Hello, World! I’m in a `when (e)`, (with e being ...

# announcements

[bod]

Hello, World! I’m in a when (e), (with e being an instance of MyEnum) and for the branches, I’m allowed to put something that is not one of the possible values of MyEnum (I can put values of other enums). I find this extremely surprising 🙂 Thoughts?

[Hamza]

can u show us an example

[arekolek]

yeah it would be nice to have at least a warning that this is an unreachable branch

[bod]

when (transaction.status) {
                    TransactionStatus.PENDING -> TODO()
                    TransactionStatus.COMPLETED -> TODO()
                    TransactionStatus.DECLINED -> TODO()
                    TransactionStatus.UNKNOWN -> TODO()
                    TransactionActivityTag.TRANSPORT -> TODO()

[arekolek]

(or maybe it’s not actually unreachable)

[bod]

compiles

[Hamza]

is there any warnings?

[bod]

nope

[bod]

how come I’m not allowed to put, say, a String but another type that happens to be an enum. I’m allowed?

[arekolek]

I remembered there was a similar discussion https://kotlinlang.slack.com/archives/C0922A726/p1530087621000037

[bod]

wow 😱

[bod]

ok, when on `enum`s is broken in Kotlin 😄 Not scary at all!

[bod]

oh wait it says it’s fixed 🙂 https://youtrack.jetbrains.net/issue/KT-24708

[bod]

(we’re not on 1.3 yet)

[arekolek]

and this one https://youtrack.jetbrains.net/issue/KT-22043 looks like what would fix the thing you originally mentioned

[bod]

(in my case, we have the same value name in 2 enums, and I “static import” them both - hilarity ensued)

[Mike]

The when is much more strict if the result is used. Still an issue here that may be addressed.

Would be curious to know what happens if you assign the when to a variable.

[arekolek]

Same thing happens

[arekolek]

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