filtered_graph problem

From: HEYA_at_[hidden]
Date: 2001-04-03 16:29:50

I'm having trouble using the filtered_graph class and I'd
like to 
know if this sounds familiar to anyone.  

All is well when I use only an edge predicate.  But when I add a 
vertex predicate, the run crashes.   The vertex predicate class has a 
default constructor as required,  but it looks like boost is 
expecting this default constructor to initialize the vertex property 
map (or a pointer to it), which of course it can't do because no 
argument is passed in.  I say this because if  I code the default 
constructor to initialize a property map pointer as null, and if I 
code the () operator to return true if that pointer is null, the code 
at least runs,  but then it still does not filter out the vertices 
correctly.

So  it looks like it's actually accessing this property pointer 
before the non-default constructor is even called.  Later, when I 
assume it starts using the valid property map, it still does not 
filter correctly. 

By the way, why is a default constructor required for the predicate 
classes?  Just curious.

I'd appreciate any info on the above problem.  I can provide the
code 
if anyone is interested.