(root)/
gcc-13.2.0/
libstdc++-v3/
include/
ext/
ropeimpl.h
       1  // SGI's rope class implementation -*- C++ -*-
       2  
       3  // Copyright (C) 2001-2023 Free Software Foundation, Inc.
       4  //
       5  // This file is part of the GNU ISO C++ Library.  This library is free
       6  // software; you can redistribute it and/or modify it under the
       7  // terms of the GNU General Public License as published by the
       8  // Free Software Foundation; either version 3, or (at your option)
       9  // any later version.
      10  
      11  // This library is distributed in the hope that it will be useful,
      12  // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14  // GNU General Public License for more details.
      15  
      16  // Under Section 7 of GPL version 3, you are granted additional
      17  // permissions described in the GCC Runtime Library Exception, version
      18  // 3.1, as published by the Free Software Foundation.
      19  
      20  // You should have received a copy of the GNU General Public License and
      21  // a copy of the GCC Runtime Library Exception along with this program;
      22  // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23  // <http://www.gnu.org/licenses/>.
      24  
      25  /*
      26   * Copyright (c) 1997
      27   * Silicon Graphics Computer Systems, Inc.
      28   *
      29   * Permission to use, copy, modify, distribute and sell this software
      30   * and its documentation for any purpose is hereby granted without fee,
      31   * provided that the above copyright notice appear in all copies and
      32   * that both that copyright notice and this permission notice appear
      33   * in supporting documentation.  Silicon Graphics makes no
      34   * representations about the suitability of this software for any
      35   * purpose.  It is provided "as is" without express or implied warranty.
      36   */
      37  
      38  /** @file ropeimpl.h
      39   *  This is an internal header file, included by other library headers.
      40   *  Do not attempt to use it directly. @headername{ext/rope}
      41   */
      42  
      43  #include <cstdio>
      44  #include <ostream>
      45  #include <bits/functexcept.h>
      46  
      47  #include <ext/algorithm> // For copy_n and lexicographical_compare_3way
      48  #include <ext/memory> // For uninitialized_copy_n
      49  #include <ext/numeric> // For power
      50  
      51  namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
      52  {
      53  _GLIBCXX_BEGIN_NAMESPACE_VERSION
      54  
      55    // Set buf_start, buf_end, and buf_ptr appropriately, filling tmp_buf
      56    // if necessary.  Assumes _M_path_end[leaf_index] and leaf_pos are correct.
      57    // Results in a valid buf_ptr if the iterator can be legitimately
      58    // dereferenced.
      59    template <class _CharT, class _Alloc>
      60      void
      61      _Rope_iterator_base<_CharT, _Alloc>::
      62      _S_setbuf(_Rope_iterator_base<_CharT, _Alloc>& __x)
      63      {
      64        using std::size_t;
      65        const _RopeRep* __leaf = __x._M_path_end[__x._M_leaf_index];
      66        size_t __leaf_pos = __x._M_leaf_pos;
      67        size_t __pos = __x._M_current_pos;
      68  
      69        switch(__leaf->_M_tag)
      70  	{
      71  	case __detail::_S_leaf:
      72  	  __x._M_buf_start = ((_Rope_RopeLeaf<_CharT, _Alloc>*)__leaf)->_M_data;
      73  	  __x._M_buf_ptr = __x._M_buf_start + (__pos - __leaf_pos);
      74  	  __x._M_buf_end = __x._M_buf_start + __leaf->_M_size;
      75  	  break;
      76  	case __detail::_S_function:
      77  	case __detail::_S_substringfn:
      78  	  {
      79  	    size_t __len = _S_iterator_buf_len;
      80  	    size_t __buf_start_pos = __leaf_pos;
      81  	    size_t __leaf_end = __leaf_pos + __leaf->_M_size;
      82  	    char_producer<_CharT>* __fn = ((_Rope_RopeFunction<_CharT,
      83  					    _Alloc>*)__leaf)->_M_fn;
      84  	    if (__buf_start_pos + __len <= __pos)
      85  	      {
      86  		__buf_start_pos = __pos - __len / 4;
      87  		if (__buf_start_pos + __len > __leaf_end)
      88  		  __buf_start_pos = __leaf_end - __len;
      89  	      }
      90  	    if (__buf_start_pos + __len > __leaf_end)
      91  	      __len = __leaf_end - __buf_start_pos;
      92  	    (*__fn)(__buf_start_pos - __leaf_pos, __len, __x._M_tmp_buf);
      93  	    __x._M_buf_ptr = __x._M_tmp_buf + (__pos - __buf_start_pos);
      94  	    __x._M_buf_start = __x._M_tmp_buf;
      95  	    __x._M_buf_end = __x._M_tmp_buf + __len;
      96  	  }
      97  	  break;
      98  	default:
      99  	  break;
     100  	}
     101      }
     102  
     103    // Set path and buffer inside a rope iterator.  We assume that
     104    // pos and root are already set.
     105    template <class _CharT, class _Alloc>
     106      void
     107      _Rope_iterator_base<_CharT, _Alloc>::
     108      _S_setcache(_Rope_iterator_base<_CharT, _Alloc>& __x)
     109      {
     110        using std::size_t;
     111        const _RopeRep* __path[int(__detail::_S_max_rope_depth) + 1];
     112        const _RopeRep* __curr_rope;
     113        int __curr_depth = -1;  /* index into path    */
     114        size_t __curr_start_pos = 0;
     115        size_t __pos = __x._M_current_pos;
     116        unsigned char __dirns = 0; // Bit vector marking right turns in the path
     117  
     118        if (__pos >= __x._M_root->_M_size)
     119  	{
     120  	  __x._M_buf_ptr = 0;
     121  	  return;
     122  	}
     123        __curr_rope = __x._M_root;
     124        if (0 != __curr_rope->_M_c_string)
     125  	{
     126  	  /* Treat the root as a leaf. */
     127  	  __x._M_buf_start = __curr_rope->_M_c_string;
     128  	  __x._M_buf_end = __curr_rope->_M_c_string + __curr_rope->_M_size;
     129  	  __x._M_buf_ptr = __curr_rope->_M_c_string + __pos;
     130  	  __x._M_path_end[0] = __curr_rope;
     131  	  __x._M_leaf_index = 0;
     132  	  __x._M_leaf_pos = 0;
     133  	  return;
     134  	}
     135        for(;;)
     136  	{
     137  	  ++__curr_depth;
     138  	  __path[__curr_depth] = __curr_rope;
     139  	  switch(__curr_rope->_M_tag)
     140  	    {
     141  	    case __detail::_S_leaf:
     142  	    case __detail::_S_function:
     143  	    case __detail::_S_substringfn:
     144  	      __x._M_leaf_pos = __curr_start_pos;
     145  	      goto done;
     146  	    case __detail::_S_concat:
     147  	      {
     148  		_Rope_RopeConcatenation<_CharT, _Alloc>* __c =
     149  		  (_Rope_RopeConcatenation<_CharT, _Alloc>*)__curr_rope;
     150  		_RopeRep* __left = __c->_M_left;
     151  		size_t __left_len = __left->_M_size;
     152  
     153  		__dirns <<= 1;
     154  		if (__pos >= __curr_start_pos + __left_len)
     155  		  {
     156  		    __dirns |= 1;
     157  		    __curr_rope = __c->_M_right;
     158  		    __curr_start_pos += __left_len;
     159  		  }
     160  		else
     161  		  __curr_rope = __left;
     162  	      }
     163  	      break;
     164  	    }
     165  	}
     166      done:
     167        // Copy last section of path into _M_path_end.
     168        {
     169  	int __i = -1;
     170  	int __j = __curr_depth + 1 - int(_S_path_cache_len);
     171  
     172  	if (__j < 0) __j = 0;
     173  	while (__j <= __curr_depth)
     174  	  __x._M_path_end[++__i] = __path[__j++];
     175  	__x._M_leaf_index = __i;
     176        }
     177        __x._M_path_directions = __dirns;
     178        _S_setbuf(__x);
     179      }
     180  
     181    // Specialized version of the above.  Assumes that
     182    // the path cache is valid for the previous position.
     183    template <class _CharT, class _Alloc>
     184      void
     185      _Rope_iterator_base<_CharT, _Alloc>::
     186      _S_setcache_for_incr(_Rope_iterator_base<_CharT, _Alloc>& __x)
     187      {
     188        using std::size_t;
     189        int __current_index = __x._M_leaf_index;
     190        const _RopeRep* __current_node = __x._M_path_end[__current_index];
     191        size_t __len = __current_node->_M_size;
     192        size_t __node_start_pos = __x._M_leaf_pos;
     193        unsigned char __dirns = __x._M_path_directions;
     194        _Rope_RopeConcatenation<_CharT, _Alloc>* __c;
     195  
     196        if (__x._M_current_pos - __node_start_pos < __len)
     197  	{
     198  	  /* More stuff in this leaf, we just didn't cache it. */
     199  	  _S_setbuf(__x);
     200  	  return;
     201  	}
     202        //  node_start_pos is starting position of last_node.
