How to return null from a generic function in Scala?

Question

I am writing my own simple javax.sql.DataSource implementation, the only method of it I need to work is getConnection: Connection, but the interfac

Answer 1

This is because T could be a non-nullable type. It works when you enforce T to be a nullable type:

def unwrap[T >: Null](iface: Class[T]): T = null

unwrap(classOf[String]) // compiles

unwrap(classOf[Int]) // does not compile, because Int is not nullable