|Re: [eigen] Indexes: why signed instead of unsigned?|
[ Thread Index |
| More lists.tuxfamily.org/eigen Archives
On Tue, 11 May 2010, Benoit Jacob wrote:
What about the other debate, between int (32bit) and ptrdiff_t (same
size as void*) ?
A disadvantage of the potentially bigger ptrdiff_t is that it costs more
memory. I guess this is usually not an issue, but it does make a
difference for sparse matrices. In fact, we earlier had somebody who
wanted to use 16-bit instead of 32-bit for this reason:
The performance hit of using 64-bit indices may not be so big, 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.
No opinion on the signed/unsigned debate.