--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-fn4.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,11 @@
+// Testcase from [expr.prim.id]/5
+// { dg-do compile { target c++2a } }
+
+template<typename T> struct A {
+  static void f(int) requires false;
+};
+void g() {
+  A<int>::f(0);			// { dg-error "" "cannot call f" }
+  void (*p1)(int) = A<int>::f;  // { dg-error "" "cannot take the address of f" }
+  decltype(A<int>::f)* p2 = nullptr; // { dg-error "" "the type decltype(A<int>::f) is invalid" }
+}