Given this code which is suggested by David Abraham.... template <class T, class U> char (& is_op_test(boost::operators<T,U> const&) )[2]; template <class T> char is_op_test(T const&); template<class T> T const& make(); template <class T> struct is_operators : boost::mpl::bool_<(sizeof(is_op_test(make<T>())) == 2)> {}; and this function declaration. template <typename T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT

typename boost::enable_if<boost::mpl::or_<boost::is_integral<T>, boost::is_operators<T> >, CONT<T> >::type primelist(const T& MAX_BOUND, const T& K, boost::function<bool(const T&, const T&)> f); I compile with T = int and it works. When i compile with T = BigInteger I get the following errors. ./cs512/c++/primeMain.cpp(78) : error C2770: invalid explicit template argument(s) for 'boost::enable_if<boost::mpl::or_<boost::is_integral<T>,boost::is_operators<T>

,CONT<T>>::type primelist(const T &,const T &,boost::function<bool(const T &,const T &)>)' ./cs512/c++/primeMain.cpp(24) : see declaration of 'primelist'"

BigInteger class declaration looks like this.. class BigInteger : public BigUnsigned, boost::operators<BigInteger>, boost::operators<BigInteger, int> { }; thanks for the help.