Trait Send

unsafe auto trait Send

Types that can be transferred across thread boundaries.

This trait is automatically implemented when the compiler determines it's appropriate.

An example of a non-Send type is the reference-counting pointer rc::Rc. If two threads attempt to clone Rcs that point to the same reference-counted value, they might try to update the reference count at the same time, which is undefined behavior because Rc doesn't use atomic operations. Its cousin sync::Arc does use atomic operations (incurring some overhead) and thus is Send.

See the Nomicon and the Sync trait for more details.

Implementors