Function cursive::view::scroll::required_size

pub fn required_size<T, RequiredSize>(
    scroller: &mut T, 
    size: Vec2, 
    needs_relayout: bool, 
    required_size: RequiredSize
) -> Vec2 where
    T: Scroller,
    RequiredSize: FnMut(&mut T, Vec2) -> Vec2, 

Performs View::required_size on a scroll::Scroller.