Listing 10-45 extracted from chapter The .NET 2 type system from a C#2 point of view

Listing 10-44<     > Listing 10-46

This listing can be compiled with the command line:
csc.exe /target:exe Example_10_45.cs
Errors: 0 Warnings: 0

class Program{
   static void Main(){
     int? ni = null;
     object o = ni;    // boxing
     System.Diagnostics.Debug.Assert( o == null );   
   }
}