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.

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 Exp1

fn clone(&self) -> Exp1

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

impl Clone for ChaChaRng

fn clone(&self) -> ChaChaRng

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

impl Clone for XorShiftRng

fn clone(&self) -> XorShiftRng

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

impl Clone for StandardNormal

fn clone(&self) -> StandardNormal

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

impl Clone for Normal

fn clone(&self) -> Normal

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

impl Clone for LogNormal

fn clone(&self) -> LogNormal

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

impl Clone for IsaacRng

fn clone(&self) -> IsaacRng

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

impl Clone for ReseedWithDefault

fn clone(&self) -> ReseedWithDefault

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

impl Clone for Isaac64Rng

fn clone(&self) -> Isaac64Rng

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

impl Clone for Exp

fn clone(&self) -> Exp

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

impl Clone for _Unwind_Action

fn clone(&self) -> _Unwind_Action

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

impl Clone for _Unwind_Reason_Code

fn clone(&self) -> _Unwind_Reason_Code

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

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

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

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 sockaddr_nl

fn clone(&self) -> sockaddr_nl

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

impl Clone for stat64

fn clone(&self) -> stat64

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

impl Clone for timespec

fn clone(&self) -> timespec

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

impl Clone for winsize

fn clone(&self) -> winsize

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

impl Clone for iovec

fn clone(&self) -> iovec

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

impl Clone for statvfs

fn clone(&self) -> statvfs

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

impl Clone for group

fn clone(&self) -> group

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

impl Clone for tms

fn clone(&self) -> tms

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

impl Clone for in6_addr

fn clone(&self) -> in6_addr

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

impl Clone for pthread_attr_t

fn clone(&self) -> pthread_attr_t

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

impl Clone for sockaddr

fn clone(&self) -> sockaddr

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

impl Clone for fd_set

fn clone(&self) -> fd_set

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

impl Clone for sockaddr_in

fn clone(&self) -> sockaddr_in

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

impl Clone for signalfd_siginfo

fn clone(&self) -> signalfd_siginfo

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

impl Clone for ip_mreq

fn clone(&self) -> ip_mreq

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

impl Clone for epoll_event

fn clone(&self) -> epoll_event

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

impl Clone for sockaddr_un

fn clone(&self) -> sockaddr_un

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

impl Clone for utsname

fn clone(&self) -> utsname

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

impl Clone for hostent

fn clone(&self) -> hostent

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

impl Clone for pthread_cond_t

fn clone(&self) -> pthread_cond_t

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

impl Clone for tm

fn clone(&self) -> tm

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

impl Clone for sched_param

fn clone(&self) -> sched_param

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

impl Clone for termios

fn clone(&self) -> termios

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

impl Clone for statfs

fn clone(&self) -> statfs

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

impl Clone for sockaddr_storage

fn clone(&self) -> sockaddr_storage

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

impl Clone for addrinfo

fn clone(&self) -> addrinfo

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

impl Clone for in_addr

fn clone(&self) -> in_addr

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

impl Clone for cmsghdr

fn clone(&self) -> cmsghdr

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

impl Clone for passwd

fn clone(&self) -> passwd

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

impl Clone for stack_t

fn clone(&self) -> stack_t

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

impl Clone for stat

fn clone(&self) -> stat

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

impl Clone for sigevent

fn clone(&self) -> sigevent

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

impl Clone for dirent64

fn clone(&self) -> dirent64

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

impl Clone for sockaddr_in6

fn clone(&self) -> sockaddr_in6

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

impl Clone for statfs64

