1.0.0[][src]Trait std::clone::Clone

#[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.

For a generic struct, #[derive] implements Clone conditionally by adding bound Clone on generic parameters.

// `derive` implements Clone for Reading<T> when T is Clone.
#[derive(Clone)]
struct Reading<T> {
    frequency: T,
}Run

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 a generic struct holding a function pointer. In this case, the implementation of Clone cannot be derived, but can be implemented as:

struct Generate<T>(fn() -> T);

impl<T> Copy for Generate<T> {}

impl<T> Clone for Generate<T> {
    fn clone(&self) -> Self {
        *self
    }
}Run

Additional implementors

In addition to the implementors listed below, the following types also implement Clone:

Required methods

#[must_use = "cloning is often expensive and is not expected to have side effects"] fn clone(&self) -> Self

Returns a copy of the value.

Examples

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

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

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Implementations on Foreign Types

impl Clone for __m256i[src]

impl Clone for __m256d[src]

impl Clone for __m512[src]

impl Clone for __m64[src]

impl Clone for __m512i[src]

impl Clone for __m128d[src]

impl Clone for __m128[src]

impl Clone for __m512d[src]

impl Clone for __m256[src]

impl Clone for __m128i[src]

impl Clone for CpuidResult[src]

impl Clone for Frame[src]

impl Clone for PrintFmt[src]

impl Clone for TryDemangleError

impl<T, S> Clone for HashSet<T, S> where
    S: Clone,
    T: Clone

impl<'_, T, S> Clone for Difference<'_, T, S>

impl<'_, K, V> Clone for Iter<'_, K, V>

impl Clone for CollectionAllocErr

impl<'_, K, V> Clone for Keys<'_, K, V>

impl<'_, T, S> Clone for Union<'_, T, S>

impl<'_, K, V> Clone for Values<'_, K, V>

impl<'_, T, S> Clone for SymmetricDifference<'_, T, S>

impl<'_, T, S> Clone for Intersection<'_, T, S>

impl<K, V, S> Clone for HashMap<K, V, S> where
    K: Clone,
    S: Clone,
    V: Clone

impl<'_, K> Clone for Iter<'_, K>

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Implementors

impl Clone for std::cmp::Ordering[src]

impl Clone for TryReserveError[src]

impl Clone for Infallible[src]

impl Clone for VarError[src]

impl Clone for ErrorKind[src]

impl Clone for SeekFrom[src]

impl Clone for IpAddr[src]

impl Clone for Ipv6MulticastScope[src]

impl Clone for Shutdown[src]

impl Clone for std::net::SocketAddr[src]

impl Clone for FpCategory[src]

impl Clone for IntErrorKind[src]

impl Clone for SearchStep[src]

impl Clone for std::sync::atomic::Ordering[src]

impl Clone for RecvTimeoutError[src]

impl Clone for TryRecvError[src]

impl Clone for bool[src]

impl Clone for char[src]

impl Clone for f32[src]

impl Clone for f64[src]

impl Clone for i128[src]

impl Clone for i16[src]

impl Clone for i32[src]

impl Clone for i64[src]

impl Clone for i8[src]

impl Clone for isize[src]

impl Clone for ![src]

impl Clone for u128[src]

impl Clone for u16[src]

impl Clone for u32[src]

impl Clone for u64[src]

impl Clone for u8[src]

impl Clone for usize[src]

impl Clone for AllocErr[src]

impl Clone for CannotReallocInPlace[src]

impl Clone for Global[src]

impl Clone for Layout[src]

impl Clone for LayoutErr[src]

impl Clone for System[src]

impl Clone for TypeId[src]

impl Clone for TryFromSliceError[src]

impl Clone for std::ascii::EscapeDefault[src]

impl Clone for Box<str>[src]

impl Clone for Box<CStr>[src]

impl Clone for Box<OsStr>[src]

impl Clone for Box<Path>[src]

impl Clone for CharTryFromError[src]

impl Clone for DecodeUtf16Error[src]

impl Clone for std::char::EscapeDebug[src]

impl Clone for std::char::EscapeDefault[src]

impl Clone for std::char::EscapeUnicode[src]

impl Clone for ParseCharError[src]

impl Clone for ToLowercase[src]

impl Clone for ToUppercase[src]

impl Clone for UnicodeVersion[src]

impl Clone for DefaultHasher[src]

impl Clone for RandomState[src]

impl Clone for CString[src]

impl Clone for FromBytesWithNulError[src]

impl Clone for IntoStringError[src]

impl Clone for NulError[src]

impl Clone for OsString[src]

impl Clone for Error[src]

impl Clone for FileType[src]

impl Clone for Metadata[src]

impl Clone for OpenOptions[src]

impl Clone for Permissions[src]

impl Clone for SipHasher[src]

