List of all instances of a class

[luni]

I added a helper class which automatically maintains a list of all currently existing instances of a class to my TeensyHelpers repository.

Such a thing comes in handy if you design a class which requires the user to call some update function on all instances periodically. Here detailed usage information https://github.com/luni64/TeensyHelpers#instancelist and here the instanceList source (header only): https://github.dev/luni64/TeensyHelpers/blob/master/src/instanceList/instanceList.h


The following code shows a simple example which implements a Blinker class which periodically toggles a pin. It shows how to call a member function (blink()) on all instances of the Blinker class:
To get the list of instances, all you need to do is to derive your class from the instanceList helper class:

class Blinker : protected InstanceList<Blinker>  // <- derive from InstanceList
{
 public:
    Blinker(int _pin, unsigned ms)
        : pin(_pin), period(ms * 1000)
    {
        pinMode(pin, OUTPUT);
    }

    void blink()
    {
        if (t > period)
        {
            digitalToggleFast(pin);
            t -= period;
        }
    }

    static void tick()
    {
        for (Blinker& b : instanceList) // for each Blinker b in the instance list
        {
            b.blink();
        }
    }

 private:
    elapsedMicros t;
    unsigned pin, period;
};

Usage:

Blinker b0(0, 10);
Blinker b1(1, 60);
Blinker b2(2, 24);
Blinker b3(3, 150);
Blinker LED(13, 500);

void setup()
{
}

void loop()
{
    Blinker::tick();
}

The tick() function will automatically call blink() on all currently existing instances of the Blinker class.