From 3913959d23ba052bb7a118e1d694ecf6dffc5297 Mon Sep 17 00:00:00 2001
From: Felix Thaler <thaler@cscs.ch>
Date: Tue, 29 Oct 2024 13:55:23 +0100
Subject: [PATCH] Fix sid::as_const for C arrays

---
 include/gridtools/sid/as_const.hpp         |  4 ++--
 tests/unit_tests/sid/test_sid_as_const.cpp | 10 ++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/gridtools/sid/as_const.hpp b/include/gridtools/sid/as_const.hpp
index 0e8f1ba8b..88d90cf75 100644
--- a/include/gridtools/sid/as_const.hpp
+++ b/include/gridtools/sid/as_const.hpp
@@ -51,14 +51,14 @@ namespace gridtools {
          *                 probably might we need the `host` and `device` variations as well
          */
         template <class Src,
-            class Ptr = sid::ptr_type<std::decay_t<Src>>,
+            class Ptr = sid::ptr_type<std::remove_cv_t<std::remove_reference_t<Src>>>,
             std::enable_if_t<std::is_pointer_v<Ptr> && !std::is_const_v<std::remove_pointer_t<Ptr>>, int> = 0>
         as_const_impl_::const_adapter<Src> as_const(Src &&src) {
             return {std::forward<Src>(src)};
         }
 
         template <class Src,
-            class Ptr = sid::ptr_type<std::decay_t<Src>>,
+            class Ptr = sid::ptr_type<std::remove_cv_t<std::remove_reference_t<Src>>>,
             std::enable_if_t<!std::is_pointer_v<Ptr> || std::is_const_v<std::remove_pointer_t<Ptr>>, int> = 0>
         decltype(auto) as_const(Src &&src) {
             return std::forward<Src>(src);
diff --git a/tests/unit_tests/sid/test_sid_as_const.cpp b/tests/unit_tests/sid/test_sid_as_const.cpp
index 7f32ebf98..e6af42e0c 100644
--- a/tests/unit_tests/sid/test_sid_as_const.cpp
+++ b/tests/unit_tests/sid/test_sid_as_const.cpp
@@ -32,5 +32,15 @@ namespace gridtools {
             static_assert(std::is_same_v<sid::ptr_type<testee_t>, double const *>);
             EXPECT_EQ(sid::get_origin(src)(), sid::get_origin(testee)());
         }
+
+        TEST(as_const, c_array) {
+            int src[3][2] = {{0, 1}, {10, 11}, {20, 21}};
+            auto testee = sid::as_const(src);
+            using testee_t = decltype(testee);
+
+            static_assert(is_sid<testee_t>());
+            static_assert(std::is_same_v<sid::ptr_type<testee_t>, int const *>);
+            EXPECT_EQ(sid::get_origin(src)(), sid::get_origin(testee)());
+        }
     } // namespace
 } // namespace gridtools