fun: (forward s1 : std::string, forward s2 : std::string, forward s3 : std::string) = {
    std::cout << s1 << s2 << s3 << std::endl;
}

main: () = {
    b : std::string = "b";
    c : std::string = "c";
    fun(std::string("a"), b, c);
    b = "";
}