     203        while (--__current_index >= 0)
     204  	{
     205  	  if (!(__dirns & 1) /* Path turned left */)
     206  	    break;
     207  	  __current_node = __x._M_path_end[__current_index];
     208  	  __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
     209  	  // Otherwise we were in the right child.  Thus we should pop
     210  	  // the concatenation node.
     211  	  __node_start_pos -= __c->_M_left->_M_size;
     212  	  __dirns >>= 1;
     213  	}
     214        if (__current_index < 0)
     215  	{
     216  	  // We underflowed the cache. Punt.
     217  	  _S_setcache(__x);
     218  	  return;
     219  	}
     220        __current_node = __x._M_path_end[__current_index];
     221        __c = (_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node;
     222        // current_node is a concatenation node.  We are positioned on the first
     223        // character in its right child.
     224        // node_start_pos is starting position of current_node.
     225        __node_start_pos += __c->_M_left->_M_size;
     226        __current_node = __c->_M_right;
     227        __x._M_path_end[++__current_index] = __current_node;
     228        __dirns |= 1;
     229        while (__detail::_S_concat == __current_node->_M_tag)
     230  	{
     231  	  ++__current_index;
     232  	  if (int(_S_path_cache_len) == __current_index)
     233  	    {
     234  	      int __i;
     235  	      for (__i = 0; __i < int(_S_path_cache_len) - 1; __i++)
     236  		__x._M_path_end[__i] = __x._M_path_end[__i+1];
     237  	      --__current_index;
     238  	    }
     239  	  __current_node =
     240  	    ((_Rope_RopeConcatenation<_CharT, _Alloc>*)__current_node)->_M_left;
     241  	  __x._M_path_end[__current_index] = __current_node;
     242  	  __dirns <<= 1;
     243  	  // node_start_pos is unchanged.
     244  	}
     245        __x._M_leaf_index = __current_index;
     246        __x._M_leaf_pos = __node_start_pos;
     247        __x._M_path_directions = __dirns;
     248        _S_setbuf(__x);
     249      }
     250  
     251    template <class _CharT, class _Alloc>
     252      void
     253      _Rope_iterator_base<_CharT, _Alloc>::
     254      _M_incr(std::size_t __n)
     255      {
     256        _M_current_pos += __n;
     257        if (0 != _M_buf_ptr)
     258  	{
     259  	  std::size_t __chars_left = _M_buf_end - _M_buf_ptr;
     260  	  if (__chars_left > __n)
     261  	    _M_buf_ptr += __n;
     262  	  else if (__chars_left == __n)
     263  	    {
     264  	      _M_buf_ptr += __n;
     265  	      _S_setcache_for_incr(*this);
     266  	    }
     267  	  else
     268  	    _M_buf_ptr = 0;
     269  	}
     270      }
     271  
     272    template <class _CharT, class _Alloc>
     273      void
     274      _Rope_iterator_base<_CharT, _Alloc>::
     275      _M_decr(std::size_t __n)
     276      {
     277        if (0 != _M_buf_ptr)
     278  	{
     279  	  std::size_t __chars_left = _M_buf_ptr - _M_buf_start;
     280  	  if (__chars_left >= __n)
     281  	    _M_buf_ptr -= __n;
     282  	  else
     283  	    _M_buf_ptr = 0;
     284  	}
     285        _M_current_pos -= __n;
     286      }
     287  
     288    template <class _CharT, class _Alloc>
     289      void
     290      _Rope_iterator<_CharT, _Alloc>::
     291      _M_check()
     292      {
     293        if (_M_root_rope->_M_tree_ptr != this->_M_root)
     294  	{
     295  	  // _Rope was modified.  Get things fixed up.
     296  	  _RopeRep::_S_unref(this->_M_root);
     297  	  this->_M_root = _M_root_rope->_M_tree_ptr;
     298  	  _RopeRep::_S_ref(this->_M_root);
     299  	  this->_M_buf_ptr = 0;
     300  	}
     301      }
     302  
     303    template <class _CharT, class _Alloc>
     304      inline
     305      _Rope_const_iterator<_CharT, _Alloc>::
     306      _Rope_const_iterator(const _Rope_iterator<_CharT, _Alloc>& __x)
     307      : _Rope_iterator_base<_CharT, _Alloc>(__x)
     308      { }
     309  
     310    template <class _CharT, class _Alloc>
     311      inline
     312      _Rope_iterator<_CharT, _Alloc>::
     313      _Rope_iterator(rope<_CharT, _Alloc>& __r, std::size_t __pos)
     314      : _Rope_iterator_base<_CharT,_Alloc>(__r._M_tree_ptr, __pos),
     315        _M_root_rope(&__r)
     316      { _RopeRep::_S_ref(this->_M_root); }
     317  
     318    template <class _CharT, class _Alloc>
     319      inline std::size_t
     320      rope<_CharT, _Alloc>::
     321      _S_char_ptr_len(const _CharT* __s)
     322      {
     323        const _CharT* __p = __s;
     324        
     325        while (!_S_is0(*__p))
     326  	++__p;
     327        return (__p - __s);
     328      }
     329  
     330  
     331  #ifndef __GC
     332  
     333    template <class _CharT, class _Alloc>
     334      inline void
     335      _Rope_RopeRep<_CharT, _Alloc>::
     336      _M_free_c_string()
     337      {
     338        _CharT* __cstr = _M_c_string;
     339        if (0 != __cstr)
     340  	{
     341  	  std::size_t __size = this->_M_size + 1;
     342  	  std::_Destroy(__cstr, __cstr + __size, _M_get_allocator());
     343  	  this->_Data_deallocate(__cstr, __size);
     344  	}
     345      }
     346  
     347    template <class _CharT, class _Alloc>
     348      inline void
     349      _Rope_RopeRep<_CharT, _Alloc>::
     350      _S_free_string(_CharT* __s, std::size_t __n, allocator_type& __a)
     351      {
     352        if (!_S_is_basic_char_type((_CharT*)0))
     353  	std::_Destroy(__s, __s + __n, __a);
     354        
     355        //  This has to be a static member, so this gets a bit messy
     356        __a.deallocate(__s,
     357  		     _Rope_RopeLeaf<_CharT, _Alloc>::_S_rounded_up_size(__n));
     358      }
     359  
     360    //  There are several reasons for not doing this with virtual destructors
     361    //  and a class specific delete operator:
     362    //  - A class specific delete operator can't easily get access to
     363    //    allocator instances if we need them.
     364    //  - Any virtual function would need a 4 or byte vtable pointer;
     365    //    this only requires a one byte tag per object.
     366    template <class _CharT, class _Alloc>
     367      void
     368      _Rope_RopeRep<_CharT, _Alloc>::
     369      _M_free_tree()
     370      {
     371        switch(_M_tag)
     372  	{
     373  	case __detail::_S_leaf:
     374  	  {
     375  	    _Rope_RopeLeaf<_CharT, _Alloc>* __l
     376  	      = (_Rope_RopeLeaf<_CharT, _Alloc>*)this;
     377  	    __l->_Rope_RopeLeaf<_CharT, _Alloc>::~_Rope_RopeLeaf();
     378  	    this->_L_deallocate(__l, 1);
     379  	    break;
     380  	  }
     381  	case __detail::_S_concat:
     382  	  {
     383  	    _Rope_RopeConcatenation<_CharT,_Alloc>* __c
     384  	      = (_Rope_RopeConcatenation<_CharT, _Alloc>*)this;
     385  	    __c->_Rope_RopeConcatenation<_CharT, _Alloc>::
     386  	      ~_Rope_RopeConcatenation();
     387  	    this->_C_deallocate(__c, 1);
     388  	    break;
     389  	  }
     390  	case __detail::_S_function:
     391  	  {
     392  	    _Rope_RopeFunction<_CharT, _Alloc>* __f
     393  	      = (_Rope_RopeFunction<_CharT, _Alloc>*)this;
     394  	    __f->_Rope_RopeFunction<_CharT, _Alloc>::~_Rope_RopeFunction();
     395  	    this->_F_deallocate(__f, 1);
     396  	    break;
     397  	  }
     398  	case __detail::_S_substringfn:
     399  	  {
     400  	    _Rope_RopeSubstring<_CharT, _Alloc>* __ss =
     401  	      (_Rope_RopeSubstring<_CharT, _Alloc>*)this;
     402  	    __ss->_Rope_RopeSubstring<_CharT, _Alloc>::
     403  	      ~_Rope_RopeSubstring();
     404  	    this->_S_deallocate(__ss, 1);
     405  	    break;
     406  	  }
     407  	}
     408      }
     409  #else
     410  
     411    template <class _CharT, class _Alloc>
     412      inline void
     413      _Rope_RopeRep<_CharT, _Alloc>::
     414      _S_free_string(const _CharT*, std::size_t, allocator_type)
     415      { }
     416  
     417  #endif
     418  
     419    // Concatenate a C string onto a leaf rope by copying the rope data.
