Trait std::clone::Clone 1.0.0[−][src]
#[lang = "clone"]pub trait Clone {#[must_use = "cloning is often expensive and is not expected to have side effects"]fn clone(&self) -> Self; fn clone_from(&mut self, source: &Self) { ... } }
A common trait for the ability to explicitly duplicate an object.
Differs from Copy in that Copy is implicit and extremely inexpensive, while
Clone is always explicit and may or may not be expensive. In order to enforce
these characteristics, Rust does not allow you to reimplement Copy, but you
may reimplement Clone and run arbitrary code.
Since Clone is more general than Copy, you can automatically make anything
Copy be Clone as well.
Derivable
This trait can be used with #[derive] if all fields are Clone. The derived
implementation of clone calls clone on each field.
How can I implement Clone?
Types that are Copy should have a trivial implementation of Clone. More formally:
if T: Copy, x: T, and y: &T, then let x = y.clone(); is equivalent to let x = *y;.
Manual implementations should be careful to uphold this invariant; however, unsafe code
must not rely on it to ensure memory safety.
An example is an array holding more than 32 elements of a type that is Clone; the standard
library only implements Clone up until arrays of size 32. In this case, the implementation of
Clone cannot be derived, but can be implemented as:
#[derive(Copy)] struct Stats { frequencies: [i32; 100], } impl Clone for Stats { fn clone(&self) -> Stats { *self } }Run
Additional implementors
In addition to the implementors listed below,
the following types also implement Clone:
- Function item types (i.e. the distinct types defined for each function)
- Function pointer types (e.g.
fn() -> i32) - Array types, for all sizes, if the item type also implements
Clone(e.g.[i32; 123456]) - Tuple types, if each component also implements
Clone(e.g.(),(i32, bool)) - Closure types, if they capture no value from the environment
or if all such captured values implement
Clonethemselves. Note that variables captured by shared reference always implementClone(even if the referent doesn't), while variables captured by mutable reference never implementClone.
Required Methods
#[must_use = "cloning is often expensive and is not expected to have side effects"]
fn clone(&self) -> Self
Provided Methods
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source.
a.clone_from(&b) is equivalent to a = b.clone() in functionality,
but can be overridden to reuse the resources of a to avoid unnecessary
allocations.
Implementations on Foreign Types
impl Clone for TryFromSliceError[src]
impl Clone for TryFromSliceErrorfn clone(&self) -> TryFromSliceError[src]
fn clone(&self) -> TryFromSliceErrorfn clone_from(&mut self, source: &Self)1.0.0[src]
fn clone_from(&mut self, source: &Self)Implementors
impl<T> Clone for std::result::IntoIter<T> where
T: Clone,impl Clone for i8x4impl Clone for NoneErrorimpl<T> Clone for PhantomData<T> where
T: ?Sized,impl Clone for u32x4impl<I> Clone for Fuse<I> where
I: Clone,impl Clone for EscapeDefaultimpl Clone for m8x8impl Clone for u16x32impl Clone for i16x32impl<'a> Clone for CharSearcher<'a>impl<'a> Clone for LinesAny<'a>impl Clone for UnicodeVersionimpl Clone for u16impl<'a> Clone for Lines<'a>impl Clone for NonZeroU8impl<'a, P> Clone for RMatchIndices<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<I> Clone for DecodeUtf16<I> where
