/*

  * © Portions copyright (c) 2006-2007 Nokia Corporation.  All rights reserved.

  * Copyright (c) 1996,1997

  * Silicon Graphics Computer Systems, Inc.

  *

  * Copyright (c) 1999 

  * Boris Fomitchev

  *

  * This material is provided "as is", with absolutely no warranty expressed

  * or implied. Any use is at your own risk.

  *

  * Permission to use or copy this software for any purpose is hereby granted 

  * without fee, provided the above notices are retained on all copies.

  * Permission to modify the code and to distribute modified code is granted,

  * provided the above notices are retained, and a notice that the code was

  * modified is included with the above copyright notice.

  *

  */

 /* NOTE: This is an internal header file, included by other STL headers.

  *   You should not attempt to use it directly.

  */

 // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf

 // if necessary.  Assumes path_end[leaf_index] and leaf_pos are correct.

 // Results in a valid buf_ptr if the iterator can be legitimately

 // dereferenced.

 # ifndef _STLP_ROPEIMPL_H

 # define _STLP_ROPEIMPL_H

 #ifndef _STLP_INTERNAL_ROPE_H

 # include <stl/_rope.h>

 #endif

 # ifndef _STLP_CSTDIO

 #  include <cstdio>

 # endif

 #ifndef _STLP_IOSTREAM

 # include <iostream>

 #endif

 # include <stl/_range_errors.h>

 _STLP_BEGIN_NAMESPACE

 # if defined ( _STLP_NESTED_TYPE_PARAM_BUG )

 # define __allocator__ _Alloc

 # else

 # define __allocator__ allocator_type

 # endif

 template<class _CharT, class _Alloc>

 _Rope_iterator<_CharT, _Alloc>::_Rope_iterator(rope<_CharT,_Alloc>* __r, size_t __pos)

   : _Rope_iterator_base<_CharT,_Alloc>(__r->_M_tree_ptr._M_data, __pos),

   _M_root_rope(__r) { _RopeRep::_S_ref(this->_M_root); }

 template<class _CharT, class _Alloc>

 _Rope_iterator<_CharT, _Alloc>::_Rope_iterator(rope<_CharT,_Alloc>& __r, size_t __pos): 

   _Rope_iterator_base<_CharT,_Alloc>(__r._M_tree_ptr._M_data, __pos), 

   _M_root_rope(&__r) {

   _RopeRep::_S_ref(this->_M_root); if (!(__r.empty()))_S_setcache(*this);

 }

 template<class _CharT, class _Alloc>

 void 

 _Rope_RopeRep<_CharT, _Alloc>::_M_free_c_string()

 {

   _CharT* __cstr = _M_c_string;

   if (0 != __cstr) {

     size_t _p_size = _M_size._M_data + 1;

     _STLP_STD::_Destroy(__cstr, __cstr + _p_size);

     _M_size.deallocate(__cstr, _p_size);

   }

 }

 // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf

 // if necessary.  Assumes _M_path_end[leaf_index] and leaf_pos are correct.

 // Results in a valid buf_ptr if the iterator can be legitimately

 // dereferenced.

 template <class _CharT, class _Alloc>

 void _Rope_iterator_base<_CharT,_Alloc>::_S_setbuf( 

   _Rope_iterator_base<_CharT,_Alloc>& __x)

 {

     const _RopeRep* __leaf = __x._M_path_end[__x._M_leaf_index];

     size_t __leaf_pos = __x._M_leaf_pos;

     size_t __pos = __x._M_current_pos;

     switch(__leaf->_M_tag) {

 	case _RopeRep::_S_leaf:

 	    __x._M_buf_start = 

 	      ((_Rope_RopeLeaf<_CharT,_Alloc>*)__leaf)->_M_data;

 	    __x._M_buf_ptr = __x._M_buf_start + (__pos - __leaf_pos);

 	    __x._M_buf_end = __x._M_buf_start + __leaf->_M_size._M_data;

 	    break;

 	case _RopeRep::_S_function:

 	case _RopeRep::_S_substringfn:

 	    {

 		size_t __len = _S_iterator_buf_len;

 		size_t __buf_start_pos = __leaf_pos;

 		size_t __leaf_end = __leaf_pos + __leaf->_M_size._M_data;

 		char_producer<_CharT>* __fn =

 			((_Rope_RopeFunction<_CharT,_Alloc>*)__leaf)->_M_fn;

 		if (__buf_start_pos + __len <= __pos) {

 		    __buf_start_pos = __pos - __len/4;

 		    if (__buf_start_pos + __len > __leaf_end) {

 			__buf_start_pos = __leaf_end - __len;

 		    }

 		}

 		if (__buf_start_pos + __len > __leaf_end) {

 		    __len = __leaf_end - __buf_start_pos;

 		}

 		(*__fn)(__buf_start_pos - __leaf_pos, __len, __x._M_tmp_buf);

 		__x._M_buf_ptr = __x._M_tmp_buf + (__pos - __buf_start_pos);

 		__x._M_buf_start = __x._M_tmp_buf;

 		__x._M_buf_end = __x._M_tmp_buf + __len;

 	    }

 	    break;

 	default:

       _STLP_ASSERT(0)

         ;

     }

 }

 // Set path and buffer inside a rope iterator.  We assume that 

 // pos and root are already set.

 template <class _CharT, class _Alloc>

 void _Rope_iterator_base<_CharT,_Alloc>::_S_setcache

 (_Rope_iterator_base<_CharT,_Alloc>& __x)

 {

     const _RopeRep* __path[_RopeRep::_S_max_rope_depth+1];

     const _RopeRep* __curr_rope;

     int __curr_depth = -1;  /* index into path    */

     size_t __curr_start_pos = 0;

     size_t __pos = __x._M_current_pos;

     unsigned char __dirns = 0; // Bit vector marking right turns in the path

     _STLP_ASSERT(__pos <= __x._M_root->_M_size._M_data)

     if (__pos >= __x._M_root->_M_size._M_data) {

 	__x._M_buf_ptr = 0;

 	return;

     }

     __curr_rope = __x._M_root;

     if (0 != __curr_rope->_M_c_string) {

 	/* Treat the root as a leaf. */

 	__x._M_buf_start = __curr_rope->_M_c_string;

 	__x._M_buf_end = __curr_rope->_M_c_string + __curr_rope->_M_size._M_data;

 	__x._M_buf_ptr = __curr_rope->_M_c_string + __pos;

 	__x._M_path_end[0] = __curr_rope;

 	__x._M_leaf_index = 0;

 	__x._M_leaf_pos = 0;

 	return;

     }

     for(;;) {

 	++__curr_depth;

 	_STLP_ASSERT(__curr_depth <= _RopeRep::_S_max_rope_depth)

 	__path[__curr_depth] = __curr_rope;

 	switch(__curr_rope->_M_tag) {

 	  case _RopeRep::_S_leaf:

 	  case _RopeRep::_S_function:

 	  case _RopeRep::_S_substringfn:

 	    __x._M_leaf_pos = __curr_start_pos;

 	    goto done;

 	  case _RopeRep::_S_concat:

 	    {

 		_Rope_RopeConcatenation<_CharT,_Alloc>* __c =

 			(_Rope_RopeConcatenation<_CharT,_Alloc>*)__curr_rope;

 		_RopeRep* __left = __c->_M_left;

 		size_t __left_len = __left->_M_size._M_data;

 		__dirns <<= 1;

 		if (__pos >= __curr_start_pos + __left_len) {

 		    __dirns |= 1;

 		    __curr_rope = __c->_M_right;

 		    __curr_start_pos += __left_len;

 		} else {

 		    __curr_rope = __left;

 		}

 	    }

 	    break;

 	}

     }

   done:

     // Copy last section of path into _M_path_end.

