Fix retroactive conformance warnings

Realm/Swift/RLMSupport.swift

@@ -66,7 +66,7 @@ extension RLMObject {
 }
 
 /// A protocol defining iterator support for RLMArray, RLMSet & RLMResults.
-public protocol _RLMCollectionIterator {
+public protocol _RLMCollectionIterator: Sequence {
     /**
      Returns a `RLMCollectionIterator` that yields successive elements in the collection.
      This enables support for sequence-style enumeration of `RLMObject` subclasses in Swift.
@@ -97,10 +97,17 @@ extension _RLMDictionaryIterator where Self: RLMCollection {
 
 // Sequence conformance for RLMArray, RLMDictionary, RLMSet and RLMResults is provided by RLMCollection's
 // `makeIterator()` implementation.
+#if compiler(<6.0)
 extension RLMArray: Sequence, _RLMCollectionIterator { }
 extension RLMDictionary: Sequence, _RLMDictionaryIterator {}
 extension RLMSet: Sequence, _RLMCollectionIterator {}
 extension RLMResults: Sequence, _RLMCollectionIterator {}
+#else
+extension RLMArray: @retroactive Sequence, _RLMCollectionIterator { }
+extension RLMDictionary: @retroactive Sequence, _RLMDictionaryIterator {}
+extension RLMSet: @retroactive Sequence, _RLMCollectionIterator {}
+extension RLMResults: @retroactive Sequence, _RLMCollectionIterator {}
+#endif
 
 /**
  This struct enables sequence-style enumeration for RLMObjects in Swift via `RLMCollection.makeIterator`

RealmSwift/App.swift

@@ -397,14 +397,19 @@ public struct AppPublisher: Publisher, @unchecked Sendable { // DispatchQueue
 }
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-extension App: ObservableObject {
+extension App {
     /// A publisher that emits Void each time the app changes.
     ///
     /// Despite the name, this actually emits *after* the app has changed.
     public var objectWillChange: AppPublisher {
         return AppPublisher(self, scheduler: DispatchQueue.main)
     }
 }
+#if compiler(>=6)
+extension App: @retroactive ObservableObject {}
+#else
+extension App: ObservableObject {}
+#endif
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
 internal func promisify(_ fn: @escaping (@escaping @Sendable (Error?) -> Void) -> Void) -> Future<Void, Error> {

RealmSwift/Combine.swift

@@ -612,7 +612,7 @@ extension Realm {
 // MARK: - Object
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-extension Object: ObservableObject {
+extension Object {
     /// A publisher that emits Void each time the object changes.
     ///
     /// Despite the name, this actually emits *after* the object has changed.
@@ -621,7 +621,7 @@ extension Object: ObservableObject {
     }
 }
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-extension EmbeddedObject: ObservableObject {
+extension EmbeddedObject {
     /// A publisher that emits Void each time the object changes.
     ///
     /// Despite the name, this actually emits *after* the embedded object has changed.
@@ -647,6 +647,18 @@ extension ObjectBase: RealmSubscribable {
     }
 }
 
+#if compiler(>=6)
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension Object: @retroactive ObservableObject {}
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension EmbeddedObject: @retroactive ObservableObject {}
+#else
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension Object: ObservableObject {}
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension EmbeddedObject: ObservableObject {}
+#endif
+
 // MARK: - List
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)

RealmSwift/Error.swift

@@ -48,7 +48,11 @@ extension Realm.Error {
 
 // MARK: Equatable
 
+#if compiler(>=6)
+extension Realm.Error: @retroactive Equatable {}
+#else
 extension Realm.Error: Equatable {}
+#endif
 
 // FIXME: we should not be defining this but it's a breaking change to remove
 /// Returns a Boolean indicating whether the errors are identical.

RealmSwift/Impl/ObjcBridgeable.swift

@@ -202,11 +202,16 @@ extension ResultsSection: BuiltInObjcBridgeable {
     }
 }
 
-extension RLMSwiftCollectionBase: Equatable {
+extension RLMSwiftCollectionBase {
     public static func == (lhs: RLMSwiftCollectionBase, rhs: RLMSwiftCollectionBase) -> Bool {
         return lhs.isEqual(rhs)
     }
 }
+#if compiler(>=6)
+extension RLMSwiftCollectionBase: @retroactive Equatable {}
+#else
+extension RLMSwiftCollectionBase: Equatable {}
+#endif
 
 extension Projection: BuiltInObjcBridgeable {
     public static func _rlmFromObjc(_ value: Any) -> Self? {

RealmSwift/Sync.swift

@@ -1098,7 +1098,7 @@ public class UserPublisher: Publisher {
 }
 
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-extension User: ObservableObject {
+extension User {
     /// A publisher that emits Void each time the user changes.
     ///
     /// Despite the name, this actually emits *after* the user has changed.
@@ -1107,6 +1107,14 @@ extension User: ObservableObject {
     }
 }
 
+#if compiler(>=6)
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension User: @retroactive ObservableObject {}
+#else
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension User: ObservableObject {}
+#endif
+
 public extension User {
     // NEXT-MAJOR: This function returns the incorrect type. It should be Document
     // rather than `[AnyHashable: Any]`

RealmSwift/Tests/ObjectSchemaInitializationTests.swift

@@ -806,6 +806,7 @@ class SwiftObjectWithNonOptionalLinkProperty: SwiftFakeObject {
     @objc dynamic var objectCol = SwiftBoolObject()
 }
 
+#if compiler(<6)
 extension Set: RealmOptionalType {
     public static func _rlmFromObjc(_ value: Any, insideOptional: Bool) -> Set<Element>? {
         fatalError()
@@ -815,6 +816,17 @@ extension Set: RealmOptionalType {
         fatalError()
     }
 }
+#else
+extension Set: @retroactive RealmOptionalType {
+    public static func _rlmFromObjc(_ value: Any, insideOptional: Bool) -> Set<Element>? {
+        fatalError()
+    }
+
+    public var _rlmObjcValue: Any {
+        fatalError()
+    }
+}
+#endif
 
 @available(*, deprecated) // Silence deprecation warnings for RealmOptional
 class SwiftObjectWithNonRealmOptionalType: SwiftFakeObject {

RealmSwift/Tests/RealmTests.swift

@@ -1894,12 +1894,21 @@ extension RealmTests {
     static var shared = CustomGlobalActor()
 }
 
+#if compiler(<6)
 @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
 extension CancellationError: Equatable {
     public static func == (lhs: CancellationError, rhs: CancellationError) -> Bool {
         true
     }
 }
+#else
+@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
+extension CancellationError: @retroactive Equatable {
+    public static func == (lhs: CancellationError, rhs: CancellationError) -> Bool {
+        true
+    }
+}
+#endif
 
 // Helper
 extension LogLevel {