handle: struct -> class

src/entt/entity/fwd.hpp

@@ -50,7 +50,7 @@ template<typename>
 class basic_organizer;
 
 template<typename, typename...>
-struct basic_handle;
+class basic_handle;
 
 template<typename>
 class basic_snapshot;

src/entt/entity/handle.hpp

@@ -94,7 +94,8 @@ template<typename ILhs, typename IRhs>
  * @tparam Scope Types to which to restrict the scope of a handle.
  */
 template<typename Registry, typename... Scope>
-struct basic_handle {
+class basic_handle {
+public:
     /*! @brief Type of registry accepted by the handle. */
     using registry_type = Registry;
     /*! @brief Underlying entity identifier. */