       {

 	int __i = -1;

 	int __j = __curr_depth + 1 - _S_path_cache_len;

 	if (__j < 0) __j = 0;

 	while (__j <= __curr_depth) {

 	    __x._M_path_end[++__i] = __path[__j++];

 	}

 	__x._M_leaf_index = __i;

       }

       __x._M_path_directions = __dirns;

       _S_setbuf(__x);

 }

 // Specialized version of the above.  Assumes that

 // the path cache is valid for the previous position.

 template <class _CharT, class _Alloc>

 void _Rope_iterator_base<_CharT,_Alloc>::_S_setcache_for_incr

 (_Rope_iterator_base<_CharT,_Alloc>& __x)

 {

     int __current_index = __x._M_leaf_index;

     const _RopeRep* __current_node = __x._M_path_end[__current_index];

     size_t __len = __current_node->_M_size._M_data;

     size_t __node_start_pos = __x._M_leaf_pos;

     unsigned char __dirns = __x._M_path_directions;

     _Rope_RopeConcatenation<_CharT,_Alloc>* __c;

     _STLP_ASSERT(__x._M_current_pos <= __x._M_root->_M_size._M_data)

     if (__x._M_current_pos - __node_start_pos < __len) {

 	/* More stuff in this leaf, we just didn't cache it. */

 	_S_setbuf(__x);

 	return;

     }

     _STLP_ASSERT(__node_start_pos + __len == __x._M_current_pos)

     //  node_start_pos is starting position of last_node.

     while (--__current_index >= 0) {

 	if (!(__dirns & 1) /* Path turned left */) 

 	  break;

 	__current_node = __x._M_path_end[__current_index];

 	__c = (_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node;

 	// Otherwise we were in the right child.  Thus we should pop

 	// the concatenation node.

 	__node_start_pos -= __c->_M_left->_M_size._M_data;

 	__dirns >>= 1;

     }

     if (__current_index < 0) {

 	// We underflowed the cache. Punt.

 	_S_setcache(__x);

 	return;

     }

     __current_node = __x._M_path_end[__current_index];

     __c = (_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node;

     // current_node is a concatenation node.  We are positioned on the first

     // character in its right child.

     // node_start_pos is starting position of current_node.

     __node_start_pos += __c->_M_left->_M_size._M_data;

     __current_node = __c->_M_right;

     __x._M_path_end[++__current_index] = __current_node;

     __dirns |= 1;

     while (_RopeRep::_S_concat == __current_node->_M_tag) {

 	++__current_index;

 	if (_S_path_cache_len == __current_index) {

 	    int __i;

 	    for (__i = 0; __i < _S_path_cache_len-1; __i++) {

 		__x._M_path_end[__i] = __x._M_path_end[__i+1];

 	    }

 	    --__current_index;

 	}

 	__current_node =

 	    ((_Rope_RopeConcatenation<_CharT,_Alloc>*)__current_node)->_M_left;

 	__x._M_path_end[__current_index] = __current_node;

 	__dirns <<= 1;

 	// node_start_pos is unchanged.

     }

     __x._M_leaf_index = __current_index;

     __x._M_leaf_pos = __node_start_pos;

     __x._M_path_directions = __dirns;

     _S_setbuf(__x);

 }

 template <class _CharT, class _Alloc>

 void _Rope_iterator_base<_CharT,_Alloc>::_M_incr(size_t __n) {

     _M_current_pos += __n;

     if (0 != _M_buf_ptr) {

         size_t __chars_left = _M_buf_end - _M_buf_ptr;

         if (__chars_left > __n) {

             _M_buf_ptr += __n;

         } else if (__chars_left == __n) {

             _M_buf_ptr += __n;

             _S_setcache_for_incr(*this);

         } else {

             _M_buf_ptr = 0;

         }

     }

 }

 template <class _CharT, class _Alloc>

 void _Rope_iterator_base<_CharT,_Alloc>::_M_decr(size_t __n) {

     if (0 != _M_buf_ptr) {

         size_t __chars_left = _M_buf_ptr - _M_buf_start;

         if (__chars_left >= __n) {

             _M_buf_ptr -= __n;

         } else {

             _M_buf_ptr = 0;

         }

     }

     _M_current_pos -= __n;

 }

 template <class _CharT, class _Alloc>

 void _Rope_iterator<_CharT,_Alloc>::_M_check() {

     if (_M_root_rope->_M_tree_ptr._M_data != this->_M_root) {

         // _Rope was modified.  Get things fixed up.

         _RopeRep::_S_unref(this->_M_root);

         this->_M_root = _M_root_rope->_M_tree_ptr._M_data;

         _RopeRep::_S_ref(this->_M_root);

         this->_M_buf_ptr = 0;

     }

 }

 # ifndef _GC

 //  There are several reasons for not doing this with virtual destructors

 //  and a class specific delete operator:

 //  - A class specific delete operator can't easily get access to

 //    allocator instances if we need them.

 //  - Any virtual function would need a 4 or byte vtable pointer;

 //    this only requires a one byte tag per object.

 template <class _CharT, class _Alloc>

 void _Rope_RopeRep<_CharT,_Alloc>::_M_free_tree()

 {

     switch(_M_tag) {

 	case _S_leaf:

 	    {

 	      typedef _Rope_RopeLeaf<_CharT,_Alloc> _Rope_RopeLeaf_T;

           _Rope_RopeLeaf_T* __l = (_Rope_RopeLeaf_T*)this;

           _STLP_STD::_Destroy(__l); // ->_Rope_RopeLeaf<_CharT,_Alloc>::~_Rope_RopeLeaf();

 	      _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_size, _Rope_RopeLeaf_T).deallocate(__l, 1);

 	        break;

 	    }

 	case _S_concat:

 	    {

                typedef _Rope_RopeConcatenation<_CharT,_Alloc> _Rope_RopeConcatenation_T;

                _Rope_RopeConcatenation_T* __c  = (_Rope_RopeConcatenation_T*)this;

                _STLP_STD::_Destroy(__c);

                _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_size, 

                                _Rope_RopeConcatenation_T).deallocate(__c, 1);

 	        break;

 	    }

 	case _S_function:

 	    {

             typedef _Rope_RopeFunction<_CharT,_Alloc> _Rope_RopeFunctionT;

               _Rope_RopeFunctionT* __f = (_Rope_RopeFunctionT*)this;

               _STLP_STD::_Destroy(__f);

               _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_size, 

                                  _Rope_RopeFunctionT).deallocate(__f, 1);

 	        break;

 	    }

 	case _S_substringfn:

 	    {

             typedef _Rope_RopeSubstring<_CharT,_Alloc> _Rope_RopeSubstring_T;

               _Rope_RopeSubstring_T* __ss = (_Rope_RopeSubstring_T*)this;

               _STLP_STD::_Destroy(__ss);

               _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_size, 

                               _Rope_RopeSubstring_T).deallocate(__ss, 1);

 		break;

 	    }

     }

 }

 #endif

 # if defined ( _STLP_NESTED_TYPE_PARAM_BUG )

 #   define __RopeLeaf__ _Rope_RopeLeaf<_CharT,_Alloc>

 #   define __RopeRep__ _Rope_RopeRep<_CharT,_Alloc>

 #   define _RopeLeaf _Rope_RopeLeaf<_CharT,_Alloc>

 #   define _RopeRep _Rope_RopeRep<_CharT,_Alloc>

 #   define size_type size_t

 # else

 #   define __RopeLeaf__ _STLP_TYPENAME_ON_RETURN_TYPE rope<_CharT,_Alloc>::_RopeLeaf

 #   define __RopeRep__ _STLP_TYPENAME_ON_RETURN_TYPE rope<_CharT,_Alloc>::_RopeRep

 # endif

 // Concatenate a C string onto a leaf rope by copying the rope data.

