Add dll_test (to check for visibility issues)

test/Jamfile

@@ -276,3 +276,8 @@ run lw_thread_test.cpp : : : <threading>multi ;
 compile sp_windows_h_test.cpp ;
 compile spinlock_windows_h_test.cpp ;
 compile yield_k_windows_h_test.cpp ;
+
+lib dll_test : dll_test_lib.cpp : <link>shared:<define>DLL_TEST_DYN_LINK=1 ;
+
+run dll_test_main.cpp dll_test : : : <link>static : dll_test_static ;
+run dll_test_main.cpp dll_test : : : <link>shared : dll_test_shared ;

test/dll_test_lib.cpp

@@ -0,0 +1,20 @@
+// Copyright 2018 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/shared_ptr.hpp>
+#include <boost/config.hpp>
+
+#if defined(DLL_TEST_DYN_LINK)
+# define EXPORT BOOST_SYMBOL_EXPORT
+#else
+# define EXPORT
+#endif
+
+EXPORT boost::shared_ptr<int> dll_test()
+{
+    return boost::shared_ptr<int>( new int( 42 ) );
+}

test/dll_test_main.cpp

@@ -0,0 +1,20 @@
+// Copyright 2018 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/shared_ptr.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+boost::shared_ptr<int> dll_test();
+
+int main()
+{
+    boost::shared_ptr<int> p1 = dll_test();
+
+    BOOST_TEST_EQ( *p1, 42 );
+
+    return boost::report_errors();
+}