https://useyourloaf.com/blog/objc-warnings-upgrading-to-swift-4/
@objc Warnings Upgrading To Swift 4
Open a Swift 3 project in Xcode 9 and it will warn you that you can upgrade to Swift 4. If you accept the invite you end up with another warning that Swift 4 mode deprecates the Swift 3 @objc inference rules. What is this scary sounding warning and how do you make it go away?
@objc Warnings Upgrading To Swift 4
Open a Swift 3 project in Xcode 9 and it will warn you that you can upgrade to Swift 4. If you accept the invite you end up with another warning that Swift 4 mode deprecates the Swift 3 @objc inference rules. What is this scary sounding warning and how do you make it go away?