ref: c1785ddd18f21259671a5d8347a5b39ab151b1f4
dir: /test/genericmake.myr/
use std type t(@ty) = union `Some @ty `None ;; const make = {v -> `Some v } const main = { var x x = make(123) match x | `Some v: std.put("val = {}\n", v) | `None: std.die("Unreachable\n") ;; }