Const generics, storing fn with const variables in struct

help
6

Just wanted to clarify my question a little bit. I think that I'm trying to store a fn which takes a struct with a const variable so that I can access that variable inside the fn.

The code below doesn't work as written. My feeling is that syntax changes to Fn sig won't work either, but would love to be proven wrong. From a language perspective, I feel like this is a reasonable thing to want to do with const generics, would love if somebody could help me understand why or why not.
playground

#![feature(const_generics)]

#[derive(PartialEq, Eq)]
pub enum VehicleType {
    Car,
    Boat,
}

pub struct Vehicle<const V: VehicleType> { }

pub struct World {
    compare_transport: Box<dyn Fn(Vehicle<const V1>, Vehicle<const V2>) -> bool>,
}

#[cfg(test)]
mod test {
    use super::*;
    
    #[test]
    fn test() {
        use VehicleType::*;
        
        let hatchback: Vehicle<{Car}> = Vehicle {};
        let schooner: Vehicle<{Boat}> = Vehicle {};
        
        let world = World {
            compare_transport: Box::new(|_a: Vehicle<V1>, _b: Vehicle<V2>| {
                V1 == V2
            }),
        };
        
        assert_eq!((world.compare_transport)(hatchback, schooner), true);
    }
}