[PATCH] libcamera: controls: Handle enum values without a cast

[Jacopo Mondi]

Hi Laurent

On Thu, Sep 26, 2024 at 03:24:27AM GMT, Laurent Pinchart wrote:
> When constructing a ControlValue from an enum value, an explicit cast to
> int32_t is needed as we use int32_t as the underlying type for all
> enumerated controls. This makes users of ControlValue more complex. To
> simplify them, specialize the control_type template for enum types, to
> support construction of ControlValue directly without a cast.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

brilliant, less things to type in!

Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>

Thanks
  j

> ---
>  include/libcamera/controls.h         | 6 +++++-
>  src/libcamera/pipeline/ipu3/ipu3.cpp | 2 +-
>  2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
> index 25f67ed948a3..c5131870d402 100644
> --- a/include/libcamera/controls.h
> +++ b/include/libcamera/controls.h
> @@ -39,7 +39,7 @@ enum ControlType {
>
>  namespace details {
>
> -template<typename T>
> +template<typename T, typename = std::void_t<>>
>  struct control_type {
>  };
>
> @@ -102,6 +102,10 @@ struct control_type<Span<T, N>> : public control_type<std::remove_cv_t<T>> {
>  	static constexpr std::size_t size = N;
>  };
>
> +template<typename T>
> +struct control_type<T, std::enable_if_t<std::is_enum_v<T>>> : public control_type<int32_t> {
> +};
> +
>  } /* namespace details */
>
>  class ControlValue
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index 430aa902eec8..29d3c6c194c1 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -958,7 +958,7 @@ int PipelineHandlerIPU3::updateControls(IPU3CameraData *data)
>  		values.reserve(testPatternModes.size());
>
>  		for (auto pattern : testPatternModes)
> -			values.emplace_back(static_cast<int32_t>(pattern));
> +			values.emplace_back(pattern);
>
>  		controls[&controls::draft::TestPatternMode] = ControlInfo(values);
>  	}
>
> base-commit: f2088eb91fd6477b152233b9031cb115ca1ae824
> --
> Regards,
>
> Laurent Pinchart
>