Struct holochain::prelude::kitsune_p2p::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::tokio::sync::OwnedRwLockMappedWriteGuard
source · pub struct OwnedRwLockMappedWriteGuard<T, U = T>where
T: ?Sized,
U: ?Sized,{ /* private fields */ }
Expand description
Owned RAII structure used to release the exclusive write access of a lock when dropped.
This structure is created by mapping an OwnedRwLockWriteGuard
. It is a
separate type from OwnedRwLockWriteGuard
to disallow downgrading a mapped
guard, since doing so can cause undefined behavior.
Implementations§
source§impl<T, U> OwnedRwLockMappedWriteGuard<T, U>where
T: ?Sized,
U: ?Sized,
impl<T, U> OwnedRwLockMappedWriteGuard<T, U>where T: ?Sized, U: ?Sized,
sourcepub fn map<F, V>(
this: OwnedRwLockMappedWriteGuard<T, U>,
f: F
) -> OwnedRwLockMappedWriteGuard<T, V>where
F: FnOnce(&mut U) -> &mut V,
V: ?Sized,
pub fn map<F, V>( this: OwnedRwLockMappedWriteGuard<T, U>, f: F ) -> OwnedRwLockMappedWriteGuard<T, V>where F: FnOnce(&mut U) -> &mut V, V: ?Sized,
Makes a new OwnedRwLockMappedWriteGuard
for a component of the locked
data.
This operation cannot fail as the OwnedRwLockMappedWriteGuard
passed
in already locked the data.
This is an associated function that needs to be used as
OwnedRwLockWriteGuard::map(..)
. A method would interfere with methods
of the same name on the contents of the locked data.
Examples
use std::sync::Arc;
use tokio::sync::{RwLock, OwnedRwLockWriteGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = Arc::new(RwLock::new(Foo(1)));
{
let lock = Arc::clone(&lock);
let mut mapped = OwnedRwLockWriteGuard::map(lock.write_owned().await, |f| &mut f.0);
*mapped = 2;
}
assert_eq!(Foo(2), *lock.read().await);
sourcepub fn try_map<F, V>(
this: OwnedRwLockMappedWriteGuard<T, U>,
f: F
) -> Result<OwnedRwLockMappedWriteGuard<T, V>, OwnedRwLockMappedWriteGuard<T, U>>where
F: FnOnce(&mut U) -> Option<&mut V>,
V: ?Sized,
pub fn try_map<F, V>( this: OwnedRwLockMappedWriteGuard<T, U>, f: F ) -> Result<OwnedRwLockMappedWriteGuard<T, V>, OwnedRwLockMappedWriteGuard<T, U>>where F: FnOnce(&mut U) -> Option<&mut V>, V: ?Sized,
Attempts to make a new OwnedRwLockMappedWriteGuard
for a component
of the locked data. The original guard is returned if the closure
returns None
.
This operation cannot fail as the OwnedRwLockMappedWriteGuard
passed
in already locked the data.
This is an associated function that needs to be
used as OwnedRwLockMappedWriteGuard::try_map(...)
. A method would interfere with
methods of the same name on the contents of the locked data.
Examples
use std::sync::Arc;
use tokio::sync::{RwLock, OwnedRwLockWriteGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = Arc::new(RwLock::new(Foo(1)));
{
let guard = Arc::clone(&lock).write_owned().await;
let mut guard = OwnedRwLockWriteGuard::try_map(guard, |f| Some(&mut f.0)).expect("should not fail");
*guard = 2;
}
assert_eq!(Foo(2), *lock.read().await);
Trait Implementations§
source§impl<T, U> Display for OwnedRwLockMappedWriteGuard<T, U>where
U: Display + ?Sized,
T: ?Sized,
impl<T, U> Display for OwnedRwLockMappedWriteGuard<T, U>where U: Display + ?Sized, T: ?Sized,
impl<T, U> Send for OwnedRwLockMappedWriteGuard<T, U>where T: Send + Sync + ?Sized, U: Send + Sync + ?Sized,
impl<T, U> Sync for OwnedRwLockMappedWriteGuard<T, U>where T: Send + Sync + ?Sized, U: Send + Sync + ?Sized,
Auto Trait Implementations§
impl<T, U = T> !RefUnwindSafe for OwnedRwLockMappedWriteGuard<T, U>
impl<T: ?Sized, U: ?Sized> Unpin for OwnedRwLockMappedWriteGuard<T, U>where T: Unpin,
impl<T, U = T> !UnwindSafe for OwnedRwLockMappedWriteGuard<T, U>
Blanket Implementations§
§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
§type ArchivedMetadata = ()
type ArchivedMetadata = ()
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_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
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source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
§impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere W: DeserializeWith<F, T, D>, D: Fallible + ?Sized, F: ?Sized,
§fn deserialize(
&self,
deserializer: &mut D
) -> Result<With<T, W>, <D as Fallible>::Error>
fn deserialize( &self, deserializer: &mut D ) -> Result<With<T, W>, <D as Fallible>::Error>
§impl<T> FutureExt for T
impl<T> FutureExt for T
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§impl<T> Pointable for T
impl<T> Pointable for T
§impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SPwhere SS: SubsetOf<SP>,
§fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
self
from the equivalent element of its
superset. Read more§fn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
self
is actually part of its subset T
(and can be converted to it).§fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
self.to_subset
but without any property checks. Always succeeds.§fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
self
to the equivalent element of its superset.