Trait core::clone::Clone 1.0.0
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#[lang = "clone"]pub trait Clone: Sized { 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 } }Run
Required Methods
fn clone(&self) -> Self
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.
Implementors
impl Clone for ParseFloatErrorimpl Clone for NonZeroU8impl Clone for NonZeroU16impl Clone for NonZeroU32impl Clone for NonZeroU64impl Clone for NonZeroU128impl Clone for NonZeroUsizeimpl Clone for NonZeroI8impl Clone for NonZeroI16impl Clone for NonZeroI32impl Clone for NonZeroI64impl Clone for NonZeroI128impl Clone for NonZeroIsizeimpl<T: Clone> Clone for Wrapping<T>impl Clone for FpCategoryimpl Clone for TryFromIntErrorimpl Clone for ParseIntErrorimpl<T> Clone for Discriminant<T>impl<T: Clone> Clone for ManuallyDrop<T>impl<T: Clone + Zeroable> Clone for NonZero<T>impl<T: ?Sized> Clone for Unique<T>impl<T: ?Sized> Clone for NonNull<T>impl<T: ?Sized> Clone for PhantomData<T>impl<Y: Clone, R: Clone> Clone for GeneratorState<Y, R>impl Clone for RangeFullimpl<Idx: Clone> Clone for Range<Idx>impl<Idx: Clone> Clone for RangeFrom<Idx>impl<Idx: Clone> Clone for RangeTo<Idx>impl<Idx: Clone> Clone for RangeInclusive<Idx>impl<Idx: Clone> Clone for RangeToInclusive<Idx>impl<T: Clone> Clone for Bound<T>impl Clone for core::cmp::Orderingimpl<T: Clone> Clone for Reverse<T>impl Clone for TypeIdimpl Clone for TryFromSliceErrorimpl Clone for core::sync::atomic::Orderingimpl<T: Copy> Clone for Cell<T>impl<T: Clone> Clone for RefCell<T>impl Clone for ParseCharErrorimpl Clone for CharTryFromErrorimpl Clone for EscapeUnicodeimpl Clone for EscapeDefaultimpl Clone for EscapeDebugimpl<I: Clone + Iterator<Item = u8>> Clone for DecodeUtf8<I>impl<A: Clone> Clone for Repeat<A>impl<F: Clone> Clone for RepeatWith<F>impl<T> Clone for Empty<T>impl<T: Clone> Clone for Once<T>impl<T: Clone> Clone for Rev<T>impl<I: Clone> Clone for Cloned<I>impl<I: Clone> Clone for Cycle<I>impl<I: Clone> Clone for StepBy<I>impl<A: Clone, B: Clone> Clone for Chain<A, B>impl<A: Clone, B: Clone> Clone for Zip<A, B>impl<I: Clone, F: Clone> Clone for Map<I, F>impl<I: Clone, P: Clone> Clone for Filter<I, P>impl<I: Clone, F: Clone> Clone for FilterMap<I, F>impl<I: Clone> Clone for Enumerate<I>impl<I: Clone + Iterator> Clone for Peekable<I> where
I::Item: Clone,impl<I: Clone, P: Clone> Clone for SkipWhile<I, P>impl<I: Clone, P: Clone> Clone for TakeWhile<I, P>impl<I: Clone> Clone for Skip<I>impl<I: Clone> Clone for Take<I>impl<I: Clone, St: Clone, F: Clone> Clone for Scan<I, St, F>impl<I: Clone, U: Clone + IntoIterator, F: Clone> Clone for FlatMap<I, U, F> where
<U as IntoIterator>::IntoIter: Clone,impl<I, U> Clone for Flatten<I> where
I: Iterator + Clone,
U: Iterator + Clone,
I::Item: IntoIterator<IntoIter = U, Item = U::Item>,impl<I: Clone> Clone for Fuse<I>impl<I: Clone, F: Clone> Clone for Inspect<I, F>impl<T: Clone> Clone for Option<T>impl<'a, A> Clone for core::option::Iter<'a, A>impl<A: Clone> Clone for core::option::IntoIter<A>impl Clone for NoneErrorimpl Clone for TraitObjectimpl<T: Clone, E: Clone> Clone for Result<T, E>impl<'a, T> Clone for core::result::Iter<'a, T>impl<T: Clone> Clone for core::result::IntoIter<T>impl<'a, T> Clone for core::slice::Iter<'a, T>impl<'a, T, P> Clone for core::slice::Split<'a, T, P> where
P: Clone + FnMut(&T) -> bool,impl<'a, T: Clone + 'a, P: Clone> Clone for core::slice::RSplit<'a, T, P> where
P: FnMut(&T) -> bool,impl<'a, T> Clone for Windows<'a, T>impl<'a, T> Clone for Chunks<'a, T>impl<'a, T> Clone for ExactChunks<'a, T>impl Clone for SearchStepimpl<'a> Clone for CharSearcher<'a>impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>impl<'a, F: Clone> Clone for CharPredicateSearcher<'a, F> where
F: FnMut(char) -> bool,impl<'a, 'b> Clone for StrSearcher<'a, 'b>impl Clone for ParseBoolErrorimpl Clone for Utf8Errorimpl<'a> Clone for Chars<'a>impl<'a> Clone for CharIndices<'a>impl<'a> Clone for Bytes<'a>impl<'a, P: Pattern<'a>> Clone for core::str::Split<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for core::str::RSplit<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for SplitTerminator<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for RSplitTerminator<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for SplitN<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for RSplitN<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for MatchIndices<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for RMatchIndices<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for Matches<'a, P> where
P::Searcher: Clone,impl<'a, P: Pattern<'a>> Clone for RMatches<'a, P> where
P::Searcher: Clone,impl<'a> Clone for Lines<'a>impl<'a> Clone for LinesAny<'a>impl Clone for SipHasherimpl<H> Clone for BuildHasherDefault<H>impl Clone for Errorimpl<'a> Clone for Arguments<'a>impl Clone for Durationimpl Clone for Layoutimpl Clone for AllocErrimpl Clone for CannotReallocInPlaceimpl Clone for CollectionAllocErrimpl Clone for i8x2impl Clone for u8x2impl Clone for b8x2impl Clone for i16x2impl Clone for u16x2impl Clone for i8x4impl Clone for u8x4impl Clone for b8x4impl Clone for i8x8impl Clone for u8x8impl Clone for b8x8impl Clone for i16x4impl Clone for u16x4impl Clone for i32x2impl Clone for u32x2impl Clone for f32x2impl Clone for i8x16impl Clone for u8x16impl Clone for b8x16impl Clone for i16x8impl Clone for u16x8impl Clone for i32x4impl Clone for u32x4impl Clone for f32x4impl Clone for i64x2impl Clone for u64x2impl Clone for f64x2impl Clone for i8x32impl Clone for u8x32impl Clone for b8x32impl Clone for i16x16impl Clone for u16x16impl Clone for i32x8impl Clone for u32x8impl Clone for f32x8impl Clone for i64x4impl Clone for u64x4impl Clone for f64x4impl Clone for i8x64impl Clone for u8x64impl Clone for b8x64impl Clone for i16x32impl Clone for u16x32impl Clone for i32x16impl Clone for u32x16impl Clone for f32x16impl Clone for i64x8impl Clone for u64x8impl Clone for f64x8impl Clone for CpuidResultimpl Clone for __m64impl Clone for __m128iimpl Clone for __m128impl Clone for __m128dimpl Clone for __m256iimpl Clone for __m256impl Clone for __m256d