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kotlinlang

I have a function which makes an external call and returns nothing, but I need to do something based on if it succeeded or not. 
Is returning `Result&lt;Unit&gt;` the best thing to do here or is there anything else in the std library?

could do
``` sealed class ExternalCallResult {
object Success : ExternalCallResult
object Failure : ExternalCallResult
} ```

if you dont need the value and exceptions parts of Result

If it returns `nothing`, you can also go with `Result&lt;Nothing?&gt;`

I would personally go for `Result&lt;Unit&gt;` where `Unit` represents a _side-effect_ without any meaningful result, so "succes" and the `Result.failure` holds the failure.

The only value that can be given to `Nothing?` is `null` since `Nothing` has not value, so you can only fill in `null`. So it's isomorphic to `Unit`.

Arrow has `typealias Null = Nothing?` since `Nothing?` is the generic way to represent only `null` can be a valid value.