Sloppy wording in 4.3

[mulkieran]

Recall from the borrowing rules that if we have an immutable reference to something, we cannot also take a mutable reference. Because clear needs to truncate the String, it tries to take a mutable reference, which fails. Not only has Rust made our API easier to use, but it has also eliminated an entire class of errors at compile time!

"it tries to take a mutable reference, which fails" sounds dynamic. But the whole point is that this is statically checked.

[L0uisc]

I don't think this is really such a big problem. The compiler is in fact trying to validate a mutable reference, which fails. The next sentence makes it clear that this trying and failing happened at compile time.

[mulkieran]

If I wasn't sure I understood what was going on, the sentence that follows would just look like a bewildering non-sequitur.

[L0uisc]

How about "...it needs to get a mutable reference, which the compiler disallows" ?

[mulkieran]

Yes, that would be much better.

[carols10cents]

Fixed by #1907!