Struct std::sync::MappedRwLockReadGuard
source · pub struct MappedRwLockReadGuard<'a, T: ?Sized + 'a> { /* private fields */ }
mapped_lock_guards
#117108)Expand description
RAII structure used to release the shared read access of a lock when dropped, which can point to a subfield of the protected data.
This structure is created by the map
and try_map
methods
on RwLockReadGuard
.
Implementations§
source§impl<'a, T: ?Sized> MappedRwLockReadGuard<'a, T>
impl<'a, T: ?Sized> MappedRwLockReadGuard<'a, T>
sourcepub fn map<U, F>(orig: Self, f: F) -> MappedRwLockReadGuard<'a, U>
🔬This is a nightly-only experimental API. (mapped_lock_guards
#117108)
pub fn map<U, F>(orig: Self, f: F) -> MappedRwLockReadGuard<'a, U>
mapped_lock_guards
#117108)Makes a MappedRwLockReadGuard
for a component of the borrowed data,
e.g. an enum variant.
The RwLock
is already locked for reading, so this cannot fail.
This is an associated function that needs to be used as
MappedRwLockReadGuard::map(...)
. A method would interfere with
methods of the same name on the contents of the MappedRwLockReadGuard
used through Deref
.
§Panics
If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.
sourcepub fn try_map<U, F>(
orig: Self,
f: F,
) -> Result<MappedRwLockReadGuard<'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<MappedRwLockReadGuard<'a, U>, Self>
mapped_lock_guards
#117108)Makes a MappedRwLockReadGuard
for a component of the borrowed data.
The original guard is returned as an Err(...)
if the closure returns
None
.
The RwLock
is already locked for reading, so this cannot fail.
This is an associated function that needs to be used as
MappedRwLockReadGuard::try_map(...)
. A method would interfere with
methods of the same name on the contents of the MappedRwLockReadGuard
used through Deref
.
§Panics
If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.