Zip-adaptor for use with C++17

Header only library for range-based for loop on a set of heterogeneous containers, any of which may be const or non-const.

Requirements

• A C++17 conforming compiler
• CMake for compiling tests

Usage

Copy only zip_adaptor.h and zip_adaptor.inl into your projects include directory. If desired define ZIP_NAMESPACE to your preferred namespace to find the zip_adaptor in, by default this will be zip. You may also want to define ZIP_VERBOSE to offer a more verbose zip_adaptor creation and avoid name clashing with your project. Use zip_adaptor as follows:

#include <zip_adaptor.h>

// Get the winning team based on pair-wise comparison of player scores
int getWinningTeam(std::vector<int> scoresA, std::vector<int> scoresB) {
    int winningTeam = 0;
    // If ZIP_VERBOSE is defined instead zip::make_zip_adaptor(...)
    // If ZIP_NAMESPACE is defined instead ZIP_NAMESPACE::zip(...)
    for (auto [a, b] : zip::zip(scoresA, scoresB)) {
        if (a > b) winningTeam--;
        else if (b > 0) winningTeam++;
    }
    return winningTeam;
}

You may use different types of containers as long as they support range-based for loops. i.e. they support a begin() and end() function:

#define ZIP_NAMESPACE
#include <zip_adaptor.h>

// Joins any type of container into a vector of tuples 
template<class... T>
auto join(T&&... containers) {
    // Skipping ZIP_NAMESPACE because it is defined without value
    auto zipped_containers = zip(std::forward<T>(containers)...);

    using zipped_type = decltype(zipped_containers);
    using zipped_value_type = typename zipped_type::value_type;

    std::vector<zipped_value_type> joined_containers;
    joined_containers.reserve(zipped_containers.size());
    for (auto zipped : zipped_containers)
        joined_containers.push_back(zipped);
    return joined_containers; 
}

Features

Zip-adaptor supports the following features:

• Creating a zipped range from heterogeneous container types
• Creating a zipped range from const as well as non-const container types
• Creating a zipped range from rvalues as well as lvalues
• Erasing out of a zipped range
• Throws std::length_error if attempting to zip ranges of different sizes
• Fully constexpr qualified
• Compiles and runs on MSVC, gcc and clang

Tests

To compile tests follow the following commands in a bash console opened in the repository:

mkdir build
cd build
cmake .. -G"MSYS Makefiles" # Or another generator of your choice
cmake --build .
cmd.exe /c zip_adaptor_test.exe # Or execution appropriate for your platform

Tests were compiled and executed on Windows 10 using Visual Studio 2017 as well as clang 7.0.0 and gcc 8.2.0 with MSYS2.