Function ref_mut_filter_map

pub fn ref_mut_filter_map<T: ?Sized, U: ?Sized, F: FnOnce(&mut T) -> Option<&mut U>>(
    orig: RefMut<'_, T>,
    f: F,
) -> Option<RefMut<'_, U>>

👎Deprecated since 0.2.2: Users should instead use RefMut::filter_map