1.0.0[][src]Trait ontio_std::prelude::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,
}

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
    }
}

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 Clone themselves. Note that variables captured by shared reference always implement Clone (even if the referent doesn't), while variables captured by mutable reference never 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());
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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<T> Clone for Discriminant<T>[src]

impl Clone for NonZeroI8[src]

impl Clone for NonZeroU8[src]

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

impl Clone for NonZeroI32[src]

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

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

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

impl Clone for IntErrorKind[src]

impl Clone for SipHasher[src]

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

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

impl Clone for EscapeDebug[src]

impl Clone for ToLowercase[src]

impl Clone for LayoutErr[src]

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

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

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

impl Clone for __m256[src]

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

impl Clone for TryFromIntError[src]

impl Clone for NonZeroU32[src]

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

impl Clone for NonZeroU128[src]

impl Clone for PhantomPinned[src]

impl Clone for __m512d[src]

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

impl Clone for NonZeroI128[src]

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

impl Clone for AllocErr[src]

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

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

impl Clone for __m256d[src]

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

impl Clone for ToUppercase[src]

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

impl Clone for __m128i[src]

impl Clone for Layout[src]

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

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

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

impl Clone for CpuidResult[src]

impl Clone for NonZeroI16[src]

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

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

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

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

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

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

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

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

impl Clone for NonZeroI64[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 Clone for __m64[src]

impl Clone for Waker[src]

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

impl Clone for CannotReallocInPlace[src]

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

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

impl Clone for UnicodeVersion[src]

impl Clone for NonZeroUsize[src]

impl Clone for EscapeDefault[src]

impl Clone for EscapeUnicode[src]

impl Clone for __m128d[src]

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

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

impl Clone for TraitObject[src]

impl Clone for RawWakerVTable[src]

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

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

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

impl Clone for __m256i[src]

impl Clone for TryFromSliceError[src]

impl Clone for Infallible[src]

impl Clone for __m512[src]

impl Clone for NonZeroIsize[src]

impl Clone for CharTryFromError[src]

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

impl Clone for ParseCharError[src]

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

impl Clone for __m128[src]

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

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

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

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

impl Clone for TypeId[src]

impl Clone for Error[src]

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

impl Clone for NonZeroU64[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 Clone for RangeFull[src]

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

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

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

impl Clone for ParseIntError[src]

impl Clone for Ordering[src]

impl Clone for Duration[src]

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

impl Clone for __m512i[src]

impl Clone for FpCategory[src]

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

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

impl Clone for DecodeUtf16Error[src]

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

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

impl<const N: usize, T> Clone for IntoIter<T, N> where
    T: Clone,
    [T; N]: LengthAtMost32
[src]

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

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

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

impl Clone for NonZeroU16[src]

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

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

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

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

impl Clone for ParseFloatError[src]

impl Clone for NoneError[src]

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

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

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

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

impl<'_, K, V> Clone for Iter<'_, K, V>[src]

impl<'_, K, V> Clone for Range<'_, K, V>[src]

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

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

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

impl Clone for TryReserveError[src]

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

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

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

Examples

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

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

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

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

impl<'_, T> Clone for Iter<'_, T>[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 allocation, increasing the strong reference count.

Examples

use std::rc::Rc;

let five = Rc::new(5);

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

impl Clone for Global[src]

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

impl<'_, K, V> Clone for Values<'_, K, V>[src]

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

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

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

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

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

Examples

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

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

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

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

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

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

impl<'_, K, V> Clone for Keys<'_, K, V>[src]

impl<'_, B> Clone for Cow<'_, B> where
    B: ToOwned + ?Sized
[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 allocation, increasing the strong reference count.

Examples

use std::sync::Arc;

let five = Arc::new(5);

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

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

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

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

impl Clone for LittleEndian[src]

impl Clone for BigEndian[src]

