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

#[lang = "clone"]
pub trait Clone: Sized {
#[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.

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

Additional implementors

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

Required Methods

Returns a copy of the value.

Examples

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

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

Provided Methods

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 !
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impl Clone for core::cmp::Ordering
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impl Clone for FpCategory
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impl Clone for SearchStep
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impl Clone for core::sync::atomic::Ordering
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impl Clone for AllocErr
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impl Clone for CannotReallocInPlace
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impl Clone for Layout
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impl Clone for LayoutErr
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impl Clone for TypeId
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impl Clone for float64x1_t
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impl Clone for float64x2_t
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impl Clone for float32x2_t
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impl Clone for float32x4_t
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impl Clone for int16x2_t
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impl Clone for int16x4_t
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impl Clone for int16x8_t
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impl Clone for int32x2_t
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impl Clone for int32x4_t
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impl Clone for int64x1_t
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impl Clone for int64x2_t
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impl Clone for int8x16_t
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impl Clone for int8x4_t
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impl Clone for int8x8_t
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impl Clone for poly16x4_t
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impl Clone for poly16x8_t
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impl Clone for poly8x16_t
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impl Clone for poly8x8_t
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impl Clone for uint16x2_t
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impl Clone for uint16x4_t
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impl Clone for uint16x8_t
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impl Clone for uint32x2_t
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impl Clone for uint32x4_t
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impl Clone for uint64x1_t
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impl Clone for uint64x2_t
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impl Clone for uint8x16_t
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impl Clone for uint8x4_t
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impl Clone for uint8x8_t
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impl Clone for i8x16
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impl Clone for vector_bool_long
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impl Clone for vector_double
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impl Clone for vector_signed_long
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impl Clone for vector_unsigned_long
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impl Clone for CpuidResult
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impl Clone for __m128
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impl Clone for __m128d
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impl Clone for __m128i
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impl Clone for __m256
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impl Clone for __m256d
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impl Clone for __m256i
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impl Clone for __m64
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impl Clone for TryFromSliceError
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impl Clone for CharTryFromError
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impl Clone for DecodeUtf16Error
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impl Clone for EscapeDebug
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Important traits for EscapeDebug

impl Clone for EscapeDefault
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Important traits for EscapeDefault

impl Clone for EscapeUnicode
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Important traits for EscapeUnicode

impl Clone for ParseCharError
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impl Clone for ToLowercase
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Important traits for ToLowercase

impl Clone for ToUppercase
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Important traits for ToUppercase

impl Clone for UnicodeVersion
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impl Clone for Error
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impl Clone for SipHasher
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impl Clone for Pinned
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impl Clone for NonZeroU128
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impl Clone for NonZeroU16
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impl Clone for NonZeroU32
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impl Clone for NonZeroU64
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impl Clone for NonZeroU8
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impl Clone for NonZeroUsize
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impl Clone for ParseFloatError
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impl Clone for ParseIntError
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impl Clone for TryFromIntError
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impl Clone for RangeFull
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impl Clone for NoneError
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impl Clone for TraitObject
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impl Clone for ParseBoolError
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impl Clone for Utf8Error
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impl Clone for LocalWaker
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impl Clone for Waker
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impl Clone for Duration
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impl Clone for bool
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impl Clone for char
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impl Clone for f32
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impl Clone for f64
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impl Clone for i8
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impl Clone for i16
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impl Clone for i32
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impl Clone for i64
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impl Clone for i128
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impl Clone for isize
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impl Clone for u8
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impl Clone for u16
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impl Clone for u32
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impl Clone for u64
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impl Clone for u128
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impl Clone for usize
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impl<'a> Clone for Arguments<'a>
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impl<'a> Clone for CharSearcher<'a>
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impl<'a> Clone for Bytes<'a>
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Important traits for Bytes<'a>

impl<'a> Clone for CharIndices<'a>
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Important traits for CharIndices<'a>

impl<'a> Clone for Chars<'a>
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Important traits for Chars<'a>

impl<'a> Clone for EncodeUtf16<'a>
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Important traits for EncodeUtf16<'a>

impl<'a> Clone for Lines<'a>
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Important traits for Lines<'a>

impl<'a> Clone for LinesAny<'a>
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Important traits for LinesAny<'a>

impl<'a> Clone for SplitAsciiWhitespace<'a>
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Important traits for SplitAsciiWhitespace<'a>

impl<'a> Clone for SplitWhitespace<'a>
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Important traits for SplitWhitespace<'a>

impl<'a, 'b> Clone for CharSliceSearcher<'a, 'b>
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impl<'a, 'b> Clone for StrSearcher<'a, 'b>
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impl<'a, A> Clone for core::option::Iter<'a, A>
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Important traits for Iter<'a, A>

impl<'a, F: Clone> Clone for CharPredicateSearcher<'a, F> where
    F: FnMut(char) -> bool, 
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impl<'a, P: Pattern<'a>> Clone for MatchIndices<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for Matches<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for RMatchIndices<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for RMatches<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for core::str::RSplit<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for RSplitN<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for RSplitTerminator<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for core::str::Split<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for SplitN<'a, P> where
    P::Searcher: Clone
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impl<'a, P: Pattern<'a>> Clone for SplitTerminator<'a, P> where
    P::Searcher: Clone
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impl<'a, T> Clone for core::result::Iter<'a, T>
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Important traits for Iter<'a, T>

