Struct tokio::sync::MappedMutexGuard
source · pub struct MappedMutexGuard<'a, T: ?Sized> { /* private fields */ }
sync
only.Expand description
A handle to a held Mutex
that has had a function applied to it via MutexGuard::map
.
This can be used to hold a subfield of the protected data.
Implementations§
source§impl<'a, T: ?Sized> MappedMutexGuard<'a, T>
impl<'a, T: ?Sized> MappedMutexGuard<'a, T>
sourcepub fn map<U, F>(this: Self, f: F) -> MappedMutexGuard<'a, U>where
F: FnOnce(&mut T) -> &mut U,
pub fn map<U, F>(this: Self, f: F) -> MappedMutexGuard<'a, U>where F: FnOnce(&mut T) -> &mut U,
Makes a new MappedMutexGuard
for a component of the locked data.
This operation cannot fail as the MappedMutexGuard
passed in already locked the mutex.
This is an associated function that needs to be used as MappedMutexGuard::map(...)
. A
method would interfere with methods of the same name on the contents of the locked data.
sourcepub fn try_map<U, F>(this: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>where
F: FnOnce(&mut T) -> Option<&mut U>,
pub fn try_map<U, F>(this: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>where F: FnOnce(&mut T) -> Option<&mut U>,
Attempts to make a new MappedMutexGuard
for a component of the locked data. The
original guard is returned if the closure returns None
.
This operation cannot fail as the MappedMutexGuard
passed in already locked the mutex.
This is an associated function that needs to be used as MappedMutexGuard::try_map(...)
. A
method would interfere with methods of the same name on the contents of the locked data.