fact: Definition remove_dups_fast (l : list A) : list A := match l with | [] => [] | [x] => [x] | _ => let n : Z := Z.of_nat (length l) in elements (foldr (λ x, ({[ x ]} ∪.)) ∅ l : hashset (λ x, hash x `mod` (2 * n))%Z) end.
imports: stdpp(zmap) stdpp(options)