La semaine dernière, durant le PDC, Microsoft a dévoilé le futur du language C# 4 (et VB 10).

Au programme :

• Dynamic lookup :
  Dynamic lookup allows you to write method, operator and indexer calls, property and field accesses, and even object invocations which bypass the C# static type checking and instead gets resolved at runtime.
  
• Named and optional parameters :
  Parameters in C# can now be specified as optional by providing a default value for them in a member declaration. When the member is invoked, optional arguments can be omitted. Furthermore, any argument can be passed by parameter name instead of position.
  
• COM specific interop features :
  Dynamic lookup as well as named and optional parameters both help making programming against COM less painful than today. On top of that, however, we are adding a number of other small features that further improve the interop experience.
  
• Variance :
  It used to be that an IEnumerable<string> wasn’t an IEnumerable<object>. Now it is – C# embraces type safe “co-and contravariance” and common BCL types are updated to take advantage of that.

Vous trouverez des exemples sur la code gallery :

• http://code.msdn.microsoft.com/csharpfuture

Et un document décrivant les évolutions :

• http://code.msdn.microsoft.com/Project/Download/FileDownload.aspx?ProjectName=csharpfuture&DownloadId=3550