hermite spline should be implemented as a Bezier curve
Hermite splines and Bezier curves have really similar properties, and almost equivalent meanings and use.
For code factoring purposes, Hermite should really just be implemented as a Bezier curve. In the interface, there are in fact already constructors that take into account the desired derivatives, only they are much more general.
If an api is necessary, then I suggest simply creating a free function that takes the desired parameters and return the appropriate Bezier curve.