Use Boost to get arity and paramerter types of member function? (boost::function_traits)

boost, c++, function, member

Solution

Boost Function Types would probably be the natural solution:

#include <boost/function_types/function_type.hpp>
#include <boost/function_types/parameter_types.hpp>
#include <boost/function_types/function_arity.hpp>
#include <boost/typeof/std/utility.hpp>
#include <boost/typeof/typeof.hpp>
#include <iostream>

struct bar {
    int foo(int, char) { return 0; }
};

int main() {

    typedef BOOST_TYPEOF(&bar::foo) foo_type;

    std::cout << typeid(foo_type).name() << std::endl;
    std::cout << boost::function_types::function_arity<foo_type>::value << std::endl;
    std::cout << typeid(boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,1>::type).name() << ",";
    std::cout << typeid(boost::mpl::at_c<boost::function_types::parameter_types<foo_type>,2>::type).name() << ",";

    return 0;
}

Problem

It works just fine, for plain vanilla functions. The code below works just fine. It prints just what is should: ``` int __cdecl(int, char) 2 int,char ``` ``` #include <boost/type_traits.hpp> #include <boost/function.hpp> #include <boost/typeof/std/utility.hpp> #include <iostream> using std::cout; using std::endl; int foo(int, char) { return 0; } int main() { typedef BOOST_TYPEOF(foo) foo_type;; typedef boost::function_traits<foo_type> function_traits; cout << typeid(foo_type).name() << endl; cout << function_traits::arity << endl; cout << typeid(function_traits::arg1_type).name() << ","; cout << typeid(function_traits::arg2_type).name() << endl; return 0; } ``` So, the question is, how can one do this if foo is a member function of class bar? ``` struct bar { int foo(int, char) { return 0; } }; ``` I have tried countless combinations of these constructs: BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP() BOOST_TYPEOF_REGISTER_TYPE() boost::ref boost::remove_pointer boost::bind boost::mem_fn etc., etc... No joy.

Original source