There is unofficial plugin: https://github.com/intellij-rust/intellij-rust and works very well: https://www.youtube.com/watch?v=mHa7QlFz7io (small video recorded by me)
Is that Racer happening? It look like there is still a lag in the completion suggestion... and that is a huge problem (mainly when using it as to find things).
No, this plugin works without Racer. I use it every day and I don't see any problems with code completion. Except of cases where code completion isn't supported yet :) But it's all personal and better to try - it's free.
To clarify: I'm not author of this plugin.
And I tried Racer with Microsoft Visual Code plugin - it works without any lags, very fast. Just fails sometimes :)
Jetbrains Rust IDE would genuinely make Rust my go-to language for pretty much every task I can think of.
I tried to pickup Rust, but I was super frustrated by the code/compile/run cycle with the current plugin. But, hopefully more users will make that better.