Merge pull request #72 from jrose-signal/windows-pointer-provenance-fix

Windows: Prevent pointer provenance "optimization"

src/distributed_slice.rs

@@ -268,6 +268,12 @@ impl<T> DistributedSlice<[T]> {
             // using the unsafe `private_new`.
             None => unsafe { hint::unreachable_unchecked() },
         };
+
+        // On Windows, make sure we discard provenance information.
+        // Otherwise, the compiler has enough information to see we are going "out of bounds".
+        #[cfg(target_os = "windows")]
+        let start = core::hint::black_box(start);
+
         unsafe { slice::from_raw_parts(start, len) }
     }
 }

tests/distributed_slice.rs

@@ -69,4 +69,5 @@ fn test_elided_lifetime() {
     static ELEMENT: &str = "...";
 
     assert!(!MYSLICE.is_empty());
+    assert_eq!(MYSLICE[0], "...");
 }