leppie/IronScheme — pull request #2 by abatishchev (2013-07-13 04:56:12+00:00)
Title: Update Builtins.cs

Jon Skeet recommends as/!=null rather than is/cast. Eric Lippert claims GetValueOrDefault() is more efficient.
Also redundant else in else if (R# style refactoring)
P.S.
Why is true a default value? IsTrue(new object()) returns true?