[boost] [type_traits] is_convertible regression on GCC 3.2 and 3.3

Hi, The following code causes a static assertion failure on GCC 3.2 (MinGW): #include <boost/static_assert.hpp> #include <boost/type_traits/is_convertible.hpp> struct base { }; struct middle : virtual base { }; struct derived : middle { }; BOOST_STATIC_ASSERT((boost::is_convertible<derived, middle>::value)); This problem is apparently responsible for the current failure of all the iostreams tests on the platforms gcc-3.2.3 and gcc-3.3.5. Jonathan