Scala asInstanceOf with parameterized types

Question

I would like to write a function that casts to type A, where A can be e.g. List[Int], or a more complicated parameterized type like Map[Int, List[Int]].

def          


        

Answer 1

Yes, the problem occurs due to type erasure. If you try

val x = List(1,2,3)
val y = castToType[Int](x)

The exception is thrown right away, as expected. The same occurs when trying to cast to Array[String] or even Array[Int].

I don't think you can create a generic type converter that works will types inside collections and other objects. You will need to create a converter for each object type. For example:

def castToType[A](x: List[A]) = x.map(i => i.asInstanceOf[A])