rust-lang/rust — pull request #15521 by nick29581 (2014-07-08 10:51:10+00:00)
Title: Change DST syntax: type -> Sized?

closes #13367

[breaking-change] Use `Sized?` to indicate a dynamically sized type parameter or trait (used to be `type`). E.g.,

```
trait Tr for Sized? {}

fn foo(x: X) {}
```