What's happening here? (fantoccini breaks String + &String) about fantoccini HOT 10 OPEN

I'm inclined to agree. Let's remove the impls for now 👍 We could perhaps add a helper method like Key::and?

from fantoccini.

I found something relevant here:
https://std-dev-guide.rust-lang.org/code-considerations/breaking-changes/new-trait-impls.html#deref-coercion-breaks-when-a-new-impl-is-introduced

It is caused by your

impl Add<Key> for String {
    type Output = String;

    fn add(mut self, rhs: Key) -> Self::Output {
        self.push(rhs.into());
        self
    }
}

impl AddAssign<Key> for String {
    fn add_assign(&mut self, rhs: Key) {
        self.push(rhs.into());
    }
}

from fantoccini.

That's very suspicious, and I think it should be reported upstream. Those docs are specifically for the standard library, not for crate authors, and this is certainly a footgun if it applies to all crates!

cc @stevepryde as this was introduced in #151. We could totally remove these impls as they haven't been made part of a stable release yet, though that would also hurt the ergonomics of Key a fair amount.

from fantoccini.

I added a note in rust-lang/rust#51916

from fantoccini.

Yeah that's unfortunate. I think it's better to take a small drop in ergonomics than potentially break other code just by importing fantoccini.

from fantoccini.

Hello I have an idea how to make it work and still be quite ergonomic:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=cd64fbcedcdc4e446a64d7f1c8616d43

from fantoccini.

@jonhoo should I do a pull request or will you (or @stevepryde ) do it?

from fantoccini.

It's pretty weird to have to add those & in there, but maybe that's the best we can do for now. We should call it out in the docs for Key explicitly at least.

Feel free to open a PR, that'll probably be faster!

from fantoccini.