#include<boost/function.hpp>
#include<boost/spirit/home/phoenix/core.hpp>
#include<boost/spirit/home/phoenix/bind.hpp>
#include<boost/spirit/home/phoenix/operator.hpp>
#include<boost/spirit/home/phoenix/scope.hpp>
#include<boost/spirit/home/phoenix/function.hpp>

struct divdoub_
{
    template <typename T, typename F>
    struct result { typedef T type; };
    
    template <typename T, typename F>
    T operator()(T x, F f) const
    {
        T doub = x * x;
        return f(doub) / 2;
    }
};

boost::phoenix::function<divdoub_> const divdoub = divdoub_();

using namespace std;

int main(){
    
	{
		using namespace boost::phoenix;
		using namespace boost::phoenix::arg_names;
		double const dos = 2.0;
        
        boost::function<double(double)> f
            = divdoub(_1, lambda[_1+1.0]);
        
        cout<< f(dos) << endl; // should return 2.5
	}
    return 0;
};