Hallo, Fernando. Your recent change to optional.hpp was apparently too much for the Borland compilers. The enclosed patch should set things straight. Cheers, Nicola Musatti ******Index: optional.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/optional/optional.hpp,v retrieving revision 1.9.2.1 diff -d -u -r1.9.2.1 optional.hpp --- optional.hpp 8 Jun 2006 01:39:40 -0000 1.9.2.1 +++ optional.hpp 8 Jun 2006 07:53:42 -0000 @@ -133,7 +133,11 @@ { private : +#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) + typedef BOOST_DEDUCED_TYPENAME boost::detail::make_reference_content<T>::type internal_type ; +#else typedef BOOST_DEDUCED_TYPENAME ::boost::detail::make_reference_content<T>::type internal_type ; +#endif typedef aligned_storage<internal_type> storage_type ;