Trait std::clone::Clone

#[lang = "clone"]
pub trait Clone {
    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.

Closures

Closure types automatically implement Clone if they capture no value from the environment or if all such captured values implement Clone themselves.

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 }
}

Required Methods

fn clone(&self) -> Self

Returns a copy of the value.

Examples

let hello = "Hello"; // &str implements Clone

assert_eq!("Hello", hello.clone());

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 __m256i

fn clone(&self) -> __m256i

fn clone_from(&mut self, source: &Self)

impl<T> Clone for NonZero<T> where     T: Zeroable + Clone,

fn clone(&self) -> NonZero<T>

fn clone_from(&mut self, source: &Self)

impl Clone for __m64

fn clone(&self) -> __m64

fn clone_from(&mut self, source: &Self)

impl Clone for CannotReallocInPlace

fn clone(&self) -> CannotReallocInPlace

fn clone_from(&mut self, source: &Self)

impl Clone for __m256d

fn clone(&self) -> __m256d

fn clone_from(&mut self, source: &Self)

impl Clone for __m128

fn clone(&self) -> __m128

fn clone_from(&mut self, source: &Self)

impl Clone for TryFromSliceError

fn clone(&self) -> TryFromSliceError

fn clone_from(&mut self, source: &Self)

impl Clone for __m256

fn clone(&self) -> __m256

fn clone_from(&mut self, source: &Self)

impl Clone for Layout

fn clone(&self) -> Layout

fn clone_from(&mut self, source: &Self)

impl Clone for AllocErr

fn clone(&self) -> AllocErr

fn clone_from(&mut self, source: &Self)

impl Clone for CpuidResult

fn clone(&self) -> CpuidResult

fn clone_from(&mut self, source: &Self)

impl Clone for __m128d

fn clone(&self) -> __m128d

fn clone_from(&mut self, source: &Self)

impl Clone for __m128i

fn clone(&self) -> __m128i

fn clone_from(&mut self, source: &Self)

impl<I> Clone for Utf16Encoder<I> where     I: Clone,

Important traits for Utf16Encoder<I>

impl<I> Iterator for Utf16Encoder<I> where
    I: Iterator<Item = char>,  type Item = u16;

fn clone(&self) -> Utf16Encoder<I>

fn clone_from(&mut self, source: &Self)

Implementors

• impl<I> Clone for Take<I> where     I: Clone,

• impl<I> Clone for Cycle<I> where     I: Clone,

• impl Clone for u8x8

• impl Clone for b8x64

• impl<T> Clone for NonNull<T> where     T: ?Sized,

• impl Clone for EscapeDefault

• impl Clone for f64x8

• impl Clone for b8x32

• impl<'a> Clone for Arguments<'a>

• impl Clone for NonZeroUsize

• impl<A, B> Clone for Chain<A, B> where     A: Clone,     B: Clone,

• impl Clone for u16x2

• impl<I, P> Clone for Filter<I, P> where     I: Clone,     P: Clone,

• impl<'a, P> Clone for RMatchIndices<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for TraitObject

• impl Clone for std::cmp::Ordering

• impl Clone for SearchStep

• impl<'a, P> Clone for RSplitTerminator<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for i64x4

• impl Clone for NonZeroU128

• impl<T> Clone for Wrapping<T> where     T: Clone,

• impl Clone for i16x8

• impl<Idx> Clone for std::ops::Range<Idx> where     Idx: Clone,

• impl<'a, P> Clone for Matches<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for NonZeroI64

• impl Clone for TryFromIntError

• impl<T> Clone for Once<T> where     T: Clone,

• impl<I, F> Clone for Inspect<I, F> where     F: Clone,     I: Clone,

• impl<I> Clone for StepBy<I> where     I: Clone,

• impl Clone for i8x4

• impl<'a, 'b> Clone for StrSearcher<'a, 'b>

• impl<T> Clone for Reverse<T> where     T: Clone,

• impl Clone for std::sync::atomic::Ordering

• impl<I> Clone for Peekable<I> where     I: Clone + Iterator,     <I as Iterator>::Item: Clone,

• impl Clone for i16x32

• impl Clone for i32x4

• impl<A> Clone for std::option::IntoIter<A> where     A: Clone,

• impl<'a, T> Clone for std::result::Iter<'a, T>

• impl<'a> Clone for CharIndices<'a>

• impl Clone for CharTryFromError

• impl Clone for Error

• impl<Idx> Clone for RangeToInclusive<Idx> where     Idx: Clone,

• impl Clone for NonZeroI8

• 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 u32x4

• impl Clone for i16x16

• impl<T> Clone for Unique<T> where     T: ?Sized,

• impl Clone for Duration

• impl Clone for u8x32

• impl Clone for FpCategory

• impl Clone for u8x2

• impl<'a, T, P> Clone for std::slice::RSplit<'a, T, P> where     P: Clone + FnMut(&T) -> bool,     T: 'a + Clone,

