020 reject destructure void branch

// The void half of the linear rule applies to destructures too: a branch
// that carries no payload has nothing to destructure — KORU101.
~import std/io

~pub tor check {}
| ok { code: i64, note: string }
| empty

~proc check|zig { return .{ .empty = .{} }; }

~check()
| ok { code } |> std/io:print.ln("{{ code:d }}")
| empty { x } |> std/io:print.ln("bad")