     420    // Used for short ropes.
     421    template <class _CharT, class _Alloc>
     422      typename rope<_CharT, _Alloc>::_RopeLeaf*
     423      rope<_CharT, _Alloc>::
     424      _S_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter,
     425  			     std::size_t __len)
     426      {
     427        std::size_t __old_len = __r->_M_size;
     428        _CharT* __new_data = (_CharT*)
     429  	rope::_Data_allocate(_S_rounded_up_size(__old_len + __len));
     430        _RopeLeaf* __result;
     431  
     432        uninitialized_copy_n(__r->_M_data, __old_len, __new_data);
     433        uninitialized_copy_n(__iter, __len, __new_data + __old_len);
     434        _S_cond_store_eos(__new_data[__old_len + __len]);
     435        __try
     436  	{
     437  	  __result = _S_new_RopeLeaf(__new_data, __old_len + __len,
     438  				     __r->_M_get_allocator());
     439  	}
     440        __catch(...)
     441  	{
     442  	  _RopeRep::__STL_FREE_STRING(__new_data, __old_len + __len,
     443  				      __r->_M_get_allocator());
     444  	  __throw_exception_again;
     445  	}
     446        return __result;
     447      }
     448  
     449  #ifndef __GC
     450    // As above, but it's OK to clobber original if refcount is 1
     451    template <class _CharT, class _Alloc>
     452      typename rope<_CharT,_Alloc>::_RopeLeaf*
     453      rope<_CharT, _Alloc>::
     454      _S_destr_leaf_concat_char_iter(_RopeLeaf* __r, const _CharT* __iter,
     455  				   std::size_t __len)
     456      {
     457        if (__r->_M_ref_count > 1)
     458  	return _S_leaf_concat_char_iter(__r, __iter, __len);
     459        std::size_t __old_len = __r->_M_size;
     460        if (_S_allocated_capacity(__old_len) >= __old_len + __len)
     461  	{
     462  	  // The space has been partially initialized for the standard
     463  	  // character types.  But that doesn't matter for those types.
     464  	  uninitialized_copy_n(__iter, __len, __r->_M_data + __old_len);
     465  	  if (_S_is_basic_char_type((_CharT*)0))
     466  	    _S_cond_store_eos(__r->_M_data[__old_len + __len]);
     467  	  else if (__r->_M_c_string != __r->_M_data && 0 != __r->_M_c_string)
     468  	    {
     469  	      __r->_M_free_c_string();
     470  	      __r->_M_c_string = 0;
     471  	    }
     472  	  __r->_M_size = __old_len + __len;
     473  	  __r->_M_ref_count = 2;
     474  	  return __r;
     475  	}
     476        else
     477  	{
     478  	  _RopeLeaf* __result = _S_leaf_concat_char_iter(__r, __iter, __len);
     479  	  return __result;
     480  	}
     481      }
     482  #endif
     483  
     484    // Assumes left and right are not 0.
     485    // Does not increment (nor decrement on exception) child reference counts.
     486    // Result has ref count 1.
     487    template <class _CharT, class _Alloc>
     488      typename rope<_CharT, _Alloc>::_RopeRep*
     489      rope<_CharT, _Alloc>::
     490      _S_tree_concat(_RopeRep* __left, _RopeRep* __right)
     491      {
     492        using std::size_t;
     493        _RopeConcatenation* __result = _S_new_RopeConcatenation(__left, __right,
     494  							      __left->
     495  							      _M_get_allocator());
     496        size_t __depth = __result->_M_depth;
     497        
     498        if (__depth > 20
     499  	  && (__result->_M_size < 1000
     500  	      || __depth > size_t(__detail::_S_max_rope_depth)))
     501  	{
     502  	  _RopeRep* __balanced;
     503  
     504  	  __try
     505  	    {
     506  	      __balanced = _S_balance(__result);
     507  	      __result->_M_unref_nonnil();
     508  	    }
     509  	  __catch(...)
     510  	    {
     511  	      rope::_C_deallocate(__result,1);
     512  	      __throw_exception_again;
     513  	    }
     514  	  // In case of exception, we need to deallocate
     515  	  // otherwise dangling result node.  But caller
     516  	  // still owns its children.  Thus unref is
     517  	  // inappropriate.
     518  	  return __balanced;
     519  	}
     520        else
     521  	return __result;
     522      }
     523  
     524    template <class _CharT, class _Alloc>
     525      typename rope<_CharT, _Alloc>::_RopeRep*
     526      rope<_CharT, _Alloc>::
     527      _S_concat_char_iter(_RopeRep* __r, const _CharT*__s, std::size_t __slen,
     528  			allocator_type& __a)
     529      {
     530        using std::size_t;
     531        _RopeRep* __result;
     532        if (0 == __slen)
     533  	{
     534  	  _S_ref(__r);
     535  	  return __r;
     536  	}
     537        if (0 == __r)
     538  	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
     539        if (__r->_M_tag == __detail::_S_leaf
     540  	  && __r->_M_size + __slen <= size_t(_S_copy_max))
     541  	{
     542  	  __result = _S_leaf_concat_char_iter((_RopeLeaf*)__r, __s, __slen);
     543  	  return __result;
     544  	}
     545        if (__detail::_S_concat == __r->_M_tag
     546  	  && __detail::_S_leaf == ((_RopeConcatenation*) __r)->_M_right->_M_tag)
     547  	{
     548  	  _RopeLeaf* __right =
     549  	    (_RopeLeaf* )(((_RopeConcatenation* )__r)->_M_right);
     550  	  if (__right->_M_size + __slen <= size_t(_S_copy_max))
     551  	    {
     552  	      _RopeRep* __left = ((_RopeConcatenation*)__r)->_M_left;
     553  	      _RopeRep* __nright =
     554  		_S_leaf_concat_char_iter((_RopeLeaf*)__right, __s, __slen);
     555  	      __left->_M_ref_nonnil();
     556  	      __try
     557  		{ __result = _S_tree_concat(__left, __nright); }
     558  	      __catch(...)
     559  		{
     560  		  _S_unref(__left);
     561  		  _S_unref(__nright);
     562  		  __throw_exception_again;
     563  		}
     564  	      return __result;
     565  	    }
     566  	}
     567        _RopeRep* __nright = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
     568        __try
     569  	{
     570  	  __r->_M_ref_nonnil();
     571  	  __result = _S_tree_concat(__r, __nright);
     572  	}
     573        __catch(...)
     574  	{
     575  	  _S_unref(__r);
     576  	  _S_unref(__nright);
     577  	  __throw_exception_again;
     578  	}
     579        return __result;
     580      }
     581  
     582  #ifndef __GC
     583    template <class _CharT, class _Alloc>
     584      typename rope<_CharT,_Alloc>::_RopeRep*
     585      rope<_CharT,_Alloc>::
     586      _S_destr_concat_char_iter(_RopeRep* __r, const _CharT* __s,
     587  			      std::size_t __slen, allocator_type& __a)
     588      {
     589        using std::size_t;
     590        _RopeRep* __result;
     591        if (0 == __r)
     592  	return __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
     593        size_t __count = __r->_M_ref_count;
     594        size_t __orig_size = __r->_M_size;
     595        if (__count > 1)
     596  	return _S_concat_char_iter(__r, __s, __slen, __a);
     597        if (0 == __slen)
     598  	{
     599  	  __r->_M_ref_count = 2;      // One more than before
     600  	  return __r;
     601  	}
     602        if (__orig_size + __slen <= size_t(_S_copy_max)
     603  	  && __detail::_S_leaf == __r->_M_tag)
     604  	{
     605  	  __result = _S_destr_leaf_concat_char_iter((_RopeLeaf*)__r, __s, 
     606  						    __slen);
     607  	  return __result;
     608  	}
     609        if (__detail::_S_concat == __r->_M_tag)
     610  	{
     611  	  _RopeLeaf* __right = (_RopeLeaf*)(((_RopeConcatenation*)
     612  					     __r)->_M_right);
     613  	  if (__detail::_S_leaf == __right->_M_tag
     614  	      && __right->_M_size + __slen <= size_t(_S_copy_max))
     615  	    {
     616  	      _RopeRep* __new_right =
     617  		_S_destr_leaf_concat_char_iter(__right, __s, __slen);
     618  	      if (__right == __new_right)
     619  		__new_right->_M_ref_count = 1;
     620  	      else
     621  		__right->_M_unref_nonnil();
     622  	      __r->_M_ref_count = 2;    // One more than before.
