I have some listeners: `typealias Listener<T&gt...

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[ziggy42]

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?

[spand]

Use a map like

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

val listenerMap = mutableMapOf<UserTypeKey, Listener>()

[spand]

But depends on how you need to query it and if it is fast enough to perform a linear scan

[ziggy42]

Mmm sorry but I don't understand. I need the type in Listener, right? How can I say something like mutableMapOf<T, Listener<T>>()?

[Andreas Sinz]

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