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