impl<'a, T> Clone for Chunks<'a, T>
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Important traits for Chunks<'a, T>

impl<'a, T> Clone for ExactChunks<'a, T>
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Important traits for ExactChunks<'a, T>

impl<'a, T> Clone for core::slice::Iter<'a, T>
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Important traits for Iter<'a, T>

impl<'a, T> Clone for Windows<'a, T>
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Important traits for Windows<'a, T>

impl<'a, T, P> Clone for core::slice::Split<'a, T, P> where
    P: Clone + FnMut(&T) -> bool, 
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Important traits for Split<'a, T, P>

impl<'a, T: Clone + 'a, P: Clone> Clone for core::slice::RSplit<'a, T, P> where
    P: FnMut(&T) -> bool, 
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Important traits for RSplit<'a, T, P>

impl<'a, T: ?Sized> Clone for &'a T
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impl<A: Clone> Clone for Repeat<A>
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Important traits for Repeat<A>

impl<A: Clone> Clone for core::option::IntoIter<A>
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Important traits for IntoIter<A>

impl<A: Clone, B: Clone> Clone for Chain<A, B>
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Important traits for Chain<A, B>

impl<A: Clone, B: Clone> Clone for Zip<A, B>
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Important traits for Zip<A, B>

impl<F: Clone> Clone for RepeatWith<F>
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Important traits for RepeatWith<F>

impl<H> Clone for BuildHasherDefault<H>
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impl<I, U> Clone for Flatten<I> where
    I: Iterator + Clone,
    U: Iterator + Clone,
    I::Item: IntoIterator<IntoIter = U, Item = U::Item>, 
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impl<I: Clone + Iterator> Clone for Peekable<I> where
    I::Item: Clone
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Important traits for Peekable<I>

impl<I: Clone> Clone for DecodeUtf16<I> where
    I: Iterator<Item = u16>, 
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Important traits for DecodeUtf16<I>

impl<I: Clone> Clone for Cloned<I>
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Important traits for Cloned<I>

impl<I: Clone> Clone for Cycle<I>
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Important traits for Cycle<I>

impl<I: Clone> Clone for Enumerate<I>
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Important traits for Enumerate<I>

impl<I: Clone> Clone for Fuse<I>
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Important traits for Fuse<I>

impl<I: Clone> Clone for Skip<I>
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Important traits for Skip<I>

impl<I: Clone> Clone for StepBy<I>
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Important traits for StepBy<I>

impl<I: Clone> Clone for Take<I>
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Important traits for Take<I>

impl<I: Clone, F: Clone> Clone for FilterMap<I, F>
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Important traits for FilterMap<I, F>

impl<I: Clone, F: Clone> Clone for Inspect<I, F>
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Important traits for Inspect<I, F>

impl<I: Clone, F: Clone> Clone for Map<I, F>
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Important traits for Map<I, F>

impl<I: Clone, P: Clone> Clone for Filter<I, P>
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Important traits for Filter<I, P>

impl<I: Clone, P: Clone> Clone for SkipWhile<I, P>
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Important traits for SkipWhile<I, P>

impl<I: Clone, P: Clone> Clone for TakeWhile<I, P>
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Important traits for TakeWhile<I, P>

impl<I: Clone, St: Clone, F: Clone> Clone for Scan<I, St, F>
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Important traits 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
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impl<Idx: Clone> Clone for Range<Idx>
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Important traits for Range<A>

impl<Idx: Clone> Clone for RangeFrom<Idx>
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Important traits for RangeFrom<A>

impl<Idx: Clone> Clone for RangeInclusive<Idx>
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Important traits for RangeInclusive<A>

impl<Idx: Clone> Clone for RangeTo<Idx>
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impl<Idx: Clone> Clone for RangeToInclusive<Idx>
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impl<T> Clone for Empty<T>
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Important traits for Empty<T>

impl<T> Clone for Discriminant<T>
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impl<T: Clone + ?Sized> Clone for ManuallyDrop<T>
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impl<T: Clone> Clone for Bound<T>
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impl<T: Clone> Clone for Option<T>
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impl<T: Clone> Clone for Poll<T>
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impl<T: Clone> Clone for RefCell<T>
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Panics

Panics if the value is currently mutably borrowed.

impl<T: Clone> Clone for Reverse<T>
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impl<T: Clone> Clone for Once<T>
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Important traits for Once<T>

impl<T: Clone> Clone for Rev<T>
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Important traits for Rev<I>

impl<T: Clone> Clone for Wrapping<T>
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impl<T: Clone> Clone for core::result::IntoIter<T>
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Important traits for IntoIter<T>

impl<T: Clone, E: Clone> Clone for Result<T, E>
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impl<T: Copy> Clone for Cell<T>
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impl<T: ?Sized> Clone for *const T
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impl<T: ?Sized> Clone for *mut T
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impl<T: ?Sized> Clone for PhantomData<T>
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impl<T: ?Sized> Clone for NonNull<T>
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impl<Y: Clone, R: Clone> Clone for GeneratorState<Y, R>
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