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

[Kieran Bingham]

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.
> 

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>> {
>         static constexpr std::size_t size = N;
>  };
>  
> -- 
> 2.49.0
>