--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp0x/decltype75.C	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,24 @@
+// PR c++/69694
+// This is a reduced version of decltype74.C.
+// { dg-do compile { target c++11 } }
+
+template<typename... Ts> using void_t = void;
+
+extern void *declval_void;
+
+template<typename, typename> struct Fun { };
+
+template<typename Desc>
+struct Fun<Desc, void_t<decltype (declval_void = Desc::name)>>
+{
+  void fun();
+};
+
+struct Tag { static constexpr void* name = 0; };
+
+template<typename> void a()
+{
+  Fun<Tag, void>{}.fun();
+}
+
+void b() { a<int>(); }