Make atom keys Sendable

Examples/Packages/iOS/Sources/ExampleVoiceMemo/Atoms/VoiceMemoRowAtoms.swift

@@ -7,7 +7,7 @@ import SwiftUI
 struct IsPlayingAtom: StateAtom {
     let voiceMemo: VoiceMemo
 
-    var key: some Hashable {
+    var key: URL {
         voiceMemo.url
     }
 
@@ -39,7 +39,7 @@ struct IsPlayingAtom: StateAtom {
 struct PlayingElapsedTimeAtom: PublisherAtom {
     let voiceMemo: VoiceMemo
 
-    var key: some Hashable {
+    var key: URL {
         voiceMemo.url
     }
 
@@ -58,7 +58,7 @@ struct PlayingElapsedTimeAtom: PublisherAtom {
 struct AudioPlayerAtom: ValueAtom {
     let voiceMemo: VoiceMemo
 
-    var key: some Hashable {
+    var key: URL {
         voiceMemo.url
     }
 

Sources/Atoms/Core/Atom/Atom.swift

@@ -4,7 +4,7 @@
 /// and is immediately released when no longer watched.
 public protocol Atom<Produced>: Sendable {
     /// A type representing the stable identity of this atom.
-    associatedtype Key: Hashable
+    associatedtype Key: Hashable & Sendable
 
     /// The type of value that this atom produces.
     associatedtype Produced

Sources/Atoms/Core/Atom/ModifiedAtom.swift

@@ -6,7 +6,7 @@ public struct ModifiedAtom<Node: Atom, Modifier: AtomModifier>: Atom where Node.
     public typealias Produced = Modifier.Produced
 
     /// A type representing the stable identity of this atom.
-    public struct Key: Hashable {
+    public struct Key: Hashable, Sendable {
         private let atomKey: Node.Key
         private let modifierKey: Modifier.Key
 

Sources/Atoms/Core/AtomKey.swift

@@ -1,5 +1,5 @@
-internal struct AtomKey: Hashable, CustomStringConvertible {
-    private let key: AnyHashable
+internal struct AtomKey: Hashable, Sendable, CustomStringConvertible {
+    private let key: UnsafeUncheckedSendable<AnyHashable>
     private let type: ObjectIdentifier
     private let scopeKey: ScopeKey?
     private let anyAtomType: Any.Type
@@ -20,7 +20,7 @@ internal struct AtomKey: Hashable, CustomStringConvertible {
     }
 
     init<Node: Atom>(_ atom: Node, scopeKey: ScopeKey?) {
-        self.key = AnyHashable(atom.key)
+        self.key = UnsafeUncheckedSendable(atom.key)
         self.type = ObjectIdentifier(Node.self)
         self.scopeKey = scopeKey
         self.anyAtomType = Node.self

Sources/Atoms/Core/Modifier/AtomModifier.swift

@@ -11,7 +11,7 @@ public extension Atom {
 /// A modifier that you apply to an atom, producing a new value modified from the original value.
 public protocol AtomModifier: Sendable {
     /// A type representing the stable identity of this modifier.
-    associatedtype Key: Hashable
+    associatedtype Key: Hashable & Sendable
 
     /// A type of base value to be modified.
     associatedtype Base

Sources/Atoms/Core/OverrideKey.swift

@@ -4,7 +4,7 @@ internal struct OverrideKey: Hashable, Sendable {
 
     @usableFromInline
     init<Node: Atom>(_ atom: Node) {
-        let key = AnyHashable(atom.key)
+        let key = UnsafeUncheckedSendable<AnyHashable>(atom.key)
         let type = ObjectIdentifier(Node.self)
         identifier = .node(key: key, type: type)
     }
@@ -17,8 +17,8 @@ internal struct OverrideKey: Hashable, Sendable {
 }
 
 private extension OverrideKey {
-    enum Identifier: Hashable, @unchecked Sendable {
-        case node(key: AnyHashable, type: ObjectIdentifier)
+    enum Identifier: Hashable, Sendable {
+        case node(key: UnsafeUncheckedSendable<AnyHashable>, type: ObjectIdentifier)
         case type(ObjectIdentifier)
     }
 }

