[PATCH v1] libcamera: controls: Arrays of arrays are not supported

[Barnabás Pőcze]

Hi


2025. 04. 23. 21:29 keltezéssel, Laurent Pinchart írta:
> Hi Barnabás,
> 
> Thank you for the patch.
> 
> The subject line should tell what the patch does.

"Disallow arrays of array" ?


> 
> On Wed, Apr 23, 2025 at 03:02:14PM +0100, Kieran Bingham wrote:
>> Quoting Barnabás Pőcze (2025-04-22 13:44:01)
>>> Arrays of arrays, even arrays of strings, are not supported by
>>> the current `ControlValue` mechanism, so disable them for now
>>> to trigger comptime errors if attempts are made to use them.
> 
> s/comptime/compile-time/
> 
>> This sounds safer than discovering the fault at runtime!
>>
>> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>>
>>> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>
>>> ---
>>>   include/libcamera/controls.h | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
>>> index 326452540..427517a02 100644
>>> --- a/include/libcamera/controls.h
>>> +++ b/include/libcamera/controls.h
>>> @@ -121,7 +121,7 @@ struct control_type<Point> {
>>>   };
>>>   
>>>   template<typename T, std::size_t N>
>>> -struct control_type<Span<T, N>> : public control_type<std::remove_cv_t<T>> {
>>> +struct control_type<Span<T, N>, std::enable_if_t<control_type<std::remove_cv_t<T>>::size == 0>> : public control_type<std::remove_cv_t<T>> {
> 
> Maybe with a bit of line wrap,

Everything I tried looks bad, do you have something specific in mind?


Regards,
Barnabás Pőcze

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> 
>>>          static constexpr std::size_t size = N;
>>>   };
>>>   
>