     623  	      ((_RopeConcatenation*)__r)->_M_right = __new_right;
     624  	      __r->_M_size = __orig_size + __slen;
     625  	      if (0 != __r->_M_c_string)
     626  		{
     627  		  __r->_M_free_c_string();
     628  		  __r->_M_c_string = 0;
     629  		}
     630  	      return __r;
     631  	    }
     632  	}
     633        _RopeRep* __right = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__s, __slen, __a);
     634        __r->_M_ref_nonnil();
     635        __try
     636  	{ __result = _S_tree_concat(__r, __right); }
     637        __catch(...)
     638  	{
     639  	  _S_unref(__r);
     640  	  _S_unref(__right);
     641  	  __throw_exception_again;
     642  	}
     643        return __result;
     644      }
     645  #endif /* !__GC */
     646    
     647    template <class _CharT, class _Alloc>
     648      typename rope<_CharT, _Alloc>::_RopeRep*
     649      rope<_CharT, _Alloc>::
     650      _S_concat(_RopeRep* __left, _RopeRep* __right)
     651      {
     652        using std::size_t;
     653        if (0 == __left)
     654  	{
     655  	  _S_ref(__right);
     656  	  return __right;
     657  	}
     658        if (0 == __right)
     659  	{
     660  	  __left->_M_ref_nonnil();
     661  	  return __left;
     662  	}
     663        if (__detail::_S_leaf == __right->_M_tag)
     664  	{
     665  	  if (__detail::_S_leaf == __left->_M_tag)
     666  	    {
     667  	      if (__right->_M_size + __left->_M_size <= size_t(_S_copy_max))
     668  		return _S_leaf_concat_char_iter((_RopeLeaf*)__left,
     669  						((_RopeLeaf*)__right)->_M_data,
     670  						__right->_M_size);
     671  	    }
     672  	  else if (__detail::_S_concat == __left->_M_tag
     673  		   && __detail::_S_leaf == ((_RopeConcatenation*)
     674  						   __left)->_M_right->_M_tag)
     675  	    {
     676  	      _RopeLeaf* __leftright =
     677  		(_RopeLeaf*)(((_RopeConcatenation*)__left)->_M_right);
     678  	      if (__leftright->_M_size
     679  		  + __right->_M_size <= size_t(_S_copy_max))
     680  		{
     681  		  _RopeRep* __leftleft = ((_RopeConcatenation*)__left)->_M_left;
     682  		  _RopeRep* __rest = _S_leaf_concat_char_iter(__leftright,
     683  							      ((_RopeLeaf*)
     684  							       __right)->
     685  							      _M_data,
     686  							      __right->_M_size);
     687  		  __leftleft->_M_ref_nonnil();
     688  		  __try
     689  		    { return(_S_tree_concat(__leftleft, __rest)); }
     690  		  __catch(...)
     691  		    {
     692  		      _S_unref(__leftleft);
     693  		      _S_unref(__rest);
     694  		      __throw_exception_again;
     695  		    }
     696  		}
     697  	    }
     698  	}
     699        __left->_M_ref_nonnil();
     700        __right->_M_ref_nonnil();
     701        __try
     702  	{ return(_S_tree_concat(__left, __right)); }
     703        __catch(...)
     704  	{
     705  	  _S_unref(__left);
     706  	  _S_unref(__right);
     707  	  __throw_exception_again;
     708  	}
     709      }
     710  
     711    template <class _CharT, class _Alloc>
     712      typename rope<_CharT, _Alloc>::_RopeRep*
     713      rope<_CharT, _Alloc>::
     714      _S_substring(_RopeRep* __base, std::size_t __start, std::size_t __endp1)
     715      {
     716        using std::size_t;
     717        if (0 == __base)
     718  	return 0;
     719        size_t __len = __base->_M_size;
     720        size_t __adj_endp1;
     721        const size_t __lazy_threshold = 128;
     722        
     723        if (__endp1 >= __len)
     724  	{
     725  	  if (0 == __start)
     726  	    {
     727  	      __base->_M_ref_nonnil();
     728  	      return __base;
     729  	    }
     730  	  else
     731  	    __adj_endp1 = __len;
     732  	  
     733  	}
     734        else
     735  	__adj_endp1 = __endp1;
     736  
     737        switch(__base->_M_tag)
     738  	{
     739  	case __detail::_S_concat:
     740  	    {
     741  	      _RopeConcatenation* __c = (_RopeConcatenation*)__base;
     742  	      _RopeRep* __left = __c->_M_left;
     743  	      _RopeRep* __right = __c->_M_right;
     744  	      size_t __left_len = __left->_M_size;
     745  	      _RopeRep* __result;
     746  	      
     747  	      if (__adj_endp1 <= __left_len)
     748  		return _S_substring(__left, __start, __endp1);
     749  	      else if (__start >= __left_len)
     750  		return _S_substring(__right, __start - __left_len,
     751  				    __adj_endp1 - __left_len);
     752  	      _Self_destruct_ptr __left_result(_S_substring(__left,
     753  							    __start,
     754  							    __left_len));
     755  	      _Self_destruct_ptr __right_result(_S_substring(__right, 0,
     756  							     __endp1 
     757  							     - __left_len));
     758  	      __result = _S_concat(__left_result, __right_result);
     759  	      return __result;
     760  	    }
     761  	case __detail::_S_leaf:
     762  	  {
     763  	    _RopeLeaf* __l = (_RopeLeaf*)__base;
     764  	    _RopeLeaf* __result;
     765  	    size_t __result_len;
     766  	    if (__start >= __adj_endp1)
     767  	      return 0;
     768  	    __result_len = __adj_endp1 - __start;
     769  	    if (__result_len > __lazy_threshold)
     770  	      goto lazy;
     771  #ifdef __GC
     772  	    const _CharT* __section = __l->_M_data + __start;
     773  	    __result = _S_new_RopeLeaf(__section, __result_len,
     774  				       __base->_M_get_allocator());
     775  	    __result->_M_c_string = 0;  // Not eos terminated.
     776  #else
     777  	    // We should sometimes create substring node instead.
     778  	    __result = __STL_ROPE_FROM_UNOWNED_CHAR_PTR(__l->_M_data + __start,
     779  							__result_len,
     780  							__base->
     781  							_M_get_allocator());
     782  #endif
     783  	    return __result;
     784  	  }
     785  	case __detail::_S_substringfn:
     786  	  // Avoid introducing multiple layers of substring nodes.
     787  	  {
     788  	    _RopeSubstring* __old = (_RopeSubstring*)__base;
     789  	    size_t __result_len;
     790  	    if (__start >= __adj_endp1)
     791  	      return 0;
     792  	    __result_len = __adj_endp1 - __start;
     793  	    if (__result_len > __lazy_threshold)
     794  	      {
     795  		_RopeSubstring* __result =
     796  		  _S_new_RopeSubstring(__old->_M_base,
     797  				       __start + __old->_M_start,
     798  				       __adj_endp1 - __start,
     799  				       __base->_M_get_allocator());
     800  		return __result;
     801  		
     802  	      } // *** else fall through: ***
     803  	  }
     804  	case __detail::_S_function:
     805  	  {
     806  	    _RopeFunction* __f = (_RopeFunction*)__base;
     807  	    _CharT* __section;
     808  	    size_t __result_len;
     809  	    if (__start >= __adj_endp1)
     810  	      return 0;
     811  	    __result_len = __adj_endp1 - __start;
     812  	    
     813  	    if (__result_len > __lazy_threshold)
     814  	      goto lazy;
     815  	    __section = (_CharT*)
     816  	      rope::_Data_allocate(_S_rounded_up_size(__result_len));
     817  	    __try
     818  	      {	(*(__f->_M_fn))(__start, __result_len, __section); }
     819  	    __catch(...)
     820  	      {
     821  		_RopeRep::__STL_FREE_STRING(__section, __result_len,
     822  					    __base->_M_get_allocator());
     823  		__throw_exception_again;
     824  	      }
     825  	    _S_cond_store_eos(__section[__result_len]);
     826  	    return _S_new_RopeLeaf(__section, __result_len,
     827  				   __base->_M_get_allocator());
     828  	  }
     829  	}
     830      lazy:
     831        {
     832  	// Create substring node.
