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"]    pub fn clone(&self) -> Self;

    pub 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"]pub fn clone(&self) -> Self[src]

Returns a copy of the value.

Examples

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

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

pub fn clone_from(&mut self, source: &Self)[src]

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 Duration[src]

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

impl Clone for __m256[src]

impl Clone for EscapeDefault[src]

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

impl Clone for Infallible[src]

impl Clone for NonZeroI8[src]

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

impl Clone for __m256i[src]

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

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

impl Clone for CharTryFromError[src]

impl Clone for LayoutError[src]

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

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

impl Clone for NonZeroU8[src]

impl Clone for Layout[src]

impl Clone for NoneError[src]

impl Clone for Ordering[src]

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

impl Clone for NonZeroU64[src]

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

impl Clone for ToUppercase[src]

impl Clone for NonZeroIsize[src]

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

impl Clone for __m512[src]

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

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

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

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

impl Clone for ParseFloatError[src]

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

impl Clone for TryFromSliceError[src]

impl Clone for Waker[src]

impl Clone for AllocError[src]

impl Clone for ParseIntError[src]

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

impl<'a, T, const N: usize> Clone for ArrayWindows<'a, T, N> where
    T: 'a + Clone
[src]

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

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

impl Clone for __m256d[src]

impl Clone for __m128i[src]

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

impl Clone for NonZeroU16[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<I, F> Clone for Map<I, F> where
    F: Clone,
    I: Clone
[src]

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

impl Clone for EscapeDebug[src]

impl Clone for Error[src]

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

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

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

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

impl Clone for __m512i[src]

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

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

impl Clone for __m128[src]

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

impl Clone for NonZeroI16[src]

impl Clone for FpCategory[src]

impl Clone for EscapeUnicode[src]

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

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

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

impl Clone for NonZeroI128[src]

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

impl Clone for IntErrorKind[src]

impl<B, C> Clone for ControlFlow<B, C> where
    B: Clone,
    C: Clone
[src]

impl Clone for RangeFull[src]

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

impl Clone for TryFromIntError[src]

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

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

Panics

Panics if the value is currently mutably borrowed.

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

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

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

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

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

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

impl Clone for NonZeroU32[src]

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

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

impl Clone for SipHasher[src]

impl Clone for EscapeDefault[src]

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

impl Clone for PhantomPinned[src]

impl Clone for __m128d[src]

impl Clone for RawWakerVTable[src]

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

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

impl Clone for __m512d[src]

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

impl Clone for ParseCharError[src]

impl Clone for DecodeUtf16Error[src]

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

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

impl Clone for NonZeroI64[src]

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

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

impl Clone for TypeId[src]

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

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

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

impl Clone for TraitObject[src]

impl Clone for CpuidResult[src]

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

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

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

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

impl<'_, T, const N: usize> Clone for ArrayChunks<'_, T, N>[src]

impl Clone for NonZeroI32[src]

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

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

impl Clone for NonZeroU128[src]

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

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

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

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

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

impl Clone for ToLowercase[src]

impl Clone for NonZeroUsize[src]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

pub 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 Iter<'_, T>[src]

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

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

impl Clone for TryReserveError[src]

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

impl Clone for LittleEndian[src]

impl Clone for BigEndian[src]

