Miss Dada  🏳️‍⚧️

not really: in the former situation you're looking for a type -- any type -- with the method "bar". it's a simple linear search down the deref chain in the latter you're looking for a type which satisfies certain constraints, which is much trickier

a == b is sugar for PartialEq::eq(&a, &b), not a.eq(&b). These are different, and more importantly the former situation can't be figured out as a simple search

Assuming `a` does not have an inherent method named `eq`, I don't think those resolve differently at all. They certainly both fail in the same way with the code mentioned

Oh, sorry, the problem here is b not a, my bad. Actually in that case it's far more stark, we're not looking for a method at all, we're looking to see if &b satisfies a certain trait

yes, we could implement stuff here to make it better, but "does b or *(n)b have a method foo" is different from "does b or &*(n)b work as T in PartialEq<T> for str".

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=be5ff1a4c279c3f05e1d4607391623ec … is a more concrete explanation of what I mean. `Self` is special cased in more than just dot form

I don't understand how that's special casing self types? Deref coercions give up pretty easily, that's the root of this. Here it's giving up on the UFCS form only, with the autoderef working: https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=c0197afb83c273b0f4181ddef6fd0cf6 …

Probably the biggest way that self is getting special cased here is that it won't try to deref self but it will try to deref other arguments (why is `PartialEq<Inner> for Outer` fine there but not `PartialEq<Outer> for Inner`?)