ref: cf7a20e80d1bf21c24db48d430f6603f1e82a45e
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") ;; }