Hello, The following legal snippet #include <boost/type_traits/is_convertible.hpp> #include <memory> class foo{}; typedef boost::is_convertible< const std::auto_ptr<const foo *>, const foo> type; int main() { bool b=type::value; } makes CW 9.x and 10.0 to fail with the following message (thanks to Noel Belcourt for his help in getting this): Error : function call '[std::auto_ptr<const foo *>].auto_ptr({lval} const std::auto_ptr<const foo *>)' does not match 'std::auto_ptr<const foo *>::auto_ptr(const foo **) throw()' (explicit) 'std::auto_ptr<const foo *>::auto_ptr(std::auto_ptr<const foo *> &) throw()' 'std::auto_ptr<const foo *>::auto_ptr<typename __T0>(std::auto_ptr<__T1_0> &) throw()' 'std::auto_ptr<const foo *>::auto_ptr(std::auto_ptr_ref<const foo *>) throw()' (point of instantiation: 'main()') (instantiating: 'boost::is_convertible<const std::auto_ptr<const foo *>, const foo>') (instantiating: 'boost::detail::is_convertible_impl_dispatch<const std::auto_ptr<const foo *>, const foo>') (instantiating: 'boost::detail::is_convertible_impl<const std::auto_ptr<const foo *>, const foo>') (instantiating: 'boost::detail::is_convertible_basic_impl<const std::auto_ptr<const foo *> &, const foo>') is_convertible.hpp line 204 ); (corresponding point of instantiation for 'boost::detail::is_convertible_basic_impl<const std::auto_ptr<const foo *> &, const foo>') is_convertible.hpp line 235 ); (corresponding point of instantiation for 'boost::detail::is_convertible_impl<const std::auto_ptr<const foo *>, const foo>') is_convertible.hpp line 301 : public is_convertible_impl_dispatch_base<From, To>::type (corresponding point of instantiation for 'boost::detail::is_convertible_impl_dispatch<const std::auto_ptr<const foo *>, const foo>') is_convertible.hpp line 348 BOOST_TT_AUX_BOOL_TRAIT_DEF2(is_convertible,From,To,(::boost::detail:: is_convertible_impl_dispatch<From,To>::value)) (corresponding point of instantiation for 'boost::is_convertible<const std::auto_ptr<const foo *>, const foo>') is_convertible.cpp line 12 bool b=type::value; Is there anything that can be done in boost::is_convertible to workaround this problem? I've inspected the code and seems like there's a variety of implementation methods to choose from, but being a complete stranger to Boost.TypeTraits I can't help much :( Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo