Trait nom::lib::std::prelude::v1::rust_2021::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:

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());

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.

Trait nom::lib::std::prelude::v1::rust_2021::Clone⎘1.0.0[−][src]

Derivable

How can I implement Clone?

Additional implementors

Required methods

#[must_use = "cloning is often expensive and is not expected to have side effects"]pub fn clone(&self) -> Self[src][−]

Examples

Provided methods

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

Implementations on Foreign Types

impl Clone for NonZeroU16[src][−]

pub fn clone(&self) -> NonZeroU16[src]

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

pub fn clone(&self) -> Location<'a>[src]

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

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

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

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

impl Clone for NonZeroI32[src][−]

pub fn clone(&self) -> NonZeroI32[src]

impl Clone for __m512d[src][−]

pub fn clone(&self) -> __m512d[src]

impl Clone for TryFromSliceError[src][−]

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

impl Clone for DecodeUtf16Error[src][−]

pub fn clone(&self) -> DecodeUtf16Error[src]

impl Clone for LayoutError[src][−]

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

impl Clone for __m128d[src][−]

pub fn clone(&self) -> __m128d[src]

impl Clone for NonZeroUsize[src][−]

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

impl Clone for NonZeroI8[src][−]

pub fn clone(&self) -> NonZeroI8[src]

impl Clone for NonZeroIsize[src][−]

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

impl Clone for IntErrorKind[src][−]

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

impl Clone for __m512i[src][−]

pub fn clone(&self) -> __m512i[src]

impl Clone for __m128bh[src][−]

pub fn clone(&self) -> __m128bh[src]

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

pub fn clone(&self) -> VaListImpl<'f>[src]

impl Clone for ParseIntError[src][−]

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

impl Clone for __m128i[src][−]

pub fn clone(&self) -> __m128i[src]

impl Clone for Ordering[src][−]

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

impl Clone for TraitObject[src][−]

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

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

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

impl Clone for __m256i[src][−]

pub fn clone(&self) -> __m256i[src]

impl Clone for NonZeroU8[src][−]

pub fn clone(&self) -> NonZeroU8[src]

impl Clone for NonZeroU32[src][−]

pub fn clone(&self) -> NonZeroU32[src]

impl Clone for ParseFloatError[src][−]

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

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

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

impl Clone for EscapeUnicode[src][−]

pub fn clone(&self) -> EscapeUnicodeⓘNotable traits for EscapeUnicodeimpl Iterator for EscapeUnicode type Item = char;[src]

Notable traits for EscapeUnicode

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

pub fn clone(&self) -> IntoIter<T, N>ⓘNotable traits for IntoIter<T, N>impl<T, const N: usize> Iterator for IntoIter<T, N> type Item = T;[src]

Notable traits for IntoIter<T, N>

impl Clone for PhantomPinned[src][−]

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

impl Clone for AllocError[src][−]

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

impl Clone for __m256d[src][−]

pub fn clone(&self) -> __m256d[src]

impl Clone for __m512bh[src][−]

pub fn clone(&self) -> __m512bh[src]

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

pub fn clone(&self) -> BuildHasherDefault<H>[src]

Trait nom::lib::std::prelude::v1::rust_2021::Clone1.0.0[−][src]

How can I implement `Clone`?

`#[must_use = "cloning is often expensive and is not expected to have side effects"] pub fn clone(&self) -> Self`[src][−]

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

`impl Clone for NonZeroU16`[src][−]

`pub fn clone(&self) -> NonZeroU16`[src]

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

`pub fn clone(&self) -> Location<'a>`[src]

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

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

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

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

`impl Clone for NonZeroI32`[src][−]

`pub fn clone(&self) -> NonZeroI32`[src]

`impl Clone for __m512d`[src][−]

`pub fn clone(&self) -> __m512d`[src]

`impl Clone for TryFromSliceError`[src][−]

`pub fn clone(&self) -> TryFromSliceError`[src]

`impl Clone for DecodeUtf16Error`[src][−]

`pub fn clone(&self) -> DecodeUtf16Error`[src]

`impl Clone for LayoutError`[src][−]

`pub fn clone(&self) -> LayoutError`[src]

`impl Clone for __m128d`[src][−]

`pub fn clone(&self) -> __m128d`[src]

`impl Clone for NonZeroUsize`[src][−]

`pub fn clone(&self) -> NonZeroUsize`[src]

`impl Clone for NonZeroI8`[src][−]

`pub fn clone(&self) -> NonZeroI8`[src]

`impl Clone for NonZeroIsize`[src][−]

`pub fn clone(&self) -> NonZeroIsize`[src]

`impl Clone for IntErrorKind`[src][−]

`pub fn clone(&self) -> IntErrorKind`[src]

`impl Clone for __m512i`[src][−]

`pub fn clone(&self) -> __m512i`[src]

`impl Clone for __m128bh`[src][−]

`pub fn clone(&self) -> __m128bh`[src]

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

`pub fn clone(&self) -> VaListImpl<'f>`[src]

`impl Clone for ParseIntError`[src][−]

`pub fn clone(&self) -> ParseIntError`[src]

`impl Clone for __m128i`[src][−]

`pub fn clone(&self) -> __m128i`[src]

`impl Clone for Ordering`[src][−]

`pub fn clone(&self) -> Ordering`[src]

`impl Clone for TraitObject`[src][−]

`pub fn clone(&self) -> TraitObject`[src]

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

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

`impl Clone for __m256i`[src][−]

`pub fn clone(&self) -> __m256i`[src]

`impl Clone for NonZeroU8`[src][−]

`pub fn clone(&self) -> NonZeroU8`[src]

`impl Clone for NonZeroU32`[src][−]

`pub fn clone(&self) -> NonZeroU32`[src]

`impl Clone for ParseFloatError`[src][−]

`pub fn clone(&self) -> ParseFloatError`[src]

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

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

`impl Clone for EscapeUnicode`[src][−]

`pub fn clone(&self) -> EscapeUnicodeⓘNotable traits for EscapeUnicode impl Iterator for EscapeUnicode type Item = char;`[src]

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

`pub fn clone(&self) -> IntoIter<T, N>ⓘNotable traits for IntoIter<T, N> impl<T, const N: usize> Iterator for IntoIter<T, N> type Item = T;`[src]

`impl Clone for PhantomPinned`[src][−]

`pub fn clone(&self) -> PhantomPinned`[src]

`impl Clone for AllocError`[src][−]

`pub fn clone(&self) -> AllocError`[src]

`impl Clone for __m256d`[src][−]

`pub fn clone(&self) -> __m256d`[src]

`impl Clone for __m512bh`[src][−]

`pub fn clone(&self) -> __m512bh`[src]

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

`pub fn clone(&self) -> BuildHasherDefault<H>`[src]

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

`pub fn clone(&self) -> Pin<P>`[src]

`impl Clone for EscapeDefault`[src][−]

`pub fn clone(&self) -> EscapeDefaultⓘNotable traits for EscapeDefault impl Iterator for EscapeDefault type Item = char;`[src]

`impl Clone for RawWakerVTable`[src][−]

`pub fn clone(&self) -> RawWakerVTable`[src]

`impl Clone for NonZeroU128`[src][−]

`pub fn clone(&self) -> NonZeroU128`[src]