-template <unsigned MinBits, unsigned MaxBits, boost::multiprecision::cpp_integer_type SignType, class Allocator, boost::multiprecision::expression_template_option ET>
-struct is_checked_cpp_int<boost::multiprecision::number<boost::multiprecision::cpp_int_backend<MinBits, MaxBits, SignType, boost::multiprecision::checked, Allocator>, ET> > : public boost::mpl::true_
+template <std::size_t MinBits, std::size_t MaxBits, boost::multiprecision::cpp_integer_type SignType, class Allocator, boost::multiprecision::expression_template_option ET>
+struct is_checked_cpp_int<boost::multiprecision::number<boost::multiprecision::cpp_int_backend<MinBits, MaxBits, SignType, boost::multiprecision::checked, Allocator>, ET> > : public std::integral_constant<bool, true>