This impl was effectively stable. #[unstable] had no effect here, since both Error and LayoutErr were already stable. This effectively became stable as soon as LayoutErr became stable, which was in 1.28.0.
This impl was effectively stable. #[unstable] had no effect here, since both Error and LayoutErr were already stable. This effectively became stable as soon as LayoutErr became stable, which was in 1.28.0.