Re: [eigen] Iterators with dense matrices 2

[Benoit Jacob <jacob.benoit.1@xxxxxxxxx>]

Hi,

To summarize the current situation:
 - we agree on the potential usefulness of iterators and would be OK
to have them in Eigen.
 - we already renamed the old end() function to tail() so that the
name "end()" is now available to be used for iterator stuff (and
begin() is available too).
 - but we are currently focusing on finishing Eigen 3.0 and this is
not a priority for us as this is a feature addition that can be made
at a later date.
 - patches welcome :) but anyone trying to write such a patch would
have to pay attention to consistency with the Sparse module which
already has iterators.

> Still, iterator support might be helpful to re-use algorithms that take
> iterators as input. But there is a much easier solution to achieve that
> (at least that's how I solved this problem): just use both interfaces in
> parallel. For example, initialise your matrix as uBlas matrix and then
> initialise an Eigen2 matrix using exactly the same block of memory
> occupied by the original uBlas matrix.

Indeed, you can do that by mapping the memory buffer using Map<MatrixType>.

Cheers,
Benoit