signal_ref for MutableVec

[Al M.]

Forgive me if I'm not seeing it, but is there no way to create a signal from a MutableVec where the values aren't Copy or Clone? Like an equivalent of signal_ref for Mutable?

[Pauan]

Unfortunately that's not possible, because it needs to maintain a history of the exact operations (in order). For example, let's say you had a situation like this...

let x = MutableVec::new();

let s1 = x.signal_vec_cloned();
let s2 = x.signal_vec_cloned();

x.lock_mut().push(5);
x.lock_mut().push(10);

And let's suppose that s1 is updated faster than s2. In that case s2 would have to store the push events, so it can process them later. So it cannot have a reference to the MutableVec, it must clone.

A similar situation happens if s1 or s2 are delayed for any reason (e.g. for_each, delay_remove, etc.) in that case it has to store the events.

However, you can use Rc or Arc, which allows you to clone anything very cheaply. For example, MutableVec<Rc<Foo>>