Suppose you have a trait:

trait Foo: std::ops::Index<usize> + std::ops::Index<isize> {}

How do you declare a Foo trait object, say a Box? The Output associated types need to be specified but they need to be disambiguated between the two super traits. Projections that I’ve tried don’t seem to work but it’s possible I didn’t try the right incarnation.

This stems from the https://users.rust-lang.org/t/how-to-specify-associated-types-with-same-name-in-generics/15677 post.