Re: [BGL] Strange result with internal graph properties

From: yg-boost-users_at_[hidden]
Date: 2003-02-13 15:31:13

yg-boost-users_at_[hidden] writes:

<my example snipped>

> Notice the error: The vertex properties are not chained
> together. Rather, the actual vertex property that is added to the
> graph points to vertex_type, and the vertex_index /also/ points to the
> vertex_type!
> 
> Now the strange thing: I have been running this and using all of the
> vertex properties, including vertex_index, without any problems, but
> when I noticed this, and tried setting the last template parameter of
> vertex_property to vertex_index instead I get segmentation faults. I
> have no idea why this is.

It seems like it was a compiler bug. I had originally been compiling
it with g++ version 3.2. Today I tried it using g++ version 3.2.2, and
it is working again. I'm not following the g++ development closely
enough to know exactly what fixed this. The only mystery that remains
is why the erroneous code was working to begin with. How could I be
using the vertex index property eg. as an offset map to external
property maps when it was not even properly defined as an internal
property?

Regarding my error, I'm beginning to miss having some kind of compile
time debugger for debugging all this template stuff, although I have a
feeling it wouldn't have helped me this time.

Björn