No, mixing boxed and unboxed types is very typical for garbage collected languages. As the article shows, you can distinguish with a bit whether something is a

No, mixing boxed and unboxed types is very typical for garbage collected languages. As the article shows, you can distinguish with a bit whether something is a boxed type or not, so you do that during GC. Both languages I mentioned use regular 8/16/32/64 bit size values, which is why I asked.