Struct MappedMutexGuard

pub struct MappedMutexGuard<'a, T: ?Sized, U: ?Sized> { /* private fields */ }

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

impl<'a, T: ?Sized, U: ?Sized> MappedMutexGuard<'a, T, U>

fn map<V: ?Sized, F>(this: Self, f: F) -> MappedMutexGuard<'a, T, V>
where
    F: FnOnce(&mut U) -> &mut V,

Returns a locked view over a portion of the locked data.

Example

# futures::executor::block_on(async {
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>

impl<T: ?Sized, U: ?Sized + Debug> Debug for MappedMutexGuard<'_, T, U>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

impl<T: ?Sized, U: ?Sized> Deref for MappedMutexGuard<'_, T, U>

type Target = U;
fn deref(&self) -> &U

impl<T: ?Sized, U: ?Sized> DerefMut for MappedMutexGuard<'_, T, U>

fn deref_mut(&mut self) -> &mut U

impl<T: ?Sized, U: ?Sized> Drop for MappedMutexGuard<'_, T, U>

fn drop(&mut self)

Auto Trait Implementations

impl<'a, T, U> !RefUnwindSafe for MappedMutexGuard<'a, T, U>

impl<'a, T, U> !UnwindSafe for MappedMutexGuard<'a, T, U>

impl<'a, T, U> Freeze for MappedMutexGuard<'a, T, U> where &'a Mutex<T>: Freeze, *mut U: Freeze, PhantomData<&'a mut U>: Freeze, T: ?Sized, U: ?Sized,

impl<'a, T, U> Unpin for MappedMutexGuard<'a, T, U> where &'a Mutex<T>: Unpin, *mut U: Unpin, PhantomData<&'a mut U>: Unpin, T: ?Sized, U: ?Sized,

impl<'a, T, U> UnsafeUnpin for MappedMutexGuard<'a, T, U> where &'a Mutex<T>: UnsafeUnpin, *mut U: UnsafeUnpin, PhantomData<&'a mut U>: UnsafeUnpin, T: ?Sized, U: ?Sized,

Blanket Implementations

impl<P, T> Receiver for MappedMutexGuard<'a, T, U> where P: Deref<Target = T> + ?Sized, T: ?Sized,

type Target = T;

impl<T> Any for MappedMutexGuard<'a, T, U> where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for MappedMutexGuard<'a, T, U> where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for MappedMutexGuard<'a, T, U> where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> From<T> for MappedMutexGuard<'a, T, U>

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for MappedMutexGuard<'a, T, U> where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

impl<T, U> TryFrom<U> for MappedMutexGuard<'a, T, U> where U: Into<T>,

type Error = never;
fn try_from(value: U) -> Result<T, never>

impl<T, U> TryInto<U> for MappedMutexGuard<'a, T, U> where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>