Re: [boost] Re: Re: [review] hash functions

From: Dave Harris (brangdon_at_[hidden])
Date: 2005-03-16 12:07:14

In-Reply-To: <d174ak$vp3$1_at_[hidden]>
nesotto_at_[hidden] (Thorsten Ottosen) wrote (abridged):
> are you saying we don't want to hash a Base* as a void*, but use
> object properties instead?

Sometimes. It's a reasonable thing to do. It's what my own app actually 
does. It shouldn't be the default, of course. 

Mainly I'm saying that equality tests sometimes need to be polymorphic, 
and when they are the corresponding hash_value needs to be as well. So 
sometimes we will be comparing hash values from different types. (Other 
people here have claimed that never happens.)

-- Dave Harris, Nottingham, UK