Nifty chaining

[Peter Alexander]

I must be missing something, because I don't really see the need
for this at all.

Why not just return the number of items added, and forget about
chaining? If you're worried about having to type the container's
identifier in over and over again, just use with(c) {...}, and if
you want to chain together multiple different ranges, just use
std.range.chain.

Is there any use case where these don't suffice?