How Can I Simulate Python's Zip Function for Simultaneous Looping in C 11 Using Boost?

Zip Function for Simulating Simultaneous Loops in C 11

The introduction of range-based for-loops in C 11 simplifies looping over elements in a container. However, the question arises if it's possible to replicate the functionality of Python's zip function, which allows looping over multiple sequences simultaneously.

Solution

There are several approaches to achieve this using Boost libraries:

Approach 1: Boost Combine (Boost 1.56.0 and Later)

Boost 1.56.0 introduced the boost::combine function. It allows combining multiple containers of different types into a single range:

#include <boost/range/combine.hpp>

int main() {
    std::vector<int> a = {1, 2, 3};
    std::vector<char> b = {'a', 'b', 'c'};

    for (const auto& [x, y] : boost::combine(a, b)) {
        std::cout << x << " " << y << std::endl;
    }
}

This code will output:

1 a
2 b
3 c

Approach 2: Boost Zip Iterator (Earlier Boost Versions)

Prior to Boost 1.56.0, the boost::zip_iterator and boost::range libraries can be used to implement a custom zip range:

#include <boost/iterator/zip_iterator.hpp>
#include <boost/range.hpp>

template <typename... T>
auto zip(const T&amp;&amp;... containers) {
    auto zip_begin = boost::make_zip_iterator(boost::make_tuple(std::begin(containers)...));
    auto zip_end = boost::make_zip_iterator(boost::make_tuple(std::end(containers)...));
    return boost::make_iterator_range(zip_begin, zip_end);
}

The usage remains the same:

int main() {
    std::vector<int> a = {1, 2, 3};
    std::vector<char> b = {'a', 'b', 'c'};

    for (const auto& [x, y] : zip(a, b)) {
        std::cout << x << " " << y << std::endl;
    }
}

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