• impl Clone for f64x2

• impl Clone for u32x8

• impl<'a, T> Clone for Chunks<'a, T>

• impl<T> Clone for ManuallyDrop<T> where     T: Clone,

• impl<T> Clone for RefCell<T> where     T: Clone,

• impl Clone for u8x4

• impl Clone for f32x2

• impl<I> Clone for DecodeUtf8<I> where     I: Clone + Iterator<Item = u8>,

• impl<I> Clone for Skip<I> where     I: Clone,

• impl Clone for ParseFloatError

• impl<A> Clone for Repeat<A> where     A: Clone,

• impl<I, St, F> Clone for Scan<I, St, F> where     F: Clone,     I: Clone,     St: Clone,

• impl Clone for ParseIntError

• impl<'a> Clone for Chars<'a>

• impl Clone for u16x16

• impl<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 std::str::RSplit<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for i8x32

• impl Clone for NonZeroU16

• impl<Idx> Clone for RangeFrom<Idx> where     Idx: Clone,

• impl Clone for i16x2

• impl<'a, P> Clone for RSplitN<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for i8x64

• impl<T> Clone for Cell<T> where     T: Copy,

• impl Clone for u16x4

• impl Clone for u32x2

• impl Clone for u64x2

• impl Clone for b8x16

• impl Clone for i64x8

• impl Clone for NonZeroU64

• impl Clone for b8x8

• impl<Y, R> Clone for GeneratorState<Y, R> where     R: Clone,     Y: Clone,

• impl<Idx> Clone for RangeTo<Idx> where     Idx: Clone,

• impl Clone for i32x16

• impl Clone for u8x64

• impl<'a, T, P> Clone for std::slice::Split<'a, T, P> where     P: Clone + FnMut(&T) -> bool,

• impl<'a> Clone for Bytes<'a>

• impl Clone for i32x8

• impl Clone for RangeFull

• impl Clone for SipHasher

• impl Clone for NonZeroI128

• impl<I, F> Clone for Map<I, F> where     F: Clone,     I: Clone,

• impl Clone for i8x2

• impl Clone for f32x4

• impl<I, P> Clone for SkipWhile<I, P> where     I: Clone,     P: Clone,

• impl<T> Clone for Bound<T> where     T: Clone,

• impl Clone for u64x8

• impl<I, P> Clone for TakeWhile<I, P> where     I: Clone,     P: Clone,

• impl Clone for f32x16

• impl<I, F> Clone for FilterMap<I, F> where     F: Clone,     I: Clone,

• impl<F> Clone for RepeatWith<F> where     F: Clone,

• impl Clone for NonZeroU32

• impl<'a> Clone for LinesAny<'a>

• impl<I> Clone for Cloned<I> where     I: Clone,

• impl<'a> Clone for CharSearcher<'a>

• impl Clone for EscapeDebug

• impl Clone for NonZeroI16

• impl<T, E> Clone for Result<T, E> where     E: Clone,     T: Clone,

• impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>

• impl<T> Clone for Discriminant<T>

• impl<'a, T> Clone for ExactChunks<'a, T>

• impl<T> Clone for Empty<T>

• impl<'a, P> Clone for MatchIndices<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl<'a, P> Clone for SplitN<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl<T> Clone for Rev<T> where     T: Clone,

• impl Clone for i32x2

• impl<'a, P> Clone for SplitTerminator<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl<'a, T> Clone for Windows<'a, T>

• impl<T> Clone for PhantomData<T> where     T: ?Sized,

• impl<T> Clone for Option<T> where     T: Clone,

• impl<'a, P> Clone for std::str::Split<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for NoneError

• impl Clone for b8x2

• impl<'a, A> Clone for std::option::Iter<'a, A>

• impl Clone for i64x2

• impl Clone for NonZeroI32

• impl Clone for u64x4

• impl Clone for CollectionAllocErr

• impl<I> Clone for Fuse<I> where     I: Clone,

• impl<A, B> Clone for Zip<A, B> where     A: Clone,     B: Clone,

• impl Clone for i8x8

• impl Clone for NonZeroIsize

• impl<Idx> Clone for RangeInclusive<Idx> where     Idx: Clone,

• impl Clone for ParseBoolError

• impl Clone for b8x4

• impl Clone for u8x16

• impl Clone for EscapeUnicode

• impl Clone for i8x16

• impl<'a, P> Clone for RMatches<'a, P> where     P: Pattern<'a>,     <P as Pattern<'a>>::Searcher: Clone,

• impl Clone for TypeId

• impl Clone for u32x16

• impl<T> Clone for std::result::IntoIter<T> where     T: Clone,

• impl Clone for f64x4

• impl Clone for ParseCharError

• impl<'a> Clone for Lines<'a>

• impl Clone for f32x8

• impl<'a, T> Clone for std::slice::Iter<'a, T>

• impl<'a, F> Clone for CharPredicateSearcher<'a, F> where     F: Clone + FnMut(char) -> bool,

