class Dynamic

public fun jsonOf(i: Int): Dynamic = TODO()
public fun jsonOf(s: String): Dynamic = TODO()
// ...
public fun jsonOf(l: List<Any?>): Dynamic = TODO()

private fun jsonOf(x: Any?): Dynamic = when (x) {
    is Int -> jsonOf(x)
    is String -> jsonOf(x)
    // ...
    is List<*> -> jsonOf(x)
    else -> error("entered unreachable code: $x")
}