// CS0034: Operator `!=' is ambiguous on operands of type `Program.A' and `Program.B' // Line: 36 using System; class Program { public class A { public static implicit operator string (A c) { return null; } public static implicit operator Delegate (A c) { return null; } } public class B { public static implicit operator string (B c) { return null; } public static implicit operator Delegate (B c) { return null; } } public static void Main (string [] args) { bool b = new A () != new B (); } }