So @Matthew Jasper, as suspected, proving the self-type is WF fixes
issue-28848.rs, but the more I think about it, it feels like I'm not doing the check in the right place.
This feels like something we need to enforce for any projection, whether or not a user-supplied type annotation is given.
A::f not record a user type?
presently it does
and so the type passes
but I don't think it should have to
in order for the test to fail
I am not going to try to solve this in this PR :)
I'll just add the test (that is, a variant of
issue-28848 without explicit annotations)
and open an issue to refactor this