Trait DeepClone

Source

pub trait DeepClone<S: Speed>: Sized {
    // Required method
    fn deep_clone(&self) -> Self;

    // Provided method
    fn fast_deep_clone(&self) -> Self
       where S: FastSpeed { ... }
}

Expand description

Get deep clones of a value, which do not share any semantically-important mutable state.

The goal is that the clones and their source appear to act completely independently, at least from their public interfaces; mutating or dropping one clone (among possible actions) should have no potentially-observable effect on any other independent clone.

Note also that a deep clone and its source may reference the same immutable data, even if the public interface of the type could be used to confirm that two deep clones are (or were) associated. (However, there should not be a way for either the source or any independent clone to affect that data’s value or address in memory.)

Side-channel attacks should be ignored in implementing this trait. The point is to provide deep clones, not cryptographic-quality guarantees about how those deep clones are performed.

§Exceptions

A type implementing DeepClone may specify that certain methods or accesses are not subject to these guarantees.
Debug should be assumed to be an exception. Intentionally worsening the life of someone debugging your type is not a goal.
Shared mutable data which is written to but never read, or is read with effects that can only be publicly observed through exceptions, is acceptable.

§Other edge cases

A user calling as_ptr() and friends on references, to do address comparisons: if the address returned could change, then even if the underlying value at a new address would be the same, “the address of the data” should be considered mutable state. If that mutable state can be affected by the actions of the source of the independent clone or by other clones, then the address of the data must not be publicly exposed by the type’s interface.
Copy-on-write data: while likely permissible if properly encapsulated, presumably the source, the independent clone, or both are going to be mutated; it’d be best to give the independent clone a unique owned copy of the data. Further, if some sort of reference-counted copy-on-write scheme is used where the last clone to refer to the data doesn’t need to copy it, then the reference count used to determine that is shared mutable state. This can be avoided by simply giving the new independent clone an unique owned copy of the data, as should likely be done anyway.

Required Methods§

Source

fn deep_clone(&self) -> Self

Get a deep clone of a value, which does not share any semantically-important mutable state.

The goal is that the clone and its source appear to act completely independently, at least from their public interfaces; mutating or dropping one clone (among possible actions) should have no potentially-observable effect on any other deep clone.

Read DeepClone for more.

Provided Methods§

Source

fn fast_deep_clone(&self) -> Self
where S: FastSpeed,

Get a deep clone of a value, which does not share any semantically-important mutable state.

The goal is that the clone and its source appear to act completely independently, at least from their public interfaces; mutating or dropping one clone (among possible actions) should have no potentially-observable effect on any other deep clone.

Read DeepClone for more.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Trait DeepClone Copy item path

§Exceptions

§Other edge cases

Required Methods§

fn deep_clone(&self) -> Self

Provided Methods§

fn fast_deep_clone(&self) -> Selfwhere S: FastSpeed,

Dyn Compatibility§

Implementations on Foreign Types§

impl DeepClone<MaybeSlow> for Box<str>

fn deep_clone(&self) -> Self

impl DeepClone<MaybeSlow> for Pin<Box<str>>

fn deep_clone(&self) -> Self

impl<K, V> DeepClone<MaybeSlow> for BTreeMap<K, V>where K: DeepClone<MaybeSlow> + Ord, V: DeepClone<MaybeSlow>,

fn deep_clone(&self) -> Self

impl<K, V, S> DeepClone<MaybeSlow> for HashMap<K, V, S>where K: DeepClone<MaybeSlow> + Eq + Hash, V: DeepClone<MaybeSlow>, S: BuildHasher + Default,

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for Ordering

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for Infallible

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for Ordering

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for bool

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for char

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for f32

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for f64

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for i8

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for i16

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for i32

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for i64

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for i128

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for isize

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for u8

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for u16

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for u32

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for u64

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for u128

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for ()

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for usize

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for Layout

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for TypeId

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for PhantomPinned

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<i8>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<i16>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<i32>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<i64>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<i128>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<isize>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<u8>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<u16>

fn deep_clone(&self) -> Self

impl<S: Speed> DeepClone<S> for NonZero<u32>

Trait DeepClone

fn fast_deep_clone(&self) -> Self
where S: FastSpeed,

impl<K, V> DeepClone<MaybeSlow> for BTreeMap<K, V>
where K: DeepClone<MaybeSlow> + Ord, V: DeepClone<MaybeSlow>,

impl<K, V, S> DeepClone<MaybeSlow> for HashMap<K, V, S>
where K: DeepClone<MaybeSlow> + Eq + Hash, V: DeepClone<MaybeSlow>, S: BuildHasher + Default,