5 ms·
Looking at the head of a List does not work. The class of that element is within the scope of <? extends ListType>, an is not necessarily not ListType.
by yarg 9y ago
Looking at the head of a List does not work.
The class of that element is within the scope of <? extends ListType>, an is not necessarily not ListType.
- rusanu 9y agoNot to mention that an empty list still has a type...
- yarg 9y ago*and is not necessarily ListType. Idiot.
- Twisol 9y agoFor the downvoters, the author is correcting themselves after the edit window. It's clearly self-deprecating humor, not a personal attack.
- Groxx 9y agoTo spell this out so it's a bit more obvious, given a Thing at head of a list, you could have: - a List<Thing> - a List<ThingSuperclass> - a List<? extends Thing> - a List<? super ThingSubclass> - a List<IThing> - a List<ILiterallyAnyImplementedIFace> - a List<IHaventForgottenInterfacesCanExtendOthers> - a List<Object> - a List<I'm probably forgetting some possibilities> And you have no way of knowing which it is. So yes, it's a boundary, which is significantly more than nothing. But far less useful than it feels like at first.