#include <iostream>
#include <vector>
#include <numeric>
#include <tr1/functional>

class X {
public:
    X(int i):m_i(i) { }
    static int plus(int i, X *x) {
        return i + x->m_i;
    }
    int get_i() const { return m_i; }
private:
    int m_i;
};

struct call_delete {
    template <typename T>
    void operator()(T *t) {
        delete t;
        t = 0;
    }
};

int operator+(int n, const X &x) { return n + x.get_i(); }

int main()
{
    std::vector<X*> x;
    x.push_back(new X(3));
    x.push_back(new X(5));
    std::cout << std::accumulate(x.begin(), x.end(), 2, X::plus) << std::endl;

    std::cout << std::accumulate(x.begin(), x.end(), 3,
        std::tr1::bind(std::plus<int>(), std::tr1::placeholders::_1,
            std::tr1::bind(&X::get_i, std::tr1::placeholders::_2))) << std::endl;

    std::for_each(x.begin(), x.end(), call_delete());

    std::vector<X> y;
    y.push_back(1);
    y.push_back(2);
    std::cout << std::accumulate(y.begin(), y.end(), 0) << std::endl;
}