Convert a vector to initializer_list

Question

Everyone creates std::vector from std::initializer_list, but what about the other way around?

eg. if you use a std::initializer_list

Answer 1

If you don't mind copies, then I think something like this would work:

template
using iterator_init_list = std::initializer_list::value_type>;

template
iterator_init_list to_initializer_list(Iterator start, Iterator last, Ts... xs)
{
    if (start == last) return iterator_init_list{xs...};
    else return to_initializer_list(start+1, last, xs..., *start);
}