1 files changed, 54 insertions, 0 deletions
diff --git a/src/test/ui/run-pass/traits/assignability-trait.rs b/src/test/ui/run-pass/traits/assignability-trait.rs
new file mode 100644
index 00000000000..bc95d96a8cc
--- /dev/null
+++ b/src/test/ui/run-pass/traits/assignability-trait.rs
@@ -0,0 +1,54 @@
+// Copyright 2012-4 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.
+
+// Tests that type assignability is used to search for instances when
+// making method calls, but only if there aren't any matches without
+// it.
+
+trait iterable<A> {
+    fn iterate<F>(&self, blk: F) -> bool where F: FnMut(&A) -> bool;
+}
+
+impl<'a,A> iterable<A> for &'a [A] {
+    fn iterate<F>(&self, f: F) -> bool where F: FnMut(&A) -> bool {
+        self.iter().all(f)
+    }
+}
+
+impl<A> iterable<A> for Vec<A> {
+    fn iterate<F>(&self, f: F) -> bool where F: FnMut(&A) -> bool {
+        self.iter().all(f)
+    }
+}
+
+fn length<A, T: iterable<A>>(x: T) -> usize {
+    let mut len = 0;
+    x.iterate(|_y| {
+        len += 1;
+        true
+    });
+    return len;
+}
+
+pub fn main() {
+    let x: Vec<isize> = vec![0,1,2,3];
+    // Call a method
+    x.iterate(|y| { assert_eq!(x[*y as usize], *y); true });
+    // Call a parameterized function
+    assert_eq!(length(x.clone()), x.len());
+    // Call a parameterized function, with type arguments that require
+    // a borrow
+    assert_eq!(length::<isize, &[isize]>(&*x), x.len());
+
+    // Now try it with a type that *needs* to be borrowed
+    let z = [0,1,2,3];
+    // Call a parameterized function
+    assert_eq!(length::<isize, &[isize]>(&z), z.len());
+}