I was curious why that'd be the case. I checked GCC's implementation. It seems to be here: https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/includ

I was curious why that'd be the case. I checked GCC's implementation. It seems to be here: https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-v3/include/bits/uniform_int_dist.h#L238 https://github.com/gcc-mirror/gcc/blob/master/libstdc%2B%2B-... Looks like they had to make this very generic, generic enough to account for random number generators that return value in specific ranges. If you have a generator that guarantees to return a uniformly random 32 bit value, it seems much faster to do (r%(max-min)+min) instead.