syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"(index,"}]}
source_snippet:             (index, Discr { val: index.as_usize() as u128, ty: self.discr_ty(tcx) })
context_before:         self.variant_range(def_id, tcx).map(move |index| {
context_after:         })