co-traverse two ranges

co_traverse.cpp

#include <iostream>
#include <vector>
#include <array>
#include <algorithm>

void co_traverse(auto& range1, auto& range2, auto& binary_op)
{
    struct NullIterator
    {
        int value{};
        NullIterator& operator++(){ return *this; }
        int& operator*() { return value; }
    };

    std::transform(
        std::begin(range1),
        std::end(range1),
        std::begin(range2),
        NullIterator{}, [&](auto& a, auto& b){
            binary_op(a, b);
            return 0;
        });
}

void foo(int a, int b)
{
    std::cout << a << " " << b << "\n";
}

int main()
{
    std::vector v1{1,2,3,4,5};
    std::array a1{6,7,8,9,10};

    co_traverse(v1, a1, foo);
}