1.1 --- a/lemon/list_graph.h	Thu Jun 09 09:46:34 2005 +0000
     1.2 +++ b/lemon/list_graph.h	Thu Jun 09 09:47:51 2005 +0000
     1.3 @@ -457,6 +457,13 @@
     1.4  	exit(1);
     1.5        }
     1.6  
     1.7 +      ///\bug What is this used for?
     1.8 +      ///
     1.9 +      virtual void build() {}
    1.10 +      ///\bug What is this used for?
    1.11 +      ///
    1.12 +      virtual void clear() {}
    1.13 +
    1.14        void regist(ListGraph &_g) {
    1.15  	g=&_g;
    1.16  	AlterationNotifier<Node>::ObserverBase::
    1.17 @@ -517,13 +524,14 @@
    1.18      ///
    1.19      ///\todo This function might be called undo().
    1.20        void restore() {
    1.21 +	ListGraph &old_g=*g;
    1.22  	deregist();
    1.23  	while(!added_edges.empty()) {
    1.24 -	  g->erase(added_edges.front());
    1.25 +	  old_g.erase(added_edges.front());
    1.26  	  added_edges.pop_front();
    1.27  	}
    1.28   	while(!added_nodes.empty()) {
    1.29 -	  g->erase(added_nodes.front());
    1.30 +	  old_g.erase(added_nodes.front());
    1.31  	  added_nodes.pop_front();
    1.32  	}
    1.33        }