Edit Question - KnowledgeHub

Title Body

Consider the following code: public static void Foo() { Bar(null); } public static void Bar([NotNull] string s) { if (s == null) throw new ArgumentNullException("s"); } The [NotNull] attribute is used on Bar to tell callers that s shouldn't be null. This works fine, and I get a warning when I pass null to Bar ( Possible 'null' assignment to entity marked with 'NotNull' attribute ). But it doesn't actually prevent me from passing null, so Bar must still check if s is null. So why am I also getting a warning on if (s == null) ( Expression is always false ) ? As far as I can tell, this attribute has an ambiguous meaning; depending on context, it can mean two different things: for the caller: don't pass a null argument for the callee: this argument is not null Am I using this attribute correctly, or am I missing something? BTW, I'm using Resharper 7 EAP, so it might be a bug; however I want to make sure my usage is correct before I report it... EDIT: just tried the same thing with R# 5.1 at work; it shows the warning on the call site, but not in the method. I'll report it on Jetbrain's Youtrack. EDIT2: bug reported here

Tags (comma-separated) Cancel