 // Used for short ropes.

 template <class _CharT, class _Alloc>

 __RopeLeaf__*

 rope<_CharT,_Alloc>::_S_leaf_concat_char_iter

 		(_RopeLeaf* __r, const _CharT* __iter, size_t __len)

 {

     size_t __old_len = __r->_M_size._M_data;

     _CharT* __new_data = __r->_M_size.allocate(_S_rounded_up_size(__old_len + __len));

     _RopeLeaf* __result;

     uninitialized_copy_n(__r->_M_data, __old_len, __new_data);

     uninitialized_copy_n(__iter, __len, __new_data + __old_len);

     _S_cond_store_eos(__new_data[__old_len + __len]);

     _STLP_TRY {

 	__result = _S_new_RopeLeaf(__new_data, __old_len + __len,

 				   __r->get_allocator());

     }

     _STLP_UNWIND(_RopeRep::_S_free_string(__new_data, __old_len + __len,

 					     __r->get_allocator()));

     return __result;

 }

 #ifndef __GC

 // As above, but it's OK to clobber original if refcount is 1

 template <class _CharT, class _Alloc>

 __RopeLeaf__*

 rope<_CharT,_Alloc>::_S_destr_leaf_concat_char_iter

 		(_RopeLeaf* __r, const _CharT* __iter, size_t __len)

 {

     _STLP_ASSERT(__r->_M_ref_count >= 1)

     if (__r->_M_ref_count > 1)

       return _S_leaf_concat_char_iter(__r, __iter, __len);

     size_t __old_len = __r->_M_size._M_data;

     if (_S_allocated_capacity(__old_len) >= __old_len + __len) {

 	// The space has been partially initialized for the standard

 	// character types.  But that doesn't matter for those types.

 	uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);

 	if (_S_is_basic_char_type((_CharT*)0)) {

 	    _S_cond_store_eos(__r->_M_data[__old_len + __len]);

 	    _STLP_ASSERT(__r->_M_c_string == __r->_M_data)

 	} else if (__r->_M_c_string != __r->_M_data && 0 != __r->_M_c_string) {

 	    __r->_M_free_c_string();

 	    __r->_M_c_string = 0;

 	}

 	__r->_M_size._M_data = __old_len + __len;

 	_STLP_ASSERT(__r->_M_ref_count == 1)

 	__r->_M_ref_count = 2;

 	return __r;

     } else {

 	_RopeLeaf* __result = _S_leaf_concat_char_iter(__r, __iter, __len);

 	_STLP_ASSERT(__result->_M_ref_count == 1)

 	return __result;

     }

 }

 #endif

 // Assumes left and right are not 0.

 // Does not increment (nor decrement on exception) child reference counts.

 // Result has ref count 1.

 template <class _CharT, class _Alloc>

 __RopeRep__*

 rope<_CharT,_Alloc>::_S_tree_concat (_RopeRep* __left, _RopeRep* __right)

 {

     _RopeConcatenation* __result =

       _S_new_RopeConcatenation(__left, __right, __left->get_allocator());

     size_t __depth = __result->_M_depth;

     _STLP_ASSERT(__left->get_allocator() == __right->get_allocator())

     if (__depth > 20 && (__result->_M_size._M_data < 1000 ||

 			 __depth > _RopeRep::_S_max_rope_depth)) {

         _RopeRep* __balanced;

 	_STLP_TRY {

 	   __balanced = _S_balance(__result);

 #          ifndef __GC

 	     if (__result != __balanced) {

 		_STLP_ASSERT(1 == __result->_M_ref_count

 			     && 1 == __balanced->_M_ref_count)

 	     }

 #          endif

 	   __result->_M_unref_nonnil();

         }

       _STLP_UNWIND((_STLP_CREATE_ALLOCATOR(allocator_type,(allocator_type&)__left->_M_size,

                                     _RopeConcatenation).deallocate(__result,1)));

 		// In case of exception, we need to deallocate

 		// otherwise dangling result node.  But caller

 		// still owns its children.  Thus unref is

 		// inappropriate.

 	return __balanced;

     } else {

 	return __result;

     }

 }

 template <class _CharT, class _Alloc>

 __RopeRep__*

 rope<_CharT,_Alloc>::_S_concat_char_iter

 		(_RopeRep* __r, const _CharT*__s, size_t __slen)

 {

     _RopeRep* __result;

     if (0 == __slen) {

 	_S_ref(__r);

 	return __r;

     }

     if (0 == __r)

       return _STLP_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,

 					      /* __r->get_allocator()*/ allocator_type() );

     if (_RopeRep::_S_leaf == __r->_M_tag && 

           __r->_M_size._M_data + __slen <= _S_copy_max) {

 	__result = _S_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);

 #       ifndef __GC

 	  _STLP_ASSERT(1 == __result->_M_ref_count)

 #       endif

 	return __result;

     }

     if (_RopeRep::_S_concat == __r->_M_tag

 	&& _RopeRep::_S_leaf == ((_RopeConcatenation*)__r)->_M_right->_M_tag) {

 	_RopeLeaf* __right = 

 	  (_RopeLeaf* )(((_RopeConcatenation* )__r)->_M_right);

 	if (__right->_M_size._M_data + __slen <= _S_copy_max) {

 	  _RopeRep* __left = ((_RopeConcatenation*)__r)->_M_left;

 	  _RopeRep* __nright = 

 	    _S_leaf_concat_char_iter((_RopeLeaf*)__right, __s, __slen);

 	  __left->_M_ref_nonnil();

 	  _STLP_TRY {

 	    __result = _S_tree_concat(__left, __nright);

           }

 	  _STLP_UNWIND(_S_unref(__left); _S_unref(__nright));

 #         ifndef __GC

 	    _STLP_ASSERT(1 == __result->_M_ref_count)

 #         endif

 	  return __result;

 	}

     }

     _RopeRep* __nright =

       _STLP_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->get_allocator());

     _STLP_TRY {

       __r->_M_ref_nonnil();

       __result = _S_tree_concat(__r, __nright);

     }

     _STLP_UNWIND(_S_unref(__r); _S_unref(__nright));

 #   ifndef __GC

       _STLP_ASSERT(1 == __result->_M_ref_count)

 #   endif

     return __result;

 }

 #ifndef __GC

 template <class _CharT, class _Alloc>

 __RopeRep__* 

 rope<_CharT,_Alloc>::_S_destr_concat_char_iter(

   _RopeRep* __r, const _CharT* __s, size_t __slen)

 {

     _RopeRep* __result;

     if (0 == __r)

       return _STLP_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen,

 					      /* __r-> */allocator_type());

     size_t __count = __r->_M_ref_count;

     size_t __orig_size = __r->_M_size._M_data;

     _STLP_ASSERT(__count >= 1)

     if (__count > 1) return _S_concat_char_iter(__r, __s, __slen);

     if (0 == __slen) {

 	__r->_M_ref_count = 2;      // One more than before

 	return __r;

     }

     if (__orig_size + __slen <= _S_copy_max && 

           _RopeRep::_S_leaf == __r->_M_tag) {

 	__result = _S_destr_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);

 	return __result;

     }

     if (_RopeRep::_S_concat == __r->_M_tag) {

 	_RopeLeaf* __right = (_RopeLeaf*)(((_RopeConcatenation*)__r)->_M_right);

 	if (_RopeRep::_S_leaf == __right->_M_tag

 	    && __right->_M_size._M_data + __slen <= _S_copy_max) {

 	  _RopeRep* __new_right = 

 	    _S_destr_leaf_concat_char_iter(__right, __s, __slen);

 	  if (__right == __new_right) {

 	      _STLP_ASSERT(__new_right->_M_ref_count == 2)

 	      __new_right->_M_ref_count = 1;

 	  } else {

 	      _STLP_ASSERT(__new_right->_M_ref_count >= 1)

 	      __right->_M_unref_nonnil();

 	  }

 	  _STLP_ASSERT(__r->_M_ref_count == 1)

 	  __r->_M_ref_count = 2;    // One more than before.

       ((_RopeConcatenation*)__r)->_M_right = __new_right;

       // E.Musser : moved below

       //	  __r->_M_size._M_data = __orig_size + __slen;

 	  if (0 != __r->_M_c_string) {

 	      __r->_M_free_c_string();

 	      __r->_M_c_string = 0;

 	  }

 	  __r->_M_size._M_data = __orig_size + __slen;

 	  return __r;

 	}

     }

     _RopeRep* __right =

       _STLP_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __r->get_allocator());

     __r->_M_ref_nonnil();

     _STLP_TRY {

       __result = _S_tree_concat(__r, __right);

     }

     _STLP_UNWIND(_S_unref(__r); _S_unref(__right))