I: Clone + Iterator<Item = u16>,impl Clone for m1x64impl Clone for Pinnedimpl<'a, P> Clone for SplitTerminator<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<Idx> Clone for RangeFrom<Idx> where
Idx: Clone,impl<T> Clone for Option<T> where
T: Clone,impl Clone for u8impl Clone for u32impl Clone for u32x16impl Clone for charimpl<I, P> Clone for SkipWhile<I, P> where
I: Clone,
P: Clone,impl Clone for i8x16impl Clone for i8x64impl Clone for i16x8impl<T> Clone for Wrapping<T> where
T: Clone,impl Clone for TypeIdimpl Clone for Utf8Errorimpl<'a, P> Clone for MatchIndices<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<'a, P> Clone for std::str::RSplit<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<A, B> Clone for Chain<A, B> where
A: Clone,
B: Clone,impl Clone for CannotReallocInPlaceimpl Clone for i16impl Clone for m8x2impl Clone for EscapeDebugimpl<T> Clone for Empty<T>impl Clone for f64x8impl Clone for m32x4impl<I> Clone for Skip<I> where
I: Clone,impl<T> Clone for RefCell<T> where
T: Clone,impl Clone for TryFromIntErrorimpl Clone for !impl Clone for m64x4impl Clone for Errorimpl Clone for i32impl Clone for NonZeroU128impl<'a, A> Clone for std::option::Iter<'a, A>impl Clone for u64x4impl<I, P> Clone for TakeWhile<I, P> where
I: Clone,
P: Clone,impl Clone for u16x2impl Clone for i64x8impl Clone for u32x2impl Clone for m64x2impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>impl<T> Clone for *const T where
T: ?Sized,impl Clone for std::cmp::Orderingimpl<'a, P> Clone for RSplitN<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for std::sync::atomic::Orderingimpl Clone for LayoutErrimpl Clone for f32x2impl<'a> Clone for Arguments<'a>impl<I, U> Clone for Flatten<I> where
I: Iterator + Clone,
U: Iterator + Clone,
<I as Iterator>::Item: IntoIterator,
<<I as Iterator>::Item as IntoIterator>::IntoIter == U,
<<I as Iterator>::Item as IntoIterator>::Item == <U as Iterator>::Item,impl Clone for Wakerimpl Clone for isizeimpl<A> Clone for std::option::IntoIter<A> where
A: Clone,impl<T> Clone for *mut T where
T: ?Sized,impl<Idx> Clone for std::ops::Range<Idx> where
Idx: Clone,impl Clone for f32x4impl Clone for boolimpl<Idx> Clone for RangeInclusive<Idx> where
Idx: Clone,impl<I> Clone for Take<I> where
I: Clone,impl<H> Clone for BuildHasherDefault<H>impl Clone for f32impl Clone for Durationimpl<T> Clone for Cell<T> where
T: Copy,impl<T> Clone for ManuallyDrop<T> where
T: Clone,impl Clone for i32x8impl<F> Clone for RepeatWith<F> where
F: Clone,impl<'a, P> Clone for RMatches<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<T> Clone for Reverse<T> where
T: Clone,impl<'a, P> Clone for SplitN<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for FpCategoryimpl Clone for NonZeroUsizeimpl Clone for m32x8impl<A> Clone for Repeat<A> where
A: Clone,impl<'a> Clone for Chars<'a>impl<'a, F> Clone for CharPredicateSearcher<'a, F> where
F: Clone + FnMut(char) -> bool,impl Clone for f64x2impl<A, B> Clone for Zip<A, B> where
A: Clone,
B: Clone,impl<'a> Clone for CharIndices<'a>impl Clone for NonZeroU16impl<'a, P> Clone for Matches<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<I, P> Clone for Filter<I, P> where
I: Clone,
P: Clone,impl Clone for i8x2impl Clone for i16x16impl Clone for f64impl Clone for f32x16impl Clone for u64impl Clone for m16x16impl Clone for m1x32impl Clone for EscapeUnicodeimpl Clone for u8x32impl<T> Clone for Rev<T> where
T: Clone,impl<I> Clone for Enumerate<I> where
I: Clone,impl Clone for u8x16impl Clone for u8x8impl Clone for CollectionAllocErrimpl<I> Clone for Peekable<I> where
