Add tests for null pointer opt.

src/test/run-pass/enum-null-pointer-opt.rs

@@ -0,0 +1,40 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+
+use std::gc::Gc;
+use std::mem::size_of;
+
+trait Trait {}
+
+fn main() {
+    // Closures - || / proc()
+    assert_eq!(size_of::<proc()>(), size_of::<Option<proc()>>());
+    assert_eq!(size_of::<||>(), size_of::<Option<||>>());
+
+    // Functions
+    assert_eq!(size_of::<fn(int)>(), size_of::<Option<fn(int)>>());
+    assert_eq!(size_of::<extern "C" fn(int)>(), size_of::<Option<extern "C" fn(int)>>());
+
+    // Slices - &str / &[T] / &mut [T]
+    assert_eq!(size_of::<&str>(), size_of::<Option<&str>>());
+    assert_eq!(size_of::<&[int]>(), size_of::<Option<&[int]>>());
+    assert_eq!(size_of::<&mut [int]>(), size_of::<Option<&mut [int]>>());
+
+    // Traits - Box<Trait> / &Trait / &mut Trait
+    assert_eq!(size_of::<Box<Trait>>(), size_of::<Option<Box<Trait>>>());
+    assert_eq!(size_of::<&Trait>(), size_of::<Option<&Trait>>());
+    assert_eq!(size_of::<&mut Trait>(), size_of::<Option<&mut Trait>>());
+
+    // Pointers - Box<T> / Gc<T>
+    assert_eq!(size_of::<Box<int>>(), size_of::<Option<Box<int>>>());
+    assert_eq!(size_of::<Gc<int>>(), size_of::<Option<Gc<int>>>());
+
+}