     _STLP_ASSERT(1 == __result->_M_ref_count)

     return __result;

 }

 #endif /* !__GC */

 template <class _CharT, class _Alloc>

 __RopeRep__*

 rope<_CharT,_Alloc>::_S_concat_rep(_RopeRep* __left, _RopeRep* __right)

 {

     if (0 == __left) {

 	_S_ref(__right);

 	return __right;

     }

     if (0 == __right) {

 	__left->_M_ref_nonnil();

 	return __left;

     }

     if (_RopeRep::_S_leaf == __right->_M_tag) {

 	if (_RopeRep::_S_leaf == __left->_M_tag) {

 	  if (__right->_M_size._M_data + __left->_M_size._M_data <= _S_copy_max) {

 	    return _S_leaf_concat_char_iter((_RopeLeaf*)__left,

 					 ((_RopeLeaf*)__right)->_M_data,

 					 __right->_M_size._M_data);

 	  }

 	} else if (_RopeRep::_S_concat == __left->_M_tag

 		   && _RopeRep::_S_leaf ==

 		      ((_RopeConcatenation*)__left)->_M_right->_M_tag) {

 	  _RopeLeaf* __leftright =

 		    (_RopeLeaf*)(((_RopeConcatenation*)__left)->_M_right); 

 	  if (__leftright->_M_size._M_data + __right->_M_size._M_data <= _S_copy_max) {

 	    _RopeRep* __leftleft = ((_RopeConcatenation*)__left)->_M_left;

 	    _RopeRep* __rest = _S_leaf_concat_char_iter(__leftright,

 					   ((_RopeLeaf*)__right)->_M_data,

 					   __right->_M_size._M_data);

 	    __leftleft->_M_ref_nonnil();

 	    _STLP_TRY {

 	      return(_S_tree_concat(__leftleft, __rest));

             }

 	    _STLP_UNWIND(_S_unref(__leftleft); _S_unref(__rest))

 	  }

 	}

     }

     __left->_M_ref_nonnil();

     __right->_M_ref_nonnil();

     _STLP_TRY {

       return(_S_tree_concat(__left, __right));

     }

     _STLP_UNWIND(_S_unref(__left); _S_unref(__right));

 #ifdef _STLP_THROW_RETURN_BUG

 	return 0;

 #endif

 }

 template <class _CharT, class _Alloc>

 __RopeRep__*

 rope<_CharT,_Alloc>::_S_substring(_RopeRep* __base, 

                                size_t __start, size_t __endp1)

 {

     if (0 == __base) return 0;

     size_t __len = __base->_M_size._M_data;

     size_t __adj_endp1;

     const size_t __lazy_threshold = 128;

     if (__endp1 >= __len) {

 	if (0 == __start) {

 	    __base->_M_ref_nonnil();

 	    return __base;

 	} else {

 	    __adj_endp1 = __len;

 	}

     } else {

 	__adj_endp1 = __endp1;

     }

     switch(__base->_M_tag) {

 	case _RopeRep::_S_concat:

 	    {

 		_RopeConcatenation* __c = (_RopeConcatenation*)__base;

 		_RopeRep* __left = __c->_M_left;

 		_RopeRep* __right = __c->_M_right;

 		size_t __left_len = __left->_M_size._M_data;

 		_RopeRep* __result;

 		if (__adj_endp1 <= __left_len) {

 		    return _S_substring(__left, __start, __endp1);

 		} else if (__start >= __left_len) {

 		    return _S_substring(__right, __start - __left_len,

 				  __adj_endp1 - __left_len);

 		}

 		_Self_destruct_ptr __left_result(

 		  _S_substring(__left, __start, __left_len));

 		_Self_destruct_ptr __right_result(

 		  _S_substring(__right, 0, __endp1 - __left_len));

 		_STLP_MPWFIX_TRY		//*TY 06/01/2000 - mpw forgets to call dtor on __left_result and __right_result without this try block

 		__result = _S_concat_rep(__left_result, __right_result);

 #               ifndef __GC

 		  _STLP_ASSERT(1 == __result->_M_ref_count)

 #               endif

 		return __result;

 		_STLP_MPWFIX_CATCH		//*TY 06/01/2000 - 

 	    }

 	case _RopeRep::_S_leaf:

 	    {

 		_RopeLeaf* __l = (_RopeLeaf*)__base;

 		_RopeLeaf* __result;

 		size_t __result_len;

 		if (__start >= __adj_endp1) return 0;

 		__result_len = __adj_endp1 - __start;

 		if (__result_len > __lazy_threshold) goto lazy;

 #               ifdef __GC

 		    const _CharT* __section = __l->_M_data + __start;

 		    __result = _S_new_RopeLeaf(__section, __result_len,

 					  __base->get_allocator());

 		    __result->_M_c_string = 0;  // Not eos terminated.

 #               else

 		    // We should sometimes create substring node instead.

 		    __result = _STLP_ROPE_FROM_UNOWNED_CHAR_PTR(

 					__l->_M_data + __start, __result_len,

 					__base->get_allocator());

 #               endif

 		return __result;

 	    }

 	case _RopeRep::_S_substringfn:

 	    // Avoid introducing multiple layers of substring nodes.

 	    {

 		_RopeSubstring* __old = (_RopeSubstring*)__base;

 		size_t __result_len;

 		if (__start >= __adj_endp1) return 0;

 		__result_len = __adj_endp1 - __start;

 		if (__result_len > __lazy_threshold) {

 		    _RopeSubstring* __result =

 			_S_new_RopeSubstring(__old->_M_base,

 					  __start + __old->_M_start,

 					  __adj_endp1 - __start,

 					  __base->get_allocator());

 		    return __result;

 		} // *** else fall through: ***

 	    }

 	case _RopeRep::_S_function:

 	    {

 		_RopeFunction* __f = (_RopeFunction*)__base;

 		if (__start >= __adj_endp1) return 0;

 		size_t __result_len = __adj_endp1 - __start;

 		if (__result_len > __lazy_threshold) goto lazy;

 		_CharT* __section = __base->_M_size.allocate(_S_rounded_up_size(__result_len));

 		_STLP_TRY {

 		  (*(__f->_M_fn))(__start, __result_len, __section);

                 }

 		_STLP_UNWIND(_RopeRep::_S_free_string(

 	               __section, __result_len, __base->get_allocator()));

 		_S_cond_store_eos(__section[__result_len]);

 		return _S_new_RopeLeaf(__section, __result_len,

 				       __base->get_allocator());

 	    }

     }

     /*NOTREACHED*/

     _STLP_ASSERT(false)

   lazy:

     {

 	// Create substring node.

 	return _S_new_RopeSubstring(__base, __start, __adj_endp1 - __start,

 			       __base->get_allocator());

     }

 }

 template<class _CharT>

 class _Rope_flatten_char_consumer : public _Rope_char_consumer<_CharT> {

     private:

 	_CharT* _M_buf_ptr;

     public:

 	//  _CharT* _M_buffer;  // XXX not used

 	_Rope_flatten_char_consumer(_CharT* __buffer) {

 	    _M_buf_ptr = __buffer;

 	};

 	~_Rope_flatten_char_consumer() {}

 	bool operator() (const _CharT* __leaf, size_t __n) {

 	    uninitialized_copy_n(__leaf, __n, _M_buf_ptr);

 	    _M_buf_ptr += __n;

 	    return true;

 	}

 };

 template<class _CharT>

 class _Rope_find_char_char_consumer : public _Rope_char_consumer<_CharT> {

     private:

 	_CharT _M_pattern;

     public:

 	size_t _M_count;  // Number of nonmatching characters

 	_Rope_find_char_char_consumer(_CharT __p) 

 	  : _M_pattern(__p), _M_count(0) {}

 	~_Rope_find_char_char_consumer() {}

 	bool operator() (const _CharT* __leaf, size_t __n) {

 	    size_t __i;

 	    for (__i = 0; __i < __n; __i++) {

 		if (__leaf[__i] == _M_pattern) {

 		    _M_count += __i; return false;

 		}

 	    }

 	    _M_count += __n; return true;

 	}

 };

 #if !defined (_STLP_USE_NO_IOSTREAMS)	    

 #if defined (_STLP_USE_NEW_IOSTREAMS)

   template<class _CharT, class _Traits>

   // Here _CharT is both the stream and rope character type.

