Bit-packed array may be also useful

[schveiguy]

2^24 integers comes out to about 67MB of storage required.

The largest prime number here is 71_378_569.

If you have a bitset with the bits of the prime numbers set up to this value, then this fits into 9MB, and has instantaneous lookup vs. binary search (for checking if a number is prime).

Using core.bitop, you would get both mechanisms to test for prime numbers (and I believe it's an intrinsic), and using BitRange, you get a way to iterate them.

Just food for thought. Could go in a different module in this package.