fn clone(&self) -> statfs64

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

impl Clone for msghdr

fn clone(&self) -> msghdr

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

impl Clone for itimerval

fn clone(&self) -> itimerval

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

impl Clone for linger

fn clone(&self) -> linger

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

impl Clone for __fsid_t

fn clone(&self) -> __fsid_t

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

impl Clone for lconv

fn clone(&self) -> lconv

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

impl Clone for sockaddr_ll

fn clone(&self) -> sockaddr_ll

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

impl Clone for ipv6_mreq

fn clone(&self) -> ipv6_mreq

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

impl Clone for sysinfo

fn clone(&self) -> sysinfo

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

impl Clone for statvfs64

fn clone(&self) -> statvfs64

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

impl Clone for pthread_mutex_t

fn clone(&self) -> pthread_mutex_t

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

impl Clone for cpu_set_t

fn clone(&self) -> cpu_set_t

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

impl Clone for siginfo_t

fn clone(&self) -> siginfo_t

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

impl Clone for exit_status

fn clone(&self) -> exit_status

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

impl Clone for Dl_info

fn clone(&self) -> Dl_info

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

impl Clone for sigval

fn clone(&self) -> sigval

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

impl Clone for utmp

fn clone(&self) -> utmp

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

impl Clone for rlimit

fn clone(&self) -> rlimit

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

impl Clone for sigaction

fn clone(&self) -> sigaction

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

impl Clone for sem_t

fn clone(&self) -> sem_t

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

impl Clone for timeval

fn clone(&self) -> timeval

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

impl Clone for rusage

fn clone(&self) -> rusage

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

impl Clone for flock

fn clone(&self) -> flock

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

impl Clone for utimbuf

fn clone(&self) -> utimbuf

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

impl Clone for rlimit64

fn clone(&self) -> rlimit64

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

impl Clone for lastlog

fn clone(&self) -> lastlog

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

impl Clone for dirent

fn clone(&self) -> dirent

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

impl Clone for pollfd

fn clone(&self) -> pollfd

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

impl Clone for pthread_rwlock_t

fn clone(&self) -> pthread_rwlock_t

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

Implementors

• impl<I> Clone for DecodeUtf16<I> where
    I: Clone + Iterator<Item = u16>, 
• impl Clone for DecodeUtf16Error
• impl<'a> Clone for SplitWhitespace<'a>
• impl<I> Clone for StepBy<I> where
    I: Clone, 
• impl Clone for CharTryFromError
• impl<'a> Clone for Arguments<'a>
• impl<Y, R> Clone for GeneratorState<Y, R> where
    R: Clone,
    Y: Clone, 
• impl<'a, P> Clone for MatchIndices<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl Clone for EscapeUnicode
• impl<I> Clone for Fuse<I> where
    I: Clone, 
• impl<'a, P> Clone for RMatches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl Clone for SearchStep
• impl Clone for ParseBoolError
• impl<I, P> Clone for SkipWhile<I, P> where
    I: Clone,
    P: Clone, 
• impl<'a> Clone for CharIndices<'a>
• impl<I> Clone for Enumerate<I> where
    I: Clone, 
• impl<I, U, F> Clone for FlatMap<I, U, F> where
    F: Clone,
    I: Clone,
    U: Clone + IntoIterator,
    <U as IntoIterator>::IntoIter: Clone,
    <U as IntoIterator>::IntoIter: Clone, 
• impl Clone for std::cmp::Ordering
• impl<'a, P> Clone for RSplitN<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a, P> Clone for SplitTerminator<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a, T> Clone for std::result::Iter<'a, T>
• impl<A, B> Clone for Zip<A, B> where
    A: Clone,
    B: Clone, 
• impl<'a, A> Clone for std::option::Iter<'a, A>
• impl<'a> Clone for Chars<'a>
• impl Clone for SipHasher13
• impl<'a> Clone for Bytes<'a>
• impl<I> Clone for Cloned<I> where
    I: Clone, 
• impl Clone for EscapeDebug
• impl<'a, T, P> Clone for std::slice::RSplit<'a, T, P> where
    P: Clone + FnMut(&T) -> bool,
    T: 'a + Clone, 
• impl Clone for TypeId
• impl<I, F> Clone for FilterMap<I, F> where
    F: Clone,
    I: Clone, 
• impl Clone for Utf8Error
• impl Clone for ParseIntError
• impl<'a, T> Clone for std::slice::Iter<'a, T>
• impl<T> Clone for Unique<T> where
    T: ?Sized, 
• impl Clone for TryFromIntError
• impl<'a, P> Clone for RSplitTerminator<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a, 'b> Clone for StrSearcher<'a, 'b>
• impl<A> Clone for Repeat<A> where
    A: Clone, 
• impl<'a, P> Clone for std::str::Split<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a, T> Clone for Chunks<'a, T>
