[Boost-users] [hash] Performance & distribution, variable bit width

Subject: [Boost-users] [hash] Performance & distribution, variable bit width
From: Sebastian Karlsson (sairony_at_[hidden])
Date: 2011-03-14 08:52:11

As I use boost::hash quite a bit I have a few questions which the
documentation seems to leave out. First of all it would be terrific if
there was a performance & distribution benchmark as a part of the
documentation to make it easier to evaluate the merits of using it.
Secondly I'm a bit stumped on why the return value is fixed to size_t
for a couple of reasons. Bit width of size_t isn't guaranteed to be
constant, wouldn't this severely affect the distribution properties of
the hashing algorithm used? Furthermore it would be great if the user
could choose the bit width of the hash. Often the birthday problem is
relevant, and being able to swap to using a 64 bit hash easily is
something that doesn't seem possible but often desirable.

Kind regards,
Sebastian Karlsson