tree 903c0c204dc6c4876917c5be819c233e707b6187
parent d400f60c96312f32fafcb15168bbf56970ff3d3a
author Cris Luengo <cluengo@flagshipbio.com> 1491500079 -0600
committer Dean Moldovan <dean0x7d@gmail.com> 1494201021 +0200

Making a copy when casting a numpy array with negative strides to Eigen.

`EigenConformable::stride_compatible` returns false if the strides are
negative. In this case, do not use `EigenConformable::stride`, as it
is {0,0}. We cannot write negative strides in this element, as Eigen
will throw an assertion if we do.

The `type_caster` specialization for regular, dense Eigen matrices now
does a second `array_t::ensure` to copy data in case of negative strides.
I'm not sure that this is the best way to implement this.

I have added "TODO" tags linking these changes to Eigen bug #747, which,
when fixed, will allow Eigen to accept negative strides.