How to throw a compiler error if more than one member has the same Attribute

Question

Simple question, how do you force the C# compiler to throw a compilation error.

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Update: Perhaps it\'s better to use an Assert.Fail() instead?

Answer 1

I don't believe this can be done, because it is not possible to tell compiler to check for custom errors. Of course, you can use #error, like Jon said, but there is no way to add the condition itself. Because #error will cause error each and every time.

Only thing you can be sure about is to check at runtime and then throw exception.

Edit: Damn, getting to question after it was heavily edited.