1. Sparse MapC++ implementation of a memory efficient hash map and hash set
2. Array HashC++ implementation of a fast and memory efficient hash map and hash set specialized for strings
3. Hat TrieC++ implementation of a fast and memory efficient HAT-trie
4. Robin Map C++ implementation of a fast hash map and hash set using robin hood hashing
5. Hopscotch MapC++ implementation of a fast hash map and hash set using hopscotch hashing
6. Ordered MapC++ hash map and hash set which preserve the order of insertion