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 Clone for Durationimpl Clone for EscapeDebugimpl Clone for NoneErrorimpl<T> Clone for NonNull<T> where
T: ?Sized,impl<I, F> Clone for Map<I, F> where
F: Clone,
I: Clone,impl<I, P> Clone for SkipWhile<I, P> where
I: Clone,
P: Clone,impl<I> Clone for Skip<I> where
I: Clone,impl<Idx> Clone for RangeInclusive<Idx> where
Idx: Clone,impl<I> Clone for Enumerate<I> where
I: Clone,impl<'a> Clone for EncodeUtf16<'a>impl Clone for EscapeDefaultimpl<T> Clone for Discriminant<T>impl<'a, P> Clone for RSplitTerminator<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<H> Clone for BuildHasherDefault<H>impl<T, E> Clone for Result<T, E> where
E: Clone,
T: Clone,impl<Idx> Clone for RangeToInclusive<Idx> where
Idx: Clone,impl Clone for Utf8Errorimpl<Idx> Clone for RangeFrom<Idx> where
Idx: Clone,impl<'a, T> Clone for Windows<'a, T>impl<'a> Clone for SplitAsciiWhitespace<'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 charimpl Clone for i16impl Clone for i32impl<T> Clone for Once<T> where
T: Clone,impl<'a> Clone for CharIndices<'a>impl Clone for NonZeroU64impl<T> Clone for Option<T> where
T: Clone,impl Clone for CannotReallocInPlaceimpl<I, U, F> Clone for FlatMap<I, U, F> where
F: Clone,
I: Clone,
U: Clone + IntoIterator,
<U as IntoIterator>::IntoIter: Clone,impl<'a, F> Clone for CharPredicateSearcher<'a, F> where
F: Clone + FnMut(char) -> bool,impl Clone for NonZeroUsizeimpl<'a, P> Clone for SplitTerminator<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for i128impl<'a, P> Clone for RSplitN<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<'a, T> Clone for &'a T where
T: ?Sized,impl Clone for EscapeUnicodeimpl Clone for LayoutErrimpl Clone for Errorimpl<'a> Clone for Bytes<'a>impl<I> Clone for StepBy<I> where
I: Clone,impl<T> Clone for PhantomData<T> where
T: ?Sized,impl<'a, P> Clone for std::str::RSplit<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for ToUppercaseimpl<I, F> Clone for Inspect<I, F> where
F: Clone,
I: Clone,impl<'a> Clone for Lines<'a>impl Clone for ToLowercaseimpl Clone for NonZeroU32impl<T> Clone for Rev<T> where
T: Clone,impl Clone for Pinnedimpl<A, B> Clone for Chain<A, B> where
A: Clone,
B: Clone,impl<I> Clone for Take<I> where
I: Clone,impl Clone for ParseIntErrorimpl<'a, P> Clone for Matches<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<T> Clone for *mut T where
T: ?Sized,impl Clone for NonZeroU8impl Clone for TypeIdimpl<'a> Clone for CharSearcher<'a>impl<'a, T, P> Clone for std::slice::RSplit<'a, T, P> where
P: Clone + FnMut(&T) -> bool,
T: 'a + Clone,impl<T> Clone for Cell<T> where
T: Copy,impl Clone for SearchStepimpl Clone for f32impl Clone for boolimpl Clone for RangeFullimpl Clone for u32impl<Y, R> Clone for GeneratorState<Y, R> where
R: Clone,
Y: Clone,impl<'a, P> Clone for SplitN<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<'a> Clone for Chars<'a>impl<'a, T> Clone for std::result::Iter<'a, T>impl<I> Clone for DecodeUtf16<I> where
I: Clone + Iterator<Item = u16>,impl<T> Clone for ManuallyDrop<T> where
T: Clone,impl<'a, T> Clone for ExactChunks<'a, T>impl<T> Clone for Poll<T> where
T: Clone,impl<I> Clone for Cycle<I> where
I: Clone,impl Clone for ParseFloatErrorimpl Clone for NonZeroU16impl Clone for UnicodeVersionimpl<'a, P> Clone for MatchIndices<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<Idx> Clone for std::ops::Range<Idx> where
Idx: Clone,impl Clone for i8impl Clone for f64impl Clone for u16impl<T> Clone for RefCell<T> where
T: Clone,impl<I, St, F> Clone for Scan<I, St, F> where
F: Clone,
I: Clone,
St: Clone,impl Clone for std::cmp::Orderingimpl<'a> Clone for Arguments<'a>impl Clone for Layoutimpl<'a, A> Clone for std::option::Iter<'a, A>impl<I> Clone for Cloned<I> where
I: Clone,impl<I> Clone for Fuse<I> where
I: Clone,impl<I> Clone for DecodeUtf8<I> where
I: Clone + Iterator<Item = u8>,impl<I, P> Clone for Filter<I, P> where
I: Clone,
