Test for issue #980

Author: brson

src/test/run-pass/issue-980.rs

@@ -0,0 +1,13 @@
+tag maybe_pointy {
+    no_pointy;
+    yes_pointy(@pointy);
+}
+
+type pointy = {
+    mutable x : maybe_pointy
+};
+
+fn main() {
+    let m = @{ mutable x : no_pointy };
+    m.x = yes_pointy(m);
+}