     833  	return _S_new_RopeSubstring(__base, __start, __adj_endp1 - __start,
     834  				    __base->_M_get_allocator());
     835        }
     836      }
     837  
     838    template<class _CharT>
     839      class _Rope_flatten_char_consumer
     840      : public _Rope_char_consumer<_CharT>
     841      {
     842      private:
     843        _CharT* _M_buf_ptr;
     844      public:
     845        
     846        _Rope_flatten_char_consumer(_CharT* __buffer)
     847        { _M_buf_ptr = __buffer; }
     848  
     849        ~_Rope_flatten_char_consumer() {}
     850        
     851        bool
     852        operator()(const _CharT* __leaf, std::size_t __n)
     853        {
     854  	uninitialized_copy_n(__leaf, __n, _M_buf_ptr);
     855  	_M_buf_ptr += __n;
     856  	return true;
     857        }
     858      };
     859  
     860    template<class _CharT>
     861      class _Rope_find_char_char_consumer
     862      : public _Rope_char_consumer<_CharT>
     863      {
     864      private:
     865        _CharT _M_pattern;
     866      public:
     867        std::size_t _M_count;  // Number of nonmatching characters
     868        
     869        _Rope_find_char_char_consumer(_CharT __p)
     870        : _M_pattern(__p), _M_count(0) {}
     871  	
     872        ~_Rope_find_char_char_consumer() {}
     873        
     874        bool
     875        operator()(const _CharT* __leaf, std::size_t __n)
     876        {
     877  	std::size_t __i;
     878  	for (__i = 0; __i < __n; __i++)
     879  	  {
     880  	    if (__leaf[__i] == _M_pattern)
     881  	      {
     882  		_M_count += __i;
     883  		return false;
     884  	      }
     885  	  }
     886  	_M_count += __n; return true;
     887        }
     888      };
     889  
     890    template<class _CharT, class _Traits>
     891    // Here _CharT is both the stream and rope character type.
     892      class _Rope_insert_char_consumer
     893      : public _Rope_char_consumer<_CharT>
     894      {
     895      private:
     896        typedef std::basic_ostream<_CharT,_Traits> _Insert_ostream;
     897        _Insert_ostream& _M_o;
     898      public:
     899        _Rope_insert_char_consumer(_Insert_ostream& __writer)
     900  	: _M_o(__writer) {}
     901        ~_Rope_insert_char_consumer() { }
     902        // Caller is presumed to own the ostream
     903        bool operator() (const _CharT* __leaf, std::size_t __n);
     904        // Returns true to continue traversal.
     905      };
     906  
     907    template<class _CharT, class _Traits>
     908      bool
     909      _Rope_insert_char_consumer<_CharT, _Traits>::
     910      operator()(const _CharT* __leaf, std::size_t __n)
     911      {
     912        std::size_t __i;
     913        //  We assume that formatting is set up correctly for each element.
     914        for (__i = 0; __i < __n; __i++)
     915  	_M_o.put(__leaf[__i]);
     916        return true;
     917      }
     918  
     919    template <class _CharT, class _Alloc>
     920      bool
     921      rope<_CharT, _Alloc>::
     922      _S_apply_to_pieces(_Rope_char_consumer<_CharT>& __c, const _RopeRep* __r,
     923  		       std::size_t __begin, std::size_t __end)
     924      {
     925        using std::size_t;
     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(std::basic_ostream<_CharT, _Traits>& __o, std::size_t __n)
     986      {
     987        char __f = __o.fill();
     988        std::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      std::basic_ostream<_CharT, _Traits>&
    1010      operator<<(std::basic_ostream<_CharT, _Traits>& __o,
    1011  	       const rope<_CharT, _Alloc>& __r)
    1012      {
    1013        using std::size_t;
    1014        size_t __w = __o.width();
    1015        bool __left = bool(__o.flags() & std::ios::left);
    1016        size_t __pad_len;
    1017        size_t __rope_len = __r.size();
    1018        _Rope_insert_char_consumer<_CharT, _Traits> __c(__o);
    1019        bool __is_simple = _Rope_is_simple((_CharT*)0);
    1020        
    1021        if (__rope_len < __w)
    1022  	__pad_len = __w - __rope_len;
    1023        else
    1024  	__pad_len = 0;
    1025  
    1026        if (!__is_simple)
    1027  	__o.width(__w / __rope_len);
    1028        __try
    1029  	{
    1030  	  if (__is_simple && !__left && __pad_len > 0)
    1031  	    _Rope_fill(__o, __pad_len);
    1032  	  __r.apply_to_pieces(0, __r.size(), __c);
    1033  	  if (__is_simple && __left && __pad_len > 0)
    1034  	    _Rope_fill(__o, __pad_len);
    1035  	  if (!__is_simple)
    1036  	    __o.width(__w);
    1037  	}
    1038        __catch(...)
    1039  	{
    1040  	  if (!__is_simple)
    1041  	    __o.width(__w);
    1042  	  __throw_exception_again;
    1043  	}
    1044        return __o;
    1045      }
    1046  
    1047    template <class _CharT, class _Alloc>
    1048      _CharT*
    1049      rope<_CharT, _Alloc>::
    1050      _S_flatten(_RopeRep* __r, std::size_t __start, std::size_t __len,
    1051  	       _CharT* __buffer)
    1052      {
    1053        _Rope_flatten_char_consumer<_CharT> __c(__buffer);
    1054        _S_apply_to_pieces(__c, __r, __start, __start + __len);
    1055        return(__buffer + __len);
    1056      }
    1057  
    1058    template <class _CharT, class _Alloc>
    1059      std::size_t
    1060      rope<_CharT, _Alloc>::
    1061      find(_CharT __pattern, std::size_t __start) const
    1062      {
    1063        _Rope_find_char_char_consumer<_CharT> __c(__pattern);
    1064        _S_apply_to_pieces(__c, this->_M_tree_ptr, __start, size());
    1065        size_type __result_pos = __start + __c._M_count;
    1066  #ifndef __STL_OLD_ROPE_SEMANTICS
    1067        if (__result_pos == size())
    1068  	__result_pos = npos;
    1069  #endif
    1070        return __result_pos;
    1071      }
    1072  
    1073    template <class _CharT, class _Alloc>
    1074      _CharT*
    1075      rope<_CharT, _Alloc>::
    1076      _S_flatten(_RopeRep* __r, _CharT* __buffer)
    1077      {
    1078        if (0 == __r)
    1079  	return __buffer;
    1080        switch(__r->_M_tag)
    1081  	{
    1082  	case __detail::_S_concat:
    1083  	  {
    1084  	    _RopeConcatenation* __c = (_RopeConcatenation*)__r;
    1085  	    _RopeRep* __left = __c->_M_left;
    1086  	    _RopeRep* __right = __c->_M_right;
    1087  	    _CharT* __rest = _S_flatten(__left, __buffer);
    1088  	    return _S_flatten(__right, __rest);
    1089  	  }
    1090  	case __detail::_S_leaf:
    1091  	  {
    1092  	    _RopeLeaf* __l = (_RopeLeaf*)__r;
    1093  	    return copy_n(__l->_M_data, __l->_M_size, __buffer).second;
    1094  	  }
    1095  	case __detail::_S_function:
    1096  	case __detail::_S_substringfn:
    1097  	  // We don't yet do anything with substring nodes.
    1098  	  // This needs to be fixed before ropefiles will work well.
