diff --git a/src/librustc/middle/infer/mod.rs b/src/librustc/middle/infer/mod.rs
index d38417143ce..eaa5b6d58f8 100644
--- a/src/librustc/middle/infer/mod.rs
+++ b/src/librustc/middle/infer/mod.rs
@@ -73,7 +73,7 @@ pub struct InferCtxt<'a, 'tcx: 'a> {
     // We instantiate UnificationTable with bounds<Ty> because the
     // types that might instantiate a general type variable have an
     // order, represented by its upper and lower bounds.
-    pub type_variables: RefCell<type_variable::TypeVariableTable<'tcx>>,
+    type_variables: RefCell<type_variable::TypeVariableTable<'tcx>>,
 
     // Map from integral variable to the kind of integer it represents
     int_unification_table: RefCell<UnificationTable<ty::IntVid>>,
@@ -1366,19 +1366,19 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     }
 
     pub fn report_conflicting_default_types(&self,
-                                   span: Span,
-                                   expected: type_variable::Default<'tcx>,
-                                   actual: type_variable::Default<'tcx>) {
+                                            span: Span,
+                                            expected: type_variable::Default<'tcx>,
+                                            actual: type_variable::Default<'tcx>) {
         let trace = TypeTrace {
             origin: Misc(span),
-            values: Types(ty::expected_found {
+            values: Types(ty::ExpectedFound {
                 expected: expected.ty,
                 found: actual.ty
             })
         };
 
         self.report_and_explain_type_error(trace,
-            &ty::type_err::terr_ty_param_default_mismatch(ty::expected_found {
+            &TypeError::TyParamDefaultMismatch(ty::ExpectedFound {
                 expected: expected,
                 found: actual
         }));
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 19add679bbf..4945e0766e7 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -2039,7 +2039,7 @@ pub struct ExpectedFound<T> {
 }
 
 // Data structures used in type unification
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Debug)]
 pub enum TypeError<'tcx> {
     Mismatch,
     UnsafetyMismatch(ExpectedFound<ast::Unsafety>),
@@ -2069,7 +2069,7 @@ pub enum TypeError<'tcx> {
     ConvergenceMismatch(ExpectedFound<bool>),
     ProjectionNameMismatched(ExpectedFound<ast::Name>),
     ProjectionBoundsLength(ExpectedFound<usize>),
-    TyParamDefaultMismatch(ExpectedFound<Ty<'tcx>>)
+    TyParamDefaultMismatch(ExpectedFound<type_variable::Default<'tcx>>)
 }
 
 /// Bounds suitable for an existentially quantified type parameter
@@ -5083,7 +5083,7 @@ impl<'tcx> fmt::Display for TypeError<'tcx> {
                        values.expected,
                        values.found)
             },
-            terr_ty_param_default_mismatch(ref values) => {
+            TyParamDefaultMismatch(ref values) => {
                 write!(f, "conflicting type parameter defaults {} and {}",
                        values.expected.ty,
                        values.found.ty)
@@ -5445,7 +5445,7 @@ impl<'tcx> ctxt<'tcx> {
                                   using it as a trait object"));
                 }
             },
-            terr_ty_param_default_mismatch(values) => {
+            TyParamDefaultMismatch(values) => {
                 let expected = values.expected;
                 let found = values.found;
                 self.sess.span_note(sp,
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index d93848f408c..c9b10cec44a 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1785,7 +1785,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // it had been solved by previously applying a default.
 
             // We take a snapshot for use in error reporting.
-            let snapshot = self.infcx().type_variables.borrow_mut().snapshot();
+            let snapshot = self.infcx().start_snapshot();
 
             for ty in &unbound_tyvars {
                 if self.infcx().type_var_diverges(ty) {
@@ -1815,10 +1815,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
             }
 
-            // There were some errors to report
+            // There are some errors to report
             if conflicts.len() > 0 {
-                self.infcx().type_variables.borrow_mut().rollback_to(snapshot);
+                self.infcx().rollback_to(snapshot);
 
+                // Loop through each conflicting default compute the conflict
+                // and then report the error.
                 for (conflict, default) in conflicts {
                     let conflicting_default =
                         self.find_conflicting_default(
@@ -1836,7 +1838,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 default)
                 }
             } else {
-                self.infcx().type_variables.borrow_mut().commit(snapshot)
+                self.infcx().commit_from(snapshot)
             }
         }