{"ast_node_type":"other","tokens":[{"end":92,"kind":"keyword","start":0,"text":"idx.as_u32().checked_sub(distance_to_explicit).map(VariantIdx::from_u32)"}]}
                    idx.as_u32().checked_sub(distance_to_explicit).map(VariantIdx::from_u32)
                if let Some(explicit_idx) =
                {