Given a list of Any objects, write a Kotlin function using when with smart casts to return a list of strings describing each element's type and value. What is the correct implementation?

Given a list of Any objects, write a Kotlin function using when with smart casts to return a list of strings describing each element's type and value. What is the correct implementation?

fun describeList(items: List): List {
    return items.map { item ->
        when (item) {
            is String -> "String of length ${'$'}{item.length}"
            is Int -> "Int with value ${'$'}item"
            else -> "Unknown type"
        }
    }
}