Enum Constraint

// definitions

public abstract class ClassConstraint<TClass>
where TClass : class
{

	public class GenericClassWhereIWantTEnumRestricted<TEnum>
	where TEnum : struct, TClass
	{
	}

}

public class EnumConstraint : ClassConstraint<Enum> {
}

// usage

var x = new EnumConstraint.GenericClassWhereIWantTEnumRestricted<MyEnum>();