Function elevate_degree 

pub fn elevate_degree<P: Blend>(
    knots: &KnotVector,
    control: &[P],
    tol: Tolerances,
) -> OgeomResult<Spline<P>>

Raise the degree by one, leaving the curve unchanged.

Works segment by segment on the Bézier decomposition, where degree elevation is the exact closed form Q[i] = (i/(p+1)) P[i-1] + (1 - i/(p+1)) P[i], and reassembles by removing the knots that were introduced.

Errors

As to_bezier_segments.