test: shared non_movable type

test/entt/common/non_movable.h

@@ -0,0 +1,20 @@
+#ifndef ENTT_COMMON_NON_MOVABLE_HPP
+#define ENTT_COMMON_NON_MOVABLE_HPP
+
+namespace test {
+
+struct non_movable {
+    non_movable() = default;
+
+    non_movable(const non_movable &) = default;
+    non_movable(non_movable &&) = delete;
+
+    non_movable &operator=(const non_movable &) = default;
+    non_movable &operator=(non_movable &&) = delete;
+
+    int value{};
+};
+
+} // namespace test
+
+#endif