//@ sure that the callbacks do not reference any pointers that might become invalid? This is just as crucial for spawning
//@ a thread: In general, that thread could last for much longer than the current stack frame. Thus, it must not use
//@ any pointers to data in that stack frame. This is achieved by requiring the `FnOnce` closure passed to `thread::spawn`
-//@ to be valid for lifetime `'static`, as you can see in [its documentation](http://doc.rust-lang.org/stable/std/thread/fn.spawn.html).
+//@ to be valid for lifetime `'static`, as you can see in [its documentation](https://doc.rust-lang.org/stable/std/thread/fn.spawn.html).
//@ This avoids another kind of data race, where the thread's access races with the callee deallocating its stack frame.
//@ It is only thanks to the concept of lifetimes that this can be expressed as part of the type of `spawn`.
//@ So if the environment of your closure contains an `Rc`, it won't be `Send`, preventing it from causing trouble. If however every
//@ captured variable *is* `Send`, then so is the entire environment, and you are good.
-//@ [index](main.html) | [previous](part12.html) | [next](part14.html)
+//@ [index](main.html) | [previous](part12.html) | [raw source](https://www.ralfj.de/git/rust-101.git/blob_plain/HEAD:/workspace/src/part13.rs) | [next](part14.html)