Add test for issue boostorg#69

test/Jamfile.v2

@@ -110,3 +110,5 @@ compile vector.cpp ;
 compile vector_c.cpp ;
 compile zip_view.cpp ;
 run string.cpp ;
+
+run issue_69.cpp ;

test/issue_69.cpp

@@ -0,0 +1,13 @@
+// Copyright 2024 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0. 
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/mpl/integral_c.hpp>
+
+enum test { zero, one };
+
+int main()
+{
+    boost::mpl::integral_c<test, zero> m;
+    return m.value;
+}