Error of one Snippet in `unsafe-rawpointer/raw-pointer.md`

[arrowrowe]

unsafe-rawpointer/raw-pointer.md

$ cat sample.rs 
fn main() {
  let mut x = 2;
  let y = &x as *mut i32;
}

$ rustc sample.rs 
sample.rs:3:11: 3:25 error: casting `&i32` as `*mut i32` is invalid
sample.rs:3   let y = &x as *mut i32;
                      ^~~~~~~~~~~~~~
error: aborting due to previous error

创建一个裸指针：

let a = 1;
let b = &a as *const i32;

let mut x = 2;
let y = &x as *mut i32;

[Librazy]

let y = &mut as *mut i32;

[arrowrowe]

@Librazy saw your PR. thanks. will close after its merging.