[Ryo Furue]
> 	class Data
> 	   def hello
> 	      puts "hello"
> 	   end
> 	end
> 
> 	d = Data.new
> 	d.hello
> 
> The error message was
> 
> 	./try.rb:9: undefined method `new' for Data:Class (NameError)
> 
> After a lot of trial and error, I finally found that the code works if
> I replace "Data" with "MyData".  I guess "Data" is some predefined
> class.  I looked into the pickaxe Ruby book but couldn't find it.

It is a class used internally by Ruby to represent C pointers from
extensions. I'm not sure why it is exported to the script namespace.

// Niklas