I have some listeners:

typealias Listener<T> = (T) -> Unit

and for each

T

that I accept I need to store the list of registered listeners:

val userListeners = mutableListOf<Listener<User>>()

. But this forces me to have N lists for N possible

T

. Is there a better way?

Use a map like

data class UserTypeKey(val user: User, val type: Type)

val listenerMap = mutableMapOf<UserTypeKey, Listener>()

Mmm sorry but I don't understand. I need the type in Listener, right? How can I say something like

mutableMapOf<T, Listener<T>>()

?

you can use a

Map<KClass<*>, MutableList<Function<Unit>>>

and then based on the

T::class

you can retrieve the list of Listeners, but that involves unsafe casts