Re: [eigen] Indexes: why signed instead of unsigned?

[Cyril Flaig <cflaig@xxxxxxxxxxx>]

Hi all

I'm a user of eigen2.

On 2010-05-11 14:54, Benoit Jacob wrote:
> 2) int (that is 32 bits) or same-sizeof-as-pointers (e.g. 64bit on
> 64bit platforms)?
> 
> For 2) signed, we could do ptrdiff_t, i guess. Unless you're sure that
> 'long' is actually on all platforms the size of a pointer. I still
> dont know whether 2) matters. Certainly not for cubic-complexity
> algorithms (would take forever). But for plain "level 1" operations,
> perhaps it's plausible. Feels like we shouldn't arbitrarily restrict
> sizes to 32 bits. Opinions?

The main memory of computer becomes as big, that  you can store vectors
that have more than 2^31 elements. And I think there are severals
application that uses just "level 1" operations. Especially in
complicated "level 1" operation eigen does a very good job.

I think it would be great if the indexes would be long int.

Just my 5 cents
-cyril