[fixf]

The minimum number motivated to work is also the cheapest. 2 was simply deemed insecure.

[thomasmg]

No, actually 2 would also work. It's just that 3 hash functions needs the least space for some reason (less than 2, less than 4 or more).

[fixf]

Well met, and thanks for identifying the solution using overhead.

[layoutIfNeeded]

Insecure? What does that mean in the context of a read-only data structure?

[fixf]

Good point, loose language on my part. I am thinking of false positives or collision. The required statistical properties aren't met.