syntax_data: {"ast_node_type":"variable","tokens":[{"end":44,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let tupled_args = Expr {
context_before:                     let arg_tys = args.iter().map(|e| self.typeck_results.expr_ty_adjusted(e));
context_after:                         ty: Ty::new_tup_from_iter(tcx, arg_tys),