[C++14] Python's enumerate() in C++

enumerate.hpp

#pragma once

#include <iterator>

// Inspired by / taken from:
// https://stackoverflow.com/questions/11328264/python-like-loop-enumeration-in-c
// https://www.reedbeta.com/blog/python-like-enumerate-in-cpp17/

template<typename Iterable>
auto enumerate(Iterable&& iterable) {

    using Iterator = decltype(std::begin(std::declval<Iterable>()));
    using T = decltype(*std::declval<Iterator>());

    struct Enumerated {
        std::size_t index;
        T element;
    };

    struct Enumerator {
        Iterator iterator;
        std::size_t index;

        auto operator!=(const Enumerator& other) const {
            return iterator != other.iterator;
        }

        auto& operator++() {
            ++iterator;
            ++index;
            return *this;
        }

        auto operator*() const {
            return Enumerated{index, *iterator};
        }
    };

    struct Wrapper {
        Iterable& iterable;

        [[nodiscard]] auto begin() const {
            return Enumerator{std::begin(iterable), 0U};
        }

        [[nodiscard]] auto end() const {
            return Enumerator{std::end(iterable), 0U};
        }
    };

    return Wrapper{std::forward<Iterable>(iterable)};
}

main.cpp

#include "enumerate.hpp"

#include <vector>
#include <iostream>

int main() {
    std::vector<int> data{12, 89, 654, 123, 4587, 0};

    for (auto&& enumerated: enumerate(data)) {
        std::cout << "index = " << enumerated.index << " element = " << enumerated.element << '\n';
    }

    std::cout << "*----------------------" << '\n';

    for (auto&& enumerated: enumerate(data)) {
        enumerated.element *= 2;
    }

    std::cout << "*----------------------" << '\n';

    for (auto&& enumerated: enumerate(data)) {
        std::cout << "index = " << enumerated.index << " element = " << enumerated.element << '\n';
    }

    std::cout << "*----------------------" << '\n';

    // The following requires C++17 as it uses structured binding
    for (auto&&[index, character]: enumerate("bonjour")) {
        std::cout << "index = " << index << " element = " << character << '\n';
    }
}