[Dune] How to iterate over Process Boundary edges

[Christian Engwer]

Dear Aleksejs,

OK, this now clearifies a lot :-)

> According to the picture in dune-grid-howto, the faces and edges shared by Interior and Ghost at the same time are considered Border.
> 
> So in Dune-terminology, I would like to iterate over all edges on
> partition Border, and select only those that are found on multiple
> processors (ProcessorBoundary), excluding the ones that are found
> only on one process (DomainBoundary).

This is something totally different from iterating over the processor
boundary.

As Martin suggested, the easiest way to is us the grid functionality
and us a communicate. During scatter you can tag your entities, store
the other processor ids, or what ever you think is appropriate.

Perhaps it would be helpful to understand what you are trying to
achieve in the end, because I don't think that your primary intent is
to iterator over those edges?!

Ciao
Christian