[Mono-list] Possible mcs bug: CS0019 detected for comparable instances

Rodolfo Campero rodolfocampero@hotmail.com
Sat, 18 Oct 2003 00:19:01 +0000

I'm trying to port an application I'm developing at work. Over there we use
Microsoft .Net SDK.
When I tried to compile it in mono I got:

	error CS0019: Operator != cannot be applied to operands of type `xxx' and 

I've narrowed down the problem and the smallest program which reproduces the
error is the following one:

using System;
namespace Test {
	public class Test {
		public static void Main(string[] args) {
			BaseClass baseRef = new DerivedClass();
			ITest interfaceRef = (ITest)baseRef;
			Console.WriteLine("Is this wrong? {0}", (interfaceRef!=baseRef));

	public interface ITest {}

	public class BaseClass {}

	public class DerivedClass: BaseClass, ITest {}

Actually, I haven't checked this narrowed-down version in Windows, so if a
gentle soul can do this for me in order to prove that it works I'll 
I've searched bugzilla for this bug but I didn't found it. If it's right to
you, I'll file a bug report after someone verify that the code works in 
I'm using a recent CVS version of mcs and mono, in a RedHat 9 box.
I have a workaround for this problem, so I'm not pressed with this one... 
wanted to let you know.

Thanks in advance,


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