class SomeModel : Printable {

    var a:String

    init(a:String) {
        self.a = a
    }

    var description:String {
        return "(self.a)"
    }
}


class Editor {

    var getter:()-> String
    var setter:(String)->()

    init(getter:()-> String, setter:(String)->()) {
        self.getter = getter
        self.setter = setter
    }

    convenience init(inout bindTo:String) {
        self.init(
            getter:{ return bindTo },
            setter: { v in bindTo = v })
    }

    func read() -> String {
        return self.getter()
    }

    func write(value:String) {
        self.setter(value)
    }
}


func testBindTo() {
    var readModel =  SomeModel(a:"Did not capture by reference");
    var bindForReading = Editor(bindTo: &readModel.a)
    readModel.a = "captured by reference!"
    println(bindForReading.read())

    var writeModel =  SomeModel(a:"Did not capture by reference");
    var bindForWriting = Editor(bindTo: &writeModel.a)
    bindForWriting.write("captured by reference")
    println(writeModel)
}

testBindTo()


func testExplicitGetterSetter() {

    var readModel =  SomeModel(a:"Did not capture by reference");
    var bindForReading = Editor(
        getter: { readModel.a },
        setter: { v in readModel.a = v })
    readModel.a = "captured by reference!"
    println(bindForReading.read())

    var writeModel =  SomeModel(a:"Did not capture by reference");
    var bindForWriting = Editor(
        getter: { writeModel.a },
        setter: { v in writeModel.a = v })
    bindForWriting.write("captured by reference")
    println(writeModel)
}

testExplicitGetterSetter()

Did not capture by reference
Did not capture by reference
captured by reference!
captured by reference

/// A class providing access to a resource with an inout parameter in an escaping closure.
     class ProtectedResource<ValueType> {
            private var protectedResourceArray = [ValueType]()
            private var protectedResourceArrayLock = NSRecursiveLock()
            private let opq = OperationQueue()

            func performWithResource(block: @escaping (inout [ValueType]) -> ()) {
                opq.addOperation { [weak self] in
                    guard let strongSelf = self else {
                        return
                    }
                    strongSelf.protectedResourceArrayLock.lock()
                    block(&strongSelf.protectedResourceArray)
                    strongSelf.protectedResourceArrayLock.unlock()
                }
            }
        }

/// Some other class using that in out parameter.

        func run() {

            func updateArray(array: inout [String]) {
                print("Performing on (array)")
                array.append("test")
            }

            protectedResource.performWithResource(block: updateArray)

            protectedResource.performWithResource {
                print("Performing on ($0)")
            }
    }