module app; import lib; import std.stdio : writeln; void main() { Duck duck = new MallardDuck(); Turkey turkey = new WildTurkey(); Duck turkeyAdapter = new TurkeyAdapter(turkey); writeln("The Turkey says..."); turkey.gobble(); turkey.fly(); writeln("\nThe Duck says..."); testDuck(duck); writeln("\nThe TurkeyAdapter says..."); testDuck(turkeyAdapter); } void testDuck(Duck duck) { duck.quack(); duck.fly(); }