// polymorphism/CovariantReturn.java

// (c)2017 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

class Grain {

@Override

public String toString() { return "Grain"; }

}

class Wheat extends Grain {

@Override

public String toString() { return "Wheat"; }

}

class Mill {

Grain process() { return new Grain(); }

}

class WheatMill extends Mill {

@Override

Wheat process() { return new Wheat(); }

}

public class CovariantReturn {

public static void main(String[] args) {

Mill m = new Mill();

Grain g = m.process();

System.out.println(g);

m = new WheatMill();

g = m.process();

System.out.println(g);

}

}

/* Output:

Grain

Wheat

*/