--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr80773.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,33 @@
+// { dg-do compile { target c++2a } }
+// { dg-additional-options "-fconcepts-ts" }
+
+template<typename F>
+concept bool FCallable()
+{
+  return requires(F)
+  {
+    F::f();
+  };
+}
+
+class Test1
+{
+public:
+  template<FCallable P, FCallable... Pp>
+  static void g()
+  {
+    (Pp::f(), ...);
+  }
+};
+
+class A
+{
+public:
+  static void f() {}
+};
+
+int main()
+{
+  Test1::template g<A>();
+}
+