Rustdoc does not show blanket impls with negative polarity

[jyn514]

I tried this code:

#![feature(negative_impls)]
pub struct S {}

pub trait Trait {}
impl<T> !Trait for T {}

I expected to see this happen: Rustdoc shows impl !Trait for S on the documentation for S, the same way it shows impl<T> Any for T.

Instead, this happened: Rustdoc does not show the blanket implementation.

Meta

rustdoc --version: rustdoc 1.50.0-nightly (0edce6f 2020-12-24)

[jyn514]

I think this might be because rustdoc uses for_each_relevant_impl, which only considers impls that do apply, not those that don't?

[ThePuzzlemaker]

I think I'll take a shot at this. @rustbot claim

[ThePuzzlemaker]

It appears to be shown on the trait, just not the struct.

[ThePuzzlemaker]

It appears that Cache.impls does not contain negative polarity implementations (excluding auto traits, which are obtained separately I believe)

[ThePuzzlemaker]

I'm not really sure how to solve this or what I even need to get help on to solve this so I'm going to release assignment.
@rustbot release-assignment