+;;;; Built-in structure and condition layouts should have NIL in
+;;;; LAYOUT-FOR-STD-CLASS-P, and classes should have T.
+
+(assert (not (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'warning))))
+(assert (not (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'hash-table))))
+(assert (eq t (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'standard-object))))