{"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"//"}]}
                // This is the "fallback impl" for type parameters, unnormalizable projections
            ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => {
                // and opaque types: If the `self_ty` is `Sized`, then the metadata is `()`.