ref: 5bd859be6d2246db8a5ce28f2dbc25724590cb6f
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) }