Avoid ptrtoint when checking if a pointer is null

Casting the pointer to an integer requires a ptrtoint, while casting 0 to a pointer is directly folded to a `null` value.
rust-lang · Feb 18, 2015 · 52b5150 · 52b5150
1 parent dfc5c0f
commit 52b5150
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
@@ -303,7 +303,7 @@ impl<T> PtrExt for *const T {
 
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn is_null(self) -> bool { self as usize == 0 }
+    fn is_null(self) -> bool { self == 0 as *const T }
 
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -330,7 +330,7 @@ impl<T> PtrExt for *mut T {
 
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn is_null(self) -> bool { self as usize == 0 }
+    fn is_null(self) -> bool { self == 0 as *mut T }
 
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]