graph lib dfs visitor parameter

From: rmhenne_at_[hidden]
Date: 2001-07-11 00:44:48

Howdy,

  I am working with the boost graph library.  I am performing a dfs 
with a visitor that has additional state other than the visitor event 
points.  At the end of the traversal, my visitor loses this state.  I 
think this is because the visitor object is sometimes passed by 
reference and sometime by value.  I am running VC++ 6.0 and boost lib 
1.23.0.  Although I know that there are some problems with the VC6.0 
compiler, I thought this problem might be something simpler (like 
me) ).

My first guess is that my visitor is copied by value (either 
when passed to one of the implementation calls or when it is wrapped 
as a named parameter), builds state during the traversal, and then 
loses this state when it is poped off the stack.  The first 
definition of depth_first_search_impl passes the visitor by ref but 
later functions pass by value.  I haven't explored this very deeply 
here and I may be doing something very stupid.  I am tracing this 
further but since I'm new to boost, I thought some of you experts 
might set me straight quicker.  Has anyone had similar problems or is 
this my own doing?

Thanks for any help,

Randy Henne
rmhenne_at_[hidden]