--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-dynamic6.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,25 @@
+// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr.
+// { dg-do compile { target c++2a } }
+
+// Private base.
+
+struct P1 { virtual void p1(); };
+struct P2 { virtual void p2(); };
+struct B : private P1 { virtual void b(); };
+struct C { virtual void c(); };
+struct A : B, C, private P2 { virtual void a(); };
+
+constexpr A a;
+
+// P1 is a non-public base of A.
+constexpr bool b1 = (dynamic_cast<B&>((P1&)a), false); // { 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 }
+
+// Don't error here.
+static_assert (dynamic_cast<B*>((P1*)&a) == nullptr);
+
+constexpr bool b2 = (dynamic_cast<C&>((P2&)a), false); // { 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<C*>((P1*)&a) == nullptr);
+static_assert (dynamic_cast<C*>((P2*)&a) == nullptr);