syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"std::iter::zip(args.iter(),"}]}
source_snippet:             std::iter::zip(args.iter(), variances.iter()).map(|(arg, v)| match (arg.kind(), v) {
context_before:         let args =
context_after:                 (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => arg,