Struct rustc_data_structures::owning_ref::OwningHandle
source · pub struct OwningHandle<O, H>where
O: StableAddress,
H: Deref,{
handle: H,
_owner: O,
}
Expand description
OwningHandle
is a complement to OwningRef
. Where OwningRef
allows
consumers to pass around an owned object and a dependent reference,
OwningHandle
contains an owned object and a dependent object.
OwningHandle
can encapsulate a RefMut
along with its associated
RefCell
, or an RwLockReadGuard
along with its associated RwLock
.
However, the API is completely generic and there are no restrictions on
what types of owning and dependent objects may be used.
OwningHandle
is created by passing an owner object (which dereferences
to a stable address) along with a callback which receives a pointer to
that stable location. The callback may then dereference the pointer and
mint a dependent object, with the guarantee that the returned object will
not outlive the referent of the pointer.
Since the callback needs to dereference a raw pointer, it requires unsafe
code. To avoid forcing this unsafety on most callers, the ToHandle
trait is
implemented for common data structures. Types that implement ToHandle
can
be wrapped into an OwningHandle
without passing a callback.
Fields§
§handle: H
§_owner: O
Implementations§
source§impl<O, H> OwningHandle<O, H>where
O: StableAddress<Target: ToHandle<Handle = H>>,
H: Deref,
impl<O, H> OwningHandle<O, H>where
O: StableAddress<Target: ToHandle<Handle = H>>,
H: Deref,
source§impl<O, H> OwningHandle<O, H>where
O: StableAddress<Target: ToHandleMut<HandleMut = H>>,
H: DerefMut,
impl<O, H> OwningHandle<O, H>where
O: StableAddress<Target: ToHandleMut<HandleMut = H>>,
H: DerefMut,
source§impl<O, H> OwningHandle<O, H>where
O: StableAddress,
H: Deref,
impl<O, H> OwningHandle<O, H>where
O: StableAddress,
H: Deref,
sourcepub fn new_with_fn<F>(o: O, f: F) -> Selfwhere
F: FnOnce(*const O::Target) -> H,
pub fn new_with_fn<F>(o: O, f: F) -> Selfwhere
F: FnOnce(*const O::Target) -> H,
Creates a new OwningHandle. The provided callback will be invoked with
a pointer to the object owned by o
, and the returned value is stored
as the object to which this OwningHandle
will forward Deref
and
DerefMut
.
sourcepub fn try_new<F, E>(o: O, f: F) -> Result<Self, E>where
F: FnOnce(*const O::Target) -> Result<H, E>,
pub fn try_new<F, E>(o: O, f: F) -> Result<Self, E>where
F: FnOnce(*const O::Target) -> Result<H, E>,
Creates a new OwningHandle. The provided callback will be invoked with
a pointer to the object owned by o
, and the returned value is stored
as the object to which this OwningHandle
will forward Deref
and
DerefMut
.
Trait Implementations§
source§impl<O, H> Deref for OwningHandle<O, H>where
O: StableAddress,
H: Deref,
impl<O, H> Deref for OwningHandle<O, H>where
O: StableAddress,
H: Deref,
source§impl<O, H> DerefMut for OwningHandle<O, H>where
O: StableAddress,
H: DerefMut,
impl<O, H> DerefMut for OwningHandle<O, H>where
O: StableAddress,
H: DerefMut,
impl<O, H> StableDeref for OwningHandle<O, H>where
O: StableAddress,
H: StableAddress,
Auto Trait Implementations§
impl<O, H> RefUnwindSafe for OwningHandle<O, H>where
H: RefUnwindSafe,
O: RefUnwindSafe,
impl<O, H> Send for OwningHandle<O, H>where
H: Send,
O: Send,
impl<O, H> Sync for OwningHandle<O, H>where
H: Sync,
O: Sync,
impl<O, H> Unpin for OwningHandle<O, H>where
H: Unpin,
O: Unpin,
impl<O, H> UnwindSafe for OwningHandle<O, H>where
H: UnwindSafe,
O: UnwindSafe,
Blanket Implementations§
impl<'a, T> Captures<'a> for Twhere
T: ?Sized,
impl<T> Erased for T
Layout§
Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.