Trait CloneToUninit

pub unsafe trait CloneToUninit {
    // Required method
    unsafe fn clone_to_uninit(&self, dst: *mut Self);
}

🔬This is a nightly-only experimental API. (clone_to_uninit)

A generalization of Clone to dynamically-sized types stored in arbitrary containers.

This trait is implemented for all types implementing Clone, and also slices of all such types. You may also implement this trait to enable cloning trait objects and custom DSTs (structures containing dynamically-sized fields).

Safety

Implementations must ensure that when .clone_to_uninit(dst) returns normally rather than panicking, it always leaves *dst initialized as a valid value of type Self.

See also

• Clone::clone_from is a safe function which may be used instead when Self is a Sized and the destination is already initialized; it may be able to reuse allocations owned by the destination.
• ToOwned, which allocates a new destination container.

Required Methods

unsafe fn clone_to_uninit(&self, dst: *mut Self)

🔬This is a nightly-only experimental API. (clone_to_uninit)

Performs copy-assignment from self to dst.

This is analogous to std::ptr::write(dst, self.clone()), except that self may be a dynamically-sized type (!Sized).

Before this function is called, dst may point to uninitialized memory. After this function is called, dst will point to initialized memory; it will be sound to create a &Self reference from the pointer.

Safety

Behavior is undefined if any of the following conditions are violated:

• dst must be valid for writes.
• dst must be properly aligned.
• dst must have the same pointer metadata (slice length or dyn vtable) as self.

Panics

This function may panic. (For example, it might panic if memory allocation for a clone of a value owned by self fails.) If the call panics, then *dst should be treate