--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/array-conv6.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,28 @@
+// PR c++/91364 - Implement P0388R4: Permit conversions to arrays of unknown bound.
+// { dg-do run { target c++2a } }
+
+// Ranking of reference initialization conversions
+
+int f1(const int(&)[]) { return 1; }
+int f1(const int(&)[1]) { return 2; }
+
+int f2(const int(&)[]) { return 1; }
+int f2(int(&)[1]) { return 2; }
+
+int f3(int(&)[]) { return 1; }
+int f3(const int(&)[1]) { return 2; }
+
+const int arr[1] = { 42 };
+
+int
+main ()
+{
+  if (f1(arr) != 2)
+    __builtin_abort ();
+
+  if (f2(arr) != 1)
+    __builtin_abort ();
+
+  if (f3(arr) != 2)
+    __builtin_abort ();
+}