--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/udlit-class-nttp.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,16 @@
+// PR c++/88095
+// Test class non-type template parameters for literal operator templates.
+// Validate basic support.
+// { dg-do compile { target c++2a } }
+
+struct literal_class {
+  constexpr literal_class(...) { }
+  // auto operator<=> (const fixed_string&) = default;
+};
+
+template <literal_class>
+constexpr int operator"" _udl() {
+  return 1;
+}
+
+static_assert("test"_udl == 1);