1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/template/ttp9.C b/gcc/testsuite/g++.dg/template/ttp9.C
new file mode 100644
index 00000000000..060ab7788ae
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/ttp9.C
@@ -0,0 +1,28 @@
+// { dg-do compile }
+
+// Origin: David Abrahams <dave@boost-consulting.com>
+//	   Wolfgang Bangerth <bangerth@ticam.utexas.edu>
+
+// PR c++/12170: Deducing template template parameter from nested
+// class template.
+
+template <typename> struct W {};
+
+template< template<typename> class F, typename T>
+int foo(W< F<T> >);
+
+
+template<typename T>
+struct L  {
+    static int const value = sizeof(foo(W<T>()));
+    typedef T type;
+};
+
+
+template <typename>
+struct Y {
+    template <typename> struct X { typedef int type; };
+    typedef typename L<X<int> >::type type;
+};
+
+template struct Y<int>;