@swift-main -Xfrontend -enable-experimental-named-opaque-types -Xfrontend -enable-parameterized-protocol-types

protocol P<A> { associatedtype A } protocol Q {} struct S<A>: P {} struct K: Q {} func makePair() -> <T0: Q, T1: Q> (S<T0>, S<T1>) { (S<K>(), S<K>()) } func usePair<T: Q>(_ pair: (S<T>, S<T>)) {} func main() { let pair = makePair() usePair(pair) }