syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"std::iter::zip(self.args.iter(),"}]}
source_snippet:         std::iter::zip(self.args.iter(), variances.iter()).enumerate().filter_map(
context_before:         let variances = cx.variances_of(self.def_id.into());
context_after:             |(i, (arg, v))| match (arg.kind(), v) {