typedef void (*fptr)(void);
struct Mystruct
{
    int id;
    int priority;
    double timeSaved;
    double aktivationTime;
    fptr eventPointer;
    MystructnextPtr;

    Mystruct(int id, int priority, double timeSaved, double aktivationTime, fptr eventPointer);
};

bool operator <(const Mystruct& x, const Mystruct& y)
{
    return std::tie(x.aktivationTime, x.priority, x.timeSaved) < std::tie(y.aktivationTime, y.priority, y.timeSaved);
}

Mystruct* struct1 = new Mystruct(5, 10, 0, 15.3, f1);
Mystruct* struct2 = new Mystruct(5, 10, 0, 14.3, fi);

if (struct1 < struct2)
{
    cout << "struct1 is smaller!" << endl;
}
else
{
    cout << "struct2 is smaller!" << endl;
}