Trouble with non-escaping closures in Swift 3

Question

I have an extension Array in the form of:

extension Array
{
    private func someFunction(someClosure: (() -> Int)?)
    {
        // Do Something
    }

    func someOtherFunction(someOtherClosure: () -> Int)
    {
        someFunction(someClosure: someOtherClosure)
    }
}

But I'm getting the error: Passing non-escaping parameter 'someOtherClosure' to function expecting an @escaping closure.

Both closures are indeed non-escaping (by default), and explicitly adding @noescape to someFunction yields a warning indicating that this is the default in Swift 3.1.

Any idea why I'm getting this error?

-- UPDATE -- Screenshot attached:

Answer 1

Optional closures are always escaping.

Why is that? That's because the optional (which is an enum) wraps the closure and internally saves it.

There is an excellent article about the quirks of @escaping here.