I have `val items: Set<Any>` that contains d...

# announcements

[Jakub]

I have val items: Set<Any> that contains different types including EventItem . I wanna find in my set the index of EventItem with the specific date like:

val event = state.items
    .filterIsInstance(EventItem::class.java)
    .find { it.start == date.atStartOfDay() }
                
val index = state.items.indexOf(event)

However, it gives me Type inference failed. The value of the type parameter T should be mentioned in input types (argument types, receiver type or expected type). Try to specify it explicitly.

What’s missing?

[streetsofboston]

Seems event is of type EventItem?., a nullable type.
This will have a successful type-inference:
val index = state.items.indexOf(event!!)

[streetsofboston]

Or, the other way around, change the items type:
val items: Set<Any?>

[StavFX]

val index = state.items
      .filterIsInstance<EventItem>()
      .indexOfFirst { it.start == date.atStartOfDay() }
// index is potentially -1 (not found) in this implementation

[Hitender Pannu]

@StavFX will this one returns the actual index?

I guess we have to move the type check inside the indexOfFirst function.

[StavFX]

Ah good point. Yeah, my implementation is shit 😅