Function wayland_server::resource_is_registered

pub fn resource_is_registered<R, H>(resource: &R, handler_id: usize) -> bool where
    R: Resource,
    H: Handler<R> + Any + Send + 'static, 

Checks if a resource is registered with a given handler on an event loop

The H type must be provided and match the type of the targetted Handler, or it will panic.

Returns false if the resource is dead, even if it was registered to this handler while alive.