Type Casting

In Drift, it is easy to check and deal with native and custom types. Two main parts exist:

• Type Check using the is keyword.
• Type Down-casting using the as keyword.

Type Check

warning

At this moment, Drift does not implement type check.

fun isInteger(value: Any) : Bool {
    return value is Int
}

fun isNotInteger(value: Any) : Bool {
    return value !is Int        // 'is' keyword can be negated -> '!is'
}

Down-casting

warning

At this moment, Drift does not implement down-casting.

let a: Any = 1          // Has Any as type, not Int
let b: Int = a as Int   // a is down-casted as Int

fun toIntOrNull(value: Any) : Int? {
    return value as? Int        // Down-casted if possible, else Null
}

info

At this moment, Any is not a top-type, but the absence of a type. We plan to refactor Any to be a top-type.