{"ast_node_type":"other","tokens":[{"end":70,"kind":"keyword","start":0,"text":"(Struct,"}]}
            (Struct, Ty::Tuple(tys)) => tys.iter().copied().collect(),
        match (ctor, *self) {
            (Struct, Ty::BigStruct { arity, ty }) => (0..arity).map(|_| *ty).collect(),