{"ast_node_type":"function","tokens":[{"end":34,"kind":"keyword","start":0,"text":"fn"}]}
    fn decode(d: &mut D) -> Self {
impl<D: Decoder, I: Idx, T: Decodable<D>> Decodable<D> for IndexVec<I, T> {
        IndexVec::from_raw(Vec::<T>::decode(d))