Move unsafety out of the subtyping relation and into coercion.

1 files changed, 25 insertions, 0 deletions

diff --git a/src/test/run-pass/unsafe-coercion.rs b/src/test/run-pass/unsafe-coercion.rs
new file mode 100644
index 00000000000..06980e162c8
--- /dev/null
+++ b/src/test/run-pass/unsafe-coercion.rs
@@ -0,0 +1,25 @@
+// Copyright 2013-2014 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.
+
+// Check that safe fns are not a subtype of unsafe fns.
+
+fn foo(x: i32) -> i32 {
+    x * 22
+}
+
+fn bar(x: fn(i32) -> i32) -> unsafe fn(i32) -> i32 {
+    x // OK, coercion!
+}
+
+fn main() {
+    let f = bar(foo);
+    let x = unsafe { f(2) };
+    assert_eq!(x, 44);
+}