Singleton and init with parameter

Question

I want to use the singleton pattern in my class which has a private init with parameter. It also has a class function called setup which configures

Answer 1

This seems to be the simplest way to implement the singleton in swift:

private let _AsteroidSharedInstance: Asteroid?

class Asteroid {
    var config: ASTConfig?

    class func setup(config: config) {
        _AsteroidSharedInstance = Asteroid(config: config)
    }

    class var sharedInstance: Asteroid {
        if _AsteroidSharedInstance == nil {
            println("error: shared called before setup")
        }

        return _AsteroidSharedInstance
    }

    init(config: config) {
        self.config = config
    }
}

with the usage:

Asteroid.sharedInstance()

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