 #else

  template<class _CharT>

   // Here _CharT is the rope character type.  Unlike in the

   // above case, we somewhat handle the case in which it doesn't

   // match the stream character type, i.e. char.

 #endif

 class _Rope_insert_char_consumer : public _Rope_char_consumer<_CharT> {

     private:

 #       if defined (_STLP_USE_NEW_IOSTREAMS)

 	  typedef basic_ostream<_CharT,_Traits> _Insert_ostream;

 #	else

  	typedef ostream _Insert_ostream;

 #	endif

 	_Insert_ostream& _M_o;

     public:

 	// _CharT* buffer;    // XXX not used

 	_Rope_insert_char_consumer(_Insert_ostream& __writer) 

 	  : _M_o(__writer) {};

 #if defined(__MRC__)||(defined(__SC__) && !defined(__DMC__))		//*TY 05/23/2000 - added support for mpw compiler's trigger function approach to generate vtable

   ~_Rope_insert_char_consumer();		//*TY 05/23/2000 - 

 #else		//*TY 05/23/2000 - 

   ~_Rope_insert_char_consumer() {}

 #endif		//*TY 05/23/2000 - 

 		// Caller is presumed to own the ostream

 	bool operator() (const _CharT* __leaf, size_t __n);

 		// Returns true to continue traversal.

 };

 # if defined ( _STLP_USE_NEW_IOSTREAMS )

 #  if defined(__MRC__)||(defined(__SC__) && !defined(__DMC__))		//*TY 05/23/2000 - added support for mpw compiler's trigger function approach to generate vtable

   template<class _CharT, class _Traits>

   _Rope_insert_char_consumer<_CharT, _Traits>::  ~_Rope_insert_char_consumer() {}

 #  endif		//*TY 05/23/2000 - 

   template<class _CharT, class _Traits>

   bool _Rope_insert_char_consumer<_CharT, _Traits>::operator()

 					(const _CharT* __leaf, size_t __n)

 {

     size_t __i;

     //  We assume that formatting is set up correctly for each element.

     for (__i = 0; __i < __n; __i++) _M_o.put(__leaf[__i]);

     return true;

 }

 # else

 #  if defined(__MRC__)||(defined(__SC__) && !defined(__DMC__))		//*TY 05/23/2000 - added support for mpw compiler's trigger function approach to generate vtable

   template<class _CharT>

   _Rope_insert_char_consumer<_CharT>::  ~_Rope_insert_char_consumer() {}

 #  endif		//*TY 05/23/2000 - 

   template<class _CharT>

   bool _Rope_insert_char_consumer<_CharT>::operator()

 					(const _CharT* __leaf, size_t __n)

   {

     size_t __i;

     //  We assume that formatting is set up correctly for each element.

     for (__i = 0; __i < __n; __i++) _M_o << __leaf[__i];

     return true;

   }

 # if !defined (_STLP_NO_METHOD_SPECIALIZATION)

 _STLP_TEMPLATE_NULL

 inline bool 

 _Rope_insert_char_consumer<char>::operator()

 					(const char* __leaf, size_t __n)

 {

     size_t __i;

     for (__i = 0; __i < __n; __i++) _M_o.put(__leaf[__i]);

     return true;

 }

 #endif /* _STLP_METHOD_SPECIALIZATION */

 #endif /* _STLP_USE_NEW_IOSTREAM */

 #endif /* if !defined (_STLP_USE_NO_IOSTREAMS) */

 template <class _CharT, class _Alloc>

 bool rope<_CharT, _Alloc>::_S_apply_to_pieces(

 				_Rope_char_consumer<_CharT>& __c,

 				const _RopeRep* __r,

 				size_t __begin, size_t __end)

 {

     if (0 == __r) return true;

     switch(__r->_M_tag) {

 	case _RopeRep::_S_concat:

 	    {

 		_RopeConcatenation* __conc = (_RopeConcatenation*)__r;

 		_RopeRep* __left =  __conc->_M_left;

 		size_t __left_len = __left->_M_size._M_data;

 		if (__begin < __left_len) {

 		    size_t __left_end = (min) (__left_len, __end);

 		    if (!_S_apply_to_pieces(__c, __left, __begin, __left_end))

 			return false;

 		}

 		if (__end > __left_len) {

 		    _RopeRep* __right =  __conc->_M_right;

 		    size_t __right_start = (max)(__left_len, __begin);

 		    if (!_S_apply_to_pieces(__c, __right,

 					 __right_start - __left_len,

 					 __end - __left_len)) {

 			return false;

 		    }

 		}

 	    }

 	    return true;

 	case _RopeRep::_S_leaf:

 	    {

 		_RopeLeaf* __l = (_RopeLeaf*)__r;

 		return __c.operator()(__l->_M_data + __begin, __end - __begin);

 	    }

 	case _RopeRep::_S_function:

 	case _RopeRep::_S_substringfn:

 	    {

 		_RopeFunction* __f = (_RopeFunction*)__r;

 		size_t __len = __end - __begin;

 #ifdef __SYMBIAN32__

 		bool __result = false;

 #else

 		bool __result;

 #endif

 		_CharT* __buffer =

 		  (_CharT*)__sgi_alloc::allocate(__len * sizeof(_CharT));

 		_STLP_TRY {

 		  (*(__f->_M_fn))(__begin, __len, __buffer);

 		  __result = __c.operator()(__buffer, __len);

                   __sgi_alloc::deallocate(__buffer, __len * sizeof(_CharT));

                 }

 		_STLP_UNWIND((__sgi_alloc::deallocate(__buffer,

 						      __len * sizeof(_CharT))))

 		return __result;

 	    }

 	default:

 	    _STLP_ASSERT(false)

 	    /*NOTREACHED*/

 	    return false;

     }

 }

 template <class _CharT> inline bool _Rope_is_simple(_CharT*) { return false; }

 inline bool _Rope_is_simple(char*) { return true; }

 # ifdef _STLP_HAS_WCHAR_T

 inline bool _Rope_is_simple(wchar_t*) { return true; }

 # endif

 #if !defined (_STLP_USE_NO_IOSTREAMS)

 #if defined (_STLP_USE_NEW_IOSTREAMS)

   template<class _CharT, class _Traits>

   inline void _Rope_fill(basic_ostream<_CharT, _Traits>& __o, size_t __n)

 #else

 inline void _Rope_fill(ostream& __o, size_t __n)

 #endif

 {

     char __f = __o.fill();

     size_t __i;

     for (__i = 0; __i < __n; __i++) __o.put(__f);

 }

 #if defined (_STLP_USE_NEW_IOSTREAMS)

   template<class _CharT, class _Traits, class _Alloc>

   basic_ostream<_CharT, _Traits>& operator<<

 					(basic_ostream<_CharT, _Traits>& __o,

 					 const rope<_CharT, _Alloc>& __r)

 # else

 template<class _CharT, class _Alloc>

 ostream& operator<< (ostream& __o, const rope<_CharT, _Alloc>& __r)

 #endif

 {

     size_t __w = __o.width();

     bool __left = bool(__o.flags() & ios::left);

     size_t __pad_len;

     size_t __rope_len = __r.size();

 #   if defined (_STLP_USE_NEW_IOSTREAMS)

       _Rope_insert_char_consumer<_CharT, _Traits> __c(__o);

 #   else

     _Rope_insert_char_consumer<_CharT> __c(__o);

 #   endif

     bool __is_simple = _Rope_is_simple((_CharT*)0);

     if (__rope_len < __w) {

 	__pad_len = __w - __rope_len;

     } else {

 	__pad_len = 0;

     }

     if (!__is_simple) __o.width(__w/__rope_len);

     _STLP_TRY {

       if (__is_simple && !__left && __pad_len > 0) {

 	_Rope_fill(__o, __pad_len);

