S_eos((_CharT*)0);
1175 	      printf("%s%s\n", (char*)__buffer,
1176 		     __too_big? "...\n" : "\n");
1177 	    }
1178 	  else
1179 	    printf("\n");
1180 	}
1181     }
1182 
1183   template <class _CharT, class _Alloc>
1184     const unsigned long
1185     rope<_CharT, _Alloc>::
1186     _S_min_len[int(__detail::_S_max_rope_depth) + 1] = {
1187       /* 0 */1, /* 1 */2, /* 2 */3, /* 3 */5, /* 4 */8, /* 5 */13, /* 6 */21,
1188       /* 7 */34, /* 8 */55, /* 9 */89, /* 10 */144, /* 11 */233, /* 12 */377,
1189       /* 13 */610, /* 14 */987, /* 15 */1597, /* 16 */2584, /* 17 */4181,
1190       /* 18 */6765, /* 19 */10946, /* 20 */17711, /* 21 */28657, /* 22 */46368,
1191       /* 23 */75025, /* 24 */121393, /* 25 */196418, /* 26 */317811,
1192       /* 27 */514229, /* 28 */832040, /* 29 */1346269, /* 30 */2178309,
1193       /* 31 */3524578, /* 32 */5702887, /* 33 */9227465, /* 34 */14930352,
1194       /* 35 */24157817, /* 36 */39088169, /* 37 */63245986, /* 38 */102334155,
1195       /* 39 */165580141, /* 40 */267914296, /* 41 */433494437,
1196       /* 42 */701408733, /* 43 */1134903170, /* 44 */1836311903,
1197       /* 45 */2971215073u };
1198   // These are Fibonacci numbers < 2**32.
1199 
1200   template <class _CharT, class _Alloc>
1201     typename rope<_CharT, _Alloc>::_RopeRep*
1202     rope<_CharT, _Alloc>::
1203     _S_balance(_RopeRep* __r)
1204     {
1205       _RopeRep* __forest[int(__detail::_S_max_rope_depth) + 1];
1206       _RopeRep* __result = 0;
1207       int __i;
1208       // Invariant:
1209       // The concatenation of forest in descending order is equal to __r.
1210       // __forest[__i]._M_size >= _S_min_len[__i]
1211       // __forest[__i]._M_depth = __i
1212       // References from forest are included in refcount.
1213 
1214       for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
1215 	__forest[__i] = 0;
1216       __try
1217 	{
1218 	  _S_add_to_forest(__r, __forest);
1219 	  for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
1220 	    if (0 != __forest[__i])
1221 	      {
1222 #ifndef __GC
1223 		_Self_destruct_ptr __old(__result);
1224 #endif
1225 		__result = _S_concat(__forest[__i], __result);
1226 		__forest[__i]->_M_unref_nonnil();
1227 #if !defined(__GC) && defined(__EXCEPTIONS)
1228 		__forest[__i] = 0;
1229 #endif
1230 	      }
1231 	}
1232       __catch(...)
1233 	{
1234 	  for(__i = 0; __i <= int(__detail::_S_max_rope_depth); __i++)
1235 	    _S_unref(__forest[__i]);
1236 	  __throw_exception_again;
1237 	}
1238 
1239       if (__result->_M_depth > int(__detail::_S_max_rope_depth))
1240 	__throw_length_error(__N("rope::_S_balance"));
1241       return(__result);
1242     }
1243 
1244   template <class _CharT, class _Alloc>
1245     void
1246     rope<_CharT, _Alloc>::
1247     _S_add_to_forest(_RopeRep* __r, _RopeRep** __forest)
1248     {
1249       if (__r->_M_is_balanced)
1250 	{
1251 	  _S_add_leaf_to_forest(__r, __forest);
1252 	  return;
1253 	}
1254 
1255       {
1256 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1257 
1258 	_S_add_to_forest(__c->_M_left, __forest);
1259 	_S_add_to_forest(__c->_M_right, __forest);
1260       }
1261     }
1262 
1263 
1264   template <class _CharT, class _Alloc>
1265     void
1266     rope<_CharT, _Alloc>::
1267     _S_add_leaf_to_forest(_RopeRep* __r, _RopeRep** __forest)
1268     {
1269       _RopeRep* __insertee;		// included in refcount
1270       _RopeRep* __too_tiny = 0;		// included in refcount
1271       int __i;				// forest[0..__i-1] is empty
1272       size_t __s = __r->_M_size;
1273 
1274       for (__i = 0; __s >= _S_min_len[__i+1]/* not this bucket */; ++__i)
1275 	{
1276 	  if (0 != __forest[__i])
1277 	    {
1278 #ifndef __GC
1279 	      _Self_destruct_ptr __old(__too_tiny);
1280 #endif
1281 	      __too_tiny = _S_concat_and_set_balanced(__forest[__i],
1282 						      __too_tiny);
1283 	      __forest[__i]->_M_unref_nonnil();
1284 	      __forest[__i] = 0;
1285 	    }
1286 	}
1287       {
1288 #ifndef __GC
1289 	_Self_destruct_ptr __old(__too_tiny);
1290 #endif
1291 	__insertee = _S_concat_and_set_balanced(__too_tiny, __r);
1292       }
1293       // Too_tiny dead, and no longer included in refcount.
