Struct holochain::prelude::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::tokio::sync::OwnedRwLockReadGuard
source · pub struct OwnedRwLockReadGuard<T, U = T>where
T: ?Sized,
U: ?Sized,{ /* private fields */ }
Expand description
Owned RAII structure used to release the shared read access of a lock when dropped.
This structure is created by the read_owned
method on
RwLock
.
Implementations§
source§impl<T, U> OwnedRwLockReadGuard<T, U>where
T: ?Sized,
U: ?Sized,
impl<T, U> OwnedRwLockReadGuard<T, U>where T: ?Sized, U: ?Sized,
sourcepub fn map<F, V>(
this: OwnedRwLockReadGuard<T, U>,
f: F
) -> OwnedRwLockReadGuard<T, V>where
F: FnOnce(&U) -> &V,
V: ?Sized,
pub fn map<F, V>( this: OwnedRwLockReadGuard<T, U>, f: F ) -> OwnedRwLockReadGuard<T, V>where F: FnOnce(&U) -> &V, V: ?Sized,
Makes a new OwnedRwLockReadGuard
for a component of the locked data.
This operation cannot fail as the OwnedRwLockReadGuard
passed in
already locked the data.
This is an associated function that needs to be
used as OwnedRwLockReadGuard::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, OwnedRwLockReadGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = Arc::new(RwLock::new(Foo(1)));
let guard = lock.read_owned().await;
let guard = OwnedRwLockReadGuard::map(guard, |f| &f.0);
assert_eq!(1, *guard);
sourcepub fn try_map<F, V>(
this: OwnedRwLockReadGuard<T, U>,
f: F
) -> Result<OwnedRwLockReadGuard<T, V>, OwnedRwLockReadGuard<T, U>>where
F: FnOnce(&U) -> Option<&V>,
V: ?Sized,
pub fn try_map<F, V>( this: OwnedRwLockReadGuard<T, U>, f: F ) -> Result<OwnedRwLockReadGuard<T, V>, OwnedRwLockReadGuard<T, U>>where F: FnOnce(&U) -> Option<&V>, V: ?Sized,
Attempts to make a new OwnedRwLockReadGuard
for a component of the
locked data. The original guard is returned if the closure returns
None
.
This operation cannot fail as the OwnedRwLockReadGuard
passed in
already locked the data.
This is an associated function that needs to be used as
OwnedRwLockReadGuard::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, OwnedRwLockReadGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = Arc::new(RwLock::new(Foo(1)));
let guard = lock.read_owned().await;
let guard = OwnedRwLockReadGuard::try_map(guard, |f| Some(&f.0)).expect("should not fail");
assert_eq!(1, *guard);
Trait Implementations§
impl<T, U> Send for OwnedRwLockReadGuard<T, U>where T: Send + Sync + ?Sized, U: Sync + ?Sized,
impl<T, U> Sync for OwnedRwLockReadGuard<T, U>where T: Send + Sync + ?Sized, U: Send + Sync + ?Sized,
Auto Trait Implementations§
impl<T, U = T> !RefUnwindSafe for OwnedRwLockReadGuard<T, U>
impl<T: ?Sized, U: ?Sized> Unpin for OwnedRwLockReadGuard<T, U>where T: Unpin,
impl<T, U = T> !UnwindSafe for OwnedRwLockReadGuard<T, U>
Blanket Implementations§
§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
§type ArchivedMetadata = ()
type ArchivedMetadata = ()
§fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata ) -> <T as Pointee>::Metadata
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
§fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
§fn with_current_context(self) -> WithContext<Self> ⓘ
fn with_current_context(self) -> WithContext<Self> ⓘ
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
§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.