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