{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"if"}]}
    if let Some(infer_ret_ty) = sig.decl.output.is_suggestable_infer_ty() {
) -> ty::PolyFnSig<'tcx> {
        return recover_infer_ret_ty(icx, infer_ret_ty, generics, def_id);