GoingDeep: nside C# 4.0: dynamic typing, optional parameters, covariance and contravariance

C# Program Manager Mads Torgersen and C# compiler developers Eric Lippert, Chris Burrows, Samuel Ng discuss (and whiteboard) the details inside C# 4.0's dynamic type, optional parameters and default parameter values, and new support for COM interop (should make Office developers giddy). Samuel, Chris and Eric were very busy solving some really hard problems to pull these new features off. It's great to learn about these new features from the people who actually implemented them. Classic Channel 9!

So, how does C# 4.0's dynamic type work, exactly? What does "more COM friendly" really mean? Covariance and Contravariance? Optional parameters with default values and parameter re-ordering? Why? How? Tune in.

Enjoy!

(my apologizes for the slight glitch at the middle of the interview. My camera bluescreened! Fortunately, data captured before the system failure was stored successfuly, but a little tiny piece of the conversation was lost)