---

yaml
---
r: 3008
b: refs/heads/master
c: c9c1d86
h: refs/heads/master
v: v3

Author: pcwalton

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 5318248f24afbcc61cf948bbcacd61d8b157c24a
+refs/heads/master: c9c1d860f14d2d422106d21a30beb2ea237d9de3

trunk/src/comp/middle/typeck.rs

@@ -896,6 +896,14 @@ fn count_boxes(&@fn_ctxt fcx, &span sp, &ty::t t) -> uint {
 }
 
 
+fn resolve_type_vars_if_possible(&@fn_ctxt fcx, ty::t typ) -> ty::t {
+    alt (ty::unify::fixup_vars(fcx.ccx.tcx, fcx.var_bindings, typ)) {
+        case (fix_ok(?new_type)) { ret new_type; }
+        case (fix_err(_)) { ret typ; }
+    }
+}
+
+
 // Demands - procedures that require that two types unify and emit an error
 // message if they don't.
 
@@ -956,10 +964,13 @@ mod demand {
             }
 
             case (ures_err(?err)) {
+                auto e_err = resolve_type_vars_if_possible(fcx, expected_1);
+                auto a_err = resolve_type_vars_if_possible(fcx, actual_1);
+
                 fcx.ccx.tcx.sess.span_err
                     (sp, "mismatched types: expected "
-                     + ty_to_str(fcx.ccx.tcx, expected_1) + " but found "
-                     + ty_to_str(fcx.ccx.tcx, actual_1) + " ("
+                     + ty_to_str(fcx.ccx.tcx, e_err) + " but found "
+                     + ty_to_str(fcx.ccx.tcx, a_err) + " ("
                      + ty::type_err_to_str(err) + ")");
 
                 // TODO: In the future, try returning "expected", reporting