@swift-5.1.5
@propertyWrapper struct Foo<Value> { var wrappedValue: Value var projectedValue: Self { self } } protocol Namespace { typealias MyFoo = Foo } struct Test { @Foo var val = 0 } struct MyTest: Namespace { @MyFoo var val = 0 } let t1 = Test() print(t1.val, t1.$val) let t2 = MyTest() print(t2.val, t2.$val)
(edited)