Consistency in polynomial init / eval types

Hi,

If I create a polynomial, I have to give it an init point and an end point as pointX_ts: https://gepgitlab.laas.fr/loco-3d/curves/blob/devel/python/curves_python.cpp#L151

Then, if I evaluate it, I get a point_t: https://gepgitlab.laas.fr/loco-3d/curves/blob/devel/include/curves/polynomial.h#L242

So in this test, we are basically checking that a pointX_t object is equal to a point_t object: https://gepgitlab.laas.fr/loco-3d/curves/blob/devel/python/test/test.py#L248

This can work for X = 3, but shouldn't it always work ?