    1099  	  {
    1100  	    _RopeFunction* __f = (_RopeFunction*)__r;
    1101  	    (*(__f->_M_fn))(0, __f->_M_size, __buffer);
    1102  	    return __buffer + __f->_M_size;
    1103  	  }
    1104  	default:
    1105  	  return 0;
    1106  	}
    1107      }
    1108  
    1109    // This needs work for _CharT != char
    1110    template <class _CharT, class _Alloc>
    1111      void
    1112      rope<_CharT, _Alloc>::
    1113      _S_dump(_RopeRep* __r, int __indent)
    1114      {
    1115        using std::printf;
    1116        for (int __i = 0; __i < __indent; __i++)
    1117  	putchar(' ');
    1118        if (0 == __r)
    1119  	{
    1120  	  printf("NULL\n");
    1121  	  return;
    1122  	}
    1123        if (__detail::_S_concat == __r->_M_tag)
    1124  	{
    1125  	  _RopeConcatenation* __c = (_RopeConcatenation*)__r;
    1126  	  _RopeRep* __left = __c->_M_left;
    1127  	  _RopeRep* __right = __c->_M_right;
    1128  	  
    1129  #ifdef __GC
    1130  	  printf("Concatenation %p (depth = %d, len = %ld, %s balanced)\n",
    1131  		 __r, __r->_M_depth, __r->_M_size,
    1132  		 __r->_M_is_balanced? "" : "not");
    1133  #else
    1134  	  printf("Concatenation %p (rc = %ld, depth = %d, "
    1135  		 "len = %ld, %s balanced)\n",
    1136  		 __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size,
    1137  		 __r->_M_is_balanced? "" : "not");
    1138  #endif
    1139  	  _S_dump(__left, __indent + 2);
    1140  	  _S_dump(__right, __indent + 2);
    1141  	  return;
    1142  	}
    1143        else
    1144  	{
    1145  	  const char* __kind;
    1146  	  
    1147  	  switch (__r->_M_tag)
    1148  	    {
    1149  	    case __detail::_S_leaf:
    1150  	      __kind = "Leaf";
    1151  	      break;
    1152  	    case __detail::_S_function:
    1153  	      __kind = "Function";
    1154  	      break;
    1155  	    case __detail::_S_substringfn:
    1156  	      __kind = "Function representing substring";
    1157  	      break;
    1158  	    default:
    1159  	      __kind = "(corrupted kind field!)";
    1160  	    }
    1161  #ifdef __GC
    1162  	  printf("%s %p (depth = %d, len = %ld) ",
    1163  		 __kind, __r, __r->_M_depth, __r->_M_size);
    1164  #else
    1165  	  printf("%s %p (rc = %ld, depth = %d, len = %ld) ",
    1166  		 __kind, __r, __r->_M_ref_count, __r->_M_depth, __r->_M_size);
    1167  #endif
    1168  	  if (_S_is_one_byte_char_type((_CharT*)0))
    1169  	    {
    1170  	      const int __max_len = 40;
    1171  	      _Self_destruct_ptr __prefix(_S_substring(__r, 0, __max_len));
    1172  	      _CharT __buffer[__max_len + 1];
    1173  	      bool __too_big = __r->_M_size > __prefix->_M_size;
    1174  	      
    1175  	      _S_flatten(__prefix, __buffer);
    1176  	      __buffer[__prefix->_M_size] = _S_eos((_CharT*)0);
    1177  	      printf("%s%s\n", (char*)__buffer,
    1178  		     __too_big? "...\n" : "\n");
    1179  	    }
    1180  	  else
    1181  	    printf("\n");
    1182  	}
    1183      }
    1184  
    1185    template <class _CharT, class _Alloc>
    1186      const unsigned long
    1187      rope<_CharT, _Alloc>::
    1188      _S_min_len[int(__detail::_S_max_rope_depth) + 1] = {
    1189        /* 0 */1, /* 1 */2, /* 2 */3, /* 3 */5, /* 4 */8, /* 5 */13, /* 6 */21,
    1190        /* 7 */34, /* 8 */55, /* 9 */89, /* 10 */144, /* 11 */233, /* 12 */377,
    1191        /* 13 */610, /* 14 */987, /* 15 */1597, /* 16 */2584, /* 17 */4181,
    1192        /* 18 */6765, /* 19 */10946, /* 20 */17711, /* 21 */28657, /* 22 */46368,
    1193        /* 23 */75025, /* 24 */121393, /* 25 */196418, /* 26 */317811,
    1194        /* 27 */514229, /* 28 */832040, /* 29 */1346269, /* 30 */2178309,
    1195        /* 31 */3524578, /* 32 */5702887, /* 33 */9227465, /* 34 */14930352,
    1196        /* 35 */24157817, /* 36 */39088169, /* 37 */63245986, /* 38 */102334155,
    1197        /* 39 */165580141, /* 40 */267914296, /* 41 */433494437,
    1198        /* 42 */701408733, /* 43 */1134903170, /* 44 */1836311903,
    1199        /* 45 */2971215073u };
    1200    // These are Fibonacci numbers < 2**32.
    1201  
    1202    template <class _CharT, class _Alloc>
    1203      typename rope<_CharT, _Alloc>::_RopeRep*
    1204      rope<_CharT, _Alloc>::
    1205      _S_balance(_RopeRep* __r)
    1206      {
    1207        _RopeRep* __forest[int(__detail::_S_max_rope_depth) + 1];
    1208        _RopeRep* __result = 0;
    1209        int __i;
    1210        // Invariant:
    1211        // The concatenation of forest in descending order is equal to __r.
    1212        // __forest[__i]._M_size >= _S_min_len[__i]
    1213        // __forest[__i]._M_depth = __i
    1214        // References from forest are included in refcount.
    1215        
    1216        for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
    1217  	__forest[__i] = 0;
    1218        __try
    1219  	{
    1220  	  _S_add_to_forest(__r, __forest);
    1221  	  for (__i = 0; __i <= int(__detail::_S_max_rope_depth); ++__i)
    1222  	    if (0 != __forest[__i])
    1223  	      {
    1224  #ifndef __GC
    1225  		_Self_destruct_ptr __old(__result);
    1226  #endif
    1227  		__result = _S_concat(__forest[__i], __result);
    1228  		__forest[__i]->_M_unref_nonnil();
    1229  #if !defined(__GC) && __cpp_exceptions
    1230  
    1231  #include <bits/requires_hosted.h> // GNU extensions are currently omitted
    1232  		__forest[__i] = 0;
    1233  #endif
    1234  	      }
    1235  	}
    1236        __catch(...)
    1237  	{
    1238  	  for(__i = 0; __i <= int(__detail::_S_max_rope_depth); __i++)
    1239  	    _S_unref(__forest[__i]);
    1240  	  __throw_exception_again;
    1241  	}
    1242        
    1243        if (__result->_M_depth > int(__detail::_S_max_rope_depth))
    1244  	std::__throw_length_error(__N("rope::_S_balance"));
    1245        return(__result);
    1246      }
    1247  
    1248    template <class _CharT, class _Alloc>
    1249      void
    1250      rope<_CharT, _Alloc>::
    1251      _S_add_to_forest(_RopeRep* __r, _RopeRep** __forest)
    1252      {
    1253        if (__r->_M_is_balanced)
    1254  	{
    1255  	  _S_add_leaf_to_forest(__r, __forest);
    1256  	  return;
    1257  	}
    1258  
    1259        {
    1260  	_RopeConcatenation* __c = (_RopeConcatenation*)__r;
    1261  	
    1262  	_S_add_to_forest(__c->_M_left, __forest);
    1263  	_S_add_to_forest(__c->_M_right, __forest);
    1264        }
    1265      }
    1266  
    1267  
    1268    template <class _CharT, class _Alloc>
    1269      void
    1270      rope<_CharT, _Alloc>::
    1271      _S_add_leaf_to_forest(_RopeRep* __r, _RopeRep** __forest)
    1272      {
    1273        _RopeRep* __insertee;		// included in refcount
    1274        _RopeRep* __too_tiny = 0;		// included in refcount
    1275        int __i;				// forest[0..__i-1] is empty
    1276        std::size_t __s = __r->_M_size;
    1277        
    1278        for (__i = 0; __s >= _S_min_len[__i+1]/* not this bucket */; ++__i)
    1279  	{
    1280  	  if (0 != __forest[__i])
    1281  	    {
    1282  #ifndef __GC
    1283  	      _Self_destruct_ptr __old(__too_tiny);
    1284  #endif
    1285  	      __too_tiny = _S_concat_and_set_balanced(__forest[__i],
    1286  						      __too_tiny);
    1287  	      __forest[__i]->_M_unref_nonnil();
    1288  	      __forest[__i] = 0;
    1289  	    }
    1290  	}
    1291        {
    1292  #ifndef __GC
    1293  	_Self_destruct_ptr __old(__too_tiny);
    1294  #endif
    1295  	__insertee = _S_concat_and_set_balanced(__too_tiny, __r);
    1296        }
    1297        // Too_tiny dead, and no longer included in refcount.
    1298        // Insertee is live and included.
    1299        for (;; ++__i)
    1300  	{
    1301  	  if (0 != __forest[__i])
    1302  	    {
    1303  #ifndef __GC
    1304  	      _Self_destruct_ptr __old(__insertee);
    1305  #endif
    1306  	      __insertee = _S_concat_and_set_balanced(__forest[__i],
    1307  						      __insertee);
    1308  	      __forest[__i]->_M_unref_nonnil();
    1309  	      __forest[__i] = 0;
    1310  	    }
    1311  	  if (__i == int(__detail::_S_max_rope_depth)
    1312  	      || __insertee->_M_size < _S_min_len[__i+1])
    1313  	    {
    1314  	      __forest[__i] = __insertee;
    1315  	      // refcount is OK since __insertee is now dead.
