When you hover over a Rust code block in Zulip, you can click a link in the top-right corner that will open the code on the playground. However, it doesn't pass an edition query parameter, so the playground uses 2015 by default (like rustc). It would be better if it used 2018 edition. Not sure if this is a built-in Zulip feature though, in which case we can't fix it here.
It doesn't look like there's any organizational setting for that.
So it may be built-in. Please do file something upstream asking about that.
Last updated: Oct 11 2021 at 22:34 UTC