impl Clone for PhantomPinned[src]

impl Clone for AddrParseError[src]

impl Clone for Ipv4Addr[src]

impl Clone for Ipv6Addr[src]

impl Clone for SocketAddrV4[src]

impl Clone for SocketAddrV6[src]

impl Clone for NonZeroI128[src]

impl Clone for NonZeroI16[src]

impl Clone for NonZeroI32[src]

impl Clone for NonZeroI64[src]

impl Clone for NonZeroI8[src]

impl Clone for NonZeroIsize[src]

impl Clone for NonZeroU128[src]

impl Clone for NonZeroU16[src]

impl Clone for NonZeroU32[src]

impl Clone for NonZeroU64[src]

impl Clone for NonZeroU8[src]

impl Clone for NonZeroUsize[src]

impl Clone for ParseFloatError[src]

impl Clone for ParseIntError[src]

impl Clone for TryFromIntError[src]

impl Clone for RangeFull[src]

impl Clone for NoneError[src]

impl Clone for stat[src]

impl Clone for std::os::unix::net::SocketAddr[src]

impl Clone for PathBuf[src]

impl Clone for StripPrefixError[src]

impl Clone for ExitCode[src]

impl Clone for ExitStatus[src]

impl Clone for Output[src]

impl Clone for TraitObject[src]

impl Clone for ParseBoolError[src]

impl Clone for Utf8Error[src]

impl Clone for String[src]

impl Clone for RecvError[src]

impl Clone for WaitTimeoutResult[src]

impl Clone for RawWakerVTable[src]

impl Clone for Waker[src]

impl Clone for AccessError[src]

impl Clone for Thread[src]

impl Clone for ThreadId[src]

impl Clone for Duration[src]

impl Clone for Instant[src]

impl Clone for SystemTime[src]

impl Clone for SystemTimeError[src]

impl<'_, A> Clone for std::option::Iter<'_, A>[src]

impl<'_, B> Clone for Cow<'_, B> where
    B: ToOwned + ?Sized
[src]

impl<'_, K> Clone for std::collections::hash_set::Iter<'_, K>[src]

impl<'_, K, V> Clone for std::collections::btree_map::Iter<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::btree_map::Keys<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::btree_map::Range<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::btree_map::Values<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::hash_map::Iter<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::hash_map::Keys<'_, K, V>[src]

impl<'_, K, V> Clone for std::collections::hash_map::Values<'_, K, V>[src]

impl<'_, T> Clone for &'_ T where
    T: ?Sized
[src]

impl<'_, T> Clone for std::collections::binary_heap::Iter<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::Difference<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::Intersection<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::Iter<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::Range<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::SymmetricDifference<'_, T>[src]

impl<'_, T> Clone for std::collections::btree_set::Union<'_, T>[src]

impl<'_, T> Clone for std::collections::linked_list::Iter<'_, T>[src]

impl<'_, T> Clone for std::collections::vec_deque::Iter<'_, T>[src]

impl<'_, T> Clone for std::result::Iter<'_, T>[src]

impl<'_, T> Clone for Chunks<'_, T>[src]

impl<'_, T> Clone for ChunksExact<'_, T>[src]

impl<'_, T> Clone for std::slice::Iter<'_, T>[src]

impl<'_, T> Clone for RChunks<'_, T>[src]

impl<'_, T> Clone for Windows<'_, T>[src]

impl<'_, T, P> Clone for std::slice::Split<'_, T, P> where
    P: Clone + FnMut(&T) -> bool
[src]

impl<'_, T, S> Clone for std::collections::hash_set::Difference<'_, T, S>[src]

impl<'_, T, S> Clone for std::collections::hash_set::Intersection<'_, T, S>[src]

impl<'_, T, S> Clone for std::collections::hash_set::SymmetricDifference<'_, T, S>[src]

impl<'_, T, S> Clone for std::collections::hash_set::Union<'_, T, S>[src]

impl<'a> Clone for Component<'a>[src]

impl<'a> Clone for Prefix<'a>[src]

impl<'a> Clone for ErrorIter<'a>[src]

impl<'a> Clone for Arguments<'a>[src]

impl<'a> Clone for EncodeWide<'a>[src]

impl<'a> Clone for Ancestors<'a>[src]

impl<'a> Clone for Components<'a>[src]

impl<'a> Clone for std::path::Iter<'a>[src]

impl<'a> Clone for PrefixComponent<'a>[src]

impl<'a> Clone for CharSearcher<'a>[src]

impl<'a> Clone for Bytes<'a>[src]

impl<'a> Clone for CharIndices<'a>[src]

impl<'a> Clone for Chars<'a>[src]

impl<'a> Clone for EncodeUtf16<'a>[src]

impl<'a> Clone for std::str::EscapeDebug<'a>[src]

impl<'a> Clone for std::str::EscapeDefault<'a>[src]

impl<'a> Clone for std::str::EscapeUnicode<'a>[src]

impl<'a> Clone for Lines<'a>[src]

impl<'a> Clone for LinesAny<'a>[src]

impl<'a> Clone for SplitAsciiWhitespace<'a>[src]

impl<'a> Clone for SplitWhitespace<'a>[src]

impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>[src]

impl<'a, 'b> Clone for StrSearcher<'a, 'b>[src]

