--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/concepts/req5.C	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,18 @@
+// { dg-options "-std=c++17 -fconcepts" }
+
+struct fool { };
+
+constexpr fool operator&&(fool, fool) { return {}; }
+constexpr fool operator||(fool, fool) { return {}; }
+
+template<typename T> constexpr fool p1() { return {}; }
+template<typename T> constexpr fool p2() { return {}; }
+
+template<typename T>
+  concept bool C() { return p1<T>() && p2<T>(); }
+
+template<C T> void f(T x) { }
+
+int main() {
+  f(0); // { dg-error "cannot call|uses overloaded operator" }
+}