Cut pairs with empty values from map

Question

I'd like to filter out all the pairs with empty values

val mapOfNotEmptyPairs: Map<String, String> = mapOf("key" to Some("value"), "secondKey" to None)

expected:

print(mapOfNotEmptyPairs)
// {key=value}

Answer 1

val mapOfNotEmptyPairs =
        mapOf("key" to Some("value"), "secondKey" to None)
            .filterValues { it is Some<String> } // or { it !is None } or { it.isDefined() }
            .mapValues { (_, v) -> (v as Some<String>).t }