Swift gives “self used before all stored procedures are initialized” error when building child nodes

问题

In XCode 6.2, I have a Swift project where a main-object ("Backbone") creates sub-objects with pointers back to Backbone:

class Backbone
{
    let logManager: QCLogManager!
    let cloudJobManager: CloudJobManager!
    ...

    init() {
        logManager = QCLogManager(backbone: self)
        cloudJobManager = CloudJobManager(backbone: self)
        ...
    }

It works very nicely. However, in XCode 6.3 each line in init() now gives the error:

'self' used before all stored properties are initialized.

That seems a rather unhelpful compiler restriction. Why did it change? How should I now be doing it?

回答1:

let logManager: QCLogManager!
let cloudJobManager: CloudJobManager!

if let is not necessary, change to var

var logManager: QCLogManager!
var cloudJobManager: CloudJobManager!

回答2:

You might need to create a property of type Backbone in both QCLogManager and CloudJobManager and set that property after initialization of all store properties of BackBone class.

class Backbone
{
    let logManager: QCLogManager!
    let cloudJobManager: CloudJobManager!
    ...

    init() {
        logManager = QCLogManager()
        cloudJobManager = CloudJobManager()
        ...
        logManager.backBone = self
        cloudJobManager.backBone = self
    }

来源：https://stackoverflow.com/questions/29761219/swift-gives-self-used-before-all-stored-procedures-are-initialized-error-when