[SR-7301] Bad fixit suggested for protocol extension implementation for inherited objc protocol

Previous ID	SR-7301
Radar	None
Original Reporter	kdawgwilk (JIRA User)
Type	Bug

Attachment: Download

Xcode 9.2

Swift 4

macOS 10.13.3

Votes	0
Component/s	Compiler
Labels	Bug, StarterBug
Assignee	None
Priority	Medium

md5: f483fe309b1876278257725a1dc2b1b5

relates to:

• SR-3349 @objc methods cannot be contained in protocol extensions

Issue Description:

I have the following code that has a compiler error

@objc protocol IntroAnimationController: UIViewControllerAnimatedTransitioning {
    func frame(for view: UIView, fromView: UIView) -> CGRect
    func animations(fromView: UIView, toView: UIView) -> () -> Void
}

extension IntroAnimationController {
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.20
    }
}

The error says:


and includes a fixit that that turns my code into this:

extension IntroAnimationController {
    @objc(transitionDuration:) func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.20
    }
}

And then gives me these two wonderful new errors:


None of the fixits are helpful and the error message does not give me any clue why I can't do this