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kotlinlang

```kt
val m: Map&lt;String, Int&gt; = mapOf("a" to 42, "b" to null).filterValues { it != null }```
Any possibility to infer the not null type by the compiler? Workaround is a manual cast

This question comes up a lot, I don't know of any better workaround. I'd just do the manual cast, but hide it inside an extension function.

Just that there are no null values does not mean you don't get null returned. Ask for a key not present in the map. ;-)

Right, but that's why `Map.get` is defined to return `V?`, not `V`: <https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-map/get.html>

So there is a meaningful distinction between a `Map&lt;String, Int&gt;` and a `Map&lt;String, Int?&gt;`  :thumbsup:

I guess a good example would be when you're iterating the map entries. If you know that the values are non-null, then you know that no entry will have a null value.