       }

       __r.apply_to_pieces(0, __r.size(), __c);

       if (__is_simple && __left && __pad_len > 0) {

 	_Rope_fill(__o, __pad_len);

       }

       if (!__is_simple)

         __o.width(__w);

     }

     _STLP_UNWIND(if (!__is_simple) __o.width(__w))

     return __o;

 }

 #endif /* NO_IOSTREAMS */

 template <class _CharT, class _Alloc>

 _CharT*

 rope<_CharT,_Alloc>::_S_flatten(_RopeRep* __r,

 				 size_t __start, size_t __len,

 				 _CharT* __buffer)

 {

     _Rope_flatten_char_consumer<_CharT> __c(__buffer);

     _S_apply_to_pieces(__c, __r, __start, __start + __len);

     return(__buffer + __len);

 }

 template <class _CharT, class _Alloc>

 size_t

 rope<_CharT,_Alloc>::find(_CharT __pattern, size_t __start) const

 {

     _Rope_find_char_char_consumer<_CharT> __c(__pattern);

     _S_apply_to_pieces(__c, _M_tree_ptr._M_data, __start, size());

     size_type __result_pos = __start + __c._M_count;

 #   ifndef _STLP_OLD_ROPE_SEMANTICS

 	if (__result_pos == size()) __result_pos = npos;

 #   endif

     return __result_pos;

 }

 template <class _CharT, class _Alloc>

 _CharT*

 rope<_CharT,_Alloc>::_S_flatten(_Rope_RopeRep<_CharT, _Alloc>* __r, _CharT* __buffer)

 {

     if (0 == __r) return __buffer;

     switch(__r->_M_tag) {

 	case _RopeRep::_S_concat:

 	    {

 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;

 		_RopeRep* __left = __c->_M_left;

 		_RopeRep* __right = __c->_M_right;

 		_CharT* __rest = _S_flatten(__left, __buffer);

 		return _S_flatten(__right, __rest);

 	    }

 	case _RopeRep::_S_leaf:

 	    {

 		_RopeLeaf* __l = (_RopeLeaf*)__r;

 		return copy_n(__l->_M_data, __l->_M_size._M_data, __buffer).second;

 	    }

 	case _RopeRep::_S_function:

 	case _RopeRep::_S_substringfn:

 	    // We dont yet do anything with substring nodes.

 	    // This needs to be fixed before ropefiles will work well.

 	    {

 		_RopeFunction* __f = (_RopeFunction*)__r;

 		(*(__f->_M_fn))(0, __f->_M_size._M_data, __buffer);

 		return __buffer + __f->_M_size._M_data;

 	    }

 	default:

 	    _STLP_ASSERT(false)

 	    /*NOTREACHED*/

 	    return 0;

     }

 }

 // This needs work for _CharT != char

 template <class _CharT, class _Alloc>

 void

 rope<_CharT,_Alloc>::_S_dump(_RopeRep* __r, int __indent)

 {

     for (int __i = 0; __i < __indent; __i++) putchar(' ');

     if (0 == __r) {

       printf("NULL\n"); return;

     }

     if (_RopeRep::_S_concat == __r->_M_tag) {

 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;

 	_RopeRep* __left = __c->_M_left;

 	_RopeRep* __right = __c->_M_right;

 #       ifdef __GC

 	  printf("Concatenation %p (depth = %d, len = %ld, %s balanced)\n",

 	    __r, __r->_M_depth, __r->_M_size._M_data, __r->_M_is_balanced? "" : "not");

 #       else

 	  printf("Concatenation %p (rc = %ld, depth = %d, "

 	           "len = %ld, %s balanced)\n",

 		 __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size._M_data,

 		 __r->_M_is_balanced? "" : "not");

 #       endif

 	_S_dump(__left, __indent + 2);

 	_S_dump(__right, __indent + 2);

 	return;

     } else {

 	const char* __kind;

 	switch (__r->_M_tag) {

 	    case _RopeRep::_S_leaf:

 		__kind = "Leaf";

 		break;

 	    case _RopeRep::_S_function:

 		__kind = "Function";

 		break;

 	    case _RopeRep::_S_substringfn:

 		__kind = "Function representing substring";

 		break;

 	    default:

 		__kind = "(corrupted kind field!)";

 	}

 #       ifdef __GC

 	  printf("%s %p (depth = %d, len = %ld) ",

 		 __kind, __r, __r->_M_depth, __r->_M_size._M_data);

 #       else

 	  printf("%s %p (rc = %ld, depth = %d, len = %ld) ",

 		 __kind, __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size._M_data);

 #       endif

 	if (_S_is_one_byte_char_type((_CharT*)0)) {

 	    const int __max_len = 40;

 	    _Self_destruct_ptr __prefix(_S_substring(__r, 0, __max_len));

 	    _CharT __buffer[__max_len + 1];

 	    bool __too_big = __r->_M_size._M_data > __prefix->_M_size._M_data;

 	    _S_flatten(__prefix, __buffer);

 	    __buffer[__prefix->_M_size._M_data] = _S_eos((_CharT*)0); 

 	    printf("%s%s\n", 

 	           (char*)__buffer, __too_big? "...\n" : "\n");

 	} else {

 	    printf("\n");

 	}

     }

 }

 # define __ROPE_TABLE_BODY  = { \

 /* 0 */1, /* 1 */2, /* 2 */3, /* 3 */5, /* 4 */8, /* 5 */13, /* 6 */21,         \

 /* 7 */34, /* 8 */55, /* 9 */89, /* 10 */144, /* 11 */233, /* 12 */377,         \

 /* 13 */610, /* 14 */987, /* 15 */1597, /* 16 */2584, /* 17 */4181,             \

 /* 18 */6765ul, /* 19 */10946ul, /* 20 */17711ul, /* 21 */28657ul, /* 22 */46368ul,   \

 /* 23 */75025ul, /* 24 */121393ul, /* 25 */196418ul, /* 26 */317811ul,                \

 /* 27 */514229ul, /* 28 */832040ul, /* 29 */1346269ul, /* 30 */2178309ul,             \

 /* 31 */3524578ul, /* 32 */5702887ul, /* 33 */9227465ul, /* 34 */14930352ul,          \

 /* 35 */24157817ul, /* 36 */39088169ul, /* 37 */63245986ul, /* 38 */102334155ul,      \

 /* 39 */165580141ul, /* 40 */267914296ul, /* 41 */433494437ul,                        \

 /* 42 */701408733ul, /* 43 */1134903170ul, /* 44 */1836311903ul,                      \

 /* 45 */2971215073ul }

 # if ( _STLP_STATIC_TEMPLATE_DATA > 0 )

 template <class _CharT, class _Alloc>

 const unsigned long

 rope<_CharT,_Alloc>::_S_min_len[__ROPE_DEPTH_SIZE] __ROPE_TABLE_BODY ;

 # else 

 __DECLARE_INSTANCE(const unsigned long, 

                    crope::_S_min_len[__ROPE_DEPTH_SIZE],

                    __ROPE_TABLE_BODY);

 #  ifndef _STLP_NO_WCHAR_T

 __DECLARE_INSTANCE(const unsigned long, 

                    wrope::_S_min_len[__ROPE_DEPTH_SIZE],

                    __ROPE_TABLE_BODY);

 #  endif

 # endif

 # undef __ROPE_DEPTH_SIZE

 # undef __ROPE_MAX_DEPTH

 # undef __ROPE_TABLE_BODY

 // These are Fibonacci numbers < 2**32.

 template <class _CharT, class _Alloc>

 __RopeRep__*

 rope<_CharT,_Alloc>::_S_balance(_RopeRep* __r)

 {

     _RopeRep* __forest[_RopeRep::_S_max_rope_depth + 1];

     _RopeRep* __result = 0;

     int __i;

     // Invariant:

     // The concatenation of forest in descending order is equal to __r.

