#include <boost/parameter.hpp>
#include <iostream>

using namespace boost::parameter;

BOOST_PARAMETER_NAME(arg1)
BOOST_PARAMETER_NAME(arg2)

struct callable2
{
    BOOST_PARAMETER_CONST_FUNCTION_CALL_OPERATOR(
        (void), tag, (required (arg1,(int))(arg2,(int)))
    )
    {
        std::cout << arg1 << ", " << arg2 << std::endl;
    }
};

#include <boost/core/lightweight_test.hpp>

int main()
{
    callable2 c2;
    callable2 const& c2_const = c2;
    c2_const(1, 2);
    return boost::report_errors();
}