main-capture_list.swift

import Foundation

class OtherObject {

    var value: String = ""

    deinit {
        print("Other deinit")
    }
}

class SomeClass {

    var current = OtherObject()
    var callback: ((String) -> [String])!

    init() {
        self.callback = { [weak self] value in
            guard let current = self?.current else { return [] }

            current.value += "\(value),"
            return current.value.components(separatedBy: ",")
        }

        self.callback = { [current = self.current] value in
            current.value += "\(value),"
            return current.value.components(separatedBy: ",")
        }
    }

    deinit {
        print("Some deinit")
    }

}

var some: SomeClass! = SomeClass()
some.callback("hi")
print(some.callback("bye"))
some = nil