On Mar 5, 2010, at 11:57 AM, Krzysztof Kosiński wrote:

This will lead to less collisions. Most memory is aligned, so the
lower 2 or 3 bits of pointers are usually zero - this hash fixes that.
I did not benchmark this but I guess we can trust the Boost implementors.

Well, we can trust the boost implementors to match certain aspects for certain needs.

The key is to carefully measure usage in a live situation. Even the Boost developers have told me this. We do seem to have a situation with all sorts of interesting factors, and that might be quite informative to actually look at.