From 72c3deffbb6062713c1ba043a9b249445d65dcaf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?=
 <barnabas.pocze@ideasonboard.com>
Date: Wed, 19 Mar 2025 12:31:37 +0100
Subject: [PATCH] libcamera: controls: Disallow arrays of arrays
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Arrays of arrays, even arrays of strings, are not supported by
the current `ControlValue` mechanism, so disable them for now
to trigger compile time errors if attempts are made to use them.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@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 4bfe9615c..2ae4ec3d4 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -120,7 +120,7 @@ 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;
 };