If you recall from yesterday's blog entry, I was having some problems trying to find a way to compare some generics which may contain nullable types. My thanks go to Dinesh and his colleagues for solving this problem for me.

Here's the new code; it's much simpler than the old code.

  protected void SetProperty<T>(ref T currentPropertyValue, T newValue)
  {
   Comparer<T> comparer = System.Collections.Generic.Comparer<T>.Default;

   if (comparer.Compare(currentPropertyValue, newValue) != 0)
   {
    currentPropertyValue = newValue;
    MarkDirty();
   }
  }

Simple! Thanks again, Dinesh!

Now, the question of figuring out how to tell if a generic is nullable becomes just an academic pursuit, rather than a critical problem. I'm still interested in a solution to that, so if you have one, please feel free to comment.

[ As an aside, Dinesh also pointed out that anonymous users could not post comments to my blog. That is now fixed. ]

Update: Dinesh had this to say:

I am glad I could be of some help and thanks again from trying the CTP. Here is how you can check for a Nullable type – it is a bit more complex but actually cleaner than using INullableValue as a "marker" interface.

if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>)) {…}

I will add this to my blog for broader distribution.

Thanks.

Dinesh Kulkarni

Program Manager, Visual C#

Thanks again Dinesh! I owe you a drink or something at the PDC next week :)