Could not find an overload for '=='

Question

I have the following code:

            var settingButton:UIButton
            settingButton = appDelegate.myFunctionReturningButton()

            if (settingButton == nil) {println("WE ARE IN BAD SHAPE!!!!")}

It partly works, but not always. To see what happens in case I do not get what I expect from myFunctionReturningButton(), I added the last line. But here is the problem and my question:

I get this error message from the Swift compiler:

Could not find an overload for '==' that accepts the supplied arguments

Browsing the net, I kind of understand what that means, but what can I do about it? How should I write the last line?

For precision: I have the two following function in AppDelegate.swift and appSettingButton is declared with this line at the top of the AppDelegate class.

var appSettingButton: UIButton = UIButton.alloc()


func registerSettingButton (button:UIButton) {
    appSettingButton = button
}


func myFunctionReturningButton() -> UIButton {
    return appSettingButton
}

Answer 1

You can't compare a non-optional value to nil because it will never be nil. And you shouldn't use UIButton.alloc() to initialize a button, just use UIButton(). If your logic depends on waiting for this button to be re-defined after initialization of your app delegate subclass, you should make an optional, i.e. UIButton?. Then you can compare it to nil.