Close, but not quite. It really should have at least a `Throwable next = null` as its final parameter, and what it should really be is

    this(string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null)
    {
        super(msg, file, line);
    }

    this(string msg, Throwable next, string file = __FILE__, size_t line = __LINE__)
    {
        super(msg, file, line, next);
    }

It might be a good idea to create a mixin for that, but then it wouldn't show up in the API (though in this case, you aren't documenting the constructor anyway).