--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-lambda5.C	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,10 @@
+// PR c++/92556
+// { dg-do compile { target c++20 } }
+
+// Having this as a hard error is consistent with template argument deduction;
+// it's an open core issue (jason 2020-02-14).
+template <class T> concept has_value
+  = requires { []{T::value;}; }; // { dg-error "" }
+template <has_value T> void f() { }
+template <class T> void f() { }
+void q() { f<int>(); }