PoC: Noncopyable DisposeBag

RxSwift/Disposables/DisposeBag.swift

@@ -10,7 +10,7 @@ extension Disposable {
     /// Adds `self` to `bag`
     ///
     /// - parameter bag: `DisposeBag` to add `self` to.
-    public func disposed(by bag: DisposeBag) {
+    public func disposed(by bag: inout DisposeBag) {
         bag.insert(self)
     }
 }
@@ -27,27 +27,39 @@ or create a new one in its place.
 
 In case explicit disposal is necessary, there is also `CompositeDisposable`.
 */
-public final class DisposeBag: DisposeBase {
-
-    private var lock = SpinLock()
-
-    // state
-    private var disposables = [Disposable]()
-    private var isDisposed = false
-
+public struct DisposeBag: ~Copyable {
+    private let implementation: _DisposeBag
+
     /// Constructs new empty dispose bag.
-    public override init() {
-        super.init()
+    public init() {
+        self.implementation = _DisposeBag()
     }
 
     /// Adds `disposable` to be disposed when dispose bag is being deinited.
     ///
     /// - parameter disposable: Disposable to add.
+    public /*mutating*/ func insert(_ disposable: Disposable) {
+        implementation._insert(disposable)?.dispose()
+    }
+}
+
+private final class _DisposeBag: DisposeBase {
+
+    fileprivate var lock = SpinLock()
+
+    // state
+    fileprivate var disposables = [Disposable]()
+    fileprivate private(set) var isDisposed = false
+
+    public override init() {
+        super.init()
+    }
+
     public func insert(_ disposable: Disposable) {
         self._insert(disposable)?.dispose()
     }
 
-    private func _insert(_ disposable: Disposable) -> Disposable? {
+    fileprivate func _insert(_ disposable: Disposable) -> Disposable? {
         self.lock.performLocked {
             if self.isDisposed {
                 return disposable
@@ -86,21 +98,21 @@ public final class DisposeBag: DisposeBase {
 
 extension DisposeBag {
     /// Convenience init allows a list of disposables to be gathered for disposal.
-    public convenience init(disposing disposables: Disposable...) {
-        self.init()
-        self.disposables += disposables
+    public init(disposing disposables: Disposable...) {
+        self = DisposeBag()
+        self.implementation.disposables += disposables
     }
 
     /// Convenience init which utilizes a function builder to let you pass in a list of
     /// disposables to make a DisposeBag of.
-    public convenience init(@DisposableBuilder builder: () -> [Disposable]) {
+    public init(@DisposableBuilder builder: () -> [Disposable]) {
       self.init(disposing: builder())
     }
 
     /// Convenience init allows an array of disposables to be gathered for disposal.
-    public convenience init(disposing disposables: [Disposable]) {
+    public init(disposing disposables: [Disposable]) {
         self.init()
-        self.disposables += disposables
+        self.implementation.disposables += disposables
     }
 
     /// Convenience function allows a list of disposables to be gathered for disposal.
@@ -115,11 +127,11 @@ extension DisposeBag {
 
     /// Convenience function allows an array of disposables to be gathered for disposal.
     public func insert(_ disposables: [Disposable]) {
-        self.lock.performLocked {
-            if self.isDisposed {
+        self.implementation.lock.performLocked {
+            if self.implementation.isDisposed {
                 disposables.forEach { $0.dispose() }
             } else {
-                self.disposables += disposables
+                self.implementation.disposables += disposables
             }
         }
     }

Tests/RxCocoaTests/DelegateProxyTest.swift

@@ -786,8 +786,9 @@ extension DelegateProxyTest {
         let collection = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
         let mockDelegate = MockDelegate()
         collection.delegate = mockDelegate
-        collection.rx.contentOffset.subscribe().disposed(by: DisposeBag())
-
+        var disposeBag = DisposeBag()
+        collection.rx.contentOffset.subscribe().disposed(by: &disposeBag)
+
         let selector = #selector(getter: MockDelegate.demoText)
         if ((collection.delegate?.responds(to: selector)) != nil) {
             let performResult = collection.delegate?.perform(selector)?.takeRetainedValue()

Tests/RxCocoaTests/Driver+Test.swift

@@ -269,19 +269,19 @@ extension DriverTest {
 
         relay.asDriver()
             .drive(observer)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         prepareSampleDriver(with: "first")
             .drive(relay)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         prepareSampleDriver(with: "second")
             .drive(relay)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         Observable.just("third")
             .bind(to: relay)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         disposeBag = DisposeBag()
 

