Rust's solution is to provide the hash function as a generic parameter so you can just Fnv/Xx/Sip based on your workload, with Sip as the default if you don't p

Rust's solution is to provide the hash function as a generic parameter so you can just Fnv/Xx/Sip based on your workload, with Sip as the default if you don't pick. Unfortunately this is mostly incompatible with the adaptive scheme you suggest, because you definitely don't want the adaptive logic if you've already picked Xx/Fnv. Making it possible to disable all that if you pick something other than Sip would make things quite complicated. But yeah, data structuring is ultimately really work-load specific. Any solution a language provides will always be suboptimal for tons of use cases. The solution you describe sounds good for a "never think about it" solution that works for 85% of cases. Rust's solution kinda necessitates more thinking more often, but I think it makes it more applicable for more usecases if you're willing to do that little bit of thinking.