Avoiding Range Postblits

["Nordlöw" via Digitalmars-d-learn]

At

https://github.com/nordlow/justd/blob/master/knet/association.d#L59

I'm constructing an array of ranges that are used further down in 
the function contextOf.

The expression

     nds.map!(nd => gr.dijkstraWalker(nd, ...)).array;

however triggers postblits for the range DijkstraWalker returned 
by the instantiator dijkstraWalker.

Can this be avoided somehow?

I'm guessing that move construction plays a key role here.

Note that I can't remove the .array as they required to be 
l-values because their iteration to have side-effects at the end 
of the function contextOf().