ref: 2ff72374a574d8c4a4de02274481fe9dd98c4fe5
dir: /test/genericret.myr/
use std type t(@a) = union `Val @a `None ;; const f = {-> t(int) -> `None } const main = { match f() | `None: std.exit(42) | _: std.die("Impossible match failure\n"); ;; std.exit(0) }