Hi, Is the following program supposed to compile with the new MPL? It works fine with boost 1.31, but apparantly fails in CVS. But, maybe I was mis-using equal_to ? #include <boost/mpl/equal_to.hpp> #include <boost/mpl/bool.hpp> int main() { boost::mpl::equal_to<boost::mpl::bool_<true>, boost::mpl::bool_<true> > dummy; } Error message from CVS is: (thanks to Matthias Troyer for testing it) ../boost/boost/mpl/aux_/preprocessed/gcc/equal_to.hpp: In instantiation of `boost::mpl::equal_to_tag<mpl_::bool_< true> >': ../boost/boost/mpl/aux_/preprocessed/gcc/equal_to.hpp:72: instantiated from `boost::mpl::equal_to<mpl_::bool_< true>, mpl_::bool_< true> >' test.C:11: instantiated from here ../boost/boost/mpl/aux_/preprocessed/gcc/equal_to.hpp:60: error: no type named `tag' in `struct mpl_::bool_< true>' ../boost/boost/mpl/aux_/preprocessed/gcc/equal_to.hpp: In instantiation of `boost::mpl::equal_to<mpl_::bool_< true>, mpl_::bool_< true> >': test.C:11: instantiated from here ../boost/boost/mpl/aux_/preprocessed/gcc/equal_to.hpp:72: error: no type named `type' in `struct boost::mpl::equal_to_tag<mpl_::bool_< true> >' Cheers, Ian