In Java or Scala, how to define conditional control flow based on whether type bound is satisfied?

In scala, I have a class definition:

class A[T >: Null]{}

And a function that optionally creates an instance:

def use[T](): Option[A[T]]

now I want to define it such that:

• it returns None if condition T >: Null is not satisfied
• it returns Some[A[T]] if it is satisfied.

How to write function use in this case?

This is approach with a type class

def use[T]()(implicit sel: Selector[T]): sel.Out = sel.x

trait Selector[T] {
  type Out
  val x: Out
}

trait LowPrioritySelector {
  implicit def default[T]: Selector[T] { type Out = None.type } = new Selector[T] {
    override type Out = None.type
    override val x: Out = None
  }
}

object Selector extends LowPrioritySelector {
  implicit def superTypeOfNull[T >: Null]: Selector[T] { type Out = Some[A[T]] } = new Selector[T] {
    override type Out = Some[A[T]]
    override val x: Out = Some(new A[T])
  }
}

use[String]() // Some(App$A@34340fab)   
use[Int]() // None