{"ast_node_type":"impl","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
                // FIXME(ptr_metadata): This impl overlaps with the other impls and shouldn't
                // and opaque types: If the `self_ty` is `Sized`, then the metadata is `()`.
                // exist. Instead, `Pointee<Metadata = ()>` should be a supertrait of `Sized`.