Function swept_disk_along_arc_exact 

pub fn swept_disk_along_arc_exact(
    arc: &Circle3,
    span: Interval,
    radius: f64,
    inner_radius: Option<f64>,
    tolerance: Tolerance,
) -> Result<ExactBRep, GeomError>

A disk of radius, with an optional bore of inner_radius, swept along arc over the angle span span (radians, start to end, in arc’s own parameter): an exact torus wedge capped by two discs, or a whole torus for a span of a full turn (#223).

The disk is perpendicular to the arc at every point; the arc’s frame must be orthonormal.

Errors

Invalid input for a non-positive radius, a bore not strictly inside the disk, a zero or non-finite span, and a non-orthonormal arc frame; refused by name for a span beyond a full turn and a disk reaching the arc’s axis.