1294       // Insertee is live and included.
1295       for (;; ++__i)
1296 	{
1297 	  if (0 != __forest[__i])
1298 	    {
1299 #ifndef __GC
1300 	      _Self_destruct_ptr __old(__insertee);
1301 #endif
1302 	      __insertee = _S_concat_and_set_balanced(__forest[__i],
1303 						      __insertee);
1304 	      __forest[__i]->_M_unref_nonnil();
1305 	      __forest[__i] = 0;
1306 	    }
1307 	  if (__i == int(__detail::_S_max_rope_depth)
1308 	      || __insertee->_M_size < _S_min_len[__i+1])
1309 	    {
1310 	      __forest[__i] = __insertee;
1311 	      // refcount is OK since __insertee is now dead.
1312 	      return;
1313 	    }
1314 	}
1315     }
1316 
1317   template <class _CharT, class _Alloc>
1318     _CharT
1319     rope<_CharT, _Alloc>::
1320     _S_fetch(_RopeRep* __r, size_type __i)
1321     {
1322       __GC_CONST _CharT* __cstr = __r->_M_c_string;
1323 
1324       if (0 != __cstr)
1325 	return __cstr[__i];
1326       for(;;)
1327 	{
1328 	  switch(__r->_M_tag)
1329 	    {
1330 	    case __detail::_S_concat:
1331 	      {
1332 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1333 		_RopeRep* __left = __c->_M_left;
1334 		size_t __left_len = __left->_M_size;
1335 
1336 		if (__i >= __left_len)
1337 		  {
1338 		    __i -= __left_len;
1339 		    __r = __c->_M_right;
1340 		  }
1341 		else
1342 		  __r = __left;
1343 	      }
1344 	      break;
1345 	    case __detail::_S_leaf:
1346 	      {
1347 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1348 		return __l->_M_data[__i];
1349 	      }
1350 	    case __detail::_S_function:
1351 	    case __detail::_S_substringfn:
1352 	      {
1353 		_RopeFunction* __f = (_RopeFunction*)__r;
1354 		_CharT __result;
1355 
1356 		(*(__f->_M_fn))(__i, 1, &__result);
1357 		return __result;
1358 	      }
1359 	    }
1360 	}
1361     }
1362 
1363 #ifndef __GC
1364   // Return a uniquely referenced character slot for the given
1365   // position, or 0 if that's not possible.
1366   template <class _CharT, class _Alloc>
1367     _CharT*
1368     rope<_CharT, _Alloc>::
1369     _S_fetch_ptr(_RopeRep* __r, size_type __i)
1370     {
1371       _RopeRep* __clrstack[__detail::_S_max_rope_depth];
1372       size_t __csptr = 0;
1373 
1374       for(;;)
1375 	{
1376 	  if (__r->_M_ref_count > 1)
1377 	    return 0;
1378 	  switch(__r->_M_tag)
1379 	    {
1380 	    case __detail::_S_concat:
1381 	      {
1382 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
1383 		_RopeRep* __left = __c->_M_left;
1384 		size_t __left_len = __left->_M_size;
1385 
1386 		if (__c->_M_c_string != 0)
1387 		  __clrstack[__csptr++] = __c;
1388 		if (__i >= __left_len)
1389 		  {
1390 		    __i -= __left_len;
1391 		    __r = __c->_M_right;
1392 		  }
1393 		else
1394 		  __r = __left;
1395 	      }
1396 	      break;
1397 	    case __detail::_S_leaf:
1398 	      {
1399 		_RopeLeaf* __l = (_RopeLeaf*)__r;
1400 		if (__l->_M_c_string != __l->_M_data && __l->_M_c_string != 0)
1401 		  __clrstack[__csptr++] = __l;
1402 		while (__csptr > 0)
1403 		  {
1404 		    -- __csptr;
1405 		    _RopeRep* __d = __clrstack[__csptr];
1406 		    __d->_M_free_c_string();
1407 		    __d->_M_c_string = 0;
1408 		  }
1409 		return __l->_M_data + __i;
1410 	      }
1411 	    case __detail::_S_function:
1412 	    case __detail::_S_substringfn:
1413 	      return 0;
1414 	    }
1415 	}
1416     }
1417 #endif /* __GC */
1418 
1419   // The following could be implemented trivially using
1420   // lexicographical_compare_3way.