P: Clone,impl Clone for Wakerimpl<T> Clone for *const T where
T: ?Sized,impl<'a, T, P> Clone for std::slice::Split<'a, T, P> where
P: Clone + FnMut(&T) -> bool,impl<T> Clone for Reverse<T> where
T: Clone,impl<'a, 'b> Clone for StrSearcher<'a, 'b>impl<I, F> Clone for FilterMap<I, F> where
F: Clone,
I: Clone,impl<Idx> Clone for RangeTo<Idx> where
Idx: Clone,impl Clone for FpCategoryimpl<F> Clone for RepeatWith<F> where
F: Clone,impl<A, B> Clone for Zip<A, B> where
A: Clone,
B: Clone,impl Clone for u8impl<'a, P> Clone for RMatchIndices<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for u64impl Clone for CharTryFromErrorimpl<T> Clone for Bound<T> where
T: Clone,impl Clone for !impl Clone for LocalWakerimpl<'a> Clone for SplitWhitespace<'a>impl Clone for std::sync::atomic::Orderingimpl<'a, T> Clone for Chunks<'a, T>impl<'a, P> Clone for std::str::Split<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl Clone for TryFromIntErrorimpl Clone for i64impl Clone for ParseCharErrorimpl<T> Clone for Wrapping<T> where
T: Clone,impl Clone for AllocErrimpl<'a, T> Clone for std::slice::Iter<'a, T>impl Clone for TraitObjectimpl<I, P> Clone for TakeWhile<I, P> where
I: Clone,
P: Clone,impl<T> Clone for std::result::IntoIter<T> where
T: Clone,impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>impl Clone for ParseBoolErrorimpl Clone for DecodeUtf16Errorimpl<A> Clone for std::option::IntoIter<A> where
A: Clone,impl Clone for u128impl Clone for SipHasherimpl Clone for usizeimpl Clone for isizeimpl<'a, P> Clone for RMatches<'a, P> where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: Clone,impl<T> Clone for Empty<T>impl Clone for NonZeroU128impl<I> Clone for Peekable<I> where
I: Clone + Iterator,
<I as Iterator>::Item: Clone,impl<'a> Clone for LinesAny<'a>impl<A> Clone for Repeat<A> where
A: Clone,impl<T> Clone for BinaryHeap<T> where
T: Clone,impl<T> Clone for std::sync::Weak<T> where
T: ?Sized,impl<T> Clone for std::collections::vec_deque::IntoIter<T> where
T: Clone,impl<T> Clone for std::rc::Weak<T> where
T: ?Sized,impl<'a, T> Clone for std::collections::linked_list::Iter<'a, T>impl<'a, T> Clone for std::collections::btree_set::Range<'a, T>impl Clone for CollectionAllocErrimpl<T> Clone for Rc<T> where
T: ?Sized,impl<'a, K, V> Clone for std::collections::btree_map::Keys<'a, K, V>impl Clone for Globalimpl<'a, T> Clone for std::collections::binary_heap::Iter<'a, T>impl<T> Clone for LinkedList<T> where
T: Clone,impl<T> Clone for Arc<T> where
T: ?Sized,impl<'a, T> Clone for std::collections::btree_set::Iter<'a, T>impl<T> Clone for std::vec::IntoIter<T> where
T: Clone,impl<'a, T> Clone for std::collections::btree_set::Union<'a, T>impl Clone for Box<str>impl<'a, T> Clone for std::collections::btree_set::Intersection<'a, T>impl<'a, B> Clone for Cow<'a, B> where
B: ToOwned + ?Sized,impl<'a, K, V> Clone for std::collections::btree_map::Iter<'a, K, V>impl<T> Clone for BTreeSet<T> where
T: Clone,impl<K, V> Clone for BTreeMap<K, V> where
K: Clone,
V: Clone,impl Clone for Stringimpl Clone for ParseErrorimpl<T> Clone for Box<T> where
T: Clone,impl<T> Clone for std::collections::binary_heap::IntoIter<T> where
T: Clone,impl<T> Clone for Box<[T]> where
T: Clone,impl<T> Clone for std::collections::linked_list::IntoIter<T> where
T: Clone,impl<'a, T> Clone for std::collections::btree_set::SymmetricDifference<'a, T>impl<'a, T> Clone for std::collections::btree_set::Difference<'a, T>impl<T> Clone for VecDeque<T> where
T: Clone,impl<'a, K, V> Clone for std::collections::btree_map::Range<'a, K, V>impl<'a, T> Clone for std::collections::vec_deque::Iter<'a, T>impl<'a, K, V> Clone for std::collections::btree_map::Values<'a, K, V>impl<T> Clone for Vec<T> where
T: Clone,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 Box<CStr>impl Clone for OsStringimpl Clone for Box<OsStr>impl 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 Box<Path>impl 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