• 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<T> Clone for Shared<T> where
    T: ?Sized, 
• impl<I, St, F> Clone for Scan<I, St, F> where
    F: Clone,
    I: Clone,
    St: Clone, 
• impl Clone for FpCategory
• impl<Idx> Clone for RangeInclusive<Idx> where
    Idx: Clone, 
• impl Clone for EscapeDefault
• impl<Idx> Clone for RangeTo<Idx> where
    Idx: Clone, 
• impl<H> Clone for BuildHasherDefault<H>
• impl<I> Clone for DecodeUtf8<I> where
    I: Clone + Iterator<Item = u8>, 
• impl<T> Clone for PhantomData<T> where
    T: ?Sized, 
• impl<I> Clone for Peekable<I> where
    I: Clone + Iterator,
    <I as Iterator>::Item: Clone, 
• impl<I, P> Clone for TakeWhile<I, P> where
    I: Clone,
    P: Clone, 
• impl<'a> Clone for CharSearcher<'a>
• impl Clone for SipHasher24
• impl<I, P> Clone for Filter<I, P> where
    I: Clone,
    P: Clone, 
• impl<'a, P> Clone for SplitN<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a, F> Clone for CharPredicateSearcher<'a, F> where
    F: Clone + FnMut(char) -> bool, 
• impl<I> Clone for Take<I> where
    I: Clone, 
• impl<I, F> Clone for Map<I, F> where
    F: Clone,
    I: Clone, 
• impl Clone for ParseFloatError
• impl Clone for std::sync::atomic::Ordering
• impl<'a, T, P> Clone for std::slice::Split<'a, T, P> where
    P: Clone + FnMut(&T) -> bool, 
• impl<'a, P> Clone for Matches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<T> Clone for Cell<T> where
    T: Copy, 
• impl<T> Clone for Option<T> where
    T: Clone, 
• impl<T> Clone for Empty<T>
• impl<T> Clone for Once<T> where
    T: Clone, 
• impl<I> Clone for Skip<I> where
    I: Clone, 
• impl<A> Clone for std::option::IntoIter<A> where
    A: Clone, 
• impl Clone for SipHasher
• impl<T> Clone for ManuallyDrop<T> where
    T: Clone, 
• impl<T> Clone for Discriminant<T>
• impl Clone for TraitObject
• impl<I, F> Clone for Inspect<I, F> where
    F: Clone,
    I: Clone, 
• impl<Idx> Clone for RangeFrom<Idx> where
    Idx: Clone, 
• impl<Idx> Clone for RangeToInclusive<Idx> where
    Idx: Clone, 
• impl<T> Clone for Wrapping<T> where
    T: Clone, 
• impl<T> Clone for Rev<T> where
    T: Clone, 
• impl<'a> Clone for LinesAny<'a>
• impl Clone for Error
• impl<T> Clone for RefCell<T> where
    T: Clone, 
• impl<I> Clone for Cycle<I> where
    I: Clone, 
• impl<T, E> Clone for Result<T, E> where
    E: Clone,
    T: Clone, 
• impl<Idx> Clone for std::ops::Range<Idx> where
    Idx: Clone, 
• impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>
• impl<A, B> Clone for Chain<A, B> where
    A: Clone,
    B: Clone, 
• impl<'a, P> Clone for std::str::RSplit<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone, 
• impl<'a> Clone for Lines<'a>
• impl Clone for RangeFull
• impl Clone for ParseCharError
• impl<'a> Clone for EncodeUtf16<'a>
• impl<T> Clone for std::vec::IntoIter<T> where
    T: Clone, 
• impl<T> Clone for Rc<T> where
    T: ?Sized, 
• impl<T> Clone for std::sync::Weak<T> where
    T: ?Sized, 
• impl<'a, T> Clone for std::collections::btree_set::Union<'a, T>
• impl<'a, K, V> Clone for std::collections::btree_map::Values<'a, K, V>
• impl<T> Clone for std::rc::Weak<T> where
    T: ?Sized, 
• impl<'a, B> Clone for Cow<'a, B> where
    B: ToOwned + ?Sized, 
• impl<T> Clone for Vec<T> where
    T: Clone, 
• impl<T> Clone for std::collections::linked_list::IntoIter<T> where
    T: Clone, 
• impl<'a, T> Clone for std::collections::vec_deque::Iter<'a, T>
• impl<'a, T> Clone for std::collections::linked_list::Iter<'a, T>
• impl<T> Clone for Box<[T]> where
    T: Clone, 
• impl Clone for CannotReallocInPlace
• impl<'a, K, V> Clone for std::collections::btree_map::Range<'a, K, V>
• impl<T> Clone for BTreeSet<T> where
    T: Clone, 
• impl<T> Clone for Box<T> where
    T: Clone, 
• impl<'a, T> Clone for std::collections::btree_set::Range<'a, T>
• impl Clone for AllocErr
• impl<T> Clone for VecDeque<T> where
    T: Clone, 
• impl<T> Clone for Bound<T> where
    T: Clone, 
• impl Clone for ParseError
• impl<'a, K, V> Clone for std::collections::btree_map::Iter<'a, K, V>
• impl<T> Clone for BinaryHeap<T> where
    T: Clone, 
• impl Clone for ExchangeHeapSingleton
• impl<'a, K, V> Clone for std::collections::btree_map::Keys<'a, K, V>
• impl<T> Clone for std::collections::binary_heap::IntoIter<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::SymmetricDifference<'a, T>
• impl<K, V> Clone for BTreeMap<K, V> where
    K: Clone,
    V: Clone, 
• impl<'a, T> Clone for std::collections::btree_set::Iter<'a, T>
• impl<T> Clone for Arc<T> where
    T: ?Sized, 
• impl Clone for Heap
• impl Clone for Box<str>
• impl<T> Clone for LinkedList<T> where
    T: Clone, 
• impl Clone for String
• impl<'a, T> Clone for std::collections::btree_set::Difference<'a, T>
• impl<'a, T> Clone for std::collections::btree_set::Intersection<'a, T>
• impl Clone for Layout
• impl<T> Clone for std::collections::vec_deque::IntoIter<T> where
    T: Clone, 
• impl Clone for LocalKeyState
• 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 std::os::linux::raw::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 Clone for PathBuf
• impl Clone for StripPrefixError
• impl Clone for Output
• impl Clone for ExitStatus
• 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 Duration
• 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