1.0.0[−][src]Trait dipstick::__Deref
Used for immutable dereferencing operations, like *v
.
In addition to being used for explicit dereferencing operations with the
(unary) *
operator in immutable contexts, Deref
is also used implicitly
by the compiler in many circumstances. This mechanism is called
'Deref
coercion'. In mutable contexts, DerefMut
is used.
Implementing Deref
for smart pointers makes accessing the data behind them
convenient, which is why they implement Deref
. On the other hand, the
rules regarding Deref
and DerefMut
were designed specifically to
accommodate smart pointers. Because of this, Deref
should only be
implemented for smart pointers to avoid confusion.
For similar reasons, this trait should never fail. Failure during
dereferencing can be extremely confusing when Deref
is invoked implicitly.
More on Deref
coercion
If T
implements Deref<Target = U>
, and x
is a value of type T
, then:
- In immutable contexts,
*x
on non-pointer types is equivalent to*Deref::deref(&x)
. - Values of type
&T
are coerced to values of type&U
T
implicitly implements all the (immutable) methods of the typeU
.
For more details, visit the chapter in The Rust Programming Language as well as the reference sections on the dereference operator, method resolution and type coercions.
Examples
A struct with a single field which is accessible by dereferencing the struct.
use std::ops::Deref; struct DerefExample<T> { value: T } impl<T> Deref for DerefExample<T> { type Target = T; fn deref(&self) -> &Self::Target { &self.value } } let x = DerefExample { value: 'a' }; assert_eq!('a', *x);
Associated Types
Loading content...Required methods
Loading content...Implementations on Foreign Types
impl<'_, T> Deref for RwLockReadGuard<'_, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'a> Deref for IoSlice<'a>
[src]
impl<T> Deref for AssertUnwindSafe<T>
[src]
impl Deref for OsString
[src]
impl Deref for PathBuf
[src]
impl Deref for CString
[src]
impl<'_, T> Deref for MutexGuard<'_, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'a> Deref for IoSliceMut<'a>
[src]
impl<'_, T> Deref for RwLockWriteGuard<'_, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'_, T> Deref for &'_ mut T where
T: ?Sized,
[src]
T: ?Sized,
impl<'_, T> Deref for RefMut<'_, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'_, T> Deref for Ref<'_, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<P> Deref for Pin<P> where
P: Deref,
[src]
P: Deref,
impl<'_, T> Deref for &'_ T where
T: ?Sized,
[src]
T: ?Sized,
impl<'a, 'f> Deref for VaList<'a, 'f> where
'f: 'a,
[src]
'f: 'a,
type Target = VaListImpl<'f>
fn deref(&self) -> &VaListImpl<'f>
[src]
impl<T> Deref for ManuallyDrop<T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'_, B> Deref for Cow<'_, B> where
B: ToOwned + ?Sized,
[src]
B: ToOwned + ?Sized,
impl<'_, T> Deref for PeekMut<'_, T> where
T: Ord,
[src]
T: Ord,
impl<T> Deref for Vec<T>
[src]
impl<T> Deref for Box<T> where
T: ?Sized,
[src]
T: ?Sized,
impl<T> Deref for Rc<T> where
T: ?Sized,
[src]
T: ?Sized,
impl<T> Deref for Arc<T> where
T: ?Sized,
[src]
T: ?Sized,
impl Deref for String
[src]
impl<'a, R, G, T> Deref for ReentrantMutexGuard<'a, R, G, T> where
G: 'a + GetThreadId,
R: 'a + RawMutex,
T: 'a + ?Sized,
G: 'a + GetThreadId,
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Deref for RwLockReadGuard<'a, R, T> where
R: 'a + RawRwLock,
T: 'a + ?Sized,
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedRwLockWriteGuard<'a, R, T> where
R: 'a + RawRwLock,
T: 'a + ?Sized,
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Deref for RwLockUpgradableReadGuard<'a, R, T> where
R: 'a + RawRwLockUpgrade,
T: 'a + ?Sized,
R: 'a + RawRwLockUpgrade,
T: 'a + ?Sized,
impl<'a, R, T> Deref for RwLockWriteGuard<'a, R, T> where
R: 'a + RawRwLock,
T: 'a + ?Sized,
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedRwLockReadGuard<'a, R, T> where
R: 'a + RawRwLock,
T: 'a + ?Sized,
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, G, T> Deref for MappedReentrantMutexGuard<'a, R, G, T> where
G: 'a + GetThreadId,
R: 'a + RawMutex,
T: 'a + ?Sized,
G: 'a + GetThreadId,
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<T, F, S> Deref for ScopeGuard<T, F, S> where
F: FnOnce(T),
S: Strategy,
[src]
F: FnOnce(T),
S: Strategy,
impl<A> Deref for SmallVec<A> where
A: Array,
A: Array,
impl<'b, T> Deref for AtomicRef<'b, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'b, T> Deref for AtomicRefMut<'b, T> where
T: ?Sized,
[src]
T: ?Sized,
impl<'a, T> Deref for ShardedLockReadGuard<'a, T> where
T: ?Sized,
T: ?Sized,
impl<T> Deref for CachePadded<T>
impl<'a, T> Deref for ShardedLockWriteGuard<'a, T> where
T: ?Sized,
Loading content...
T: ?Sized,
Implementors
impl Deref for Counter
[src]
type Target = InputMetric
fn deref(&self) -> &Self::Target
[src]
impl Deref for Gauge
[src]
type Target = InputMetric
fn deref(&self) -> &Self::Target
[src]
impl Deref for Level
[src]
type Target = InputMetric
fn deref(&self) -> &Self::Target
[src]
impl Deref for Marker
[src]
type Target = InputMetric
fn deref(&self) -> &Self::Target
[src]
impl Deref for MetricName
[src]
impl Deref for NameParts
[src]
Enable use of VecDeque methods such as len(), push_*, insert()...