impl Clone for Words

impl Clone for Pages

impl Clone for Pages

impl Clone for Words

impl Clone for Bytes

impl Clone for semun

impl Clone for lconv

impl Clone for aiocb

impl Clone for dirent

impl Clone for pthread_attr_t

impl Clone for __darwin_mcontext64

impl Clone for pthread_rwlock_t

impl Clone for sigval

impl Clone for ntptimeval

impl Clone for glob_t

impl Clone for __darwin_x86_float_state64

impl Clone for siginfo_t

impl Clone for utimbuf

impl Clone for regex_t

impl Clone for sigevent

impl Clone for tm

impl Clone for servent

impl Clone for timezone

impl Clone for segment_command

impl Clone for semid_ds

impl Clone for ifaddrs

impl Clone for mach_header_64

impl Clone for rlimit

impl Clone for FILE

impl Clone for in6_addr

impl Clone for rusage

impl Clone for pthread_mutexattr_t

impl Clone for winsize

impl Clone for protoent

impl Clone for segment_command_64

impl Clone for mach_timebase_info

impl Clone for regmatch_t

impl Clone for fpos_t

impl Clone for ip_mreq

impl Clone for utmpx

impl Clone for sa_endpoints_t

impl Clone for pthread_mutex_t

impl Clone for proc_taskallinfo

impl Clone for sigaction

impl Clone for proc_threadinfo

impl Clone for sockaddr_un

impl Clone for fd_set

impl Clone for sockaddr

impl Clone for cmsghdr

impl Clone for fstore_t

impl Clone for max_align_t

impl Clone for __darwin_xmm_reg

impl Clone for group

impl Clone for DIR

impl Clone for xsw_usage

impl Clone for timeval

impl Clone for pthread_rwlockattr_t

impl Clone for timex

impl Clone for __darwin_x86_thread_state64

impl Clone for in6_pktinfo

impl Clone for passwd

impl Clone for ipv6_mreq

impl Clone for sf_hdtr

impl Clone for linger

impl Clone for flock

impl Clone for mach_header

impl Clone for proc_bsdinfo

impl Clone for timespec

impl Clone for bpf_hdr

impl Clone for if_nameindex

impl Clone for statfs

impl Clone for __darwin_x86_exception_state64

impl Clone for itimerval

impl Clone for tms

impl Clone for statvfs

impl Clone for stack_t

impl Clone for __darwin_mmst_reg

impl Clone for sockaddr_inarp

impl Clone for hostent

impl Clone for in_pktinfo

impl Clone for timeval32

impl Clone for msghdr

impl Clone for proc_taskinfo

impl Clone for sockaddr_in6

impl Clone for in_addr

impl Clone for fsid_t

impl Clone for dqblk

impl Clone for termios

impl Clone for kevent64_s

impl Clone for iovec

impl Clone for pthread_condattr_t

impl Clone for sembuf

impl Clone for shmid_ds

impl Clone for kevent

impl Clone for pthread_cond_t

impl Clone for stat

impl Clone for utsname

impl Clone for ipc_perm

impl Clone for ucontext_t

impl Clone for if_msghdr

impl Clone for arphdr

impl Clone for radvisory

impl Clone for addrinfo

impl Clone for sockaddr_ctl

impl Clone for pollfd

impl Clone for if_data

impl Clone for xucred

impl Clone for sockaddr_storage

impl Clone for load_command

impl Clone for Dl_info

impl Clone for sockaddr_dl

impl Clone for sockaddr_in

impl Clone for FromHexError

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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 I128[src]

impl Clone for String[src]

impl Clone for U128[src]

impl Clone for Box<str, Global>[src]

impl Clone for H160[src]

impl Clone for H256[src]

impl Clone for U256[src]

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 &'_ mut T where
    T: ?Sized
[src]

Shared references can be cloned, but mutable references cannot!

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

Shared references can be cloned, but mutable references cannot!

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, A> Clone for Box<T, A> where
    A: Clone + Allocator,
    T: Clone
[src]

pub fn clone(&self) -> Box<T, A>

Notable traits for Box<F, A>

impl<F, A> Future for Box<F, A> where
    A: Allocator + 'static,
    F: Unpin + Future + ?Sized
type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
    A: Allocator,
    I: Iterator + ?Sized
type Item = <I as Iterator>::Item;
[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);

pub fn clone_from(&mut self, source: &Box<T, A>)[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, A> Clone for Box<[T], A> where
    A: Clone + Allocator,
    T: Clone
[src]

impl<T, A> Clone for ontio_std::prelude::vec::IntoIter<T, A> where
    A: Clone + Allocator,
    T: Clone
[src]

impl<T, A> Clone for Vec<T, A> where
    A: Clone + Allocator,
    T: Clone
[src]

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

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