macro_rules! use_ref {
    (move || $e:expr) => { ... };
    (readonly move || $e:expr) => { ... };
    (|| $e:expr) => { ... };
    (readonly || $e:expr) => { ... };
    ($e:expr) => { ... };
    (readonly $e:expr) => { ... };
    (set_as $e:expr) => { ... };
}
Expand description

use_ref macro will auto wrap value into Rc<T>.