WeakRef

open class WeakRef : WeakRefProtocol

A structure containing a weak reference to a GObject.

A GWeakRef can either be empty (i.e. point to nil), or point to an object for as long as at least one “strong” reference to that object exists. Before the object’s GObjectClass.dispose method is called, every GWeakRef associated with becomes empty (i.e. points to nil).

Like GValue, GWeakRef can be statically allocated, stack- or heap-allocated, or embedded in larger structures.

Unlike g_object_weak_ref() and g_object_add_weak_pointer(), this weak reference is thread-safe: converting a weak pointer to a reference is atomic with respect to invalidation of weak pointers to destroyed objects.

If the object’s GObjectClass.dispose method results in additional references to the object being held (‘re-referencing’), any GWeakRefs taken before it was disposed will continue to point to nil. Any GWeakRefs taken during disposal and after re-referencing, or after disposal has returned due to the re-referencing, will continue to point to the object until its refcount goes back to zero, at which point they too will be invalidated.

It is invalid to take a GWeakRef on an object during GObjectClass.dispose without first having or creating a strong reference to the object.

The WeakRef type acts as an owner of an underlying GWeakRef instance. It provides the methods that can operate on this data type through WeakRefProtocol conformance. Use WeakRef as a strong reference or owner of a GWeakRef instance.

  • ptr
    Untyped pointer to the underlying `GWeakRef` instance.
    

    For type-safe access, use the generated, typed pointer _ptr property instead.

    Declaration

    Swift

    public let ptr: UnsafeMutableRawPointer!
  • Designated initialiser from the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init(_ op: UnsafeMutablePointer<GWeakRef>)

    Parameters

    op

    pointer to the underlying object

  • Designated initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init(_ op: UnsafePointer<GWeakRef>)

    Parameters

    op

    pointer to the underlying object

  • Optional initialiser from a non-mutating gpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init!(gpointer op: gpointer?)

    Parameters

    op

    gpointer to the underlying object

  • Optional initialiser from a non-mutating gconstpointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init!(gconstpointer op: gconstpointer?)

    Parameters

    op

    pointer to the underlying object

  • Optional initialiser from a constant pointer to the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init!(_ op: UnsafePointer<GWeakRef>?)

    Parameters

    op

    pointer to the underlying object

  • Optional initialiser from the underlying C data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init!(_ op: UnsafeMutablePointer<GWeakRef>?)

    Parameters

    op

    pointer to the underlying object

  • Designated initialiser from the underlying C data type. GWeakRef does not allow reference counting, so despite the name no actual retaining will occur. i.e., ownership is transferred to the WeakRef instance.

    Declaration

    Swift

    @inlinable
    public init(retaining op: UnsafeMutablePointer<GWeakRef>)

    Parameters

    op

    pointer to the underlying object

  • Reference intialiser for a related type that implements WeakRefProtocol GWeakRef does not allow reference counting.

    Declaration

    Swift

    @inlinable
    public init<T>(_ other: T) where T : WeakRefProtocol

    Parameters

    other

    an instance of a related type that implements WeakRefProtocol

  • Unsafe typed initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init<T>(cPointer p: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object

  • Unsafe typed, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init<T>(retainingCPointer cPointer: UnsafeMutablePointer<T>)

    Parameters

    cPointer

    pointer to the underlying object

  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init(raw p: UnsafeRawPointer)

    Parameters

    p

    raw pointer to the underlying object

  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init(retainingRaw raw: UnsafeRawPointer)
  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public required init(raw p: UnsafeMutableRawPointer)

    Parameters

    p

    mutable raw pointer to the underlying object

  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init(retainingRaw raw: UnsafeMutableRawPointer)

    Parameters

    raw

    mutable raw pointer to the underlying object

  • Unsafe untyped initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init(opaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object

  • Unsafe untyped, retaining initialiser. Do not use unless you know the underlying data type the pointer points to conforms to WeakRefProtocol.

    Declaration

    Swift

    @inlinable
    public init(retainingOpaquePointer p: OpaquePointer)

    Parameters

    p

    opaque pointer to the underlying object