rust-lang/rust — pull request #16458 by pcwalton (2014-08-12 19:53:07+00:00)
Title: librustc: Use the correct categorized mutable type for the pattern in

`for` loop heads.

This breaks code like:

let x = Some(box 1i);
for &a in x.iter() {
}

Change this code to obey the borrow checking rules. For example:

let x = Some(box 1i);
for &ref a in x.iter() {
}

Closes #16205.

[breaking-change]

r? @nikomatsakis