why is there a `kotlin.collections.LinkedHashSet` typealias that aliases to `java.util.LinkedHashSe...

# announcements

[christophsturm]

why is there a kotlin.collections.LinkedHashSet typealias that aliases to java.util.LinkedHashSet (in typealiases.kt) , but also a kotlin class kotlin.collections.LinkedHashSet defined in LinkedHashSet.kt ?

[ephemient]

are you aware of how `expect`/`actual` works in kotlin multiplatform? https://kotlinlang.org/docs/reference/mpp-connect-to-apis.html

[ephemient]

libraries/stdlib/common/.../LinkedHashSet.kt:

expect class LinkedHashSet<E>

libraries/stdlib/jvm/src/kotlin/collections/TypeAliases.kt:

public actual typealias LinkedHashSet<E> = java.util.LinkedHashSet<E>

libraries/stdlib/wasm/src/kotlin/collections/LinkedHashSet.kt:

actual open class LinkedHashSet<E>

(ditto libraries/stdlib/js... etc)

[ephemient]

this lets common code use LinkedHashSet; it will be replaced with the typealias on JVM and with a Kotlin implementation on other platforms

[christophsturm]

ok so when idea navigates to the pure kotlin version in my jvm project thats an idea bug?

[ephemient]

which one does it navigate to?

[christophsturm]

the one in common

[christophsturm]

but not always, now it navigates to the alias

[ephemient]

that would be correct, both common expect and jvm actual define what you can use on jvm

[christophsturm]

ah ok it makes sense. I missed that the LinkedHashSet in common is just an expect

[christophsturm]

thanks for your explanation!