[Dune] Iterator for all edges of a face?

[Dragan Vidovic]

Hi all

A beginner's question: I need to iterate all entities of dimension
d-1 of an element of dimension d, for any d<=dim of the grid. Is there
an iterator that would allow me to do this? I access the d-dimensional
element trough a LeafIterator.

I need all this in order to get areas and normals of tetrahedron
faces, or lengths and vectors of triangle edges, in a uniform way.

Thanks.

Dragan