Re: [boost] [functional] boost::hash with 64-bit types

From: Alexei Alexandrov (alexei.alexandrov_at_[hidden])
Date: 2006-03-20 16:06:09

Hi Daniel James, you wrote:

> This is fine for most types, but since long long typically has a much 
> larger range of values than std::size_t, it will work very badly for 
> long long.

Well, the idea of hashing is that developer knows (to some extent) the data values distribution and it's his/her responsibility not to do silly things. For example, boost does provide hash function for vector despite the vector has much more possible combinations that can fit into size_t. long long is just a vector of 2 longs after all... :-)

> 
> I think it's possible to change the definition to one that remains close 
> to the spirit of the original specification and works well for the 
> larger integer types. I'll be looking into doing this for Boost 1.35.
> 

Looking forward to it. Thanks.

-- 
Alexei Alexandrov