Why use generic constraints in C#

Question

I\'ve read an excellent article on MSDN regarding Generics in C#.

The question that popped in my head was - why should i be using generic constraints?

For ex

Answer 1

Yes you can use ISomething in place of T , but that will manually close the generic type to an ordinary class. It wont be a generic type any more. By using T, you keep the type open to as many ISomething subtypes as you want. Code reuse without compromising type safety is the key benefit here. For example if you use a Stack of ISomethings, you can push any ISomething onto the stack but a pop has to occur with a downcast to the actual subtype of ISomething for it to be useful. Downcasting creates a potential failure point, which will not be there in a generic Stack where T:ISomething