Circumvented Clang's buggy pack indexing expression evaluation

dev/functional/index_sequence_util.h

@@ -1,61 +1,61 @@
-#pragma once
-
-#include <utility>  //  std::index_sequence
-
-namespace sqlite_orm {
-    namespace internal {
-#if defined(SQLITE_ORM_PACK_INDEXING_SUPPORTED)
-        /**
-         *  Get the index value of an `index_sequence` at a specific position.
-         */
-        template<size_t Pos, size_t... Idx>
-        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<Idx...>) {
-            return Idx...[Pos];
-        }
-#elif defined(SQLITE_ORM_FOLD_EXPRESSIONS_SUPPORTED)
-        /**
-         *  Get the index value of an `index_sequence` at a specific position.
-         */
-        template<size_t Pos, size_t... Idx>
-        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<Idx...>) {
-            static_assert(Pos < sizeof...(Idx));
-#ifdef SQLITE_ORM_CONSTEVAL_SUPPORTED
-            size_t result;
-#else
-            size_t result = 0;
-#endif
-            size_t i = 0;
-            // note: `(void)` cast silences warning 'expression result unused'
-            (void)((result = Idx, i++ == Pos) || ...);
-            return result;
-        }
-#else
-        /**
-         *  Get the index value of an `index_sequence` at a specific position.
-         *  `Pos` must always be `0`.
-         */
-        template<size_t Pos, size_t I, size_t... Idx>
-        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<I, Idx...>) {
-            static_assert(Pos == 0, "");
-            return I;
-        }
-#endif
-
-        template<class... Seq>
-        struct flatten_idxseq {
-            using type = std::index_sequence<>;
-        };
-
-        template<size_t... Ix>
-        struct flatten_idxseq<std::index_sequence<Ix...>> {
-            using type = std::index_sequence<Ix...>;
-        };
-
-        template<size_t... As, size_t... Bs, class... Seq>
-        struct flatten_idxseq<std::index_sequence<As...>, std::index_sequence<Bs...>, Seq...>
-            : flatten_idxseq<std::index_sequence<As..., Bs...>, Seq...> {};
-
-        template<class... Seq>
-        using flatten_idxseq_t = typename flatten_idxseq<Seq...>::type;
-    }
-}
+#pragma once
+
+#include <utility>  //  std::index_sequence
+
+namespace sqlite_orm {
+    namespace internal {
+#if defined(SQLITE_ORM_PACK_INDEXING_SUPPORTED)
+        /**
+         *  Get the index value of an `index_sequence` at a specific position.
+         */
+        template<size_t Pos, size_t... Idx>
+        SQLITE_ORM_CONSTEVAL auto index_sequence_value_at(std::index_sequence<Idx...>) {
+            return Idx...[Pos];
+        }
+#elif defined(SQLITE_ORM_FOLD_EXPRESSIONS_SUPPORTED)
+        /**
+         *  Get the index value of an `index_sequence` at a specific position.
+         */
+        template<size_t Pos, size_t... Idx>
+        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<Idx...>) {
+            static_assert(Pos < sizeof...(Idx));
+#ifdef SQLITE_ORM_CONSTEVAL_SUPPORTED
+            size_t result;
+#else
+            size_t result = 0;
+#endif
+            size_t i = 0;
+            // note: `(void)` cast silences warning 'expression result unused'
+            (void)((result = Idx, i++ == Pos) || ...);
+            return result;
+        }
+#else
+        /**
+         *  Get the index value of an `index_sequence` at a specific position.
+         *  `Pos` must always be `0`.
+         */
+        template<size_t Pos, size_t I, size_t... Idx>
+        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<I, Idx...>) {
+            static_assert(Pos == 0, "");
+            return I;
+        }
+#endif
+
+        template<class... Seq>
+        struct flatten_idxseq {
+            using type = std::index_sequence<>;
+        };
+
+        template<size_t... Ix>
+        struct flatten_idxseq<std::index_sequence<Ix...>> {
+            using type = std::index_sequence<Ix...>;
+        };
+
+        template<size_t... As, size_t... Bs, class... Seq>
+        struct flatten_idxseq<std::index_sequence<As...>, std::index_sequence<Bs...>, Seq...>
+            : flatten_idxseq<std::index_sequence<As..., Bs...>, Seq...> {};
+
+        template<class... Seq>
+        using flatten_idxseq_t = typename flatten_idxseq<Seq...>::type;
+    }
+}

include/sqlite_orm/sqlite_orm.h

@@ -1371,7 +1371,7 @@ namespace sqlite_orm {
          *  Get the index value of an `index_sequence` at a specific position.
          */
         template<size_t Pos, size_t... Idx>
-        SQLITE_ORM_CONSTEVAL size_t index_sequence_value_at(std::index_sequence<Idx...>) {
+        SQLITE_ORM_CONSTEVAL auto index_sequence_value_at(std::index_sequence<Idx...>) {
             return Idx...[Pos];
         }
 #elif defined(SQLITE_ORM_FOLD_EXPRESSIONS_SUPPORTED)