wsl.exe replacement for pre-1709 Windows builds

my_wsl.cc

#include <cstring>
#include <iostream>
#include <numeric>
#include <string>

extern "C" {
#include <process.h>
}

// Path of bash.exe executable
#define BASH_PATH "C:\\Windows\\System32\\bash.exe"

/**
  * Concatenate args given in arguments
  *
  * @precondition: args_len >= 1
  */
static auto join_args(char ** args, int args_len)
{
    return std::accumulate<char**, std::string>(
        args + 1,
        args + args_len,
        std::string(args[0]),
        [](auto a, auto b)
        {
            a += ' ';
            a += b;

            return a;
        }
    );
}

int main(int argc, char ** argv)
{
    using namespace std::string_literals;

    if (argc < 3 || argv[1] != "run"s)
    {
        std::cerr << "Usage: " << argv[0] << " run <cmd>" << std::endl;
        return 1;
    }

    auto joined_args = join_args(argv + 2, argc - 2);

    auto ret = _spawnl(_P_WAIT, BASH_PATH, BASH_PATH, "-c", ("test; " + joined_args).c_str(), nullptr);
    
    if (ret == -1)
    {
        std::cerr << "An error occured during call to " << std::endl;
        return 1;
    }

    return ret;
}

my_wsl.exe