On Fri, Nov 15, 2024 at 12:33 PM Asahi Lina <lina@xxxxxxxxxxxxx> wrote: > > We (Asahi Linux) noticed that this doesn't support unsized types, which > is a regression from the alloc Box. drm/asahi uses boxed trait objects > to generalize across certain object types like render commands, so this > breaks the driver. > > Is there a plan to add this back in? AIUI this would need the > coerce_unsized unstable feature, but is there any other blocker? We're already using coerce_unsized for Arc, so I see no reason we can't just add that for KBox too. Soon, we should be able to use the derive macro [1] I proposed to do this without unstable language features. The limitation that the RFC mentions for custom allocators does not apply to KBox because it uses PhantomData<A> instead of A for the allocator field. Alice [1]: https://rust-lang.github.io/rfcs/3621-derive-smart-pointer.html
