The |> operator I miss, but rust have a near similar feel with iterators:

    let a= [1, 2];
    a.iter().filter(|x|..).map(|x|...)

I think I'm more functional in a lot of areas where in F# can't (or don't know how). One reason?:

https://doc.rust-lang.org/std/convert/trait.Into.html

This is THE feature I wish other langs copy. Combined with serde:

https://github.com/serde-rs/serde

Is possible to cut a lot of boilerplate related to data transformation (that is the main task in my case).