interface ICalculator<T>
{
    T compute(T a, T b);
}

struct Adder : ICalculator<float>
{
    float compute(float a, float b) { return a + b; }
}

struct Multiplier : ICalculator<float>
{
    float compute(float a, float b) { return a * b; }
}

ICalculator<float> makeCalc(int id)
{
    if (id == 0) return Adder();
    else return Multiplier();
}

void test()
{
    ICalculator<float> calc = makeCalc(0);
    float result = calc.compute(3.0, 4.0);  // Should dispatch correctly
}