import std.stdio;

​

void touch(Animal)(Animal animal)

{

    slap(animal);

}

​

void slap(Animal)(Animal animal)

{

    writeln(Animal.stringof, " say ", animal.say);

}

​

class Cat

{

    auto say()

    {

        return "Mew";

    }

}

​

class Worm

{

    void say(int n)

    {

    }

}

​

void main()

{

    touch(new Cat);

    touch(new Worm);

}