===================================================================
@@ -4940,8 +4940,15 @@ check_default_tmpl_args (tree decl, tree parms, bo
else if (is_partial)
msg = G_("default template arguments may not be used in "
"partial specializations");
+ else if (!current_class_type || CLASSTYPE_IS_TEMPLATE (current_class_type))
+ msg = G_("default argument for template parameter for class enclosing %qD");
else
- msg = G_("default argument for template parameter for class enclosing %qD");
+ /* Per [temp.param]/9, "A default template-argument shall not be
+ specified in the template-parameter-lists of the definition of
+ a member of a class template that appears outside of the member's
+ class.", thus if we aren't handling a member of a class template
+ there is no need to examine the parameters. */
+ return true;
if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
/* If we're inside a class definition, there's no need to
===================================================================
@@ -0,0 +1,15 @@
+// PR c++/53856
+
+template<typename T>
+struct A
+{
+ struct B;
+};
+
+template<typename T = int>
+struct A<T>::B // { dg-error "default argument" }
+{
+ int i;
+};
+
+A<int>::B b = { };
===================================================================
@@ -0,0 +1,15 @@
+// PR c++/53856
+
+struct A
+{
+ template<typename T>
+ struct B;
+};
+
+template<typename T = int>
+struct A::B
+{
+ int i;
+};
+
+A::B<int> b = { };