, evildictait​or wrote

The only time I ever use it is as a generic argument, where I'd really like two things instead of one generic argument.

For example, a List<Tuple<string, int>> or an GenericEventArgs<Tuple<string, TcpClient>> or some such.

I have used it when I needed something elegant like this http://stackoverflow.com/questions/4251183/wpf-two-dimensional-datagrid-listview