1421   // We do a little more work to avoid dealing with rope iterators for
1422   // flat strings.
1423   template <class _CharT, class _Alloc>
1424     int
1425     rope<_CharT, _Alloc>::
1426     _S_compare (const _RopeRep* __left, const _RopeRep* __right)
1427     {
1428       size_t __left_len;
1429       size_t __right_len;
1430 
1431       if (0 == __right)
1432 	return 0 != __left;
1433       if (0 == __left)
1434 	return -1;
1435       __left_len = __left->_M_size;
1436       __right_len = __right->_M_size;
1437       if (__detail::_S_leaf == __left->_M_tag)
1438 	{
1439 	  _RopeLeaf* __l = (_RopeLeaf*) __left;
1440 	  if (__detail::_S_leaf == __right->_M_tag)
1441 	    {
1442 	      _RopeLeaf* __r = (_RopeLeaf*) __right;
1443 	      return lexicographical_compare_3way(__l->_M_data,
1444 						  __l->_M_data + __left_len,
1445 						  __r->_M_data, __r->_M_data
1446 						  + __right_len);
1447 	    }
1448 	  else
1449 	    {
1450 	      const_iterator __rstart(__right, 0);
1451 	      const_iterator __rend(__right, __right_len);
1452 	      return lexicographical_compare_3way(__l->_M_data, __l->_M_data
1453 						  + __left_len,
1454 						  __rstart, __rend);
1455 	    }
1456 	}
1457       else
1458 	{
1459 	  const_iterator __lstart(__left, 0);
1460 	  const_iterator __lend(__left, __left_len);
1461 	  if (__detail::_S_leaf == __right->_M_tag)
1462 	    {
1463 	      _RopeLeaf* __r = (_RopeLeaf*) __right;
1464 	      return lexicographical_compare_3way(__lstart, __lend,
1465 						  __r->_M_data, __r->_M_data
1466 						  + __right_len);
1467 	    }
1468 	  else
1469 	    {
1470 	      const_iterator __rstart(__right, 0);
1471 	      const_iterator __rend(__right, __right_len);
1472 	      return lexicographical_compare_3way(__lstart, __lend,
1473 						  __rstart, __rend);
1474 	    }
1475 	}
1476     }
1477 
1478   // Assignment to reference proxies.
1479   template <class _CharT, class _Alloc>
1480     _Rope_char_ref_proxy<_CharT, _Alloc>&
1481     _Rope_char_ref_proxy<_CharT, _Alloc>::
1482     operator=(_CharT __c)
1483     {
1484       _RopeRep* __old = _M_root->_M_tree_ptr;
1485 #ifndef __GC
1486       // First check for the case in which everything is uniquely
1487       // referenced.  In that case we can do this destructively.
