syntax_data: {"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                         if unsizing_params.contains(i as u32) { args_b[i] } else { k }
context_before:                     tcx.mk_args_from_iter(args_a.iter().enumerate().map(|(i, k)| {
context_after:                     }));