--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp0x/decltype-pr66548.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,21 @@
+// PR c++/66548 - Invalid class member access expression in decltype
+//                sometimes accepted
+// { dg-do compile }
+// { dg-options "-ftrack-macro-expansion=0" }
+
+#if __cplusplus < 201103L
+# define decltype __typeof__
+#endif
+
+struct Meow {};
+
+void f ()
+{
+  decltype (Meow.purr ()) d;   // { dg-error "expected primary-expression" }
+  (void)&d;
+}
+
+void g ()
+{
+  decltype (Meow.purr);        // { dg-error "expected primary-expression" }
+}