{"ast_node_type":"other","tokens":[{"end":47,"kind":"keyword","start":0,"text":"if"}]}
    if !matches!(fn_ty.kind(), ty::FnDef(..)) {
fn adjust_activity_to_abi<'tcx>(tcx: TyCtxt<'tcx>, fn_ty: Ty<'tcx>, da: &mut Vec<DiffActivity>) {
        bug!("expected fn def for autodiff, got {:?}", fn_ty);