Modify how-to-convert-pointer-to-reference-in-rust.md so the code compiles

rust/how-to-convert-pointer-to-reference-in-rust.md

@@ -1,20 +1,23 @@
 # How to convert pointer to reference in Rust
-// plain
-
-In Rust, you can convert a pointer to a reference by using the `&` operator. For example, if you have a pointer `p` to a type `T`, you can convert it to a reference by using `&p`. This will create a reference to the same value that the pointer points to. The output of this operation will be a reference of type `&T`.
-```rust
-let p: *const i32 = &10;
-let r: &i32 = &p;
-```
-### Output example
-This code will not produce any output.
-
-### Explanation
-The `&` operator is used to convert a pointer to a reference. In this example, the pointer `p` is of type `*const i32`, which is a pointer to a constant integer. The `&` operator is used to convert this pointer to a reference of type `&i32`, which is a reference to an integer.
-
-### Relevant links
-- [Rust Pointers](https://doc.rust-lang.org/book/ch19-01-pointers.html)
-- [Rust References](https://doc.rust-lang.org/book/ch15-01-box.html)
-- [Rust Operators](https://doc.rust-lang.org/book/ch03-02-operators-and-overloading.html)
-
-group: rust-pointers
+// plain
+
+In Rust, you can convert a pointer to a reference by dereferencing the pointer with `*`, then creating a reference with `&`. For example, if you have a pointer `p` to a type `T`, you can convert it to a reference by using `&*p`. This will create a reference to the same value that the pointer points to. The output of this operation will be a reference of type `&T`.
+```rust
+let p: *const i32 = &10;
+
+unsafe {
+  let r: &i32 = &*p;
+}
+```
+### Output example
+This code will not produce any output.
+
+### Explanation
+The `&` operator is used to convert a pointer to a reference. In this example, the pointer `p` is of type `*const i32`, which is a pointer to a constant integer. The `*` in `&*p` is used to dereference `p`, then the `&` creates a reference to that location. This pointer to a reference of type `&i32`, which is a reference to an integer. The unsafe block is needed to dereference the raw pointer.
+
+### Relevant links
+- [Rust Pointers](https://doc.rust-lang.org/book/ch19-01-pointers.html)
+- [Rust References](https://doc.rust-lang.org/book/ch15-01-box.html)
+- [Rust Operators](https://doc.rust-lang.org/book/ch03-02-operators-and-overloading.html)
+
+group: rust-pointers