I've recently been toying with the idea of ephemeral classes. An ephemeral class is a class which does not have attributes. The immediate benefits of such classes is that their features can be used for objectless calls, the same way we can access constants or external features. For those not familiar to Eiffel, the features of ephemeral classes can be seen as static methods.
Another benefit of such classes is that their features can be directly used for callbacks by some external C/C++ code without having the need for creating a C wrapper for calling back the Eiffel code.
The concept is not yet implemented in EiffelStudio as it is not just a matter of checking the absence of attributes but also to adapt the code generation not to rely on a Current object.
This is something that will most likely be submitted for adoption for the ECMA Eiffel language specification. But before that, I'd like to hear what you think about this!