--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-dynamic8.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,24 @@
+// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr.
+// { dg-do compile { target c++2a } }
+
+// Unrelated type.
+
+struct B { virtual void b(); };
+struct P1 { virtual void p1(); };
+struct P2 { virtual void p2(); };
+struct A : public B, private P1, protected P2 { virtual void a(); };
+
+constexpr A a;
+
+struct U { virtual void u(); };
+
+constexpr bool b1 = (dynamic_cast<U&>((B&)a), 0); // { dg-error "reference .dynamic_cast. failed" }
+// { dg-message "dynamic type .A. of its operand does not have an unambiguous public base class .U." "" { target *-*-* } .-1 }
+constexpr bool b2 = (dynamic_cast<U&>((P1&)a), 0); // { dg-error "reference .dynamic_cast. failed" }
+// { dg-message "static type .const P1. of its operand is a non-public base class of dynamic type .A." "" { target *-*-* } .-1 }
+constexpr bool b3 = (dynamic_cast<U&>((P2&)a), 0); // { dg-error "reference .dynamic_cast. failed" }
+// { dg-message "static type .const P2. of its operand is a non-public base class of dynamic type .A." "" { target *-*-* } .-1 }
+
+static_assert (dynamic_cast<U*>((B*)&a) == nullptr);
+static_assert (dynamic_cast<U*>((P1*)&a) == nullptr);
+static_assert (dynamic_cast<U*>((P2*)&a) == nullptr);