Question

…so I have this code:

        foreach (var entry in list)
        {
            var marginOneEntry = otherList.FirstOrDefault(p => p.Margin == entry.Margin);                
            if (marginOneEntry == null) continue;
            // Do stuff with marginOneEntry
        }

and Resharper 5.1 warns me about “access to modified closure” for the use of entry in the compare-statement in the lambda expression. Isn’t the FirstOrDefault-call cancelling this issue? Is my code bad or is this warning just a shortcoming in Resharper?

Note: I have read other topics on Access to modified closure here on SO, but I want an answer for this specific case, and to get clarified whether or not Resharper is overly sensitive on this subject.

Answer 1

Yes, this is an issue in Resharper since it doesn’t distinguish methods with lazy evaluated result from methods which do not use given lambda in lazy evaluation. FirstOrDefault doesn’t do lazy evaluation (forgot the term opposite to ‘lazy’) so it safe to use it in your example but usually there is no way to understand that from method’s signature.