I can't find a KEEP for it, but I'm guessing people have been requesting

filterKeysIsInstance

and

filterValueIsInstance

on a Map? Would like to track its progress if its there.

Sounds more like #stdlib

This will usually be just discussed in YouTrack. For that particular issue, we are in holding pattern. Instead of doing more stdlib methods, we plan to have contract to rule them all: KT-19329 Contracts to express the effect of checks in the

filter

lambda on the return type