Why are all signals defined in separate structures for Windows?

[pseusys]

That actually looks really weird. All the signal structures in tokio::signal::windows:: are different. Still, all of them implement the same methods and have one field of the same type. Why was it possible to create a common type for signals on unix (tokio::signal::unix::Signal), but not on windows? Ok, maybe at least a common trait for recv and poll_recv methods?..

Is using Box<dyn Any> and then downcasting it to all the different signal types really the architecturally best way to use a common logic to handle different termination signals?..