Pattern matching on generic type in Scala

I would go with TypeTag if you’re on 2.10+

import reflect.runtime.universe._

class Observable[Foo]

def X[T: TypeTag](ob: Observable[T]) = ob match {
    case x if typeOf[T] <:< typeOf[Double]   => println("Double obs")
    case x if typeOf[T] <:< typeOf[Boolean]  => println("Boolean obs")
    case x if typeOf[T] <:< typeOf[Int]      => println("Int obs")
}

X(new Observable[Int])
// Int obs

See also this lengthy, but awesome answer

Note also that I only took a glimpse at scala reflection, so likely somebody may write a better example of TypeTag usage.