Sources/Atoms/Core/ScopeKey.swift

@@ -1,5 +1,5 @@
 @usableFromInline
-internal struct ScopeKey: Hashable, CustomStringConvertible {
+internal struct ScopeKey: Hashable, Sendable, CustomStringConvertible {
     final class Token {}
 
     private let identifier: ObjectIdentifier

Sources/Atoms/Core/StoreContext.swift

@@ -440,7 +440,7 @@ private extension StoreContext {
         lazy var shouldKeepAlive = !key.isScoped && store.state.caches[key].map { $0.atom is any KeepAlive } ?? false
         lazy var isChildrenEmpty = store.graph.children[key]?.isEmpty ?? true
         lazy var isSubscriptionEmpty = store.state.subscriptions[key]?.isEmpty ?? true
-        lazy var shouldRelease = !shouldKeepAlive && isChildrenEmpty && isSubscriptionEmpty
+        let shouldRelease = !shouldKeepAlive && isChildrenEmpty && isSubscriptionEmpty
 
         guard shouldRelease else {
             return

Sources/Atoms/Core/UnsafeUncheckedSendable.swift

@@ -7,3 +7,6 @@ internal struct UnsafeUncheckedSendable<Value>: @unchecked Sendable {
         self.value = value
     }
 }
+
+extension UnsafeUncheckedSendable: Equatable where Value: Equatable {}
+extension UnsafeUncheckedSendable: Hashable where Value: Hashable {}

Sources/Atoms/Modifier/AnimationModifier.swift

@@ -41,7 +41,7 @@ public struct AnimationModifier<Produced>: AtomModifier {
     public typealias Produced = Produced
 
     /// A type representing the stable identity of this atom associated with an instance.
-    public struct Key: Hashable {
+    public struct Key: Hashable, Sendable {
         private let animation: Animation?
 
         fileprivate init(animation: Animation?) {

Sources/Atoms/Modifier/ChangesModifier.swift

@@ -40,7 +40,7 @@ public struct ChangesModifier<Produced: Equatable>: AtomModifier {
     public typealias Produced = Produced
 
     /// A type representing the stable identity of this atom associated with an instance.
-    public struct Key: Hashable {}
+    public struct Key: Hashable, Sendable {}
 
     /// A unique value used to identify the modifier internally.
     public var key: Key {

Sources/Atoms/Modifier/ChangesOfModifier.swift

@@ -48,22 +48,35 @@ public struct ChangesOfModifier<Base, Produced: Equatable>: AtomModifier {
     /// A type of value the modified atom produces.
     public typealias Produced = Produced
 
-    /// A type representing the stable identity of this modifier.
-    public struct Key: Hashable {
-        private let keyPath: KeyPath<Base, Produced>
+    #if compiler(>=6) || hasFeature(InferSendableFromCaptures)
+        /// A type representing the stable identity of this modifier.
+        public struct Key: Hashable, Sendable {
+            private let keyPath: KeyPath<Base, Produced> & Sendable
 
-        fileprivate init(keyPath: KeyPath<Base, Produced>) {
-            self.keyPath = keyPath
+            fileprivate init(keyPath: KeyPath<Base, Produced> & Sendable) {
+                self.keyPath = keyPath
+            }
         }
-    }
 
-    #if compiler(>=6) || hasFeature(InferSendableFromCaptures)
         private let keyPath: KeyPath<Base, Produced> & Sendable
 
         internal init(keyPath: KeyPath<Base, Produced> & Sendable) {
             self.keyPath = keyPath
         }
+
+        /// A unique value used to identify the modifier internally.
+        public var key: Key {
+            Key(keyPath: keyPath)
+        }
     #else
+        public struct Key: Hashable, Sendable {
+            private let keyPath: UnsafeUncheckedSendable<KeyPath<Base, Produced>>
+
+            fileprivate init(keyPath: UnsafeUncheckedSendable<KeyPath<Base, Produced>>) {
+                self.keyPath = keyPath
+            }
+        }
+
         private let _keyPath: UnsafeUncheckedSendable<KeyPath<Base, Produced>>
         private var keyPath: KeyPath<Base, Produced> {
             _keyPath.value
@@ -72,12 +85,12 @@ public struct ChangesOfModifier<Base, Produced: Equatable>: AtomModifier {
         internal init(keyPath: KeyPath<Base, Produced>) {
             _keyPath = UnsafeUncheckedSendable(keyPath)
         }
-    #endif
 
-    /// A unique value used to identify the modifier internally.
-    public var key: Key {
-        Key(keyPath: keyPath)
-    }
+        /// A unique value used to identify the modifier internally.
+        public var key: Key {
+            Key(keyPath: _keyPath)
+        }
+    #endif
 
     /// A producer that produces the value of this atom.
     public func producer(atom: some Atom<Base>) -> AtomProducer<Produced> {

Sources/Atoms/Modifier/TaskPhaseModifier.swift

@@ -79,7 +79,7 @@ public struct TaskPhaseModifier<Success: Sendable, Failure: Error>: AsyncAtomMod
     public typealias Produced = AsyncPhase<Success, Failure>
 
     /// A type representing the stable identity of this atom associated with an instance.
-    public struct Key: Hashable {}
+    public struct Key: Hashable, Sendable {}
 
     /// A unique value used to identify the modifier internally.
     public var key: Key {