## Freezing
Borrowing an immutable pointer to an object freezes it and prevents mutation.
-`Owned` objects have freezing enforced statically at compile-time. Mutable
-managed boxes handle freezing dynamically when any of their contents are
-borrowed, and the task will fail if an attempt to modify them is made while
-they are frozen.
+`Owned` objects have freezing enforced statically at compile-time.
~~~~
let mut x = 5;
// x is now unfrozen again
~~~~
+Mutable managed boxes handle freezing dynamically when any of their contents
+are borrowed, and the task will fail if an attempt to modify them is made while
+they are frozen:
+
+~~~~
+let x = @mut 5;
+let y = x;
+{
+ let y = &*y; // the managed box is now frozen
+ // modifying it through x or y will cause a task failure
+}
+// the box is now unfrozen again
+~~~~
+
# Dereferencing pointers
Rust uses the unary star operator (`*`) to access the contents of a