The following code compiles with rustc 1.0.0-beta (9854143cb 2015-04-02) (built 2015-04-02) but does not compile with rustc 1.0.0-beta.2 (e9080ec39 2015-04-16) (built 2015-04-16)
trait Foo {
fn foo(&self);
}
struct Bar<T>(T);
impl<T> Bar<T> where Self: Foo {}
fn main() {}