{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":")"}]}
    ) -> (P<ast::Block>, P<ast::Expr>, P<ast::Expr>, P<ast::Expr>) {
        generics: &Generics,
        let blackbox_path = ecx.std_path(&[sym::hint, sym::black_box]);