How to get the bounding rect of a Vec of shapes?

[nk9]

I have a Vec of MultiPolygons. What is the best way to get a bounding rect which contains them all?

I thought it would be as simple as using union on all of them, but bounding_rect returns a Rect whereas union returns a Polygon. (And possibly a MultiPolygon when used on one of those?)

[mthh]

I think you can use a GeometryCollection (which is a collection of Geometries) for this.

let vec_mpl: Vec<MultiPolygon<f32>> = vec![mpl1, mpl2];
let gc = GeometryCollection::new_from(vec_mpl.into_iter().map(Geometry::from).collect());
println!("{:?}", gc.bounding_rect());