The rust abi isn't stable between compiler versions, but it does exist. Bevy can get away with using it because it's just to speed things up in development. Po

The rust abi isn't stable between compiler versions, but it does exist. Bevy can get away with using it because it's just to speed things up in development. Polymorphism is a separate issue. One way to do polymorphism in rust is monomorphism, where your polymorphic function is compiled to a specific version with no generics per caller. If you don't know the callers ahead of time this can't work. Another way is dynamic dispatch, where you have one polymorphic function that chooses what code to run per type at runtime. This can work with dynamic linking