#[unstable(feature = "dispatch_from_dyn", issue = "0")]
impl<T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Box<U>> for Box<T> {}
-#[unstable(feature = "boxed_slice_from_iter", issue = "0")]
+#[stable(feature = "boxed_slice_from_iter", since = "1.32.0")]
impl<A> FromIterator<A> for Box<[A]> {
fn from_iter<T: IntoIterator<Item = A>>(iter: T) -> Self {
iter.into_iter().collect::<Vec<_>>().into_boxed_slice()