Avoid inheritance for final types in compressed_pair

test/compressed_pair_final_test.cpp

@@ -0,0 +1,55 @@
+/*
+Copyright 2018 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/config.hpp>
+#if !defined(BOOST_NO_CXX11_FINAL)
+#include <boost/compressed_pair.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+struct type1 {
+    operator bool() const {
+        return false;
+    }
+};
+
+struct type2 final {
+    operator bool() const {
+        return false;
+    }
+};
+
+#if !defined(BOOST_IS_FINAL)
+namespace boost {
+
+template<>
+struct is_final<type2>
+    : true_type { };
+
+} /* boost*/
+#endif
+
+template<class T1, class T2>
+void test()
+{
+    boost::compressed_pair<T1, T2> p;
+    BOOST_TEST(!p.first());
+    BOOST_TEST(!p.second());
+}
+
+int main()
+{
+    test<type1, type2>();
+    test<type2, type1>();
+    test<type2, type2>();
+    return boost::report_errors();
+}
+#else
+int main()
+{
+    return 0;
+}
+#endif