I'm trying to allow for both bounded and unbounded channels in an interface and it's rather awkward because UnboundedSender::send is not async, because it'll never block even the task. However, that complicates trying to treat it equivalent to Sender, because it subsequently has no Sink wrapper. Is there any easy way to turn a UnboundedSender into a Sink or otherwise get around this issue so I can have a trait that allows both equally easily?
You could use futures::sink::unfold:
futures::sink::unfold(tx, |tx, item| futures::future::ready(tx.send(item).map(|()| tx)));