//@ which we already discussed in a single-threaded context in part 12.
//@
//@ ## `Mutex`
-//@ The most basic type for interior mutability that supports concurrency is [`Mutex<T>`](http://doc.rust-lang.org/stable/std/sync/struct.Mutex.html).
+//@ The most basic type for interior mutability that supports concurrency is [`Mutex<T>`](https://doc.rust-lang.org/stable/std/sync/struct.Mutex.html).
//@ This type implements *critical sections* (or *locks*), but in a data-driven way: One has to specify
//@ the type of the data that's protected by the mutex, and Rust ensures that the data is *only* accessed
//@ through the mutex. In other words, "lock data, not code" is actually enforced by the type system, which
// the data inside the lock. Change the code above to do that. Try using `unwrap_or_else` for this job.
//@ ## `RwLock`
-//@ Besides `Mutex`, there's also [`RwLock`](http://doc.rust-lang.org/stable/std/sync/struct.RwLock.html), which
+//@ Besides `Mutex`, there's also [`RwLock`](https://doc.rust-lang.org/stable/std/sync/struct.RwLock.html), which
//@ provides two ways of locking: One that grants only read-only access, to any number of concurrent readers, and another one
//@ for exclusive write access. Notice that this is the same pattern we already saw with shared vs. mutable borrows. Hence
//@ another way of explaining `RwLock` is to say that it is like `RefCell`, but works even for concurrent access. Rather than
//@
//@ In part 13, we talked about types that are marked `Send` and thus can be moved to another thread. However, we did *not*
//@ talk about the question whether a borrow is `Send`. For `&mut T`, the answer is: It is `Send` whenever `T` is send.
-//@ `&mut` allows moving values back and forth, it is even possible to [`swap`](http://doc.rust-lang.org/beta/std/mem/fn.swap.html)
+//@ `&mut` allows moving values back and forth, it is even possible to [`swap`](https://doc.rust-lang.org/stable/std/mem/fn.swap.html)
//@ the contents of two mutably borrowed values. So in terms of concurrency, sending a mutable borrow is very much like
//@ sending full ownership, in the sense that it can be used to move the object to another thread.
//@
//@ [Rust RFC](https://github.com/rust-lang/rfcs/blob/master/text/0458-send-improvements.md), which contains a type `RcMut` that would be `Sync` and not `Send`.
//@ You may also be interested in [this blog post](https://huonw.github.io/blog/2015/02/some-notes-on-send-and-sync/) on the topic.
-//@ [index](main.html) | [previous](part14.html) | [next](main.html)
+//@ [index](main.html) | [previous](part14.html) | [raw source](https://www.ralfj.de/git/rust-101.git/blob_plain/HEAD:/workspace/src/part15.rs) | [next](part16.html)