Function difference_multi 

pub fn difference_multi<G1, G2, P>(
    g1: &G1,
    g2: &G2,
) -> Result<MultiPolygon<Polygon<P>>, OverlayError>
where
    G1: MultiPolygonTrait<Point = P>,
    G2: MultiPolygonTrait<Point = P>,
    P: PointMut + Default + Copy,
    P::Scalar: CoordinateScalar + Into<f64>,
    <P::Cs as CoordinateSystem>::Family: SameAs<CartesianFamily>,

Difference of two multi-polygons — the region inside g1 but not g2.

Errors

OverlayError::Unsupported when coordinates exceed the predicate range.