oopexample.scala

// Our generic interface
trait Animal {
  def voice: String
}

// Implementation 1
class Dog extends Animal {
  override def voice: String = "woof!"
}

// Implementation 2
class Cat extends Animal {
  override def voice: String = "meow!"
}

// Generic function
def say(animal: Animal) = println(animal.voice)

// Usage
say(new Dog) // prints "woof!"
say(new Cat) // prints "meow!"