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.
-
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 theWeakRef
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 theWeakRef
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 underlyingC
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to theWeakRef
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 underlyingC
data type. This creates an instance without performing an unbalanced retain i.e., ownership is transferred to theWeakRef
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 theWeakRef
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 theWeakRef
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 theWeakRef
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