What does the keyword “where” in a class declaration do?

Question

I\'m looking at the source code for the MvcContrib Grid and see the class declared as:

public class Grid : IGrid where T : class
         


        

Answer 1

From the Docs http://msdn.microsoft.com/en-us/library/d5x73970.aspx

where T : class

The type argument must be a reference type; this applies also to any class, interface, delegate, or array type.