I: Clone + Iterator,
<I as Iterator>::Item: Clone,impl<'a, T> Clone for ExactChunks<'a, T>impl Clone for m16x2impl<'a, 'b> Clone for StrSearcher<'a, 'b>impl Clone for ParseIntErrorimpl<I, St, F> Clone for Scan<I, St, F> where
F: Clone,
I: Clone,
St: Clone,impl<'a> Clone for EncodeUtf16<'a>impl<Y, R> Clone for GeneratorState<Y, R> where
R: Clone,
Y: Clone,impl Clone for u16x4impl Clone for NonZeroU32impl Clone for AllocErrimpl<'a, T> Clone for Windows<'a, T>impl<I, U, F> Clone for FlatMap<I, U, F> where
F: Clone,
I: Clone,
U: Clone + IntoIterator,
<U as IntoIterator>::IntoIter: Clone,impl Clone for i64x4impl Clone for u16x8impl<I, F> Clone for FilterMap<I, F> where
F: Clone,
I: Clone,impl Clone for TraitObjectimpl<'a, P> Clone for std::str::Split<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for m8x16impl Clone for i32x4impl<T, E> Clone for Result<T, E> where
E: Clone,
T: Clone,impl Clone for m32x2impl Clone for i128impl Clone for i8x32impl Clone for usizeimpl Clone for i32x16impl Clone for CharTryFromErrorimpl Clone for ToLowercaseimpl<Idx> Clone for RangeTo<Idx> where
Idx: Clone,impl Clone for u64x8impl Clone for m1x8impl Clone for ParseBoolErrorimpl Clone for u64x2impl Clone for i16x2impl<T> Clone for Once<T> where
T: Clone,impl<I> Clone for Cloned<I> where
I: Clone,impl<'a, P> Clone for RSplitTerminator<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for i64x2impl<I> Clone for DecodeUtf8<I> where
I: Clone + Iterator<Item = u8>,impl<'a, T> Clone for Chunks<'a, T>impl<I> Clone for Cycle<I> where
I: Clone,impl Clone for i8impl Clone for i16x4impl Clone for f32x8impl Clone for i8x8impl<'a, T> Clone for &'a T where
T: ?Sized,impl<T> Clone for NonNull<T> where
T: ?Sized,impl<Idx> Clone for RangeToInclusive<Idx> where
Idx: Clone,impl Clone for m1x16impl<T> Clone for Bound<T> where
T: Clone,impl Clone for i32x2impl<'a, T, P> Clone for std::slice::Split<'a, T, P> where
P: Clone + FnMut(&T) -> bool,impl<I> Clone for StepBy<I> where
I: Clone,impl Clone for m8x4impl<'a, T, P> Clone for std::slice::RSplit<'a, T, P> where
P: Clone + FnMut(&T) -> bool,
T: 'a + Clone,impl Clone for u8x4impl Clone for u16x16impl<I, F> Clone for Map<I, F> where
F: Clone,
I: Clone,impl Clone for u8x2impl Clone for m8x32impl<'a> Clone for Bytes<'a>impl Clone for ParseCharErrorimpl<T> Clone for Poll<T> where
T: Clone,impl Clone for LocalWakerimpl Clone for f64x4impl Clone for SipHasherimpl Clone for ParseFloatErrorimpl Clone for u32x8impl<I, F> Clone for Inspect<I, F> where
F: Clone,
I: Clone,impl Clone for SearchStepimpl Clone for ToUppercaseimpl Clone for i64impl<T> Clone for Discriminant<T>impl Clone for Layoutimpl Clone for DecodeUtf16Errorimpl Clone for m16x8impl<'a, T> Clone for std::result::Iter<'a, T>impl<'a, T> Clone for std::slice::Iter<'a, T>impl Clone for m16x4impl Clone for u8x64impl<'a> Clone for SplitWhitespace<'a>impl Clone for RangeFullimpl Clone for NonZeroU64impl Clone for u128impl<T> Clone for std::rc::Weak<T> where
T: ?Sized,impl<'a, T> Clone for std::collections::binary_heap::Iter<'a, T>impl<'a, T> Clone for std::collections::btree_set::Range<'a, T>impl<'a, T> Clone for std::collections::btree_set::Union<'a, T>impl<T> Clone for std::collections::linked_list::IntoIter<T> where
T: Clone,impl<'a, K, V> Clone for std::collections::btree_map::Iter<'a, K, V>impl<K, V> Clone for BTreeMap<K, V> where
K: Clone,
V: Clone,impl<T> Clone for Box<T> where
