Re: [eigen] Mapping array of scalars into quaternions

[Mathieu Gautier <mathieu.gautier@xxxxxx>]

> constructors and have different ei_traits. Now looking at the case of
> quaternions, there too we need different constructors: the
> QuaternionWrapper needs a ctor taking a pointer and doesn't want the
> ctor taking 4 numbers, for example.

With my patch, the pointer or the 4 scalars are given to the 
constructors of Matrix or Map<Matrix>. So, using the wrong constructor 
(Quaternion<,Map<Matrix>> with 4 scalars) will fail at build time. But 
it may not be explicit enough.

The only specific function that I see would be a Remap(const Scalar*) 
function for the QuaternionWrapper.

If the RotationBase <- QuaternionBase <- (QuaternionWrapper, Quaternion) 
inheritance layout is prefered, I could make a first version for 
QuaternionBase, Quaternion and QuaternionWrapper based on 
DiagonalMatrix, since I need it.

--
Mathieu