is there a way to choose what concrete type

associateWith

returns?

No.

LinkedHashMap

is hardcoded in the stdlib. You could only use

associateWithTo

to add the results to an existing (mutable) map of your choice.

thanks!

Kotlin specifies that

mapOf

,

mutableMapOf

, and most Map-returning methods preserve insertion order, so in practice they are backed by LinkedHashMap