There is something that must be said about anything that increases complexity in order to get efficiency: 1. It increases developer time. 2. It increases the

There is something that must be said about anything that increases complexity in order to get efficiency: 1. It increases developer time. 2. It increases the number of bugs of the system as it increases enormously the different possibilities. We have systems that actually meta program with Lisp our hash tables with different degrees of complexities. It is already programmed, the designs already debug. And even then for most of our hash tables we just use the minimum level of complexity, that is having a memory that is 10 to 20 times bigger than the elements on the hash and just have one or two collisions for the entire set. That way the code is way easier to understand, and the memory differences are just negligible(compared to the total amount of memory the program needs), if sets are well designed.