• impl Clone for NonZeroU8

• impl Clone for u16x32

• impl Clone for u16x8

• impl Clone for Utf8Error

• impl<I> Clone for Enumerate<I> where     I: Clone,

• impl<H> Clone for BuildHasherDefault<H>

• impl Clone for i16x4

• 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<K, V> Clone for BTreeMap<K, V> where     K: Clone,     V: Clone,

• impl<T> Clone for std::rc::Weak<T> where     T: ?Sized,

• impl<'a, K, V> Clone for std::collections::btree_map::Values<'a, K, V>

• impl<T> Clone for std::collections::linked_list::IntoIter<T> where     T: Clone,

• impl<T> Clone for Rc<T> where     T: ?Sized,

• impl<'a, K, V> Clone for std::collections::btree_map::Range<'a, K, V>

• impl<T> Clone for std::sync::Weak<T> where     T: ?Sized,

• impl<T> Clone for VecDeque<T> where     T: Clone,

• impl<T> Clone for LinkedList<T> where     T: Clone,

• impl<T> Clone for BinaryHeap<T> where     T: Clone,

• impl<T> Clone for Box<T> where     T: Clone,

• impl<'a, T> Clone for std::collections::btree_set::Intersection<'a, T>

• impl<'a, T> Clone for std::collections::linked_list::Iter<'a, T>

• impl Clone for Heap

• impl<'a, T> Clone for std::collections::btree_set::Difference<'a, T>

• impl<T> Clone for Arc<T> where     T: ?Sized,

• impl<'a, B> Clone for Cow<'a, B> where     B: ToOwned + ?Sized,

• impl Clone for ParseError

• impl<T> Clone for BTreeSet<T> where     T: Clone,

• impl<'a, T> Clone for std::collections::btree_set::Iter<'a, T>

• impl<T> Clone for std::collections::vec_deque::IntoIter<T> where     T: Clone,

• impl<T> Clone for std::vec::IntoIter<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 Clone for ExchangeHeapSingleton

• impl<'a, T> Clone for std::collections::btree_set::SymmetricDifference<'a, T>

• impl<'a> Clone for EncodeUtf16<'a>

• impl Clone for Box<str>

• impl<'a, T> Clone for std::collections::vec_deque::Iter<'a, T>

• impl Clone for String

• impl<T> Clone for Box<[T]> where     T: Clone,

• impl<'a, T> Clone for std::collections::binary_heap::Iter<'a, T>

• impl<'a, T> Clone for std::collections::btree_set::Union<'a, T>

• impl<'a, K, V> Clone for std::collections::btree_map::Iter<'a, K, V>

• impl Clone for DecodeUtf16Error

• impl<'a> Clone for SplitWhitespace<'a>

• impl Clone for ToUppercase

• impl Clone for UnicodeVersion

• impl<I> Clone for DecodeUtf16<I> where     I: Clone + Iterator<Item = u16>,

• impl Clone for ToLowercase

• impl Clone for ThreadId

• impl Clone for Thread

• impl<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 RandomState

• impl Clone for DefaultHasher

• impl<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 VarError

• impl Clone for CString

• impl Clone for NulError

• impl Clone for FromBytesWithNulError

• impl Clone for IntoStringError

• impl Clone for OsString

• impl Clone for Metadata

• impl Clone for OpenOptions

• impl Clone for Permissions

• impl Clone for FileType

• impl<T: Clone> Clone for Cursor<T>

• impl Clone for ErrorKind

• impl Clone for SeekFrom

• impl Clone for IpAddr

• impl Clone for Ipv6MulticastScope

• impl Clone for Ipv4Addr

• impl Clone for Ipv6Addr

• impl Clone for std::net::SocketAddr

• impl Clone for SocketAddrV4

• impl Clone for SocketAddrV6

• impl Clone for AddrParseError

• impl Clone for Shutdown

• impl Clone for stat

• impl<'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 PathBuf

• impl Clone for StripPrefixError

• impl Clone for Output

• impl Clone for ExitStatus

• impl Clone for ExitCode

• impl<T: Clone> Clone for SendError<T>

• impl Clone for RecvError

• impl Clone for TryRecvError

• impl Clone for RecvTimeoutError

• impl<T: Clone> Clone for TrySendError<T>

• impl<T> Clone for Sender<T>

• impl<T> Clone for SyncSender<T>

• impl Clone for WaitTimeoutResult

• impl Clone for Instant

• impl Clone for SystemTime

• impl Clone for SystemTimeError

• impl<'a> Clone for EncodeWide<'a>

• impl Clone for std::os::unix::net::SocketAddr