dpgao

Keybase proof

I hereby claim:

• I am dpgao on github.
• I am dpgao (https://keybase.io/dpgao) on keybase.
• I have a public key whose fingerprint is 57D4 23CE 922E 0B6E B380 34A5 EE48 8EDD A59E 1E88

To claim this, I am signing this object:

dpgao

final class ImageDownloader {

    typealias CompletionHandler = (UIImage?) -> Void

    private struct ResponseHandler {
        let dataTask: URLSessionDataTask
        var completionHandlers: [CompletionHandler]
    }

    private let lock = NSLock()

dpgao

infix operator !=> { associativity left precedence 125 }

func !=><T>(lhs: T?, @noescape rhs: () -> Void) -> T? {
    if let lhs = lhs { return lhs }
    rhs()
    return nil
}