Vsevolod Tolstopyatov

@Tmpod we are evaluating this change on IDEA codebase. Could you please elaborate on your interest in this primitive? E.g. what use-cases are you aiming to solve with it?

Closing as duplciate

We are going to promote it to delicate API along with `isClosedForReceive`

Copying my response from the PR, so the discussion can be continued here if necessary: With stateful transformations in their current form, we are heavily approaching the readability boundary and...

[mingwX86 is deprecated](https://kotlinlang.org/docs/native-target-support.html#deprecated-targets) thus we are not adding support for that target

Let's finalize and merge it?

(preliminary looks good, will take a one final look when #3603 is merged)

Could you please rebase this one on the recent `develop`?

Exactly, nicely done!

Actually, `concurrentMap` can be expressed via `flatMapMerge` without using any private API: ``` private fun Flow.concurrentMap(dispatcher: CoroutineDispatcher, concurrencyLevel: Int, bufferSize: Int, transform: suspend (T) -> R): Flow { return flatMapMerge(concurrencyLevel,...