Function iron_shapes_booleanop::connect_edges::xor_cancel_double_edges

fn xor_cancel_double_edges<T, Ctr, P>(
    sorted_events: Vec<Rc<SweepEvent<T, Ctr, P>>>
) -> Vec<Rc<SweepEvent<T, Ctr, P>>>where
    T: CoordinateType + Debug,

Remove duplicate edges which would form empty polygons.