What is the equivalent of @autoreleasepool in Swift?

Question

In Swift, I notice there is no @autoreleasepool{} construct, although Swift does use ARC. What is the proper way to manage an autoreleasepool in Swift, or has it be

Answer 1

I used this kind of structure in my code. This function is create thumbnail image from Video URL.

func getThumbnailImage(forUrl url: URL) -> UIImage? {
    return autoreleasepool{ () -> UIImage in
        let asset: AVAsset = AVAsset(url: url)
        let imageGenerator = AVAssetImageGenerator(asset: asset)
        var thumbnailImage: CGImage?
        do {
            thumbnailImage = try imageGenerator.copyCGImage(at: CMTimeMake(value: 1, timescale: 60) , actualTime: nil)
            return UIImage(cgImage: thumbnailImage!)
        } catch let error {
            print(error)
        }
        return UIImage(cgImage: thumbnailImage!)
    }
}

Answer 2

This is explained in detail in WWDC 2014 session video number 418 "Improving Your App with Instruments", which you can also download as a PDF.

But in short, the syntax is:

autoreleasepool {
  /* code */ 
}

Answer 3

There is! It's just not really mentioned anywhere.

autoreleasepool {
    Do things....
}

Answer 4

Just FYI, Xcode constructed the full code as follows:

autoreleasepool({ () -> () in
    // code              
})

Guess the parentheses identifies the functions closure.