--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr78752-2.C	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,21 @@
+// { dg-do compile { target c++2a } }
+// { dg-additional-options "-fconcepts-ts" }
+
+template <class T, class U>
+concept bool Same = __is_same(T, U);
+
+struct test {
+  void func(Same<int>... ints) {}
+};
+
+void func(Same<int>... ints) {}
+
+int main()
+{
+  test t;
+  t.func(1, 2, 3);
+  func(1, 2, 3);
+
+  t.func(1, 2, ""); // { dg-error "no match" }
+  func(1, 2, ""); // { dg-error "unsatisfied constraints" }
+}