template <class _AllocNode>

struct _NODISCARD _Erase_tree_and_orphan_guard {

_Tree_val* _Val_ptr;

_AllocNode& _Al;

_Nodeptr _New_root;

_Erase_tree_and_orphan_guard& operator=(const _Erase_tree_and_orphan_guard&) = delete;

~_Erase_tree_and_orphan_guard() noexcept {

if (_Val_ptr != nullptr) {

_Val_ptr->_Erase_tree_and_orphan(_Al, _New_root); // subtree copy failed, bail out

}

}

};

_Newroot = _Copy_or_move<_Strat>(_Rootnode->_Myval); // memorize new root

_Newroot->_Parent = _Wherenode;

_Newroot->_Color = _Rootnode->_Color;

typename _Scary_val::template _Erase_tree_and_orphan_guard<_Alnode> _Guard{_Scary, _Getal(), _Newroot};

_Newroot->_Left = _Copy_nodes<_Strat>(_Rootnode->_Left, _Newroot);

_Newroot->_Right = _Copy_nodes<_Strat>(_Rootnode->_Right, _Newroot);

_Guard._Val_ptr = nullptr;