self map

//
//  Example using self.map to get a strong reference to a weak reference on self.
//

import Foundation
import PlaygroundSupport

final class Test {
    
    private let queue: DispatchQueue
    private var items: [Int]
    
    init(queue: DispatchQueue, items: [Int]) {
        self.queue = queue
        self.items = items
    }
    
    func test() {
        queue.async { [weak self] in
            self.map { `self` in
                let sum = self.items.reduce(0, +)
                print("Sum is \(sum)")
            }
        }
    }
}

let t = Test(
    queue: .global(),
    items: Array(1 ... 100)
)
t.test()

PlaygroundPage.current.needsIndefiniteExecution = true