Struct futures_util::lock::MappedMutexGuard
source · pub struct MappedMutexGuard<'a, T: ?Sized, U: ?Sized> { /* private fields */ }
Expand description
An RAII guard returned by the MutexGuard::map
and MappedMutexGuard::map
methods.
When this structure is dropped (falls out of scope), the lock will be unlocked.
Implementations§
source§impl<'a, T: ?Sized, U: ?Sized> MappedMutexGuard<'a, T, U>
impl<'a, T: ?Sized, U: ?Sized> MappedMutexGuard<'a, T, U>
sourcepub fn map<V: ?Sized, F>(this: Self, f: F) -> MappedMutexGuard<'a, T, V>
pub fn map<V: ?Sized, F>(this: Self, f: F) -> MappedMutexGuard<'a, T, V>
Returns a locked view over a portion of the locked data.
§Example
use futures::lock::{MappedMutexGuard, Mutex, MutexGuard};
let data = Mutex::new(Some("value".to_string()));
{
let locked_str = MutexGuard::map(data.lock().await, |opt| opt.as_mut().unwrap());
let locked_char = MappedMutexGuard::map(locked_str, |s| s.get_mut(0..1).unwrap());
assert_eq!(&*locked_char, "v");
}
Trait Implementations§
impl<T: ?Sized + Send, U: ?Sized + Send> Send for MappedMutexGuard<'_, T, U>
impl<T: ?Sized + Sync, U: ?Sized + Sync> Sync for MappedMutexGuard<'_, T, U>
Auto Trait Implementations§
impl<'a, T, U> Freeze for MappedMutexGuard<'a, T, U>
impl<'a, T, U> !RefUnwindSafe for MappedMutexGuard<'a, T, U>
impl<'a, T, U> Unpin for MappedMutexGuard<'a, T, U>
impl<'a, T, U> !UnwindSafe for MappedMutexGuard<'a, T, U>
Blanket Implementations§
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
Mutably borrows from an owned value. Read more