Re: [BGL] negative_edge thrown inside dijsktra for boost' file dependency example.

From: Dan Dimerman (yg-boost-users_at_[hidden])
Date: 2003-06-21 05:41:20

Hello Vladimir,

You've hit the exact spot. I noted as well the "confusing" comment there.
The problem was in the configuration of my development environment, i.e., I
read files from boost 1.30.0, but the compiler used files from 1.29.0, hence
the problem with the m_zero.

It works now.

Many thanks for your time and patience.

"Vladimir Prus" <yg-boost-users_at_[hidden]> wrote in message
news:bcu6ed$d8u$1_at_main.gmane.org...
> Hi Dan,
>
> >> I'm at loss... nothing suspicious so far. And without VC7, I can't
debug
> >> this. Let's try to narrow the problem down.
> >> 1. You compile examples/file_dependency.cpp, right?
> >> 2. It throws exception inside dijskta_shortets_path_no_init, right?
> >> 3. Exception is thrown from 'examine_edge' and the exception is
> >> 'negative_edge', right?
> >> 4. Could you tell what's the value of 'm_zero' and what's the value of
> >> 'e' --- I mean what's the source and target vertex? What's result of
> >> 'get' invocation?
> >
> > 1. yes.
> > 2. yes.
> > 3. yes.
> > 4. m_zero = 0x00000000, get( m_weight, e) = 0x00000001.
> > e.m_source = 0x00000000, e.m_target = 0x00000004
> >
> > when I changed the compare object from std::greater<int> to
std::less<int>
> > or std::less_equal<int>, I got no exceptions, but the results were all
the
> > files on time slot 0.
> >
> > Needless to say, it's somewhat confusing. Any insight ?
>
> That's *confusing*. Also, there's very stange comment in
> file_dependency.cpp:
>
>          compare, combine, 0,  // Since we are using > instead of >, we
>            std::numeric_limits<int>::max(), // flip 0 and inf.
>
> "Using >" instead of ">" :-) Well, anyway, in my case m_zero is
2147483647,
> which makes me suspect std::numeric_limits<int>::max() is buggy on your
> compiler/system. Could you try chaning it by literal 2147483647, and
report
> your results?
>
> - Volodya
>
>
>
>
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