1488       _CharT* __ptr = _My_rope::_S_fetch_ptr(__old, _M_pos);
1489       if (0 != __ptr)
1490 	{
1491 	  *__ptr = __c;
1492 	  return *this;
1493 	}
1494 #endif
1495       _Self_destruct_ptr __left(_My_rope::_S_substring(__old, 0, _M_pos));
1496       _Self_destruct_ptr __right(_My_rope::_S_substring(__old, _M_pos + 1,
1497 							__old->_M_size));
1498       _Self_destruct_ptr __result_left(_My_rope::
1499 				       _S_destr_concat_char_iter(__left,
1500 								 &__c, 1));
1501 
1502       _RopeRep* __result = _My_rope::_S_concat(__result_left, __right);
1503 #ifndef __GC
1504       _RopeRep::_S_unref(__old);
1505 #endif
1506       _M_root->_M_tree_ptr = __result;
1507       return *this;
1508     }
1509 
1510   template <class _CharT, class _Alloc>
1511     inline _Rope_char_ref_proxy<_CharT, _Alloc>::
1512     operator _CharT() const
1513     {
1514       if (_M_current_valid)
1515 	return _M_current;
1516       else
1517 	return _My_rope::_S_fetch(_M_root->_M_tree_ptr, _M_pos);
1518     }
1519 
1520   template <class _CharT, class _Alloc>
1521     _Rope_char_ptr_proxy<_CharT, _Alloc>
1522     _Rope_char_ref_proxy<_CharT, _Alloc>::
1523     operator&() const
1524     { return _Rope_char_ptr_proxy<_CharT, _Alloc>(*this); }
1525 
1526   template <class _CharT, class _Alloc>
1527     rope<_CharT, _Alloc>::
1528     rope(size_t __n, _CharT __c, const allocator_type& __a)
1529     : _Base(__a)
1530     {
1531       rope<_CharT,_Alloc> __result;
1532       const size_t __exponentiate_threshold = 32;
1533       size_t __exponent;
1534       size_t __rest;
1535       _CharT* __rest_buffer;
1536       _RopeRep* __remainder;
1537       rope<_CharT, _Alloc> __remainder_rope;
1538 
1539       if (0 == __n)
1540 	return;
1541 
1542       __exponent = __n / __exponentiate_threshold;
1543       __rest = __n % __exponentiate_threshold;
1544       if (0 == __rest)
1545 	__remainder = 0;
1546       else
1547 	{
1548 	  __rest_buffer = this->_Data_allocate(_S_rounded_up_size(__rest));
1549 	  __uninitialized_fill_n_a(__rest_buffer, __rest, __c,
1550 				   _M_get_allocator());
1551 	  _S_cond_store_eos(__rest_buffer[__rest]);
1552 	  __try
1553 	    { __remainder = _S_new_RopeLeaf(__rest_buffer, __rest,
1554 					    _M_get_allocator()); }
1555 	  __catch(...)
1556 	    {
1557 	      _RopeRep::__STL_FREE_STRING(__rest_buffer, __rest,
1558 					  _M_get_allocator());
1559 	      __throw_exception_again;
1560 	    }
1561 	}
1562       __remainder_rope._M_tree_ptr = __remainder;
1563       if (__exponent != 0)
1564 	{
1565 	  _CharT* __base_buffer =
1566 	    this->_Data_allocate(_S_rounded_up_size(__exponentiate_threshold));
1567 	  _RopeLeaf* __base_leaf;
1568 	  rope __base_rope;
1569 	  __uninitialized_fill_n_a(__base_buffer, __exponentiate_threshold, __c,
1570 				   _M_get_allocator());
1571 	  _S_cond_store_eos(__base_buffer[__exponentiate_threshold]);
1572 	  __try
1573 	    {
1574 	      __base_leaf = _S_new_RopeLeaf(__base_buffer,
1575 					    __exponentiate_threshold,
1576 					    _M_get_allocator());
1577 	    }
1578 	  __catch(...)
1579 	    {
1580 	      _RopeRep::__STL_FREE_STRING(__base_buffer,
1581 					  __exponentiate_threshold,
1582 					  _M_get_allocator());
1583 	      __throw_exception_again;
1584 	    }
1585 	  __base_rope._M_tree_ptr = __base_leaf;
1586 	  if (1 == __exponent)
1587 	    __result = __base_rope;
1588 	  else
1589 	    __result = power(__base_rope, __exponent,
1590 			     _Rope_Concat_fn<_CharT, _Alloc>());
1591 
1592 	  if (0 != __remainder)
1593 	    __result += __remainder_rope;
1594 	}
1595       else
1596 	__result = __remainder_rope;
1597 
1598       this->_M_tree_ptr = __result._M_tree_ptr;
1599       this->_M_tree_ptr->_M_ref_nonnil();
1600     }
1601 
1602   template<class _CharT, class _Alloc>
1603     _CharT
1604     rope<_CharT, _Alloc>::_S_empty_c_str[1];
1605 
1606   template<class _CharT, class _Alloc>
1607     const _CharT*
1608     rope<_CharT, _Alloc>::
1609     c_str() const
1610     {
1611       if (0 == this->_M_tree_ptr)
1612 	{
1613 	  _S_empty_c_str[0] = _S_eos((_CharT*)0);  // Possibly redundant,
1614 	                                           // but probably fast.
