Function curve_bounds_over 

pub fn curve_bounds_over(
    curve: &Curve,
    range: (f64, f64),
    tol: Tolerances,
) -> OgeomResult<Aabb>

A guaranteed bound for the part of a curve an edge actually uses.

curve_bounds answers for the whole curve, which is the right answer to a different question: a line’s carrier runs to the ends of the world, and an imported edge sits on a stretch of it a few millimetres long. Where the range can be honoured exactly it is (a segment is the hull of its two ends, an arc the hull of its ends and whichever of its frame’s four extremes it sweeps past), and where it cannot, the whole curve’s bound stands, which is still a bound.

Errors

Whatever the curve reports when asked for a point.