> (Out of curiosity what does the distribution have to do with it -- > what's a distribution for which something besides identity is better?)
Oh, I don't know... let's say you know that your keys are always even, then you could have a hash that divides by two so that you avoid collisions in the hash table before it fills up. This said, it requires you to know your keys, the hash table implementation... most likely not worth the effort to have a custom hash anyway. I did implement custom hash functions in HPPC, but I strongly believe they are useful only in one scenario -- when you have objects of classes you have no control of (cannot override hashCode()) and you know their implementation of hashCode is weak. Dawid