     // __forest[__i]._M_size._M_data >= _S_min_len[__i]

     // __forest[__i]._M_depth = __i

     // References from forest are included in refcount.

     for (__i = 0; __i <= _RopeRep::_S_max_rope_depth; ++__i) 

       __forest[__i] = 0;

     _STLP_TRY {

       _S_add_to_forest(__r, __forest);

       for (__i = 0; __i <= _RopeRep::_S_max_rope_depth; ++__i) 

         if (0 != __forest[__i]) {

 #	ifndef __GC

 	  _Self_destruct_ptr __old(__result);

 #	endif

 	  __result = _S_concat_rep(__forest[__i], __result);

 	__forest[__i]->_M_unref_nonnil();

 #	if !defined(__GC) && defined(_STLP_USE_EXCEPTIONS)

 	  __forest[__i] = 0;

 #	endif

       }

     }

     _STLP_UNWIND(for(__i = 0; __i <= _RopeRep::_S_max_rope_depth; __i++)

 		 _S_unref(__forest[__i]))

     if (__result->_M_depth > _RopeRep::_S_max_rope_depth) {

 	__stl_throw_range_error("rope too long");

     }

     return(__result);

 }

 template <class _CharT, class _Alloc>

 void

 rope<_CharT,_Alloc>::_S_add_to_forest(_RopeRep* __r, _RopeRep** __forest)

 {

     if (__r -> _M_is_balanced) {

 	_S_add_leaf_to_forest(__r, __forest);

 	return;

     }

     _STLP_ASSERT(__r->_M_tag == _RopeRep::_S_concat)

     {

 	_RopeConcatenation* __c = (_RopeConcatenation*)__r;

 	_S_add_to_forest(__c->_M_left, __forest);

 	_S_add_to_forest(__c->_M_right, __forest);

     }

 }

 template <class _CharT, class _Alloc>

 void

 rope<_CharT,_Alloc>::_S_add_leaf_to_forest(_RopeRep* __r, _RopeRep** __forest)

 {

     _RopeRep* __insertee;   		// included in refcount

     _RopeRep* __too_tiny = 0;    	// included in refcount

     int __i;  				// forest[0..__i-1] is empty

     size_t __s = __r->_M_size._M_data;

     for (__i = 0; __s >= _S_min_len[__i+1]/* not this bucket */; ++__i) {

 	if (0 != __forest[__i]) {

 #	    ifndef __GC

 	      _Self_destruct_ptr __old(__too_tiny);

 #	    endif

 	    __too_tiny = _S_concat_and_set_balanced(__forest[__i], __too_tiny);

 	    __forest[__i]->_M_unref_nonnil();

 	    __forest[__i] = 0;

 	}

     }

     {

 #	ifndef __GC

 	  _Self_destruct_ptr __old(__too_tiny);

 #	endif

 	__insertee = _S_concat_and_set_balanced(__too_tiny, __r);

     }

     // Too_tiny dead, and no longer included in refcount.

     // Insertee is live and included.

     _STLP_ASSERT(_S_is_almost_balanced(__insertee))

     _STLP_ASSERT(__insertee->_M_depth <= __r->_M_depth + 1)

     for (;; ++__i) {

 	if (0 != __forest[__i]) {

 #	    ifndef __GC

 	      _Self_destruct_ptr __old(__insertee);

 #	    endif

 	    __insertee = _S_concat_and_set_balanced(__forest[__i], __insertee);

 	    __forest[__i]->_M_unref_nonnil();

 	    __forest[__i] = 0;

 	    _STLP_ASSERT(_S_is_almost_balanced(__insertee))

 	}

 	_STLP_ASSERT(_S_min_len[__i] <= __insertee->_M_size._M_data)

 	_STLP_ASSERT(__forest[__i] == 0)

 	if (__i == _RopeRep::_S_max_rope_depth || 

 	      __insertee->_M_size._M_data < _S_min_len[__i+1]) {

 	    __forest[__i] = __insertee;

 	    // refcount is OK since __insertee is now dead.

 	    return;

 	}

     }

 }

 template <class _CharT, class _Alloc>

 _CharT

 rope<_CharT,_Alloc>::_S_fetch(_RopeRep* __r, size_type __i)

 {

     __GC_CONST _CharT* __cstr = __r->_M_c_string;

     _STLP_ASSERT(__i < __r->_M_size._M_data)

     if (0 != __cstr) return __cstr[__i]; 

     for(;;) {

       switch(__r->_M_tag) {

 	case _RopeRep::_S_concat:

 	    {

 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;

 		_RopeRep* __left = __c->_M_left;

 		size_t __left_len = __left->_M_size._M_data;

 		if (__i >= __left_len) {

 		    __i -= __left_len;

 		    __r = __c->_M_right;

 		} else {

 		    __r = __left;

 		}

 	    }

 	    break;

 	case _RopeRep::_S_leaf:

 	    {

 		_RopeLeaf* __l = (_RopeLeaf*)__r;

 		return __l->_M_data[__i];

 	    }

 	case _RopeRep::_S_function:

 	case _RopeRep::_S_substringfn:

 	    {

 		_RopeFunction* __f = (_RopeFunction*)__r;

 		_CharT __result;

 		(*(__f->_M_fn))(__i, 1, &__result);

 		return __result;

 	    }

       }

     }

 #if defined(_STLP_NEED_UNREACHABLE_RETURN)

     return 0;

 #endif

 }

 # ifndef __GC

 // Return a uniquely referenced character slot for the given

 // position, or 0 if that's not possible.

 template <class _CharT, class _Alloc>

 _CharT*

 rope<_CharT,_Alloc>::_S_fetch_ptr(_RopeRep* __r, size_type __i)

 {

     _RopeRep* __clrstack[_RopeRep::_S_max_rope_depth];

     size_t __csptr = 0;

     for(;;) {

       if (__r->_M_ref_count > 1) return 0;

       switch(__r->_M_tag) {

 	case _RopeRep::_S_concat:

 	    {

 		_RopeConcatenation* __c = (_RopeConcatenation*)__r;

 		_RopeRep* __left = __c->_M_left;

 		size_t __left_len = __left->_M_size._M_data;

 		if (__c->_M_c_string != 0) __clrstack[__csptr++] = __c;

 		if (__i >= __left_len) {

 		    __i -= __left_len;

 		    __r = __c->_M_right;

 		} else {

 		    __r = __left;

 		}

 	    }

 	    break;

 	case _RopeRep::_S_leaf:

 	    {

 		_RopeLeaf* __l = (_RopeLeaf*)__r;

 		if (__l->_M_c_string != __l->_M_data && __l->_M_c_string != 0)

 		    __clrstack[__csptr++] = __l;

 		while (__csptr > 0) {

 		    -- __csptr;

 		    _RopeRep* __d = __clrstack[__csptr];

 		    __d->_M_free_c_string();

 		    __d->_M_c_string = 0;

 		}

 		return __l->_M_data + __i;

 	    }

 	case _RopeRep::_S_function:

 	case _RopeRep::_S_substringfn:

 	    return 0;

       }

     }

 #if defined(_STLP_NEED_UNREACHABLE_RETURN)

     return 0;

 #endif

 }

 # endif /* __GC */

 // The following could be implemented trivially using

 // lexicographical_compare_3way.

