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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] new tutorial on writing functions taking Eigen types as paramters
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Tue, 17 Aug 2010 17:08:49 +0200
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On Tue, Aug 17, 2010 at 3:26 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> wrote:
> Note that since the only values that will ever be used are 1,2,Dynamic, we
> could also make typedefs for them, so that in 99.9% of cases one wouldn't
> need the template keyword.
good point. Moreover, with the current cost model, it is enough to
expose only the cases where N==1 and N==Dynamic. Even for the simplest
expression 2*m, if N=2, then it gets evaluated.
Of course, to be future proof it would still make sense to expose the
N=2 case but others are really useless, so what about defining only
the following three types (without the generic template one):
typedef typename ei_nested<Derived,1>::type Nested;
typedef typename ei_nested<Derived,2>::type NestedForTwoAccess;
typedef typename ei_nested<Derived,Dynamic>::type NestedForMultipleAccess;
alternative names: NestedOnce, NestedTwice, NestedManyTimes ???
gael