Timer arduino

/*
** Made by Biduleohm
** 2016/05
*/

typedef uint32_t    ulong;

class           Timer
{
    public:
        ulong   time;

        Timer();
        void    reset();
        void    reset(ulong _duration);
        void    update();
        bool    hasEnded();
        bool    hasEnded(ulong _duration);

    private:
        ulong   start;
        ulong   duration;
};

Timer::Timer()
{
    this->reset();
}

void    Timer::reset()
{
    this->start = millis();
    this->time = 0;
    this->duration = 0;
}

void    Timer::reset(ulong _duration)
{
    this->start = millis();
    this->time = 0;
    this->duration = _duration;
}

void    Timer::update()
{
    ulong   current = millis();

    if (current < this->start) { // takes care of the overflow after ~50 days
        this->start = current;
    }
    this->time = current - this->start;
}

bool    Timer::hasEnded()
{
    return (this->time >= this->duration);
}

bool    Timer::hasEnded(ulong _duration)
{
    return (this->time >= _duration);
}