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    <p>As <a href="https://stackoverflow.com/questions/19283349/c-sharp-generics-wildcards/19302047#comment28574943_19284078">Brian</a> pointed out in comments above, maybe <code>dynamic</code> is the way to go here.</p> <p>Check out the following code. You get the benefits of generics to tie down the API nicely and under the hoods you use <code>dynamic</code> to make things <em>work</em>.</p> <pre><code>public interface IAnimal { } public class Dog : IAnimal { } public class Cat : IAnimal { } public class BigBadWolf : IAnimal { } //I changed `IAnimalGroomer` to an abstract class so you don't have to implement the `AnimalType` property all the time. public abstract class AnimalGroomer&lt;T&gt; where T:IAnimal { public Type AnimalType { get { return typeof(T); } } public abstract void Groom(T animal); } public class CatGroomer : AnimalGroomer&lt;Cat&gt; { public override void Groom(Cat animal) { Console.WriteLine("{0} groomed by {1}", animal.GetType(), this.GetType()); } } public class DogGroomer : AnimalGroomer&lt;Dog&gt; { public override void Groom(Dog animal) { Console.WriteLine("{0} groomed by {1}", animal.GetType(), this.GetType()); } } public class AnimalClinic { private Dictionary&lt;Type, dynamic&gt; groomers = new Dictionary&lt;Type, dynamic&gt;(); public void EmployGroomer&lt;T&gt;(AnimalGroomer&lt;T&gt; groomer) where T:IAnimal { groomers.Add(groomer.AnimalType, groomer); } public void Groom(IAnimal animal) { dynamic groomer; groomers.TryGetValue(animal.GetType(), out groomer); if (groomer != null) groomer.Groom((dynamic)animal); else Console.WriteLine("Sorry, no groomer available for your {0}", animal.GetType()); } } </code></pre> <p>And now you can do:</p> <pre><code>var animalClinic = new AnimalClinic(); animalClinic.EmployGroomer(new DogGroomer()); animalClinic.EmployGroomer(new CatGroomer()); animalClinic.Groom(new Dog()); animalClinic.Groom(new Cat()); animalClinic.Groom(new BigBadWolf()); </code></pre> <p>I'm not sure if this is somewhat what you were looking for. Hope it helps!</p>
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    1. CODo I get a badge for "stealing" an accepted from Eric Lippert? :p
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    2. COOne thing I really like about this solution is that all of the dynamic dispatching is localized to the `AnimalClinic`. I usually worry that `dynamic` will increase the likelihood of introducing runtime exceptions, but here the risk seems very low.
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    3. COI disagree with this approach. Using dynamic for conveniently ignoring the type system is not a good programming practice. There are several answers that define a non-generic interface that meet the requirement without resorting to dynamic. Personally, I would rank the above as an anti-pattern.
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