fn decode_arena_allocable_slice<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>, T: ArenaAllocatable<'tcx> + Decodable<D>>(
    decoder: &mut D
) -> &'tcx [T]ⓘNotable traits for &'_ mut [u8]impl<'_> Write for &'_ mut [u8]impl<'_> Read for &'_ [u8] where
    D: TyDecoder,