Hello, is there a reason why there are only integral types in the boost MPL, no double or alike? http://www.boost.org/doc/libs/1_65_1/libs/mpl/doc/refmanual/numeric.html What is the best way to achieve: template<> struct getArg<Multiquadrics> : boost::mpl::double_<1e-3> {}; so that it is compatible with mpl::list? besides just writing the struct myself :-) Thanks, Florian