@swift-6.2.3 @swift-6.1.3 @swift-6.0.3 -swift-version 6

struct S<K, V> {} extension S: Sendable where K: Sendable {} struct S2<K> {} extension S2: Sendable where K: Sendable {} typealias A<Field: Sendable> = S<Field, String> typealias B<Field: Sendable> = S2<Field> extension A: Error {} extension B: Error {}

(edited)