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Send and Sync

The two marker traits that say whether a type may be moved to, or shared with, another thread.

T: Send means a T can be moved to another thread; T: Sync means &T can be shared between threads. They are implemented automatically when all fields qualify; Rc is neither, Arc<Mutex> is both (for T: Send).

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Examples

  • Moving an Rc<i32> into thread::spawn fails with E0277 (Rc<i32> cannot be sent between threads safely); the same code with Arc<i32> compiles.

See also

reference counting mutex data race atomic type
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