Needless Return at the end of function inside a closure suggests invalid code

[fee1-dead]

This code:

fn foo(bar: Result<(), ()>) {
    bar.unwrap_or_else(|_| return)
}

is suggested to remove the return, like this:

fn foo(bar: Result<(), ()>) {
    bar.unwrap_or_else(|_| )
}

Which is invalid rust code.

Meta

• cargo clippy -V: clippy 0.0.212 (bb1fbbf 2020-12-22)
• rustc -Vv:

rustc 1.50.0-nightly (bb1fbbf84 2020-12-22)
binary: rustc
commit-hash: bb1fbbf84455fbad9afd26c17e0f725019322655
commit-date: 2020-12-22
host: x86_64-unknown-linux-gnu
release: 1.50.0-nightly

[ThibsG]

@fee1-dead commented (by email):

Hey, I am the issue reporter, and I think it is still incorrect behavior in some cases, because when the result is Result<(), ()>, it is fine to use an empty closure, but when I use unwrap_or_else on an actual result with type (Result<Foo, u8>), I can't use |_| {} because that would return () instead of Foo, but return works.

[ThibsG]

@fee1-dead If I understand correctly, you have something like:

struct Foo;
fn bar(foo: Result<Foo, u8>) -> Foo {
    foo.unwrap_or_else(|_| return Foo)
}

the suggestion would be to remove the return statement like this:

    foo.unwrap_or_else(|_| Foo)

Playground

Is that the correct situation you are referring to?

[fee1-dead]

@ThibsG, I first commented on the PR, but after some experimenting I realized I can’t return from closure so I just removed the comment.