ref: 3ca7a098ddb3aacabafb6c20a57feec1dbafe4ab
dir: /test/nestucon.myr/
use std type t = struct x : union `Int int `Str byte[:] ;; ;; const main = { var a : t a = [.x = `Str "asdf"] match a | [.x=`Str s]: std.put("{}\n", s) | _: std.die("Impossible match failure\n") ;; }