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

impl<'a, P> Clone for MatchIndices<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for Matches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for RMatchIndices<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for RMatches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for std::str::RSplit<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for RSplitN<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for RSplitTerminator<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

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

impl<'a, P> Clone for SplitN<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for SplitTerminator<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, T> Clone for RChunksExact<'a, T>[src]

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

impl<'f> Clone for VaListImpl<'f>[src]

impl<A> Clone for Repeat<A> where
    A: Clone
[src]

impl<A> Clone for std::option::IntoIter<A> where
    A: Clone
[src]

impl<A, B> Clone for Chain<A, B> where
    A: Clone,
    B: Clone
[src]

impl<A, B> Clone for Zip<A, B> where
    A: Clone,
    B: Clone
[src]

impl<F> Clone for FromFn<F> where
    F: Clone
[src]

impl<F> Clone for OnceWith<F> where
    F: Clone
[src]

impl<F> Clone for RepeatWith<F> where
    F: Clone
[src]

impl<H> Clone for BuildHasherDefault<H>[src]

impl<I> Clone for DecodeUtf16<I> where
    I: Clone + Iterator<Item = u16>, 
[src]

impl<I> Clone for Cloned<I> where
    I: Clone
[src]

impl<I> Clone for Copied<I> where
    I: Clone
[src]

impl<I> Clone for Cycle<I> where
    I: Clone
[src]

impl<I> Clone for Enumerate<I> where
    I: Clone
[src]

impl<I> Clone for Fuse<I> where
    I: Clone
[src]

impl<I> Clone for Peekable<I> where
    I: Clone + Iterator,
    <I as Iterator>::Item: Clone
[src]

impl<I> Clone for Skip<I> where
    I: Clone
[src]

impl<I> Clone for StepBy<I> where
    I: Clone
[src]

impl<I> Clone for Take<I> where
    I: Clone
[src]

impl<I, F> Clone for FilterMap<I, F> where
    F: Clone,
    I: Clone
[src]

impl<I, F> Clone for Inspect<I, F> where
    F: Clone,
    I: Clone
[src]

impl<I, F> Clone for Map<I, F> where
    F: Clone,
    I: Clone
[src]

impl<I, P> Clone for Filter<I, P> where
    I: Clone,
    P: Clone
[src]

impl<I, P> Clone for SkipWhile<I, P> where
    I: Clone,
    P: Clone
[src]

impl<I, P> Clone for TakeWhile<I, P> where
    I: Clone,
    P: Clone
[src]

impl<I, St, F> Clone for Scan<I, St, F> where
    F: Clone,
    I: Clone,
    St: Clone
[src]

impl<I, U> Clone for Flatten<I> where
    I: Clone + Iterator,
    U: Clone + Iterator,
    <I as Iterator>::Item: IntoIterator,
    <<I as Iterator>::Item as IntoIterator>::IntoIter == U,
    <<I as Iterator>::Item as IntoIterator>::Item == <U as Iterator>::Item
[src]

impl<I, U, F> Clone for FlatMap<I, U, F> where
    F: Clone,
    I: Clone,
    U: Clone + IntoIterator,
    <U as IntoIterator>::IntoIter: Clone
[src]

impl<Idx> Clone for std::ops::Range<Idx> where
    Idx: Clone
[src]

impl<Idx> Clone for RangeFrom<Idx> where
    Idx: Clone
[src]

impl<Idx> Clone for RangeInclusive<Idx> where
    Idx: Clone
[src]

impl<Idx> Clone for RangeTo<Idx> where
    Idx: Clone
[src]

impl<Idx> Clone for RangeToInclusive<Idx> where
    Idx: Clone
[src]

impl<K, V> Clone for BTreeMap<K, V> where
    K: Clone,
    V: Clone
[src]

impl<K: Clone, V: Clone, S: Clone> Clone for std::collections::HashMap<K, V, S>[src]

impl<P> Clone for Pin<P> where
    P: Clone
[src]

impl<T> Clone for Bound<T> where
    T: Clone
[src]

impl<T> Clone for Option<T> where
    T: Clone
[src]

impl<T> Clone for Poll<T> where
    T: Clone
[src]

impl<T> Clone for *const T where
    T: ?Sized
[src]

impl<T> Clone for *mut T where
    T: ?Sized
[src]

impl<T> Clone for Box<[T]> where
    T: Clone
[src]

impl<T> Clone for Box<T> where
    T: Clone
[src]

Important traits for Box<I>
fn clone(&self) -> Box<T>[src]

Returns a new box with a clone() of this box's contents.

