Pseudo-classes - CSS: Cascading Style Sheets
r not). note: in contrast to pseudo-classes, pseudo-elements can be used to style a specific part of an element. syntax selector:pseudo-class { property: value; } like regular classes, you can chain together as many pseudo-classes as you want in a selector. ...
...:target-within :user-invalid :valid :visited :where() specifications specification status comment fullscreen api living standard defined :fullscreen. html living standard living standard defines when particular selectors match html elements. selectors level 4 working draft defined :any-link, :blank, :local-link, :scope, :drop, :current, :past, :future, :placeholder-shown, :user-invalid, :nth-col(), :nth-last-col(), :is() and :where(). changed :empty to behave like :-moz-only-whitespace . no significant change for other pseudo-classes defined in selectors level 3 and html5 (though semantic meaning not taken over). html5 recommendation copies the relevant section from the canonical (whatwg) html ...

Interfacing with the XPCOM cycle collector
his); ... in the unlink method (or destructor) you need to set the object pointer to null: ns_impl_cycle_collection_unlink_begin(nsfoo) ... ns_impl_cycle_collection_unlink(msomemember) ... //if your class is a wrapper cache: //ns_impl_cycle_collection_unlink_preserved_wrapper tmp->msomeobj = nullptr; ns_impl_cycle_collection_unlink_end in the destructor, you should call mozilla::dropjsobjects(this); in your traverse method you need to list members involved in the cycle collector, i-e no js objects: ns_impl_cycle_collection_traverse_begin(nsfoo) ... ns_impl_cycle_collection_traverse(msomemember) ... ns_impl_cycle_collection_traverse_end finally, you need to manually add the js object to the trace method: ns_impl_cycle_collection_trace_begin(nsfoo) //if your class ...