On Tuesday, 24 October 2017 at 09:56:50 UTC, rikki cattermole wrote: > scope+ref+out as arguments would be a no-no. > Now if we could ditch registers usage crossing before/after > yield, we wouldn't need to do 'patching' like fibers do. That's basically what asnyc/await does, some implementations as continuation (callback) some as jump rewrite.