Weak

Module std.memory

import std.memory;

Public declaration contracts and authored examples. A page can document several related symbols. Implementation bodies are excluded.

pub final class Weak<T, A = DefaultAllocator>
    where T: Movable where A: Allocator, Defaultable, Movable

Retains a shared control block while permitting the payload to expire.

Copying retains only weak control ownership and never copies T. Upgrade atomically acquires a new strong handle or returns none after expiry; it never resurrects a destroyed payload. Separate published handles support concurrent retention/release, while access to the same mutable handle requires external synchronization. No payload borrow is available directly from Weak. T: Movable payload observed only after a successful strong upgrade. A: Movable Defaultable allocator retained until final control cleanup.

Weak.init

pub init()

Creates an empty weak observer without allocation.

Weak.init

pub init(Source: readonly Self&)

Retains the source control block without retaining its payload. Source: Existing weak observer or empty handle.

Weak.init

pub init(Source: mut Self&&)

Transfers one weak lease without retention. Source: Writable observer left empty.

Weak.operator

pub fn operator =(Source: readonly Self&) -> void

Retains source control before releasing the destination lease. Source: Observer to retain; exact self-assignment is unchanged. Return: No value.

Weak.operator

pub fn operator =(Source: mut Self&&) -> void

Releases old control ownership and transfers Source. Source: Observer left empty; exact self-move is unchanged. Return: No value.

Weak.IsEmpty

pub IsEmpty: bool;

Reports absence of a control lease, independently of payload expiry. Return: True only for empty/moved-from observers.

Weak.Upgrade

pub readonly fn Upgrade() -> Shared<T, A>?

Atomically acquires a strong owner while the payload is still live. Return: New strong owner, or none for an empty/expired observer; no allocation.

Weak.Clear

pub fn Clear() -> void

Releases this weak lease, possibly freeing the final control record. Return: No value; the observer is empty before control cleanup begins.