Struct RefCountInner 

#[repr(C)]
pub struct RefCountInner {
    pub _internal_ptr: *const c_void,
    pub num_copies: AtomicUsize,
    pub num_refs: AtomicUsize,
    pub num_mutable_refs: AtomicUsize,
    pub _internal_len: usize,
    pub _internal_layout_size: usize,
    pub _internal_layout_align: usize,
    pub type_id: u64,
    pub type_name: AzString,
    pub custom_destructor: extern "C" fn(*mut c_void),
    pub serialize_fn: usize,
    pub deserialize_fn: usize,
}

Internal reference counting metadata for RefAny.

This struct tracks:

• How many RefAny clones exist (num_copies)
• How many shared borrows are active (num_refs)
• How many mutable borrows are active (num_mutable_refs)
• Memory layout information for correct deallocation
• Type information for runtime type checking

Thread Safety

All counters are AtomicUsize with SeqCst ordering, making them safe to access from multiple threads simultaneously. The strong ordering ensures no thread can observe inconsistent states (e.g., both seeing count=1 during final drop).

Fields

_internal_ptr: *const c_void

Type-erased pointer to heap-allocated data.

SAFETY: Must be properly aligned for the stored type (guaranteed by Layout::from_size_align in new_c). Never null for non-ZST types.

This pointer is shared by all RefAny clones, so replace_contents updates are visible to all clones.

num_copies: AtomicUsize

Number of RefAny instances sharing the same data. When this reaches 0, the data is deallocated.

num_refs: AtomicUsize

Number of active shared borrows (Ref<T>). While > 0, mutable borrows are forbidden.

num_mutable_refs: AtomicUsize

Number of active mutable borrows (RefMut<T>). While > 0, all other borrows are forbidden.

_internal_len: usize

Size of the stored type in bytes (from size_of::<T>()).

_internal_layout_size: usize

Layout size for deallocation (from Layout::size()).

_internal_layout_align: usize

Required alignment for the stored type (from align_of::<T>()). CRITICAL: Must match the alignment used during allocation to prevent UB.

type_id: u64

Runtime type identifier computed from TypeId::of::<T>(). Used to prevent invalid downcasts.

type_name: AzString

Human-readable type name (e.g., “MyStruct”) for debugging.

custom_destructor: extern "C" fn(*mut c_void)

Function pointer to correctly drop the type-erased data. SAFETY: Must be called with a pointer to data of the correct type.

serialize_fn: usize

Function pointer to serialize RefAny to JSON (0 = not set). Cast to RefAnySerializeFnType (defined in azul_layout::json) when called. Type: extern “C” fn(RefAny) -> Json

deserialize_fn: usize

Function pointer to deserialize JSON to new RefAny (0 = not set). Cast to RefAnyDeserializeFnType (defined in azul_layout::json) when called. Type: extern “C” fn(Json) -> ResultRefAnyString

Trait Implementations

impl Debug for RefCountInner

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

Formats the value using the given formatter.