Trait nom::lib::std::prelude::v1::rust_2015::Clone1.0.0[][src]

#[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:

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());
Loading content...

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.

Loading content...

Implementations on Foreign Types

impl Clone for NonZeroU16[src]

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

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

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

impl Clone for NonZeroI32[src]

impl Clone for __m512d[src]

impl Clone for TryFromSliceError[src]

impl Clone for DecodeUtf16Error[src]

impl Clone for LayoutError[src]

impl Clone for __m128d[src]

impl Clone for NonZeroUsize[src]

impl Clone for NonZeroI8[src]

impl Clone for NonZeroIsize[src]

impl Clone for IntErrorKind[src]

impl Clone for __m512i[src]

impl Clone for __m128bh[src]

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

impl Clone for ParseIntError[src]

impl Clone for __m128i[src]

impl Clone for Ordering[src]

impl Clone for TraitObject[src]

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

impl Clone for __m256i[src]

impl Clone for NonZeroU8[src]

impl Clone for NonZeroU32[src]

impl Clone for ParseFloatError[src]

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

impl Clone for EscapeUnicode[src]

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

impl Clone for PhantomPinned[src]

impl Clone for AllocError[src]

impl Clone for __m256d[src]

impl Clone for __m512bh[src]

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

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

impl Clone for EscapeDefault[src]

impl Clone for RawWakerVTable[src]

impl Clone for NonZeroU128[src]

impl Clone for __m256[src]

impl Clone for Duration[src]

impl Clone for __m512[src]

impl Clone for ToUppercase[src]

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

impl Clone for EscapeDebug[src]

impl<Dyn> Clone for DynMetadata<Dyn> where
    Dyn: ?Sized
[src]

impl Clone for CharTryFromError[src]

impl Clone for Waker[src]

impl Clone for NonZeroU64[src]

impl Clone for NonZeroI64[src]

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

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

impl Clone for __m256bh[src]

impl Clone for FpCategory[src]

impl Clone for SipHasher[src]

impl Clone for CpuidResult[src]

impl Clone for TypeId[src]

impl Clone for Layout[src]

impl Clone for __m128[src]

impl Clone for EscapeDefault[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 Clone for ToLowercase[src]

impl Clone for TryFromIntError[src]

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

impl Clone for NonZeroI16[src]

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

impl Clone for ParseCharError[src]

impl Clone for NonZeroI128[src]

Loading content...

Implementors

impl Clone for ![src]

impl Clone for Needed[src]

impl Clone for ErrorKind[src]

impl Clone for nom::lib::std::cmp::Ordering[src]

impl Clone for Infallible1.34.0[src]

impl Clone for SearchStep[src]

impl Clone for Endianness[src]

impl Clone for Error[src]

impl Clone for RangeFull[src]

impl Clone for NoneError[src]

impl Clone for ParseBoolError[src]

impl Clone for Utf8Error[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<'_, A> Clone for nom::lib::std::option::Iter<'_, A>[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<'_, T> Clone for nom::lib::std::result::Iter<'_, T>[src]

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

impl<'_, T> Clone for ChunksExact<'_, T>1.31.0[src]

impl<'_, T> Clone for nom::lib::std::slice::Iter<'_, T>[src]

impl<'_, T> Clone for RChunks<'_, T>1.31.0[src]

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

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

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

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

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

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

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

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

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

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

impl<'a> Clone for EncodeUtf16<'a>1.8.0[src]

impl<'a> Clone for nom::lib::std::str::EscapeDebug<'a>1.34.0[src]

impl<'a> Clone for nom::lib::std::str::EscapeDefault<'a>1.34.0[src]

impl<'a> Clone for nom::lib::std::str::EscapeUnicode<'a>1.34.0[src]

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

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

impl<'a> Clone for SplitAsciiWhitespace<'a>1.34.0[src]

impl<'a> Clone for SplitWhitespace<'a>1.1.0[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
1.5.0[src]

impl<'a, P> Clone for Matches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
1.2.0[src]

impl<'a, P> Clone for RMatchIndices<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
1.5.0[src]

impl<'a, P> Clone for RMatches<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
1.2.0[src]

impl<'a, P> Clone for nom::lib::std::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 nom::lib::std::str::Split<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
[src]

impl<'a, P> Clone for nom::lib::std::str::SplitInclusive<'a, P> where
    P: Pattern<'a>,
    <P as Pattern<'a>>::Searcher: Clone
1.51.0[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<'a, T> Clone for RChunksExact<'a, T>1.31.0[src]

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

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

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

impl<A> Clone for nom::lib::std::option::IntoIter<A> where
    A: Clone
[src]

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

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

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

impl<E: Clone> Clone for Err<E>[src]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

impl<Idx> Clone for RangeToInclusive<Idx> where
    Idx: Clone
1.26.0[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 Bound<T> where
    T: Clone
1.17.0[src]

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

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

impl<T> Clone for Empty<T>1.2.0[src]

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

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

impl<T> Clone for Discriminant<T>1.21.0[src]

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

impl<T> Clone for nom::lib::std::result::IntoIter<T> where
    T: Clone
[src]

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

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

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

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

Loading content...