Miss Dada  🏳️‍⚧️

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`?)

but your example is already asymmetric, it's breaking because `y` is MyRc, not because it's not self. It fails if you swap y with x, it has nothing to do with the receiver being special cased

What's happening is that for x it's managing to find a single impl that doesn't require coercion. it's done! it's able to coerce for y because there's a single impl, so all the expected types are known

Right, which is my point. It's willing to try coercing y, it's not willing to try coercing x. It's a special case for `Self`. I'm not saying it's bad, I'm saying it's arbitrary

I think my issue is with the term "special case" here, because the underlying reason here is that trait search fundamentally works off of self, and this isn't the only way that manifests. this isn't specific to deref coercions.