Function try_from_fn_erased 

fn try_from_fn_erased<T, E, F>(
    buffer: &mut [MaybeUninit<T>],
    f: F,
) -> Result<(), E>
where
    F: FnMut(usize) -> Result<T, E>,

Fills a MaybeUninit slice using the given fallible generator function.

Using a slice avoids monomorphizing for each array size.