rust-lang/rust — pull request #15515 by pcwalton (2014-07-07 23:37:46+00:00)
Title: librustc: Remove cross-borrowing of `Box<T>` to `&T` from the language,

except where trait objects are involved.

Part of issue #15349, though I'm leaving it open for trait objects.
Cross borrowing for trait objects remains because it is needed until we
have DST.

This will break code like:

fn foo(x: &int) { ... }

let a = box 3i;
foo(a);

Change this code to:

fn foo(x: &int) { ... }

let a = box 3i;
foo(&*a);

[breaking-change]

r? @alexcrichton