Open Radar

 
What I'd like to be able to do: 

NEHotspotConfigurationManager.shared.apply(config) { possibleError in
    if let error = possibleError {
        switch error {
        case NEHotspotConfigurationError.alreadyAssociated:
            // ...
        case NEHotspotConfigurationError.pending:
            // ...
        default:
            // ...
        }
    }
}

This is similar to other error types like URLError, which make use of NS_ERROR_ENUM:
https://twitter.com/kostaskremizas/status/923228453784170497

This would also allow catching NEHotspotConfigurationError from throwing functions. There aren't any in the NEHotspotConfigurationManager API right now, but these could be thrown from user-created functions that wrap it, or come from future first-party APIs.
https://developer.apple.com/library/content/documentation/Swift/Conceptual/BuildingCocoaApps/AdoptingCocoaDesignPatterns.html#//apple_ref/doc/uid/TP40014216-CH7-ID223

What I currently have to do:

NEHotspotConfigurationManager.shared.apply(config) { possibleError in
    if let error = possibleError {
        let nsError = error as NSError
        if nsError.domain == "NEHotspotConfigurationErrorDomain" {
            switch nsError.code {
            case NEHotspotConfigurationError.alreadyAssociated.rawValue:
                // ...
            case NEHotspotConfigurationError.pending.rawValue:
                // ...
            default:
                // ...
            }
            return
        }
    }
}