Struct OwnedClosureBlock 

pub struct OwnedClosureBlock { /* private fields */ }

Owning handle for a raw TypedClosureHeader block paired with its layout.

Closure spec §14.6 (H6.5)

Wraps a *const TypedClosureHeader returned by alloc_typed_closure alongside the Arc<ClosureLayout> needed to decode/release its captures. Clone bumps the block’s refcount via retain_typed_closure; Drop decrements via release_typed_closure so ownership mirrors the Arc<HeapValue> convention used by every other heap-backed value.

The raw pointer is stashed as *const u8 internally (erased) because TypedClosureHeader is !Send + !Sync; the owner’s manual unsafe impl Send + Sync is justified by the fact that the block itself is immutable (refcount aside) and the layout is already Send + Sync via Arc.

Safety invariant

For every live OwnedClosureBlock, ptr was allocated by alloc_typed_closure with the exact layout carried in this owner, and the block is refcount-owned by this instance.

Implementations

impl OwnedClosureBlock

pub unsafe fn from_raw(ptr: *const u8, layout: Arc<ClosureLayout>) -> Self

Construct an OwnedClosureBlock from a freshly-allocated raw pointer. The caller transfers exactly one refcount share.

Safety

• ptr must have been returned by alloc_typed_closure with the exact layout passed in here.
• The caller must not call release_typed_closure on ptr independently — Drop takes over that responsibility.

pub fn as_ptr(&self) -> *const u8

Borrow the underlying raw pointer. The returned pointer is live for at least as long as self.

pub fn as_header_ptr(&self) -> *const TypedClosureHeader

Borrow the underlying raw pointer typed as TypedClosureHeader.

pub fn layout(&self) -> &Arc<ClosureLayout>

Borrow the layout that describes this block’s captures. Shared with the program’s closure_function_layouts side-table; clones are cheap Arc bumps.

pub unsafe fn read_capture_kinded(&self, idx: usize) -> (u64, NativeKind)

Read capture idx’s raw 8-byte payload paired with its NativeKind from the layout’s per-capture kind track (ADR-006 §2.7.8 / Q10).

This is the cell-bound mirror of the §2.7.7 stack-side read_owned_kinded accessor: returns (bits, kind) lockstep so the caller can route through clone_with_kind / drop_with_kind (the canonical KindedSlot dispatch) without reconstructing the kind from the slot bits or probing a tag.

For Immutable captures the returned bits are the raw payload bit pattern (e.g. f64::to_bits(v), Arc::into_raw::<T> raw pointer) and kind classifies it directly.

For OwnedMutable and Shared captures the returned bits are the raw cell pointer (*mut T from Box::into_raw or *const SharedCell from Arc::into_raw); kind classifies the cell’s interior payload — the same shape capture_inner_kind resolves to at the FieldKind level, but lifted to NativeKind so heap-bearing interior payloads dispatch through the same table the stack-tier uses. Wave-β B6-variables-loadptr consumes this accessor to migrate the Load*Ptr / Store*Ptr handlers off NotImplemented(SURFACE).

Safety

The block’s captures area for idx must have been initialised (zero-initialised by alloc_typed_closure and then written by the make-closure init stage). The 8-byte read is always in-bounds because the layout rounds total size up to 8-byte alignment and idx < layout.capture_count().

Panics

Panics if idx >= self.layout.capture_count().

Trait Implementations

impl Clone for OwnedClosureBlock

fn clone(&self) -> Self

Bumps the block’s refcount and the layout Arc’s refcount.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for OwnedClosureBlock

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

Formats the value using the given formatter.

impl Drop for OwnedClosureBlock

fn drop(&mut self)

Releases the block’s refcount share. If this was the last share the block is walked (heap_capture_mask bits drop their shares) and deallocated. The layout Arc is decremented by the default field-drop below.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Send for OwnedClosureBlock

impl Sync for OwnedClosureBlock