Selector type of expression is ambiguous without more context-CodePudding

I'm trying to get ARSessionDelegate method using selector, but im getting this error: Type of expression is ambiguous without more context

There is mine code:

#selector(ARSessionDelegate.session(_:didUpdate:) as ((ARSessionDelegate) -> (ARSession, ARFrame) -> Void))

That's how this method looks like:

public protocol ARSessionDelegate : ARSessionObserver {
    optional func session(_ session: ARSession, didUpdate frame: ARFrame)
}

And also, I am trying to make an rx extension for the ARKit session using this answer, but im not sure it's caused the problem.

CodePudding user response：

Because there are multiple methods with the same selector name, you are forced to implement the method in the delegate and forward the calls using a subject. Like this:

extension ARSession: HasDelegate { }

extension Reactive where Base: ARSession {
    var delegate: ARSessionDelegateProxy {
        return ARSessionDelegateProxy.proxy(for: base)
    }

    var didUpdate: Observable<ARFrame> {
        return delegate.didUpdate.asObservable()
    }
}

final class ARSessionDelegateProxy
: DelegateProxy<ARSession, ARSessionDelegate>
, DelegateProxyType
, ARSessionDelegate {
    init(parentObject: ARSession) {
        super.init(
            parentObject: parentObject,
            delegateProxy: ARSessionDelegateProxy.self
        )
    }

    deinit {
        didUpdate.onCompleted()
    }

    public static func registerKnownImplementations() {
        self.register { ARSessionDelegateProxy(parentObject: $0) }
    }

    func session(_ session: ARSession, didUpdate frame: ARFrame) {
        didUpdate.onNext(frame)
    }

    fileprivate let didUpdate = PublishSubject<ARFrame>()
}