import UIKit class ViewController: UIViewController { var provider = Provider() override func viewDidLoad() { super.viewDidLoad() provider.reload { self.provider.layout() // 1) Simultaneous access ! } } struct Provider { let cache = Cache() // 2) comment out mutating func reload(completion: @escaping ()->Void) { // 3) remove mutating keyword completion() } func layout() { } } class Cache { } }
