// RUN: %target-swift-frontend %s -emit-ir protocol P20 { } protocol P21b { associatedtype T func foo(_: (T?) -> Void) } protocol P21a { associatedtype T func bar(_: ([T]) -> Void) } extension P21b where Self: P21a, T: P20 { func foo(_: (T?) -> Void) { bar { _ in } } }