[minimax]

Any reasonably good optimizing compiler will implement that switch statement as a jump table so it's really just one conditional branch even though it doesn't look like it.

[rurban]

But this compiler will add unneeded bounds checking (3-10% perf. hit). A computed goto table would fix that. (on modern compilers).

Anyway, Lemire's fastrange modulo solved that problem better. https://github.com/lemire/fastrange There's no need for a slow modulo.