Hash array mapped trie

I’m familiar with the implementation of HAMTs - if anyone wants to study one in C I recommend https://github.com/Jamesbarford/hash-array-mapped-trie https://github.com/Jamesbarford/hash-array-mapped-trie or my polymorphic fork of it https://github.com/fromheten/hash-array-mapped-trie-poly https://github.com/fromheten/hash-array-mapped-trie-poly.