Re: [boost] [hash] regular behaviour of hash function for double values

Subject: Re: [boost] [hash] regular behaviour of hash function for double values
From: Daniel James (dnljms_at_[hidden])
Date: 2012-02-02 17:28:35

On 1 February 2012 21:32, Topher Cooper <topher_at_[hidden]> wrote:
> On 2/1/2012 4:01 PM, Daniel James wrote:
>> On 1 February 2012 20:15, Topher Cooper<topher_at_[hidden]>  wrote:
>>>
>>> I've seen that claim, and I might well be missing something, but I
>>> believe
>>> that coalesced hashing would also work.
>>
>> Container elements can be uncopyable and unmovable.
>
> Ah, I did miss that, but it just means that the underlying table include
> indirection as open chaining generally does intrinsically (I say generally,
> because it is possible to implement open chaining if that were not a
> requirement with the first entry contained in the table).

Wouldn't that defeat the purpose? If you have to follow an indirection
for every key comparison, then you've lost the main advantage of using
coalesced hashing.