1615 	  return _S_empty_c_str;
1616 	}
1617       __gthread_mutex_lock (&this->_M_tree_ptr->_M_c_string_lock);
1618       __GC_CONST _CharT* __result = this->_M_tree_ptr->_M_c_string;
1619       if (0 == __result)
1620 	{
1621 	  size_t __s = size();
1622 	  __result = this->_Data_allocate(__s + 1);
1623 	  _S_flatten(this->_M_tree_ptr, __result);
1624 	  __result[__s] = _S_eos((_CharT*)0);
1625 	  this->_M_tree_ptr->_M_c_string = __result;
1626 	}
1627       __gthread_mutex_unlock (&this->_M_tree_ptr->_M_c_string_lock);
1628       return(__result);
1629     }
1630 
1631   template<class _CharT, class _Alloc>
1632     const _CharT* rope<_CharT, _Alloc>::
1633     replace_with_c_str()
1634     {
1635       if (0 == this->_M_tree_ptr)
1636 	{
1637 	  _S_empty_c_str[0] = _S_eos((_CharT*)0);
1638 	  return _S_empty_c_str;
1639 	}
1640       __GC_CONST _CharT* __old_c_string = this->_M_tree_ptr->_M_c_string;
1641       if (__detail::_S_leaf == this->_M_tree_ptr->_M_tag
1642 	  && 0 != __old_c_string)
1643 	return(__old_c_string);
1644       size_t __s = size();
1645       _CharT* __result = this->_Data_allocate(_S_rounded_up_size(__s));
1646       _S_flatten(this->_M_tree_ptr, __result);
1647       __result[__s] = _S_eos((_CharT*)0);
1648       this->_M_tree_ptr->_M_unref_nonnil();
1649       this->_M_tree_ptr = _S_new_RopeLeaf(__result, __s,
1650 					  this->_M_get_allocator());
1651       return(__result);
1652     }
1653 
1654   // Algorithm specializations.  More should be added.
1655 
1656   template<class _Rope_iterator>  // was templated on CharT and Alloc
1657     void		          // VC++ workaround
1658     _Rope_rotate(_Rope_iterator __first,
1659 		 _Rope_iterator __middle,
1660 		 _Rope_iterator __last)
1661     {
1662       typedef typename _Rope_iterator::value_type _CharT;
1663       typedef typename _Rope_iterator::_allocator_type _Alloc;
1664 
1665       rope<_CharT, _Alloc>& __r(__first.container());
1666       rope<_CharT, _Alloc> __prefix = __r.substr(0, __first.index());
1667       rope<_CharT, _Alloc> __suffix =
1668 	__r.substr(__last.index(), __r.size() - __last.index());
1669       rope<_CharT, _Alloc> __part1 =
1670 	__r.substr(__middle.index(), __last.index() - __middle.index());
1671       rope<_CharT, _Alloc> __part2 =
1672 	__r.substr(__first.index(), __middle.index() - __first.index());
1673       __r = __prefix;
1674       __r += __part1;
1675       __r += __part2;
1676       __r += __suffix;
1677     }
1678 
1679 #if !defined(__GNUC__)
1680   // Appears to confuse g++
1681   inline void
1682   rotate(_Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __first,
1683 	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __middle,
1684 	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __last)
1685   { _Rope_rotate(__first, __middle, __last); }
1686 #endif
1687 
1688 # if 0
1689   // Probably not useful for several reasons:
1690   // - for SGIs 7.1 compiler and probably some others,
1691   //   this forces lots of rope<wchar_t, ...> instantiations, creating a
1692   //   code bloat and compile time problem.  (Fixed in 7.2.)
1693   // - wchar_t is 4 bytes wide on most UNIX platforms, making it
1694   //   unattractive for unicode strings.  Unsigned short may be a better
1695   //   character type.
1696   inline void
1697   rotate(_Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __first,
1698 	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __middle,
1699 	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __last)
1700   { _Rope_rotate(__first, __middle, __last); }
1701 # endif
1702 
1703 _GLIBCXX_END_NAMESPACE_VERSION
1704 } // namespace
1705