syntax_data: {"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"ty::ConstKind::Unevaluated(ty::UnevaluatedConst"}]}
source_snippet:             ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args, .. }) => {
context_before:             // logic sometimes passing identity-substituted impl headers.
context_after:                 return self.print_def_path(def, args);