Type Alias Handler 

type Handler = Option<Arc<dyn Fn(&mut Registers) + Send + Sync>>;

Aliased Type

enum Handler {
    None,
    Some(Arc<dyn Fn(&mut Registers) + Sync + Send>),
}

Variants

None

No value.

Some(Arc<dyn Fn(&mut Registers) + Sync + Send>)

Some value of type T.