On Sat, Oct 30, 2010 at 6:21 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> 3. To hash, apply the element type's hash function to each array
> element. Combine these values by rotating the accumulator left
> one bit at each step and xor'ing in the next element's hash value.
>
> Thoughts? In particular, is anyone aware of a better method
> for combining the element hash values?
>
This would make the hash the same for arrays with elements 32 apart swapped.
This is what boost does:
http://www.systomath.com/include/Boost-1_34/doc/html/boost/hash_combine.html
Greetings