Method stash

aiscript-arena/src/dynamic_roots.rs:49–69

Puts a root inside this root set. The returned handle can be freely stored outside the current arena, and will keep the root alive across garbage collections.

(
        &self,
        mc: &Mutation<'gc>,
        root: Gc<'gc, Root<'gc, R>>,
    )

    /// The returned handle can be freely stored outside the current arena, and will keep the root
    /// alive across garbage collections.
    pub fn stash<R: for<'a> Rootable<'a>>(
        &self,
        mc: &Mutation<'gc>,
        root: Gc<'gc, Root<'gc, R>>,
    ) -> DynamicRoot<R> {
        // SAFETY: We are adopting a new `Gc` pointer, so we must invoke a write barrier.
        mc.backward_barrier(Gc::erase(self.0), Some(Gc::erase(root)));

        let mut slots = self.0.slots.borrow_mut();
        let index = slots.add(unsafe { Gc::cast(root) });

        let ptr =
            unsafe { mem::transmute::<Gc<'gc, Root<'gc, R>>, Gc<'static, Root<'static, R>>>(root) };
        let slots = unsafe {
            mem::transmute::<Weak<RefCell<Slots<'gc>>>, Weak<RefCell<Slots<'static>>>>(
                Rc::downgrade(&self.0.slots),
            )
        };

        DynamicRoot { ptr, slots, index }
    }

    /// Gets immutable access to the given root.
    ///