Tests/RxCocoaTests/KVOObservableTests.swift

@@ -39,7 +39,7 @@ final class Parent : NSObject {
 
         self.rx.observe(String.self, "val", options: [.initial, .new], retainSelf: false)
             .subscribe(onNext: callback)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
     }
 
     deinit {
@@ -48,13 +48,13 @@ final class Parent : NSObject {
 }
 
 final class Child : NSObject {
-    let disposeBag = DisposeBag()
+    var disposeBag = DisposeBag()
 
     init(parent: ParentWithChild, callback: @escaping (String?) -> Void) {
         super.init()
         parent.rx.observe(String.self, "val", options: [.initial, .new], retainSelf: false)
             .subscribe(onNext: callback)
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
     }
 
     deinit {

Tests/RxCocoaTests/RxTest+Controls.swift

@@ -103,14 +103,14 @@ extension RxTest {
     func ensureControlObserverHasWeakReference<C, T>(file: StaticString = #file, line: UInt = #line, _ createControl: @autoclosure() -> (C), _ observerSelector: (C) -> AnyObserver<T>, _ observableSelector: () -> (Observable<T>)) where C: NSObject {
         var deallocated = false
 
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
 
         autoreleasepool {
             let control = createControl()
             let propertyObserver = observerSelector(control)
             let observable = observableSelector()
 
-            observable.bind(to: propertyObserver).disposed(by: disposeBag)
+            observable.bind(to: propertyObserver).disposed(by: &disposeBag)
 
             _ = (control as NSObject).rx.deallocated.subscribe(onNext: { _ in
                 deallocated = true

Tests/RxCocoaTests/SentMessageTest.swift

@@ -645,11 +645,11 @@ extension SentMessageTest {
     func testFailsInCaseObjectIsAlreadyBeingInterceptedWithKVO_sentMessage() {
         let target = SentMessageTest_shared()
 
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
         target.rx.observe(NSArray.self, "messages")
             .subscribe(onNext: { _ in
             })
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         do {
             _ = try target.rx.sentMessage(#selector(SentMessageTestBase_shared.justCalledBool(toSay:)))
@@ -672,11 +672,11 @@ extension SentMessageTest {
     func testFailsInCaseObjectIsAlreadyBeingInterceptedWithKVO_methodInvoked() {
         let target = SentMessageTest_shared()
 
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
         target.rx.observe(NSArray.self, "messages")
             .subscribe(onNext: { _ in
             })
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
 
         do {
             _ = try target.rx.methodInvoked(#selector(SentMessageTestBase_shared.justCalledBool(toSay:)))
@@ -863,7 +863,7 @@ extension SentMessageTest {
         var messages: Observable<MethodParameters>!
         var recordedMessages = [MethodParameters]()
         var completed = false
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
 
         var stages: [MessageProcessingStage] = []
 
@@ -883,7 +883,7 @@ extension SentMessageTest {
                 stages.append(.sentMessage)
                 }, onCompleted: {
                     completed = true
-            }).disposed(by: disposeBag)
+            }).disposed(by: &disposeBag)
 
             target.justCalledBool(toSay: true)
         }
@@ -897,7 +897,7 @@ extension SentMessageTest {
         var messages: Observable<MethodParameters>!
         var recordedMessages = [MethodParameters]()
         var completed = false
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
 
         var stages: [MessageProcessingStage] = []
 
@@ -917,7 +917,7 @@ extension SentMessageTest {
                 stages.append(.methodInvoked)
                 }, onCompleted: {
                     completed = true
-            }).disposed(by: disposeBag)
+            }).disposed(by: &disposeBag)
 
             target.justCalledBool(toSay: true)
         }

Tests/RxSwiftTests/Anomalies.swift

@@ -100,7 +100,7 @@ extension AnomaliesTest {
     }
 
     func test1344(){
-        let disposeBag = DisposeBag()
+        var disposeBag = DisposeBag()
         let foo = Observable<Int>.create({ observer in
                 observer.on(.next(1))
                 Thread.sleep(forTimeInterval: 0.1)
@@ -119,7 +119,7 @@ extension AnomaliesTest {
 
         Observable.merge(foo, .just([42]))
             .subscribe()
-            .disposed(by: disposeBag)
+            .disposed(by: &disposeBag)
     }
 
     func testSeparationBetweenOnAndSubscriptionLocks() {