Mutable statics have the same restrictions as normal statics, except that the
type of the value is not required to ascribe to `Sync`.
-#### `'static` lifetime elision [unstable]
+#### `'static` lifetime elision
-Both constant and static declarations of reference types have *implicit*
-`'static` lifetimes unless an explicit lifetime is specified. As such, the
-constant declarations involving `'static` above may be written without the
-lifetimes. Returning to our previous example:
+[Unstable] Both constant and static declarations of reference types have
+*implicit* `'static` lifetimes unless an explicit lifetime is specified. As
+such, the constant declarations involving `'static` above may be written
+without the lifetimes. Returning to our previous example:
```rust
#[feature(static_in_const)]