Why does Socket.Select(...) take IList and not (also) IList<Socket>?

Question

I'm implementing some networking code using the selector pattern in C# / .NET 3.5. However, I was surprised to find that the Select method takes nongeneric IList's rather than IList<Socket>'s. It says clearly in the help documentation though that a list of sockets is expected here and nothing else.

Does anyone know why this is the case?

Answer 1

Socket.Select (which I assume you mean by Select) is a method that was already present in .NET 1.0, and Microsoft apparently never bothered to update it, probably because it is a quaint and seldom-used API.

Answer 2

From the docs:

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

That would have been a pretty interesting signature in .NET 1.0...

The signature can't be changed without breaking existing callers. They could have added an overload, but I'm not sure it would have helped very much - if you'd tried to use the "new" overload with the wrong argument types (e.g. List<string> instead of List<Socket>) it would just have bound to the old overload.