Miss Dada  🏳️‍⚧️

oh, because the method calls pass down to the Box contents... okay then I need to better understand what "Box implementing a trait" means, hopefully these new boxed closure features will tell me!

but also, someone told me you can impl a trait for another trait, rather than for all types that implement said trait, i.e. `impl Trait for Other` rather than `impl<T: Other> Trait for T` and I still don't know what that means or if it's relevant here

That's the same as `impl Trait for dyn Other` (`dyn` is optional, it's an idiom for marking a trait in a type position to mark it as dynamically dispatched). You're implementing the trait only for trait objects of type Other

ah so only for &dyn Other, Box<dyn Other>, etc, but not for any T: Other ?

well, to be precise, it implements it for one type: `dyn Other`. &dyn Other, Box<dyn other> get it through deref, but they do not get the trait implemented

Box<dyn Other> and &dyn Other are not T: Other, as I mentioned before. They get Other methods through deref. Some traits (eg. Fn*) may choose to blanket implement themselves on these types.

dyn Other is a single type. It's a virtually dispatched trait object, with a concrete value of *some* type implementing that trait behind it. It can only exist behind a pointer, because we don't know its size.

"virtually" == dispatch is done at runtime?