Re: [PATCH v5 20/20] rust: io: implement `IoSysMap`

On Fri Jun 26, 2026 at 11:45 PM JST, Gary Guo wrote:
> Add an enum as sum type for `Mmio` and `SysMem`. This serves similar
> purpose of `iosys_map`. Thanks to Rust's type system, all of projection and
> struct read/write can be handled by the generic I/O projection mechanism
> (i.e. `io_project!`, `io_read!, `io_write!`) for free, and there is no need
> to provide things like `iosys_map_rd_field` or `iosys_map_wr_field`. An
> enum type also makes it very easy to construct or destruct.
>
> This could be made more generic by implementing on a general purpose sum
> type like `Either`; however this is kept specific unless a need arises that
> warrants this to be generic over other I/O backends.
>
> Signed-off-by: Gary Guo <[email protected]>

Reviewed-by: Alexandre Courbot <[email protected]>