// Module B authors `Pair { x, y }` with the SAME field shape as A's. The two
// still get distinct nominal identities (not collapsed): each keeps its own
// TypeId / per-source author, so both register and format independently.
Pair :: struct { x: i64; y: i64; }
b_pair :: () -> Pair { return Pair.{ x = 5, y = 6 }; }