The number of unique int32 values is not that great, and a full bitset would only be 512MB. Hard to bit a dense bitset in performance.
As a general purpose data structure, I would look at roaring bitmaps for this purpose, which has good trade-offs with great performance for most use-cases.
If only simple lookups are needed over a static set, then it's worth looking at minimal perfect hash functions (https://sux.di.unimi.it).
As a general purpose data structure, I would look at roaring bitmaps for this purpose, which has good trade-offs with great performance for most use-cases.
If only simple lookups are needed over a static set, then it's worth looking at minimal perfect hash functions (https://sux.di.unimi.it).