Final return statements versus implicit return

[ketsuban]

Exhibit A

fn i_am_the_walrus(foo: u32) -> u64 {
    ((foo as u64) << 32) + (foo as u64)
}

Exhibit B

fn i_am_the_walrus(foo: u32) -> u64 {
    return ((foo as u64) << 32) + (foo as u64);
}

Given that the Book refers to B as “poor style”, is it within rustfmt's bailiwick (being that it is a tool for resolving stylistic disagreements) to replace it with A?

[nrc]

Yes, this would be good to do. I wonder how general we can make the rule? I expect at some point you need more semantic info than rustfmt has access to.

[eefriedman]

See also rust-lang/rust#31439 .

[sanxiyn]

This (the rule part, not the formatting part) is implemented as needless_return in Clippy.

[topecongiro]

Closing this as this is more of clippy-stuff.