///
/// ```
/// let mut vec = vec![1, 2, 3, 4];
- /// vec.retain(|&x| x%2 == 0);
+ /// vec.retain(|&x| x % 2 == 0);
/// assert_eq!(vec, [2, 4]);
/// ```
///
/// # Examples
///
/// ```
+ /// # #![feature(vec_remove_item)]
/// let mut vec = vec![1, 2, 3, 1];
///
/// vec.remove_item(&1);