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
52namespace __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	    _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	    _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	    _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	    _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	_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	      _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	      _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