Examples

let x = Box::new(5);
let y = x.clone();

// The value is the same
assert_eq!(x, y);

// But they are unique objects
assert_ne!(&*x as *const i32, &*y as *const i32);Run

fn clone_from(&mut self, source: &Box<T>)[src]

Copies source's contents into self without creating a new allocation.

Examples

let x = Box::new(5);
let mut y = Box::new(10);
let yp: *const i32 = &*y;

y.clone_from(&x);

// The value is the same
assert_eq!(x, y);

// And no allocation occurred
assert_eq!(yp, &*y);Run

impl<T> Clone for Cell<T> where
    T: Copy
[src]

impl<T> Clone for RefCell<T> where
    T: Clone
[src]

fn clone(&self) -> RefCell<T>[src]

Panics

Panics if the value is currently mutably borrowed.

impl<T> Clone for Reverse<T> where
    T: Clone
[src]

impl<T> Clone for BinaryHeap<T> where
    T: Clone
[src]

impl<T> Clone for std::collections::binary_heap::IntoIter<T> where
    T: Clone
[src]

impl<T> Clone for BTreeSet<T> where
    T: Clone
[src]

impl<T> Clone for std::collections::linked_list::IntoIter<T> where
    T: Clone
[src]

impl<T> Clone for LinkedList<T> where
    T: Clone
[src]

impl<T> Clone for std::collections::vec_deque::IntoIter<T> where
    T: Clone
[src]

impl<T> Clone for VecDeque<T> where
    T: Clone
[src]

impl<T> Clone for Empty<T>[src]

impl<T> Clone for Once<T> where
    T: Clone
[src]

impl<T> Clone for Rev<T> where
    T: Clone
[src]

impl<T> Clone for PhantomData<T> where
    T: ?Sized
[src]

impl<T> Clone for Discriminant<T>[src]

impl<T> Clone for ManuallyDrop<T> where
    T: Clone + ?Sized
[src]

impl<T> Clone for Wrapping<T> where
    T: Clone
[src]

impl<T> Clone for NonNull<T> where
    T: ?Sized
[src]

impl<T> Clone for Rc<T> where
    T: ?Sized
[src]

fn clone(&self) -> Rc<T>[src]

Makes a clone of the Rc pointer.

This creates another pointer to the same inner value, increasing the strong reference count.

Examples

use std::rc::Rc;

let five = Rc::new(5);

let _ = Rc::clone(&five);Run

impl<T> Clone for std::rc::Weak<T> where
    T: ?Sized
[src]

fn clone(&self) -> Weak<T>[src]

Makes a clone of the Weak pointer that points to the same value.

Examples

use std::rc::{Rc, Weak};

let weak_five = Rc::downgrade(&Rc::new(5));

let _ = Weak::clone(&weak_five);Run

impl<T> Clone for std::result::IntoIter<T> where
    T: Clone
[src]

impl<T> Clone for Sender<T>[src]

impl<T> Clone for SyncSender<T>[src]

impl<T> Clone for Arc<T> where
    T: ?Sized
[src]

fn clone(&self) -> Arc<T>[src]

Makes a clone of the Arc pointer.

This creates another pointer to the same inner value, increasing the strong reference count.

Examples

use std::sync::Arc;

let five = Arc::new(5);

let _ = Arc::clone(&five);Run

impl<T> Clone for std::sync::Weak<T> where
    T: ?Sized
[src]

fn clone(&self) -> Weak<T>[src]

Makes a clone of the Weak pointer that points to the same value.

Examples

use std::sync::{Arc, Weak};

let weak_five = Arc::downgrade(&Arc::new(5));

let _ = Weak::clone(&weak_five);Run

impl<T> Clone for std::vec::IntoIter<T> where
    T: Clone
[src]

impl<T> Clone for Vec<T> where
    T: Clone
[src]

impl<T> Clone for MaybeUninit<T> where
    T: Copy
[src]

impl<T, E> Clone for Result<T, E> where
    E: Clone,
    T: Clone
[src]

impl<T, F> Clone for Successors<T, F> where
    F: Clone,
    T: Clone
[src]

impl<T: Clone> Clone for TrySendError<T>[src]

impl<T: Clone> Clone for Cursor<T>[src]

impl<T: Clone> Clone for SendError<T>[src]

impl<T: Clone, S: Clone> Clone for std::collections::HashSet<T, S>[src]

impl<Y, R> Clone for GeneratorState<Y, R> where
    R: Clone,
    Y: Clone
[src]

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