@swiftbot
class A : CustomStringConvertible { let value: Int init(_ value: Int) { self.value = value } var description: String { return "A(\(value))" } deinit { print("deinit \(self)") } } var i = 0 do { var x: ArraySlice<A> = [] do { for _ in 0..<20 { x.append(A(i)) i += 1 } while let a = x.popFirst() { print("pop \(a)") if !x.isEmpty { x[x.endIndex - 1] = A(i) i += 1 } } } print("-----") }