nullable-pointer-size.rs

Author: Kivooeo

tests/ui/layout/nullable-pointer-size-optimization.rs

@@ -1,31 +1,41 @@
+//! Nullable pointer optimization preserves type sizes.
+//!
+//! Verifies that Option<T> has the same size as T for nullable pointer types,
+//! and that custom enums get the same optimization.
+
 //@ run-pass
 
+// Needs for Nothing variat in Enum
 #![allow(dead_code)]
 
 use std::mem;
 
-enum E<T> { Thing(isize, T), Nothing((), ((), ()), [i8; 0]) }
+enum E<T> {
+    Thing(isize, T),
+    Nothing((), ((), ()), [i8; 0]),
+}
+
 struct S<T>(isize, T);
 
 // These are macros so we get useful assert messages.
 
 macro_rules! check_option {
     ($T:ty) => {
         assert_eq!(mem::size_of::<Option<$T>>(), mem::size_of::<$T>());
-    }
+    };
 }
 
 macro_rules! check_fancy {
     ($T:ty) => {
         assert_eq!(mem::size_of::<E<$T>>(), mem::size_of::<S<$T>>());
-    }
+    };
 }
 
 macro_rules! check_type {
     ($T:ty) => {{
         check_option!($T);
         check_fancy!($T);
-    }}
+    }};
 }
 
 pub fn main() {