Trying to use Boost.Parameter as Daniel showed. Wow, that's truly hairy stuff. Obviously I get it wrong somewhere as matching Parameters constructor cannot be found. I am trying to call int ii = convert_to<int>("1", boost::convert_parameters::default_ = -1); when I have declarations below as (I think) Daniel indicated. namespace convert_parameters { BOOST_PARAMETER_NAME((from_, tag) from_) BOOST_PARAMETER_NAME((default_, tag) default_) } template<class TypeOut, class ArgumentPack> TypeOut test(ArgumentPack const& args) { return TypeOut(); } template< class TypeOut, class TypeIn, class A0> convert<TypeIn, TypeOut> convert_to(TypeIn const& value_in, A0 const& a0) { typedef parameter::parameters<parameter::required<convert_parameters::tag::from_>
Parameters;
return test<TypeOut>(Parameters(value_in, a0)); } Any help? Please? Thanks, Vladimir.