Struct ObjectSlab 

pub struct ObjectSlab {
    pub free_list: Vec<usize>,
    /* private fields */
}

A deterministic slab allocator for type-erased objects.

Replaces the old mark-sweep GcHeap. Objects are reference-counted and freed automatically when no references remain. The slab provides stable indexed access and deterministic slot reuse.

Fields

free_list: Vec<usize>

Free-list for slot reuse (LIFO for determinism).

Implementations

impl ObjectSlab

pub fn new() -> Self

Create a new empty slab.

pub fn alloc<T: Any + 'static>(&mut self, value: T) -> SlabRef

Allocate a value in the slab, returning a handle.

Reuses a freed slot if available (LIFO), otherwise extends the slab.

pub fn get<T: Any + 'static>(&self, slab_ref: SlabRef) -> Option<&T>

Read a reference to the value behind slab_ref, downcasting to T. Returns None if the slot is empty or the type does not match.

pub fn get_mut<T: Any + 'static>( &self, slab_ref: SlabRef, ) -> Option<RefMut<'_, Box<dyn Any>>>

Get a mutable reference to the value behind slab_ref.

pub fn live_count(&self) -> usize

Number of live (non-None) objects in the slab.

pub fn capacity(&self) -> usize

Total number of slots (including freed ones).

pub fn alloc_count(&self) -> usize

Total allocations performed since creation.

pub fn free(&mut self, slab_ref: SlabRef)

Explicitly free a slot (return to free-list).

This is optional — objects are also freed when their Rc drops to zero. Use this for explicit lifecycle management.

pub fn collect_noop(&self)

No-op collect for backward compatibility with GC API.

The object slab uses reference counting; there is nothing to collect. This method exists so that gc_collect builtins don’t need to be removed from user code immediately.

Trait Implementations

impl Debug for ObjectSlab

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ObjectSlab

fn default() -> Self

Returns the “default value” for a type.