ref: bed033d73b58b686cc0367e41eb78b3c6a57c9d6
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 | `std.Some v: std.put("val = {}\n", v) | `std.None: std.die("Unreachable\n") ;; }