If it actually is a unlimited-width integer, bit logic/shifting can work fine, and network packets have to be x&0xFF,x>>8&0xFF,etc anyway. But that's painful for direct translation to machine code (what happens when I try to return 340'282'366'920'938'463'463'374'607'431'768'211'456 from a function?), so either it's secretly a fixed-width integer (and they're being deliberately vague about what width, which is suspicious), or the language defaults to possibly allocating memory (and possibly getting a OOM error) on every single arithmetic operation, which is a catastrophically undesirable property in a systems programming language.