Hi,
gobject-introspection should handle non-GObject GTypeInstances/Classes properly. An example is below:

struct _GstMiniObject {
  GTypeInstance instance;
  /*< public >*/ /* with COW */
  gint refcount;
  guint flags;

  /*< private >*/
  gpointer _gst_reserved;
};

struct _GstMiniObjectClass {
  GTypeClass type_class;

  GstMiniObjectCopyFunction copy;
  GstMiniObjectFinalizeFunction finalize;

  /*< private >*/
  gpointer _gst_reserved;
};

Currently this creates a normal record for GstMiniObjectClass, without the glib:is-gtype-struct-for="GstMiniObject" attribute.