slidingSplitter + retro

["Nordlöw" via Digitalmars-d-learn]

On Monday, 6 October 2014 at 22:11:50 UTC, Nordlöw wrote:
> https://github.com/nordlow/justd/blob/master/range_ex.d#L18

One more thing: I'm unsure how the indexes lower and upper should 
be treated for narrow strings. Should an index represent a code 
point or a code unit? I'm not sure. In either way I would really 
like this range to just work for narrow strings. What do you say 
monarch_dodra? What's standard D-style way of handling this?