//There is no static initialization block in Swift.
//A stored type property is initialized lazily, on
//the first access, and only once - even when
//several threads reach it at the same time.
class Config {
    static let table: [String: Int] = {
        print("the block runs on first access")
        return ["a": 1, "b": 2]
    }()

    //An instance is set up in init()
    var name: String
    init() {
        name = "config"
    }
}

print("before the first access")

let a = Config.table["a"]!
//a is 1
print("a is \(a)")

//The block does not run a second time
let b = Config.table["b"]!
//b is 2
print("b is \(b)")