read_ref doe not need to mutate master
authorRalf Jung <post@ralfj.de>
Sun, 10 Mar 2019 19:29:45 +0000 (20:29 +0100)
committerRalf Jung <post@ralfj.de>
Sun, 10 Mar 2019 19:29:47 +0000 (20:29 +0100)
thanks to @amosonn!

ralf/_posts/2018-04-05-a-formal-look-at-pinning.md

index 72dccc1..5e51e7c 100644 (file)
@@ -68,11 +68,11 @@ impl SelfReferential {
     fn init(mut self: Pin<SelfReferential>) {
         let this : &mut SelfReferential = unsafe { Pin::get_mut(&mut self) };
         // Set up self_ref to point to this.data.
-        this.self_ref = &mut this.data as *const i32;
+        this.self_ref = &this.data as *const i32;
     }
 
-    fn read_ref(mut self: Pin<SelfReferential>) -> Option<i32> {
-        let this : &mut SelfReferential = unsafe { Pin::get_mut(&mut self) };
+    fn read_ref(self: Pin<SelfReferential>) -> Option<i32> {
+        let this : &SelfReferential = &*self;
         // Dereference self_ref if it is non-NULL.
         if this.self_ref == ptr::null() {
             None