Function try_as_dyn_mut 

pub const fn try_as_dyn_mut<'a, T, U>(t: &mut T) -> Option<&mut U>
where
    T: 'a + ?Sized,
    U: TryAsDynCompatible<'a> + ?Sized,

🔬This is a nightly-only experimental API. (try_as_dyn #144361)

Returns Some(&mut U) if T can be coerced to the trait object type U. Otherwise, it returns None.

See documentation of try_as_dyn for details about the behaviour and limitations.