Why is the new Tuple type in .Net 4.0 a reference type (class) and not a value type (struct)

Question

Does anyone know the answer and/or have an opinion about this?

Since tuples would normally not be very large, I would assume it would make more sense to use structs

Answer 1

For 2-tuples, you can still always use the KeyValuePair from earlier versions of the Common Type System. It's a value type.

A minor clarification to the Matt Ellis article would be that the difference in use semantics between reference and value types is only "slight" when immutability is in effect (which, of course, would be the case here). Nevertheless, I think it would have been best in the BCL design not to introduce the confusion of having Tuple cross over to a reference type at some threshold.