Is there a particular reason why `AtomicInt` from ...

# coroutines

[Dico]

Is there a particular reason why AtomicInt from kotlinx:atomicfu doesn't declare these:
operator fun plusAssign (+=)
operator fun minusAssign (-=)
operator fun inc (++)
operator fun dec (--)

In Java, these couldn't be atomic, but since you can implement them yourself, they would be.
For inc and dec I guess it might be because they would have to return AtomicInt, instead of Int.

Asking here because I didn't see an atomicfu channel.

[Ruckus]

For inc and dec, it would violate:

The inc() and dec() functions must return a value, which will be assigned to the variable on which the ++ or -- operation was used. They shouldn't mutate the object on which the inc or dec was invoked.

(Emphasis added)
https://kotlinlang.org/docs/reference/operator-overloading.html

[Dico]

maybe there should be incAssign then 😂

[Dico]

alright, so it wouldn't work for those. Maybe that's a reason not to do it for the other two.

[Ruckus]

There was a discussion about that a while ago in #language-proposals: https://kotlinlang.slack.com/archives/C0B9K7EP2/p1558292249060600

[Ruckus]

(Speaking of channels, I'm not sure #coroutines was the best place for your question)

[Dico]

I know kotlinfu as used extensively by the coroutines library, I didn't find something more adequate.

[Ruckus]

The question itself has nothing to do with coroutines, so it may have fit better somewhere like #general, as it more about general Kotlin language functionality and design. Not a huge deal, but good to keep in mind for the future.