Space filling curves would work in some situations, but wouldn't be as efficient as a purpose-designed hash. A space filling curve, for example, would break dow

Space filling curves would work in some situations, but wouldn't be as efficient as a purpose-designed hash. A space filling curve, for example, would break down under 50+ dimensions, which is why you'd be using one of these hashes in the first place rather than a tree. If you want to know more, I'd suggest researching Locality Sensitive Hashing. Flann[1] has a decent implementation. 1. https://www.cs.ubc.ca/research/flann/ https://www.cs.ubc.ca/research/flann/