http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660Ooh, nice solution. I was thinking about this: using MyFunnyType = System.Nullable <int; As far as I recall, Nullable structs are not applicable for the "struct" constraint (which is actually defined as "non-nullable value type"), so I guess they might be applicable for the "class" constraint. I'm probably wrong, but it'd be a nice solution. >http://ayende.com/4307/can-you-hack-this-out-hint-1#comment19http://ayende.com/4307/can-you-hack-this-out-hint-1#comment19Mon, 30 Nov 2009 21:08:57 GMTCool post, I hate to say but I think you misspelled 'instance' as 'instnace' in your code example. Peace! http://ayende.com/4307/can-you-hack-this-out-hint-1#comment18http://ayende.com/4307/can-you-hack-this-out-hint-1#comment18Mon, 30 Nov 2009 15:17:49 GMTI've used a programming language in which you can return a value from a constructor, even null. Insanity :) http://ayende.com/4307/can-you-hack-this-out-hint-1#comment17http://ayende.com/4307/can-you-hack-this-out-hint-1#comment17Sat, 28 Nov 2009 14:34:52 GMTLooks like this would work. public class InterceptionProxy : RealProxy { public InterceptionProxy() : base(typeof(MyFunnyType)) { } public override IMessage Invoke(IMessage msg) { // Does not get here .... } public override object GetTransparentProxy() { return null; } } http://ayende.com/4307/can-you-hack-this-out-hint-1#comment16http://ayende.com/4307/can-you-hack-this-out-hint-1#comment16Wed, 25 Nov 2009 15:48:28 GMT@Reshef - it isn't that the T is unknown; it is that the operator can't be resolved via static analysis (which it must) to a single implementation. Similar to how +-*/ don't work (unless you cheat, like in MiscUtil's Operator class). I suspect there is some scenarios (involving subclassing and a constraint like T : SomeType) where it /would/ pick up the operator, but that ("T : SomeType") isn't in the question. http://ayende.com/4307/can-you-hack-this-out-hint-1#comment15http://ayende.com/4307/can-you-hack-this-out-hint-1#comment15Wed, 25 Nov 2009 15:02:14 GMTRight. When creating the object with new T() somehow the type is unknown and it won't call the != operator. Generics oddity... http://ayende.com/4307/can-you-hack-this-out-hint-1#comment14http://ayende.com/4307/can-you-hack-this-out-hint-1#comment14Wed, 25 Nov 2009 13:55:46 GMTReshef, Try that, it won't work :-) http://ayende.com/4307/can-you-hack-this-out-hint-1#comment13http://ayende.com/4307/can-you-hack-this-out-hint-1#comment13Wed, 25 Nov 2009 13:41:48 GMTApparently this will do the trick: public static bool operator !=(object left, MyFunnyType right) { return false; } http://ayende.com/4307/can-you-hack-this-out-hint-1#comment12http://ayende.com/4307/can-you-hack-this-out-hint-1#comment12Wed, 25 Nov 2009 13:37:57 GMTIndeed - pure evil; and definitely worthy of an update to my similar corner-case on stackoverflow: [http://stackoverflow.com/questions/194484#194671](http://stackoverflow.com/questions/194484#194671)http://ayende.com/4307/can-you-hack-this-out-hint-1#comment11http://ayende.com/4307/can-you-hack-this-out-hint-1#comment11Wed, 25 Nov 2009 12:06:09 GMTI did not know that ProxyAttribute exists :) It opens so many possibilities!!! http://ayende.com/4307/can-you-hack-this-out-hint-1#comment10http://ayende.com/4307/can-you-hack-this-out-hint-1#comment10Wed, 25 Nov 2009 11:58:53 GMTDamn, thats a NASTY solution :S http://ayende.com/4307/can-you-hack-this-out-hint-1#comment9http://ayende.com/4307/can-you-hack-this-out-hint-1#comment9Wed, 25 Nov 2009 11:14:01 GMTDennis, Yes. http://ayende.com/4307/can-you-hack-this-out-hint-1#comment8http://ayende.com/4307/can-you-hack-this-out-hint-1#comment8Wed, 25 Nov 2009 11:03:22 GMTDo you mean to break var instnace = new <whatever; object.ReferenceEquals(instnace, null) == false? >http://ayende.com/4307/can-you-hack-this-out-hint-1#comment7http://ayende.com/4307/can-you-hack-this-out-hint-1#comment7Wed, 25 Nov 2009 11:00:15 GMTMarc, :-) Yeah. Once the previous hack was solved, this is pretty easy. http://ayende.com/4307/can-you-hack-this-out-hint-1#comment6http://ayende.com/4307/can-you-hack-this-out-hint-1#comment6Wed, 25 Nov 2009 10:53:47 GMTclass MyFunnyTypeAttribute : ProxyAttribute { public override MarshalByRefObject CreateInstance(Type serverType) { return null; } } [MyFunnyType] class MyFunnyType : ContextBoundObject{} http://ayende.com/4307/can-you-hack-this-out-hint-1#comment5http://ayende.com/4307/can-you-hack-this-out-hint-1#comment5Wed, 25 Nov 2009 10:46:36 GMTHazzik, No :-) http://ayende.com/4307/can-you-hack-this-out-hint-1#comment4http://ayende.com/4307/can-you-hack-this-out-hint-1#comment4Wed, 25 Nov 2009 10:46:36 GMTCan we modify CanThisHappen method of program? http://ayende.com/4307/can-you-hack-this-out-hint-1#comment3http://ayende.com/4307/can-you-hack-this-out-hint-1#comment3Wed, 25 Nov 2009 10:43:12 GMTHazzik, That would work, yes, but that doesn't match the challenge that I set. http://ayende.com/4307/can-you-hack-this-out-hint-1#comment2http://ayende.com/4307/can-you-hack-this-out-hint-1#comment2Wed, 25 Nov 2009 10:39:10 GMTperhaps like this: public class Program { private static void Main() { CanThisHappen <myfunnytype(); } public static void CanThisHappen <t() where T : class, new() { var instnace = new T(); Debug.Assert(!instnace.Equals(null), "How did we break the CLR?"); } } internal class MyFunnyType { public override bool Equals(object obj) { return true; } } >http://ayende.com/4307/can-you-hack-this-out-hint-1#comment1http://ayende.com/4307/can-you-hack-this-out-hint-1#comment1Wed, 25 Nov 2009 10:33:27 GMT