All the same reasons as for `[T]`: more general, less pointer chasing, and `&mut IndexSlice` emphasizes that it doesn't change *length*.
Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.
All the same reasons as for `[T]`: more general, less pointer chasing, and `&mut IndexSlice` emphasizes that it doesn't change *length*.
Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.