Convert String to Bool in Swift – via API or most Swift-like approach

There is not built in way AFAIK. Similar method to standard toInt() could be:

extension String {
    var bool: Bool? {
        switch self.lowercased() {
        case "true", "t", "yes", "y":
            return true
        case "false", "f", "no", "n", "":
            return false
        default:
            if let int = Int(self) {
                return int != 0
            }
            return nil
        }
    }
}