--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp0x/udlit-friend.C	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,28 @@
+// { dg-do compile { target c++11 } }
+
+long double
+operator"" _Hertz(long double);
+
+class Foo
+{
+public:
+  Foo() { }
+
+  friend Foo operator"" _Bar(char);
+
+  friend long double
+  operator"" _Hertz(long double omega)
+  { return omega / 6.28318530717958648; }
+};
+
+Foo
+operator"" _Bar(char)
+{ return Foo(); }
+
+Foo f1 = operator"" _Bar('x');
+
+Foo f2 = 'x'_Bar;
+
+long double fm1 = operator"" _Hertz(552.92L);
+
+long double fm2 = 552.92_Hertz;