Trait nom::lib::std::prelude::v1::rust_2018::Clone1.0.0[−][src]

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_2018::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<'a> Clone for Chain<'a>[src]

pub fn clone(&self) -> Chain<'a>ⓘNotable traits for Chain<'a>impl<'a> Iterator for Chain<'a> type Item = &'a (dyn Error + 'static);[src]

Notable traits for Chain<'a>

impl Clone for AddrParseError[src]

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

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

pub fn clone(&self) -> Components<'a>ⓘNotable traits for Components<'a>impl<'a> Iterator for Components<'a> type Item = Component<'a>;[src]

Notable traits for Components<'a>

impl Clone for FromVecWithNulError[src]

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

impl Clone for AccessError[src]

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

impl Clone for SocketAddrV6[src]

pub fn clone(&self) -> SocketAddrV6[src]

impl Clone for Shutdown[src]

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

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

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

impl Clone for VarError[src]

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

impl Clone for SocketAddrV4[src]

pub fn clone(&self) -> SocketAddrV4[src]

impl Clone for SocketCred[src]

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

impl Clone for SystemTimeError[src]

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

impl Clone for WaitTimeoutResult[src]

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

impl Clone for PathBuf[src]

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

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

impl Clone for SocketAddr[src]

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

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

pub fn clone(&self) -> Ancestors<'a>ⓘNotable traits for Ancestors<'a>impl<'a> Iterator for Ancestors<'a> type Item = &'a Path;[src]

Notable traits for Ancestors<'a>

impl Clone for ThreadId[src]

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

impl Clone for Metadata[src]

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

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

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

impl Clone for SocketAddr[src]

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

impl Clone for SeekFrom[src]

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

impl Clone for NulError[src]

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

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

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

impl Clone for Permissions[src]

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

impl Clone for ErrorKind[src]

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

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

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

impl Clone for Thread[src]

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

impl Clone for Ipv4Addr[src]

pub fn clone(&self) -> Ipv4Addr[src]

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

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

impl Clone for TryRecvError[src]

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

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

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

impl Clone for OpenOptions[src]

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

impl Clone for FromBytesWithNulError[src]

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

Trait nom::lib::std::prelude::v1::rust_2018::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<'a> Clone for Chain<'a>`[src]

`pub fn clone(&self) -> Chain<'a>ⓘNotable traits for Chain<'a> impl<'a> Iterator for Chain<'a> type Item = &'a (dyn Error + 'static);`[src]

`impl Clone for AddrParseError`[src]

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

`impl<'a> Clone for Components<'a>`[src]

`pub fn clone(&self) -> Components<'a>ⓘNotable traits for Components<'a> impl<'a> Iterator for Components<'a> type Item = Component<'a>;`[src]

`impl Clone for FromVecWithNulError`[src]

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

`impl Clone for AccessError`[src]

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

`impl Clone for SocketAddrV6`[src]

`pub fn clone(&self) -> SocketAddrV6`[src]

`impl Clone for Shutdown`[src]

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

`impl<'a> Clone for Prefix<'a>`[src]

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

`impl Clone for VarError`[src]

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

`impl Clone for SocketAddrV4`[src]

`pub fn clone(&self) -> SocketAddrV4`[src]

`impl Clone for SocketCred`[src]

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

`impl Clone for SystemTimeError`[src]

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

`impl Clone for WaitTimeoutResult`[src]

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

`impl Clone for PathBuf`[src]

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

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

`impl Clone for SocketAddr`[src]

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

`impl<'a> Clone for Ancestors<'a>`[src]

`pub fn clone(&self) -> Ancestors<'a>ⓘNotable traits for Ancestors<'a> impl<'a> Iterator for Ancestors<'a> type Item = &'a Path;`[src]

`impl Clone for ThreadId`[src]

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

`impl Clone for Metadata`[src]

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

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

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

`impl Clone for SocketAddr`[src]

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

`impl Clone for SeekFrom`[src]

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

`impl Clone for NulError`[src]

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

`impl<'a> Clone for PrefixComponent<'a>`[src]

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

`impl Clone for Permissions`[src]

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

`impl Clone for ErrorKind`[src]

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

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

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

`impl Clone for Thread`[src]

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

`impl Clone for Ipv4Addr`[src]

`pub fn clone(&self) -> Ipv4Addr`[src]

`impl<'a> Clone for Component<'a>`[src]

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

`impl Clone for TryRecvError`[src]

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

`impl<'a> Clone for IoSlice<'a>`[src]

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

`impl Clone for OpenOptions`[src]

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

`impl Clone for FromBytesWithNulError`[src]

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

`impl Clone for Instant`[src]

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

`impl<'a> Clone for Iter<'a>`[src]

`pub fn clone(&self) -> Iter<'a>ⓘNotable traits for Iter<'a> impl<'a> Iterator for Iter<'a> type Item = &'a OsStr;`[src]

`impl Clone for Ipv6Addr`[src]

`pub fn clone(&self) -> Ipv6Addr`[src]

`impl Clone for RecvTimeoutError`[src]

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

`impl Clone for OsString`[src]