Struct std::sync::MappedMutexGuard
source · pub struct MappedMutexGuard<'a, T: ?Sized + 'a> { /* private fields */ }
mapped_lock_guards
#117108)Expand description
An RAII mutex guard returned by MutexGuard::map
, which can point to a
subfield of the protected data. When this structure is dropped (falls out
of scope), the lock will be unlocked.
The main difference between MappedMutexGuard
and MutexGuard
is that the
former cannot be used with Condvar
, since that
could introduce soundness issues if the locked object is modified by another
thread while the Mutex
is unlocked.
The data protected by the mutex can be accessed through this guard via its
Deref
and DerefMut
implementations.
This structure is created by the map
and try_map
methods on
MutexGuard
.
Implementations§
source§impl<'a, T: ?Sized> MappedMutexGuard<'a, T>
impl<'a, T: ?Sized> MappedMutexGuard<'a, T>
sourcepub fn map<U, F>(orig: Self, f: F) -> MappedMutexGuard<'a, U>
🔬This is a nightly-only experimental API. (mapped_lock_guards
#117108)
pub fn map<U, F>(orig: Self, f: F) -> MappedMutexGuard<'a, U>
mapped_lock_guards
#117108)Makes a MappedMutexGuard
for a component of the borrowed data, e.g.
an enum variant.
The Mutex
is already locked, so this cannot fail.
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 MutexGuard
used through Deref
.
sourcepub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>
🔬This is a nightly-only experimental API. (mapped_lock_guards
#117108)
pub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>
mapped_lock_guards
#117108)Makes a MappedMutexGuard
for a component of the borrowed data. The
original guard is returned as an Err(...)
if the closure returns
None
.
The Mutex
is already locked, so this cannot fail.
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 MutexGuard
used through Deref
.