Interest in std.algorithm.joiner?

[bearophile]

dsimcha:
> Absolutely.  I was thinking a while back I was going to suggest a
> std.range.flattener() or std.algorithm.flattener() that takes a range of ranges
> and turns them into a single range, one right after the other.

That's a chain() not a flattener() :-)
A flatten operation is usually meant when you have a tree (sometimes even a tree of arbitrary and dis-uniform depth) of iterables and you want to fully linearise it.

Bye,
bearophile