forked from mpusz/mp-units
Chip Hogg
04b80f0827
Certain existing units in the library require very large prime numbers---so large, in fact, that our naive trial division hits the _iteration limit_ for `constexpr` loops. We don't want to force users to provide a compiler option override, so we'd better find another way. The solution is to use the "wheel factorization" algorithm: https://en.wikipedia.org/wiki/Wheel_factorization This lets us skip most composite numbers in our trial division. The implementation presented here is configurable in terms of the size of the "basis" of primes we use. Bigger bases let us skip more primes, but at the cost of storing more numbers. Fortunately, it turns out that N=3 was good enough for our purposes.