Struct tokio::sync::RwLockReadGuard
source · [−]pub struct RwLockReadGuard<'a, T: ?Sized> { /* private fields */ }
Expand description
Implementations
sourceimpl<'a, T: ?Sized> RwLockReadGuard<'a, T>
impl<'a, T: ?Sized> RwLockReadGuard<'a, T>
sourcepub fn map<F, U: ?Sized>(this: Self, f: F) -> RwLockReadGuard<'a, U> where
F: FnOnce(&T) -> &U,
pub fn map<F, U: ?Sized>(this: Self, f: F) -> RwLockReadGuard<'a, U> where
F: FnOnce(&T) -> &U,
Makes a new RwLockReadGuard
for a component of the locked data.
This operation cannot fail as the RwLockReadGuard
passed in already
locked the data.
This is an associated function that needs to be
used as RwLockReadGuard::map(...)
. A method would interfere with
methods of the same name on the contents of the locked data.
This is an asynchronous version of RwLockReadGuard::map
from the
parking_lot
crate.
Examples
use tokio::sync::{RwLock, RwLockReadGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = RwLock::new(Foo(1));
let guard = lock.read().await;
let guard = RwLockReadGuard::map(guard, |f| &f.0);
assert_eq!(1, *guard);
sourcepub fn try_map<F, U: ?Sized>(
this: Self,
f: F
) -> Result<RwLockReadGuard<'a, U>, Self> where
F: FnOnce(&T) -> Option<&U>,
pub fn try_map<F, U: ?Sized>(
this: Self,
f: F
) -> Result<RwLockReadGuard<'a, U>, Self> where
F: FnOnce(&T) -> Option<&U>,
Attempts to make a new RwLockReadGuard
for a component of the
locked data. The original guard is returned if the closure returns
None
.
This operation cannot fail as the RwLockReadGuard
passed in already
locked the data.
This is an associated function that needs to be used as
RwLockReadGuard::try_map(..)
. A method would interfere with methods of the
same name on the contents of the locked data.
This is an asynchronous version of RwLockReadGuard::try_map
from the
parking_lot
crate.
Examples
use tokio::sync::{RwLock, RwLockReadGuard};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let lock = RwLock::new(Foo(1));
let guard = lock.read().await;
let guard = RwLockReadGuard::try_map(guard, |f| Some(&f.0)).expect("should not fail");
assert_eq!(1, *guard);
Trait Implementations
sourceimpl<'a, T: ?Sized> Debug for RwLockReadGuard<'a, T> where
T: Debug,
impl<'a, T: ?Sized> Debug for RwLockReadGuard<'a, T> where
T: Debug,
sourceimpl<T: ?Sized> Deref for RwLockReadGuard<'_, T>
impl<T: ?Sized> Deref for RwLockReadGuard<'_, T>
sourceimpl<'a, T: ?Sized> Display for RwLockReadGuard<'a, T> where
T: Display,
impl<'a, T: ?Sized> Display for RwLockReadGuard<'a, T> where
T: Display,
sourceimpl<'a, T: ?Sized> Drop for RwLockReadGuard<'a, T>
impl<'a, T: ?Sized> Drop for RwLockReadGuard<'a, T>
impl<T> Send for RwLockReadGuard<'_, T> where
T: ?Sized + Sync,
impl<T> Sync for RwLockReadGuard<'_, T> where
T: ?Sized + Send + Sync,
Auto Trait Implementations
impl<'a, T> !RefUnwindSafe for RwLockReadGuard<'a, T>
impl<'a, T: ?Sized> Unpin for RwLockReadGuard<'a, T>
impl<'a, T> !UnwindSafe for RwLockReadGuard<'a, T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more