Well that's exactly kotlin's problem :slightly_smi...

# announcements

[Czar]

Well that's exactly kotlin's problem 🙂 Since it is solved for Kt collections, why not in J8 streams support?
Added another map to the end of the chain (seems silly to me, but works): .map { it as SomeSpecificType }

[gildor]

czar: It’s definitely not a Kotlin problem. And actually not a problem at all.
You can rewrite this code to java and will get exactly the same behavior:

Stream.of(1, "two")
                .filter(it -> it instanceof String)
                .collect(Collectors.toList());

Return type of this steam is List<? extends Serializable>

[gildor]

Compiler cannot analyze code of filter to cast it implicitly, and actually should not do that