ref: 1af62a6b4e9e10444098c57f64b1ad1b9cb03b95
dir: /test/fmtalign.myr/
use std pkg = type msg = union `Tversion tversion ;; type tversion = struct tag : uint16 version : byte[:] ;; ;; const main = { var msg=`Tversion [.tag=45, .version="9P2000"] std.put("{}\n", msg) }