    1316  	      return;
    1317  	    }
    1318  	}
    1319      }
    1320  
    1321    template <class _CharT, class _Alloc>
    1322      _CharT
    1323      rope<_CharT, _Alloc>::
    1324      _S_fetch(_RopeRep* __r, size_type __i)
    1325      {
    1326        __GC_CONST _CharT* __cstr = __r->_M_c_string;
    1327        
    1328        if (0 != __cstr)
    1329  	return __cstr[__i];
    1330        for(;;)
    1331  	{
    1332  	  switch(__r->_M_tag)
    1333  	    {
    1334  	    case __detail::_S_concat:
    1335  	      {
    1336  		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
    1337  		_RopeRep* __left = __c->_M_left;
    1338  		std::size_t __left_len = __left->_M_size;
    1339  		
    1340  		if (__i >= __left_len)
    1341  		  {
    1342  		    __i -= __left_len;
    1343  		    __r = __c->_M_right;
    1344  		  } 
    1345  		else
    1346  		  __r = __left;
    1347  	      }
    1348  	      break;
    1349  	    case __detail::_S_leaf:
    1350  	      {
    1351  		_RopeLeaf* __l = (_RopeLeaf*)__r;
    1352  		return __l->_M_data[__i];
    1353  	      }
    1354  	    case __detail::_S_function:
    1355  	    case __detail::_S_substringfn:
    1356  	      {
    1357  		_RopeFunction* __f = (_RopeFunction*)__r;
    1358  		_CharT __result;
    1359  		
    1360  		(*(__f->_M_fn))(__i, 1, &__result);
    1361  		return __result;
    1362  	      }
    1363  	    }
    1364  	}
    1365      }
    1366    
    1367  #ifndef __GC
    1368    // Return a uniquely referenced character slot for the given
    1369    // position, or 0 if that's not possible.
    1370    template <class _CharT, class _Alloc>
    1371      _CharT*
    1372      rope<_CharT, _Alloc>::
    1373      _S_fetch_ptr(_RopeRep* __r, size_type __i)
    1374      {
    1375        _RopeRep* __clrstack[__detail::_S_max_rope_depth];
    1376        std::size_t __csptr = 0;
    1377        
    1378        for(;;)
    1379  	{
    1380  	  if (__r->_M_ref_count > 1)
    1381  	    return 0;
    1382  	  switch(__r->_M_tag)
    1383  	    {
    1384  	    case __detail::_S_concat:
    1385  	      {
    1386  		_RopeConcatenation* __c = (_RopeConcatenation*)__r;
    1387  		_RopeRep* __left = __c->_M_left;
    1388  		std::size_t __left_len = __left->_M_size;
    1389  		
    1390  		if (__c->_M_c_string != 0)
    1391  		  __clrstack[__csptr++] = __c;
    1392  		if (__i >= __left_len)
    1393  		  {
    1394  		    __i -= __left_len;
    1395  		    __r = __c->_M_right;
    1396  		  } 
    1397  		else
    1398  		  __r = __left;
    1399  	      }
    1400  	      break;
    1401  	    case __detail::_S_leaf:
    1402  	      {
    1403  		_RopeLeaf* __l = (_RopeLeaf*)__r;
    1404  		if (__l->_M_c_string != __l->_M_data && __l->_M_c_string != 0)
    1405  		  __clrstack[__csptr++] = __l;
    1406  		while (__csptr > 0)
    1407  		  {
    1408  		    -- __csptr;
    1409  		    _RopeRep* __d = __clrstack[__csptr];
    1410  		    __d->_M_free_c_string();
    1411  		    __d->_M_c_string = 0;
    1412  		  }
    1413  		return __l->_M_data + __i;
    1414  	      }
    1415  	    case __detail::_S_function:
    1416  	    case __detail::_S_substringfn:
    1417  	      return 0;
    1418  	    }
    1419  	}
    1420      }
    1421  #endif /* __GC */
    1422  
    1423    // The following could be implemented trivially using
    1424    // lexicographical_compare_3way.
    1425    // We do a little more work to avoid dealing with rope iterators for
    1426    // flat strings.
    1427    template <class _CharT, class _Alloc>
    1428      int
    1429      rope<_CharT, _Alloc>::
    1430      _S_compare (const _RopeRep* __left, const _RopeRep* __right)
    1431      {
    1432        std::size_t __left_len;
    1433        std::size_t __right_len;
    1434        
    1435        if (0 == __right)
    1436  	return 0 != __left;
    1437        if (0 == __left)
    1438  	return -1;
    1439        __left_len = __left->_M_size;
    1440        __right_len = __right->_M_size;
    1441        if (__detail::_S_leaf == __left->_M_tag)
    1442  	{
    1443  	  _RopeLeaf* __l = (_RopeLeaf*) __left;
    1444  	  if (__detail::_S_leaf == __right->_M_tag)
    1445  	    {
    1446  	      _RopeLeaf* __r = (_RopeLeaf*) __right;
    1447  	      return lexicographical_compare_3way(__l->_M_data,
    1448  						  __l->_M_data + __left_len,
    1449  						  __r->_M_data, __r->_M_data
    1450  						  + __right_len);
    1451  	    }
    1452  	  else
    1453  	    {
    1454  	      const_iterator __rstart(__right, 0);
    1455  	      const_iterator __rend(__right, __right_len);
    1456  	      return lexicographical_compare_3way(__l->_M_data, __l->_M_data
    1457  						  + __left_len,
    1458  						  __rstart, __rend);
    1459  	    }
    1460  	}
    1461        else
    1462  	{
    1463  	  const_iterator __lstart(__left, 0);
    1464  	  const_iterator __lend(__left, __left_len);
    1465  	  if (__detail::_S_leaf == __right->_M_tag)
    1466  	    {
    1467  	      _RopeLeaf* __r = (_RopeLeaf*) __right;
    1468  	      return lexicographical_compare_3way(__lstart, __lend,
    1469  						  __r->_M_data, __r->_M_data
    1470  						  + __right_len);
    1471  	    }
    1472  	  else
    1473  	    {
    1474  	      const_iterator __rstart(__right, 0);
    1475  	      const_iterator __rend(__right, __right_len);
    1476  	      return lexicographical_compare_3way(__lstart, __lend,
    1477  						  __rstart, __rend);
    1478  	    }
    1479  	}
    1480      }
    1481  
    1482    // Assignment to reference proxies.
    1483    template <class _CharT, class _Alloc>
    1484      _Rope_char_ref_proxy<_CharT, _Alloc>&
    1485      _Rope_char_ref_proxy<_CharT, _Alloc>::
    1486      operator=(_CharT __c)
    1487      {
    1488        _RopeRep* __old = _M_root->_M_tree_ptr;
    1489  #ifndef __GC
    1490        // First check for the case in which everything is uniquely
    1491        // referenced.  In that case we can do this destructively.
