For anyone in a situation where an unordered_set or unordered_map is in a hot part of the code, I'd also highly recommend Robin Hood: https://github.com/martinu

For anyone in a situation where an unordered_set or unordered_map is in a hot part of the code, I'd also highly recommend Robin Hood: https://github.com/martinus/robin-hood-hashing https://github.com/martinus/robin-hood-hashing It made a huge difference in one of the programs I was running. EDIT: I could have sworn they used to also support the ordered versions, but maybe not.