rem: (void*) userdata;
add: (void) userdata;
context:   void check(gpointer* data, gpointer* userdata) {    struct glgfx_rasinfo* rasinfo = (struct glgfx_rasinfo*) data;    (void*) userdata;    if (glgfx_bitmap_haschanged(rasinfo->bitmap) || rasinfo->has_changed) {      has_changed = true;    }    rasinfo->has_changed = false;  }