Trait flo_render_gl_offscreen::winapi::_core::prelude::rust_2021::Clone

1.0.0 · source ·

pub trait Clone: Sized {
    // Required method
    fn clone(&self) -> Self;

    // Provided method
    fn clone_from(&mut self, source: &Self) { ... }
}

Expand description

A common trait for the ability to explicitly duplicate an object.

Differs from Copy in that Copy is implicit and an inexpensive bit-wise copy, 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)
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§

source

fn clone(&self) -> Self

Returns a copy of the value.

Examples

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

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

Provided Methods§

source

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.

Trait flo_render_gl_offscreen::winapi::_core::prelude::rust_2021::Clone

Required Methods§

fn clone(&self) -> Self

Provided Methods§

fn clone_from(&mut self, source: &Self)

Implementors§

impl Clone for flo_render_gl_offscreen::winapi::_core::cmp::Ordering

impl Clone for Infallible

impl Clone for flo_render_gl_offscreen::winapi::_core::fmt::Alignment

impl Clone for IpAddr

impl Clone for Ipv6MulticastScope

impl Clone for SocketAddr

impl Clone for FpCategory

impl Clone for IntErrorKind

impl Clone for Which

impl Clone for SearchStep

impl Clone for flo_render_gl_offscreen::winapi::_core::sync::atomic::Ordering

impl Clone for TryReserveErrorKind

impl Clone for VarError

impl Clone for SeekFrom

impl Clone for ErrorKind

impl Clone for Shutdown

impl Clone for BacktraceStyle

impl Clone for RecvTimeoutError

impl Clone for TryRecvError

impl Clone for bool

impl Clone for char

impl Clone for f32

impl Clone for f64

impl Clone for i8

impl Clone for i16

impl Clone for i32

impl Clone for i64

impl Clone for i128

impl Clone for isize

impl Clone for !

impl Clone for u8

impl Clone for u16

impl Clone for u32

impl Clone for u64

impl Clone for u128

impl Clone for usize

impl Clone for FnPtr

impl Clone for Wgl

impl Clone for DEVPROPCOMPKEY

impl Clone for DEVPROPERTY

impl Clone for DEVPROPKEY

impl Clone for GUID

impl Clone for KCRM_MARSHAL_HEADER

impl Clone for KCRM_PROTOCOL_BLOB

impl Clone for KCRM_TRANSACTION_BLOB

impl Clone for TRANSACTION_NOTIFICATION

impl Clone for TRANSACTION_NOTIFICATION_MARSHAL_ARGUMENT

impl Clone for TRANSACTION_NOTIFICATION_PROPAGATE_ARGUMENT

impl Clone for TRANSACTION_NOTIFICATION_RECOVERY_ARGUMENT

impl Clone for TRANSACTION_NOTIFICATION_SAVEPOINT_ARGUMENT

impl Clone for TRANSACTION_NOTIFICATION_TM_ONLINE_ARGUMENT

impl Clone for FILETIME

impl Clone for CSTRING

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::FLOAT128

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::GROUP_AFFINITY

impl Clone for LARGE_INTEGER_s

impl Clone for LARGE_INTEGER_u

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::LIST_ENTRY32

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::LIST_ENTRY64

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::LIST_ENTRY

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::OBJECTID

impl Clone for OBJECT_ATTRIBUTES32

impl Clone for OBJECT_ATTRIBUTES64

impl Clone for OBJECT_ATTRIBUTES

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::PROCESSOR_NUMBER

impl Clone for QUAD

impl Clone for RTL_BALANCED_NODE

impl Clone for RTL_BALANCED_NODE_s

impl Clone for RTL_BALANCED_NODE_u

impl Clone for SINGLE_LIST_ENTRY32

impl Clone for flo_render_gl_offscreen::winapi::shared::ntdef::SINGLE_LIST_ENTRY

impl Clone for STRING32

impl Clone for STRING64

impl Clone for STRING