impl Clone for Words

impl Clone for Pages

impl Clone for Words

impl Clone for Bytes

impl Clone for Pages

impl Clone for nlmsghdr

impl Clone for statx

impl Clone for nl_pktinfo

impl Clone for ff_effect

impl Clone for sysinfo

impl Clone for dqblk

impl Clone for sigset_t

impl Clone for Dl_info

impl Clone for mcontext_t

impl Clone for input_mask

impl Clone for spwd

impl Clone for ip_mreq

impl Clone for inotify_event

impl Clone for nl_mmap_hdr

impl Clone for posix_spawn_file_actions_t

impl Clone for timespec

impl Clone for pthread_mutex_t

impl Clone for msghdr

impl Clone for sockaddr

impl Clone for utimbuf

impl Clone for statvfs

impl Clone for stack_t

impl Clone for if_nameindex

impl Clone for dirent

impl Clone for Elf32_Chdr

impl Clone for __timeval

impl Clone for ucred

impl Clone for _libc_fpstate

impl Clone for termios

impl Clone for af_alg_iv

impl Clone for sigval

impl Clone for sched_param

impl Clone for arphdr

impl Clone for sockaddr_in

impl Clone for user_fpxregs_struct

impl Clone for input_keymap_entry

impl Clone for pollfd

impl Clone for pthread_attr_t

impl Clone for nlattr

impl Clone for Elf64_Ehdr

impl Clone for ip_mreq_source

impl Clone for dirent64

impl Clone for Elf32_Sym

impl Clone for aiocb

impl Clone for fpos_t

impl Clone for in6_addr

impl Clone for ff_replay

impl Clone for fsid_t

impl Clone for winsize

impl Clone for user

impl Clone for hostent

impl Clone for input_id

impl Clone for nl_mmap_req

impl Clone for siginfo_t

impl Clone for stat64

impl Clone for Elf32_Shdr

impl Clone for Elf64_Sym

impl Clone for tms

impl Clone for iovec

impl Clone for statfs64

impl Clone for passwd

impl Clone for in_addr

impl Clone for flock64

impl Clone for ff_ramp_effect

impl Clone for cmsghdr

impl Clone for _libc_fpreg

impl Clone for sigevent

impl Clone for flock

impl Clone for rusage

impl Clone for timezone

impl Clone for msqid_ds

impl Clone for ff_envelope

impl Clone for rlimit64

impl Clone for in6_pktinfo

impl Clone for mmsghdr

impl Clone for __exit_status

impl Clone for sockaddr_vm

impl Clone for glob64_t

impl Clone for tm

impl Clone for sigaction

impl Clone for addrinfo

impl Clone for FILE

impl Clone for pthread_rwlock_t

impl Clone for ipc_perm

impl Clone for sockaddr_alg

impl Clone for sockaddr_ll

impl Clone for ff_rumble_effect

impl Clone for max_align_t

impl Clone for sockaddr_nl

impl Clone for Elf32_Ehdr

impl Clone for DIR

impl Clone for timeval

impl Clone for group

impl Clone for mntent

impl Clone for genlmsghdr

impl Clone for statx_timestamp

impl Clone for ifaddrs

impl Clone for arpreq

impl Clone for Elf32_Phdr

impl Clone for glob_t

impl Clone for pthread_rwlockattr_t

impl Clone for Elf64_Shdr

impl Clone for sockaddr_in6

impl Clone for ff_constant_effect

impl Clone for utmpx

impl Clone for msginfo

impl Clone for protoent

impl Clone for posix_spawnattr_t

impl Clone for termios2

impl Clone for servent

impl Clone for Elf64_Phdr

impl Clone for rlimit

impl Clone for rtentry

impl Clone for Elf64_Chdr

impl Clone for stat

impl Clone for utsname

impl Clone for ff_periodic_effect

impl Clone for mq_attr

impl Clone for ucontext_t

impl Clone for fpos64_t

impl Clone for sockaddr_un

impl Clone for arpd_request

impl Clone for cpu_set_t

impl Clone for fd_set

impl Clone for ff_condition_effect

impl Clone for linger

impl Clone for sembuf

impl Clone for itimerval

impl Clone for input_absinfo

impl Clone for epoll_event

impl Clone for pthread_mutexattr_t

impl Clone for user_fpregs_struct

impl Clone for ipv6_mreq

impl Clone for dl_phdr_info

impl Clone for in_pktinfo

impl Clone for user_regs_struct

impl Clone for statfs

impl Clone for in6_rtmsg

impl Clone for input_event

impl Clone for pthread_cond_t

impl Clone for shmid_ds

impl Clone for packet_mreq

impl Clone for nlmsgerr

impl Clone for pthread_condattr_t

impl Clone for lconv

impl Clone for ff_trigger

impl Clone for statvfs64

impl Clone for arpreq_old

impl Clone for mallinfo

impl Clone for sockaddr_storage

impl Clone for sem_t

impl Clone for signalfd_siginfo

impl Clone for itimerspec

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Implementors

impl Clone for ![src]

impl Clone for ontio_std::prelude::cmp::Ordering[src]

impl Clone for SearchStep[src]

impl Clone for ParseBoolError[src]

impl Clone for Utf8Error[src]

impl Clone for FromUtf8Error[src]

impl Clone for String[src]

impl Clone for Box<str>[src]

impl Clone for H160

impl Clone for H256

impl Clone for bool[src]

impl Clone for char[src]

impl Clone for f32[src]

impl Clone for f64[src]

impl Clone for i8[src]

impl Clone for i16[src]

impl Clone for i32[src]

impl Clone for i64[src]

impl Clone for i128[src]

impl Clone for isize[src]

impl Clone for u8[src]

impl Clone for u16[src]

impl Clone for u32[src]

impl Clone for u64[src]

impl Clone for u128[src]

impl Clone for usize[src]

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

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

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

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

impl<'a> Clone for ontio_std::prelude::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 ontio_std::prelude::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 ontio_std::prelude::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<T> Clone for *const T where
    T: ?Sized
[src]

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

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

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

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

Important traits for Box<F>
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);

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);

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

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

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

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

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