Re: [Boost-users] [boost-users][graph] There is graph::null_vertex, but no "null_edge"!

17 Feb 2011


      On Fri, 18 Feb 2011, al.zatv wrote:
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Jeremiah Willcock  писал(а) в своём письме Fri, 18 Feb 
2011 02:04:35 +0300:
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On Fri, 18 Feb 2011, al.zatv wrote:
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Jeremiah Willcock  писал(а) в своём письме Fri, 18 
Feb
2011 01:47:39 +0300:
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There is graph::null_vertex, but no "null_edge".
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But, I think, it will be much better if null_edge will be added to the
library. It can be -1 for vector containers and null for pointer-based
descriptors, etc.
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It would be, but that would be a change to base concepts that may cause
old graph types to fail with new algorithms that use null_edge().  What
does your code that may return a null edge descriptor do?  Would it be
possible to return an iterator instead?
My code just search one specific edge in graph. Actually, I think I can 
return an iterator. I just don't think about it. "Null edge-descriptor" was 
more natural idea for me:).
So, looks like absence of null-edge is small "error-in-design" of library, or 
it was caused by some reason?
OK.  I do not know if there was a reason; it is likely that nobody thought 
they would need it when designing the library.

-- Jeremiah Willcock