diff options
| -rw-r--r-- | src/libcore/marker.rs | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs index 455517c9294..38c9fe79f84 100644 --- a/src/libcore/marker.rs +++ b/src/libcore/marker.rs @@ -618,14 +618,16 @@ unsafe impl<T: ?Sized> Freeze for &mut T {} /// So this, for example, can only be done on types implementing `Unpin`: /// /// ```rust -/// use std::mem::replace; +/// use std::mem; /// use std::pin::Pin; /// /// let mut string = "this".to_string(); /// let mut pinned_string = Pin::new(&mut string); /// -/// // dereferencing the pointer mutably is only possible because String implements Unpin -/// replace(&mut *pinned_string, "other".to_string()); +/// // We need a mutable reference to call `mem::replace`. +/// // We can obtain such a reference by (implicitly) invoking `Pin::deref_mut`, +/// // but that is only possible because `String` implements `Unpin`. +/// mem::replace(&mut *pinned_string, "other".to_string()); /// ``` /// /// This trait is automatically implemented for almost every type. |