I've written a Dijkstra-style graph traversal range at
https://github.com/nordlow/justd/blob/master/knet/traversal.d#L105
that needs to internally store the AA distance map in member
variable distMap.
1.
All the data members except distMap have reference semantics.
Therefore I've made my range a class instead of a struct. Is this
the correct way to do it?
2.
To make it a ForwardRange I've also add a save() member. For now
I've hardcoded the single member that needs to be duped. Is this
correct way of doing it?
