Confusing behavior of data-race safety

Using Swift
1

Hi,

I have the following snippet

final class A {
    let b: B

    init(b: B) {
        self.b = b
    }

    func execute1() async {
        await b.doSomething() // error: Sending 'self.b' risks causing data races 
    }

    func execute2() async {
        let doSomething = b.doSomething
        await doSomething() // This is ok
    }
}

final class B {
    @MainActor func doSomething() async {
        print("did something")
    }
}

I cannot understand why execute2 method compiles successfully.
I would have expected to encounter the same error as in execute1 method.

4 Likes
2

I agree, both cases should be rejected by the compiler.