Why does intellij not accept this scala code

Asked Aug 17 '16 at 11:14

Active Aug 17 '16 at 22:57

Viewed 190 times

The following code is compiling just fine with nsc:

trait A {
  type B[+T]
  type C[+T] <: B[T]
  def c: C[Int]
}

object Q {
  val a: A = ???
  val b: a.B[Int] = a.c
}

but intellij doesn't accept it with the error message

expression of type Q.a.C[Int] doesn't conform to expected type Q.a.B[Int]

Why is this the case? Is it defined somewhere what subset of Scala is allowed in IntelliJ?

edited Aug 17 '16 at 22:57

asked Aug 17 '16 at 11:14

can you try doing this: import scala.language.higherKinds I get this as warnings in the repl. Maybe that could fix this. – Samar Aug 17 '16 at 11:43
Does the file fail to compile when you build the project, or is it just highlighted as an error? In the second case, this just happens with IDEA (both ways): report it (after making sure it isn't a duplicate). – Alexey Romanov Aug 17 '16 at 12:18
no, that doesn't solve the problem. Note, that I'm talking about IntelliJ's syntax highlighting/code completion, not the normal compiling – Fabian Schmitthenner Aug 17 '16 at 12:25
@AlexeyRomanov where do I report this? – Fabian Schmitthenner Aug 17 '16 at 12:27
https://www.jetbrains.com/help/idea/2016.2/reporting-issues-and-sharing-your-feedback.html – Yuval Itzchakov Aug 17 '16 at 12:35
created an issue: https://youtrack.jetbrains.com/issue/SCL-10692 let's see what happens – Fabian Schmitthenner Aug 17 '16 at 23:18

0 Answers0