an example of zip for N.K.

ziptest.cc

#include <iostream>
#include <iterator>
#include <tuple>

template <typename C1, typename C2>
struct zip_container {
    C1& c1; C2& c2;
    typedef std::tuple<
        decltype(std::begin(c1)), decltype(std::begin(c2))
    > tuple;
    struct iterator: public std::iterator<
                        std::input_iterator_tag,
                        tuple,
                        std::ptrdiff_t,
                        const tuple*,
                        const tuple&> {
        tuple current;
        explicit iterator(const tuple& t) : current(t) {}
        iterator& operator++() {
            ++std::get<0>(current);
            ++std::get<1>(current);
            return *this;
        }
        iterator operator++(int) { iterator cp = *this; ++(*this); return cp;}
        bool operator==(iterator other) const { return current == other.current; }
        bool operator!=(iterator other) const { return !(*this == other); }
        tuple& operator*() {return current; }
    };
    iterator begin() { return iterator(tuple(std::begin(c1), std::begin(c2))); }
    iterator end() { return iterator(tuple(std::end(c1), std::end(c2))); }
    zip_container(C1& c1, C2& c2) : c1(c1), c2(c2) {}
};

template <typename C1, typename C2>
zip_container<C1, C2> zip(C1& c1, C2& c2) {
    return zip_container<C1, C2>(c1, c2);
}

int main() {
    int a[] { 1, 2, 3 };
    const char* b[] { "a", "b", "c" };
    for (auto& [av, bv] : zip(a,b)) {
        std::cout << *av << ' ' << *bv << '\n';
    }
}