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Two very important traits we need to talk about are sink and sin.

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Types that implement sin are safe to pass by value to another thread.

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And when I say safe, I mean that they are free from data races and other undefined behavior types that

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implements and can also be moved across threads.

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Now types that implement sink are safe to pass by non mutable reference to another thread.

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These types can be shared across threads so Syn can be moved across threads and sync can be shared across

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threads.

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Almost every rust type is cind, but there are some exceptions such as our RC reference counter smart

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pointer.

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So let's take a look at that real quick.

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So we'll say let RC one equals a new RC, so a new reference counter smart pointer and we'll say string

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from and then we'll just do tests to keep it simple and then we'll say led RC two equals RC one dot

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clone and now we'll spawn a thread.

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And we'll just try to use RC to in here.

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And if we run this.

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Let me correct that real quick.

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And if we run this, it says our C string cannot be sent between threads safely.

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Now, remember, in the last section when we were talking about reference counter, I mentioned the

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atomic reference counter.

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So let's make this a atomic reference counter.

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Which I said is safe to use across threads.

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And now we are able to safely use a reference counter smart pointer inside of a thread.

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So I just wanted to make you aware of this because these two traits are important to help ensure rust

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is safe when using threads.