--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp0x/fntmpdefarg10.C	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,18 @@
+// PR c++/85765
+// { dg-do compile { target c++11 } }
+
+struct il { il(); il(const il&); };
+
+int* begin(il);
+
+template<class T> T&& declval();
+
+template<class T, class U = decltype(begin(declval<T&>())), decltype(*U(),0) = 0>
+U g(T& t, long) { return begin(t); } // #1
+
+template<class T>
+int g(T& t, ...); // #2
+
+volatile il a;
+
+auto n = g(a, 0); // calls #1 and ends with a hard error, should call #2