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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] Indexes: why signed instead of unsigned?
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Tue, 11 May 2010 11:47:42 -0400
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I just had a diabolic idea, if we agree that bigger-than-2^31-support
is not a top priority and will at most be used by relatively few
people, then we can keep things unchanged for now, so keep 'int' in
Eigen 3.0, and later on, when actual people actually need it (perhaps
in eigen 3.45), add a non-default compile-time option
EIGEN_USE_LONG_INDICES. Such an option would then break the ABI of
Eigen classes, so it couldn't become default.
Question - is BLAS/LAPACK using int or ptrdiff_t ?
Benoit
2010/5/11 Mark Borgerding <mark@xxxxxxxxxxxxxx>:
> Benoit Jacob wrote:
>>
>> 2010/5/11 Jitse Niesen <jitse@xxxxxxxxxxxxxxxxx>:
>>
>>>
>>> but we never
>>> had somebody complain about eigen using only 32-bit indices. And on a
>>> practical note, it seems rather short before the planned beta tagging to
>>> make such a radical change.
>>>
>>
>> True. This is not optimal. On the other hand, releasing a beta with
>> int and getting people to complain about that later, would be even
>> worse :)
>
> This will only happen if someone is using 2^31 elements or more. Even then,
> it should be a non-astonishing failure.
> http://en.wikipedia.org/wiki/Principle_of_least_astonishment
>
>
>
>