T: Clone,impl<'a, T> Clone for std::collections::btree_set::Iter<'a, T>impl<T> Clone for std::collections::binary_heap::IntoIter<T> where
T: Clone,impl<'a, K, V> Clone for std::collections::btree_map::Values<'a, K, V>impl Clone for Stringimpl<T> Clone for Arc<T> where
T: ?Sized,impl<T> Clone for Vec<T> where
T: Clone,impl Clone for ParseErrorimpl<'a, T> Clone for std::collections::vec_deque::Iter<'a, T>impl<T> Clone for std::sync::Weak<T> where
T: ?Sized,impl<T> Clone for BTreeSet<T> where
T: Clone,impl<T> Clone for VecDeque<T> where
T: Clone,impl<'a, K, V> Clone for std::collections::btree_map::Keys<'a, K, V>impl<T> Clone for Box<[T]> where
T: Clone,impl<T> Clone for LinkedList<T> where
T: Clone,impl<T> Clone for BinaryHeap<T> where
T: Clone,impl<'a, B> Clone for Cow<'a, B> where
B: ToOwned + ?Sized,impl Clone for Box<str>impl<T> Clone for std::vec::IntoIter<T> where
T: Clone,impl<'a, K, V> Clone for std::collections::btree_map::Range<'a, K, V>impl Clone for Globalimpl<'a, T> Clone for std::collections::btree_set::Intersection<'a, T>impl<T> Clone for std::collections::vec_deque::IntoIter<T> where
T: Clone,impl<T> Clone for Rc<T> where
T: ?Sized,impl<'a, T> Clone for std::collections::btree_set::SymmetricDifference<'a, T>impl<'a, T> Clone for std::collections::linked_list::Iter<'a, T>impl<'a, T> Clone for std::collections::btree_set::Difference<'a, T>impl Clone for ThreadIdimpl Clone for Threadimpl<K: Clone, V: Clone, S: Clone> Clone for HashMap<K, V, S>impl<'a, K, V> Clone for std::collections::hash_map::Iter<'a, K, V>impl<'a, K, V> Clone for std::collections::hash_map::Keys<'a, K, V>impl<'a, K, V> Clone for std::collections::hash_map::Values<'a, K, V>impl Clone for RandomStateimpl Clone for DefaultHasherimpl<T: Clone, S: Clone> Clone for HashSet<T, S>impl<'a, K> Clone for std::collections::hash_set::Iter<'a, K>impl<'a, T, S> Clone for std::collections::hash_set::Intersection<'a, T, S>impl<'a, T, S> Clone for std::collections::hash_set::Difference<'a, T, S>impl<'a, T, S> Clone for std::collections::hash_set::SymmetricDifference<'a, T, S>impl<'a, T, S> Clone for std::collections::hash_set::Union<'a, T, S>impl Clone for VarErrorimpl Clone for CStringimpl Clone for NulErrorimpl Clone for FromBytesWithNulErrorimpl Clone for IntoStringErrorimpl Clone for OsStringimpl Clone for Metadataimpl Clone for OpenOptionsimpl Clone for Permissionsimpl Clone for FileTypeimpl<T: Clone> Clone for Cursor<T>impl Clone for ErrorKindimpl Clone for SeekFromimpl Clone for IpAddrimpl Clone for Ipv6MulticastScopeimpl Clone for Ipv4Addrimpl Clone for Ipv6Addrimpl Clone for std::net::SocketAddrimpl Clone for SocketAddrV4impl Clone for SocketAddrV6impl Clone for AddrParseErrorimpl Clone for Shutdownimpl Clone for statimpl<'a> Clone for Prefix<'a>impl<'a> Clone for PrefixComponent<'a>impl<'a> Clone for Component<'a>impl<'a> Clone for Components<'a>impl<'a> Clone for std::path::Iter<'a>impl<'a> Clone for Ancestors<'a>impl Clone for PathBufimpl Clone for StripPrefixErrorimpl Clone for Outputimpl Clone for ExitStatusimpl Clone for ExitCodeimpl<T: Clone> Clone for SendError<T>impl Clone for RecvErrorimpl Clone for TryRecvErrorimpl Clone for RecvTimeoutErrorimpl<T: Clone> Clone for TrySendError<T>impl<T> Clone for Sender<T>impl<T> Clone for SyncSender<T>impl Clone for WaitTimeoutResultimpl Clone for Instantimpl Clone for SystemTimeimpl Clone for SystemTimeErrorimpl<'a> Clone for EncodeWide<'a>impl Clone for std::os::unix::net::SocketAddr