For when you miss Ruby's map_with_index

gistfile1.cpp

template <typename InputIt1, typename InputIt2, typename BinaryFunction>
auto map_with_index(InputIt1 first, InputIt2 last, BinaryFunction f) -> vector<typename iterator_traits<InputIt1>::value_type>
{
    vector<typename iterator_traits<InputIt1>::value_type> result(distance(first, last));
    size_t i = 0;

    generate(begin(result), end(result), [&](){
        return f(*first++, i++);
    });

    return result;
}