ARKit – Why there's no 'ARPlaneDetection' Enum anymore?

Question

Why Apple's software engineers did remove ARPlaneDetection enum and made ARWorldTrackingConfiguration.PlaneDetection struct instead?

Was:

public enum ARPlaneDetection: UInt {
    case .none
    case .horizontal
}

Now:

public struct PlaneDetection: OptionSet {
    public init(rawValue: UInt)
    public var horizontal: ARWorldTrackingConfiguration.PlaneDetection { get }
    public var vertical: ARWorldTrackingConfiguration.PlaneDetection { get }
}

What advantages does new PlaneDetection struct have over obsolete ARPlaneDetection enum in ARKit?

Answer 1

This all is because PlaneDetection struct conforms to OptionSet protocol which allows you to set multiple options for some settings like this plane detection

let options: ARWorldTrackingConfiguration.PlaneDetection = [.horizontal, .vertical]
let options: ARWorldTrackingConfiguration.PlaneDetection = []

... this is advantage of OptionSet and this simply isn't possible with just enum.