1 files changed, 27 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/template/partial12.C b/gcc/testsuite/g++.dg/template/partial12.C
new file mode 100644
index 000000000..05a3eca97
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/partial12.C
@@ -0,0 +1,27 @@
+// PR c++/46105
+
+template< typename T >
+struct empty { // support class is like stripped-down enable_if
+    typedef void type;
+};
+
+template< class T, typename v = void > // v is always void!
+struct element {
+    typedef typename T::value_type type;
+};
+
+template< class T > // T in deduced context, T::element_type is SFINAE:
+struct element< T, typename empty< typename T::element_type >::type > {
+    typedef typename T::element_type type;
+};
+
+template< class T >
+struct element< T const, typename empty< typename T::element_type >::type > {
+    typedef typename T::element_type const type;
+};
+
+struct has_et {
+    typedef int element_type;
+};
+
+element<has_et const>::type ip = 0;