I would have expected the inliner to just copy the code as i kotlinlang #announcements

11/21/2018, 10:16 AM

I would have expected the inliner to just copy the code as is and file in all the type parameters with the real type variable

11/21/2018, 10:18 AM

Can you clarify what you mean? Type parameters are still erased, there is no

Class<T>

Class<String>

after compilation, only

Class

. But if you do

T::class

reified T

, then you will get the proper

Class

You can't do that with a normal type parameter

11/21/2018, 10:25 AM

exactly, you can do T::class

for instance in Gson you can parse a list of things by using:

mapper.fromJson<ArrayList<AdditionalFunction>>(it, object : TypeToken<ArrayList<AdditionalFunction>>() {}.type)

what I tried to do was to generalize it like this:

mapper.fromJson<ArrayList<T>>(it, object : TypeToken<ArrayList<T>>() {}.type)

where T is reified

11/21/2018, 10:28 AM

That should work™ 😄

11/21/2018, 10:28 AM

and call it like this:

func<AdditionalFunction>()

turn out it deserializes to a linked hashmap instead of a List<AdditionalFunction>

when you println what TypeToken<ArrayList<T>>() {}.type evaluates to, you get “ArrayList<T>>”

instead of “ArrayList<AdditionalFunction>”

so it feels like T is only reified if you access it via ::class

and inlining happens after type checking and is type erased

11/21/2018, 10:33 AM

It seems like the compositing of types causes the issue here. The following prints `ArrayList<String>`:

private inline fun <reified R> a() {
    println(object : TypeToken<R>() {})
}

fun main(args: Array<String>) {
    a<ArrayList<String>>()
}

11/21/2018, 10:34 AM

compiler bug?

or works as expected?

11/21/2018, 10:37 AM

Not sure. Sounds like a bug to me, but I am not sure if it's possible to do properly.