Type in expressions to have them evaluated.
Type :help for more information.

scala> class M[@specialized T] { override def toString = "mmm" }
defined class M

scala> val m1 = new M[Int]()
m1: M[Int] = mmm

scala> val m2 = new M[Float]()
m2: M[Float] = mmm

scala> val m3 = new M[String]()
m3: M[String] = mmm

scala> :quit