I am compelled to point out how much "For uint64_t and UINT64_MAX you will be waiting a long time" really undersells it. If we assume that the uint32_t version runs in one second, the u64 version will take 136 years. In reality, on the machine in my lap, u32 takes 0.6s, so we can expect the u64 version to take at least 81 years! Statistically, "you" will not be waiting a long time, because you will die first.

"128 bit values? Even longer." Yes, 2^64 times longer than u64, and 2^96 times longer than for u32! 2^96 just about 80e27. Age of the universe is ~13.8 billion (13.8e9) years, or ~435e15 seconds.

If we consider a more moderate 96-bit size, and I started at the very beginning of the universe, I will only have been able to run that program just over 25 times by now. That's all.