nces 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 __detail::_S_leaf:
	  {
	    _Rope_RopeLeaf<_CharT, _Alloc>* __l
	      = (_Rope_RopeLeaf<_CharT, _Alloc>*)this;
	    __l->_Rope_RopeLeaf<_CharT, _Alloc>::~_Rope_RopeLeaf();
	    this->_L_deallocate(__l, 1);
	    break;
	  }
	case __detail::_S_concat:
	  {
	    _Rope_RopeConcatenation<_CharT,_Alloc>* __c
	      = (_Rope_RopeConcatenation<_CharT, _Alloc>*)this;
	    __c->_Rope_RopeConcatenation<_CharT, _Alloc>::
	      ~_Rope_RopeConcatenation();
	    this->_C_deallocate(__c, 1);
	    break;
	  }
	case __detail::_S_function:
	  {
	    _Rope_RopeFunction<_CharT, _Alloc>* __f
	      = (_Rope_RopeFunction<_CharT, _Alloc>*)this;
	    __f->_Rope_RopeFunction<_CharT, _Alloc>::~_Rope_RopeFunction();
	    this->_F_deallocate(__f, 1);
	    break;
	  }
	case __detail::_S_substringfn:
	  {
	    _Rope_RopeSubstring<_CharT, _Alloc>* __ss =
	      (_Rope_RopeSubstring<_CharT, _Alloc>*)this;
	    __ss->_Rope_RopeSubstring<_CharT, _Alloc>::
	      ~_Rope_RopeSubstring();
	    this->_S_deallocate(__ss, 1);
	    break;
	  }
	}
    }
#else

  template <class _CharT, class _Alloc>
    inline void
    _Rope_RopeRep<_CharT, _Alloc>::
    _S_free_string(const _CharT*, size_t, allocator_type)
    { }

#endif

  // Concatenate a C string onto a leaf rope by copying the rope data.
  // Used for short ropes.
  template <class _CharT, class _Alloc>
    typename rope<_CharT, _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;
      _CharT* __new_data = (_CharT*)
	rope::_Data_allocate(_S_rounded_up_size(__old_len + __len));
      _RopeLeaf* __result;

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