[tutorial] functional zip()

#include <algorithm>
#include <iostream>
#include <vector>
#include <iomanip>
#include <functional>
#include <iterator>

template<typename Collection, typename unop>
void for_each(Collection col, unop op) {
    std::for_each(col.begin(), col.end(), op);
}

template<typename Collection, typename binop>
Collection zip(Collection fc, Collection src, binop op) {
    std::transform(fc.begin(), fc.end(), src.begin(), fc.begin(), op);
    return fc;
}

int main()
{
    auto println = [](const char *message) { std::cout << "\n" << message << '\n'; };
    auto lambda_echo = [](int i) { std::cout << std::setw(3) << i; };
    std::vector<int> col{ 23, 23, 37, 42, 23, 23, 37 };
    std::vector<int> another_col = {40, 22, 22, 24, 23, 45, 34};

    // collections addition
    auto zip_col = zip(col, another_col, std::plus<int>());
    println("running zip<T> operation");
    for_each(zip_col, lambda_echo);

    return 0;
}