    1492        _CharT* __ptr = _My_rope::_S_fetch_ptr(__old, _M_pos);
    1493        if (0 != __ptr)
    1494  	{
    1495  	  *__ptr = __c;
    1496  	  return *this;
    1497  	}
    1498  #endif
    1499        _Self_destruct_ptr __left(_My_rope::_S_substring(__old, 0, _M_pos));
    1500        _Self_destruct_ptr __right(_My_rope::_S_substring(__old, _M_pos + 1,
    1501  							__old->_M_size));
    1502        typename _RopeRep::allocator_type __a = _M_root->_M_get_allocator();
    1503        _Self_destruct_ptr __result_left(_My_rope::
    1504  				       _S_destr_concat_char_iter(__left,
    1505  								 &__c, 1,
    1506  								 __a));
    1507  
    1508        _RopeRep* __result = _My_rope::_S_concat(__result_left, __right);
    1509  #ifndef __GC
    1510        _RopeRep::_S_unref(__old);
    1511  #endif
    1512        _M_root->_M_tree_ptr = __result;
    1513        return *this;
    1514      }
    1515  
    1516    template <class _CharT, class _Alloc>
    1517      inline _Rope_char_ref_proxy<_CharT, _Alloc>::
    1518      operator _CharT() const
    1519      {
    1520        if (_M_current_valid)
    1521  	return _M_current;
    1522        else
    1523  	return _My_rope::_S_fetch(_M_root->_M_tree_ptr, _M_pos);
    1524      }
    1525  
    1526    template <class _CharT, class _Alloc>
    1527      _Rope_char_ptr_proxy<_CharT, _Alloc>
    1528      _Rope_char_ref_proxy<_CharT, _Alloc>::
    1529      operator&() const
    1530      { return _Rope_char_ptr_proxy<_CharT, _Alloc>(*this); }
    1531  
    1532    template <class _CharT, class _Alloc>
    1533      rope<_CharT, _Alloc>::
    1534      rope(std::size_t __n, _CharT __c, const allocator_type& __a)
    1535      : _Base(__a)
    1536      {
    1537        using std::__uninitialized_fill_n_a;
    1538  
    1539        rope<_CharT,_Alloc> __result;
    1540        const std::size_t __exponentiate_threshold = 32;
    1541        std::size_t __exponent;
    1542        std::size_t __rest;
    1543        _CharT* __rest_buffer;
    1544        _RopeRep* __remainder;
    1545        rope<_CharT, _Alloc> __remainder_rope;
    1546  
    1547        if (0 == __n)
    1548  	return;
    1549  
    1550        __exponent = __n / __exponentiate_threshold;
    1551        __rest = __n % __exponentiate_threshold;
    1552        if (0 == __rest)
    1553  	__remainder = 0;
    1554        else
    1555  	{
    1556  	  __rest_buffer = this->_Data_allocate(_S_rounded_up_size(__rest));
    1557  	  __uninitialized_fill_n_a(__rest_buffer, __rest, __c,
    1558  				   _M_get_allocator());
    1559  	  _S_cond_store_eos(__rest_buffer[__rest]);
    1560  	  __try
    1561  	    { __remainder = _S_new_RopeLeaf(__rest_buffer, __rest,
    1562  					    _M_get_allocator()); }
    1563  	  __catch(...)
    1564  	    {
    1565  	      _RopeRep::__STL_FREE_STRING(__rest_buffer, __rest,
    1566  					  _M_get_allocator());
    1567  	      __throw_exception_again;
    1568  	    }
    1569  	}
    1570        __remainder_rope._M_tree_ptr = __remainder;
    1571        if (__exponent != 0)
    1572  	{
    1573  	  _CharT* __base_buffer =
    1574  	    this->_Data_allocate(_S_rounded_up_size(__exponentiate_threshold));
    1575  	  _RopeLeaf* __base_leaf;
    1576  	  rope __base_rope;
    1577  	  __uninitialized_fill_n_a(__base_buffer, __exponentiate_threshold, __c,
    1578  				   _M_get_allocator());
    1579  	  _S_cond_store_eos(__base_buffer[__exponentiate_threshold]);
    1580  	  __try
    1581  	    {
    1582  	      __base_leaf = _S_new_RopeLeaf(__base_buffer,
    1583  					    __exponentiate_threshold,
    1584  					    _M_get_allocator());
    1585  	    }
    1586  	  __catch(...)
    1587  	    {
    1588  	      _RopeRep::__STL_FREE_STRING(__base_buffer,
    1589  					  __exponentiate_threshold,
    1590  					  _M_get_allocator());
    1591  	      __throw_exception_again;
    1592  	    }
    1593  	  __base_rope._M_tree_ptr = __base_leaf;
    1594  	  if (1 == __exponent)
    1595  	    __result = __base_rope;
    1596  	  else
    1597  	    __result = power(__base_rope, __exponent,
    1598  			     _Rope_Concat_fn<_CharT, _Alloc>());
    1599  	    
    1600  	  if (0 != __remainder)
    1601  	    __result += __remainder_rope;
    1602  	}
    1603        else
    1604  	__result = __remainder_rope;
    1605  	  
    1606        this->_M_tree_ptr = __result._M_tree_ptr;
    1607        this->_M_tree_ptr->_M_ref_nonnil();
    1608      }
    1609        
    1610    template<class _CharT, class _Alloc>
    1611      _CharT
    1612      rope<_CharT, _Alloc>::_S_empty_c_str[1];
    1613        
    1614    template<class _CharT, class _Alloc>
    1615      const _CharT*
    1616      rope<_CharT, _Alloc>::
    1617      c_str() const
    1618      {
    1619        if (0 == this->_M_tree_ptr)
    1620  	{
    1621  	  _S_empty_c_str[0] = _S_eos((_CharT*)0);  // Possibly redundant,
    1622  	                                           // but probably fast.
    1623  	  return _S_empty_c_str;
    1624  	}
    1625        __gthread_mutex_lock (&this->_M_tree_ptr->_M_c_string_lock);
    1626        __GC_CONST _CharT* __result = this->_M_tree_ptr->_M_c_string;
    1627        if (0 == __result)
    1628  	{
    1629  	  std::size_t __s = size();
    1630  	  __result = this->_Data_allocate(__s + 1);
    1631  	  _S_flatten(this->_M_tree_ptr, __result);
    1632  	  __result[__s] = _S_eos((_CharT*)0);
    1633  	  this->_M_tree_ptr->_M_c_string = __result;
    1634  	}
    1635        __gthread_mutex_unlock (&this->_M_tree_ptr->_M_c_string_lock);
    1636        return(__result);
    1637      }
    1638    
    1639    template<class _CharT, class _Alloc>
    1640      const _CharT* rope<_CharT, _Alloc>::
    1641      replace_with_c_str()
    1642      {
    1643        if (0 == this->_M_tree_ptr)
    1644  	{
    1645  	  _S_empty_c_str[0] = _S_eos((_CharT*)0);
    1646  	  return _S_empty_c_str;
    1647  	}
    1648        __GC_CONST _CharT* __old_c_string = this->_M_tree_ptr->_M_c_string;
    1649        if (__detail::_S_leaf == this->_M_tree_ptr->_M_tag
    1650  	  && 0 != __old_c_string)
    1651  	return(__old_c_string);
    1652        std::size_t __s = size();
    1653        _CharT* __result = this->_Data_allocate(_S_rounded_up_size(__s));
    1654        _S_flatten(this->_M_tree_ptr, __result);
    1655        __result[__s] = _S_eos((_CharT*)0);
    1656        this->_M_tree_ptr->_M_unref_nonnil();
    1657        this->_M_tree_ptr = _S_new_RopeLeaf(__result, __s,
    1658  					  this->_M_get_allocator());
    1659        return(__result);
    1660      }
    1661  
    1662    // Algorithm specializations.  More should be added.
    1663    
    1664    template<class _Rope_iterator>  // was templated on CharT and Alloc
    1665      void		          // VC++ workaround
    1666      _Rope_rotate(_Rope_iterator __first,
    1667  		 _Rope_iterator __middle,
    1668  		 _Rope_iterator __last)
    1669      {
    1670        typedef typename _Rope_iterator::value_type _CharT;
    1671        typedef typename _Rope_iterator::_allocator_type _Alloc;
    1672        
    1673        rope<_CharT, _Alloc>& __r(__first.container());
    1674        rope<_CharT, _Alloc> __prefix = __r.substr(0, __first.index());
    1675        rope<_CharT, _Alloc> __suffix =
    1676  	__r.substr(__last.index(), __r.size() - __last.index());
    1677        rope<_CharT, _Alloc> __part1 =
    1678  	__r.substr(__middle.index(), __last.index() - __middle.index());
    1679        rope<_CharT, _Alloc> __part2 =
    1680  	__r.substr(__first.index(), __middle.index() - __first.index());
    1681        __r = __prefix;
    1682        __r += __part1;
    1683        __r += __part2;
    1684        __r += __suffix;
    1685      }
    1686  
    1687  #if !defined(__GNUC__)
    1688    // Appears to confuse g++
    1689    inline void
    1690    rotate(_Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __first,
    1691  	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __middle,
    1692  	 _Rope_iterator<char, __STL_DEFAULT_ALLOCATOR(char)> __last)
    1693    { _Rope_rotate(__first, __middle, __last); }
    1694  #endif
    1695  
    1696  # if 0
    1697    // Probably not useful for several reasons:
    1698    // - for SGIs 7.1 compiler and probably some others,
    1699    //   this forces lots of rope<wchar_t, ...> instantiations, creating a
    1700    //   code bloat and compile time problem.  (Fixed in 7.2.)
    1701    // - wchar_t is 4 bytes wide on most UNIX platforms, making it
    1702    //   unattractive for unicode strings.  Unsigned short may be a better
    1703    //   character type.
    1704    inline void
    1705    rotate(_Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __first,
    1706  	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __middle,
    1707  	 _Rope_iterator<wchar_t, __STL_DEFAULT_ALLOCATOR(char)> __last)
    1708    { _Rope_rotate(__first, __middle, __last); }
    1709  # endif
    1710  
    1711  _GLIBCXX_END_NAMESPACE_VERSION
    1712  } // namespace