Re: [boost] filtered_graph problem

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2001-04-03 20:09:04

Hello,

Could you please show a small example demonstrating the problem?

Thanks,
Jeremy

On Tue, 3 Apr 2001 HEYA_at_[hidden] wrote:

HEYA> I'm having trouble using the filtered_graph class and I'd
HEYA> like to 
HEYA> know if this sounds familiar to anyone.  
HEYA> 
HEYA> All is well when I use only an edge predicate.  But when I add a 
HEYA> vertex predicate, the run crashes.   The vertex predicate class has a 
HEYA> default constructor as required,  but it looks like boost is 
HEYA> expecting this default constructor to initialize the vertex property 
HEYA> map (or a pointer to it), which of course it can't do because no 
HEYA> argument is passed in.  I say this because if  I code the default 
HEYA> constructor to initialize a property map pointer as null, and if I 
HEYA> code the () operator to return true if that pointer is null, the code 
HEYA> at least runs,  but then it still does not filter out the vertices 
HEYA> correctly.
HEYA> 
HEYA> So  it looks like it's actually accessing this property pointer 
HEYA> before the non-default constructor is even called.  Later, when I 
HEYA> assume it starts using the valid property map, it still does not 
HEYA> filter correctly. 
HEYA> 
HEYA> By the way, why is a default constructor required for the predicate 
HEYA> classes?  Just curious.
HEYA> 
HEYA> I'd appreciate any info on the above problem.  I can provide the
HEYA> code 
HEYA> if anyone is interested.
HEYA> 
HEYA> 
HEYA> 
HEYA> 
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HEYA> 

----------------------------------------------------------------------
 Jeremy Siek                        www: http://www.lsc.nd.edu/~jsiek/
 Ph.D. Candidate                  email: jsiek_at_[hidden]
 Univ. of Notre Dame         work phone: [phone]
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