Tweak pedantic with desugaring; add f_mut_bad example

nikomatsakis · nikomatsakis · commit 2d740e527889 · 2016-02-19T08:53:23.000-05:00
diff --git a/litmus_tests/f_mut_bad.md b/litmus_tests/f_mut_bad.md
@@ -0,0 +1,18 @@
+### Example
+
+```rust
+fn f_mut_bad<'s>(&'s mut self) -> &'s mut Self {
+    let ret = unsafe { transmute::<&'s Self, &'s mut Self>(self.f()) };
+    ret // β-expansion should have no effect
+}
+```
+
+### Explanation
+
+In this variation on the lovely and delightful `f_mut` series, the
+`self.f()` point has a lifetime of `'s`, and thus the scope of the
+shared borrow extends past the unsafe block.
+
+### Source
+
+- https://github.com/rust-lang/rust/issues/30424#issuecomment-168541165
diff --git a/litmus_tests/f_mut_pedantic.md b/litmus_tests/f_mut_pedantic.md
@@ -3,7 +3,7 @@
 ```rust
 fn f_mut_pedantic<'s>(&'s mut self) -> &'s mut Self {
     let captured_self = self as *mut Self;
-    unsafe { &mut *((*captured_self).f() as *const Self as *mut Self) }
+    unsafe { &mut *((&*captured_self).f() as *const Self as *mut Self) }
 }
 ```
 
@@ -17,4 +17,5 @@ again.
 
 ### Source
 
-https://github.com/rust-lang/rust/issues/30424#issuecomment-167009462
+- https://github.com/rust-lang/rust/issues/30424#issuecomment-167009462
+- https://github.com/rust-lang/rust/issues/30424#issuecomment-168539718