 // We do a little more work to avoid dealing with rope iterators for

 // flat strings.

 template <class _CharT, class _Alloc>

 int

 rope<_CharT,_Alloc>::_S_compare (const _RopeRep* __left, 

                                  const _RopeRep* __right)

 {

     size_t __left_len;

     size_t __right_len;

     if (0 == __right) return 0 != __left;

     if (0 == __left) return -1;

     __left_len = __left->_M_size._M_data;

     __right_len = __right->_M_size._M_data;

     if (_RopeRep::_S_leaf == __left->_M_tag) {

 	_RopeLeaf* __l = (_RopeLeaf*) __left;

 	if (_RopeRep::_S_leaf == __right->_M_tag) {

 	    _RopeLeaf* __r = (_RopeLeaf*) __right;

 	    return lexicographical_compare_3way(

 			__l->_M_data, __l->_M_data + __left_len,

 			__r->_M_data, __r->_M_data + __right_len);

 	} else {

 	    const_iterator __rstart(__right, 0);

 	    const_iterator __rend(__right, __right_len);

 	    return lexicographical_compare_3way(

 			__l->_M_data, __l->_M_data + __left_len,

 			__rstart, __rend);

 	}

     } else {

 	const_iterator __lstart(__left, 0);

 	const_iterator __lend(__left, __left_len);

 	if (_RopeRep::_S_leaf == __right->_M_tag) {

 	    _RopeLeaf* __r = (_RopeLeaf*) __right;

 	    return lexicographical_compare_3way(

 				   __lstart, __lend,

 				   __r->_M_data, __r->_M_data + __right_len);

 	} else {

 	    const_iterator __rstart(__right, 0);

 	    const_iterator __rend(__right, __right_len);

 	    return lexicographical_compare_3way(

 				   __lstart, __lend,

 				   __rstart, __rend);

 	}

     }

 }

 // Assignment to reference proxies.

 template <class _CharT, class _Alloc>

 _Rope_char_ref_proxy<_CharT, _Alloc>&

 _Rope_char_ref_proxy<_CharT, _Alloc>::operator= (_CharT __c) {

     _RopeRep* __old = _M_root->_M_tree_ptr._M_data;

 #   ifndef __GC

 	// First check for the case in which everything is uniquely

 	// referenced.  In that case we can do this destructively.

 	_CharT* __ptr = _My_rope::_S_fetch_ptr(__old, _M_pos);

 	if (0 != __ptr) {

 	    *__ptr = __c;

 	    return *this;

 	}

 #   endif

     _Self_destruct_ptr __left(

       _My_rope::_S_substring(__old, 0, _M_pos));

     _Self_destruct_ptr __right(

       _My_rope::_S_substring(__old, _M_pos+1, __old->_M_size._M_data));

     _Self_destruct_ptr __result_left(

       _My_rope::_S_destr_concat_char_iter(__left, &__c, 1));

 #   ifndef __GC

       _STLP_ASSERT(__left == __result_left || 1 == __result_left->_M_ref_count)

 #   endif

     _RopeRep* __result =

       _My_rope::_S_concat_rep(__result_left, __right);

 #   ifndef __GC

       _STLP_ASSERT(1 <= __result->_M_ref_count)

       _RopeRep::_S_unref(__old);

 #   endif

     _M_root->_M_tree_ptr._M_data = __result;

     return *this;

 }

 template <class _CharT, class _Alloc>

 _Rope_char_ptr_proxy<_CharT, _Alloc>

 _Rope_char_ref_proxy<_CharT, _Alloc>::operator& () const {

     return _Rope_char_ptr_proxy<_CharT, _Alloc>(*this);

 }

 # if ( _STLP_STATIC_TEMPLATE_DATA > 0 )

 template<class _CharT, class _Alloc>

 _CharT rope<_CharT,_Alloc>::_S_empty_c_str[1] = { _CharT() };

 # else

 __DECLARE_INSTANCE(char, crope::_S_empty_c_str[1], ={0});

 # ifdef _STLP_HAS_WCHAR_T

 __DECLARE_INSTANCE(wchar_t, wrope::_S_empty_c_str[1], ={0});

 # endif /* _STLP_HAS_WCHAR_T */

 # endif /* _STLP_STATIC_TEMPLATE_DATA */

 // # endif

 template<class _CharT, class _Alloc>

 const _CharT* rope<_CharT,_Alloc>::c_str() const {

     if (0 == _M_tree_ptr._M_data) {

         _S_empty_c_str[0] = _S_eos((_CharT*)0);  // Possibly redundant,

 					     // but probably fast.

         return _S_empty_c_str;

     }

     __GC_CONST _CharT* __old_c_string = _M_tree_ptr._M_data->_M_c_string;

     if (0 != __old_c_string) return(__old_c_string);

     size_t __s = size();

    _CharT* __result = _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_tree_ptr, _CharT).allocate(__s + 1);

     _S_flatten(_M_tree_ptr._M_data, __result);

     __result[__s] = _S_eos((_CharT*)0);

 #   ifdef __GC

 	_M_tree_ptr._M_data->_M_c_string = __result;

 #   else

       if ((__old_c_string = (__GC_CONST _CharT*)

 	   _Atomic_swap((__stl_atomic_t *)(&(_M_tree_ptr._M_data->_M_c_string)),

 			(__stl_atomic_t)__result)) != 0) {

 	// It must have been added in the interim.  Hence it had to have been

 	// separately allocated.  Deallocate the old copy, since we just

 	// replaced it.

 	_STLP_STD::_Destroy(__old_c_string, __old_c_string + __s + 1);

       _STLP_CREATE_ALLOCATOR(allocator_type,(const allocator_type&)_M_tree_ptr, _CharT).deallocate(__old_c_string, __s + 1);

       }

 #   endif

     return(__result);

 }

 template<class _CharT, class _Alloc>

 const _CharT* rope<_CharT,_Alloc>::replace_with_c_str() {

     if (0 == _M_tree_ptr._M_data) {

         _S_empty_c_str[0] = _S_eos((_CharT*)0);

         return _S_empty_c_str;

     }

     __GC_CONST _CharT* __old_c_string = _M_tree_ptr._M_data->_M_c_string;

     if (_RopeRep::_S_leaf == _M_tree_ptr._M_data->_M_tag && 0 != __old_c_string) {

 	return(__old_c_string);

     }

     size_t __s = size();

     _CharT* __result = _M_tree_ptr.allocate(_S_rounded_up_size(__s));

     _S_flatten(_M_tree_ptr._M_data, __result);

     __result[__s] = _S_eos((_CharT*)0);

     _M_tree_ptr._M_data->_M_unref_nonnil();

     _M_tree_ptr._M_data = _S_new_RopeLeaf(__result, __s, get_allocator());

     return(__result);

 }

 // Algorithm specializations.  More should be added.

 #ifndef _STLP_MSVC

 // I couldn't get this to work with VC++

 template<class _CharT,class _Alloc>

 void

 _Rope_rotate(_Rope_iterator<_CharT,_Alloc> __first,

               _Rope_iterator<_CharT,_Alloc> __middle,

               _Rope_iterator<_CharT,_Alloc> __last)

 {

     _STLP_ASSERT(__first.container() == __middle.container()

                  && __middle.container() == __last.container())

     rope<_CharT,_Alloc>& __r(__first.container());

     rope<_CharT,_Alloc> __prefix = __r.substr(0, __first.index());

     rope<_CharT,_Alloc> __suffix = 

       __r.substr(__last.index(), __r.size() - __last.index());

     rope<_CharT,_Alloc> __part1 = 

       __r.substr(__middle.index(), __last.index() - __middle.index());

     rope<_CharT,_Alloc> __part2 = 

       __r.substr(__first.index(), __middle.index() - __first.index());

     __r = __prefix;

     __r += __part1;

     __r += __part2;

     __r += __suffix;

 }

 # if 0

 // Probably not useful for several reasons:

 // - for SGIs 7.1 compiler and probably some others,

 //   this forces lots of rope<wchar_t, ...> instantiations, creating a

 //   code bloat and compile time problem.  (Fixed in 7.2.)

 // - wchar_t is 4 bytes wide on most UNIX platforms, making it unattractive

 //   for unicode strings.  Unsigned short may be a better character

 //   type.

 inline void rotate(

 		_Rope_iterator<wchar_t,_STLP_DEFAULT_ALLOCATOR(char) > __first,

                 _Rope_iterator<wchar_t,_STLP_DEFAULT_ALLOCATOR(char) > __middle,

                 _Rope_iterator<wchar_t,_STLP_DEFAULT_ALLOCATOR(char) > __last) {

     _Rope_rotate(__first, __middle, __last);

 }

 # endif

 #endif /* _STLP_MSVC */

 #   undef __RopeLeaf__ 

 #   undef __RopeRep__ 

 #   undef __RopeLeaf 

 #   undef __RopeRep 

 #   undef size_type

 _STLP_END_NAMESPACE

 # endif /* ROPEIMPL_H */

 // Local Variables:

 // mode:C++

 // End: