intordouble.cs

[StructLayout(LayoutKind.Explicit)]
public struct IntOrDouble
{
    private enum Type : byte
    {
        Integral,
        Floating
    }

    [FieldOffset(0)]
    private readonly Type _type;

    [FieldOffset(1)]
    private readonly int _intValue;

    [FieldOffset(1)]
    private readonly double _doubleValue;

    public IntOrDouble(int value) : this()
    {
        _type = Type.Integral;
        _intValue = value;
    }

    public IntOrDouble(double value) : this()
    {
        _type = Type.Floating;
        _doubleValue = value;
    }

    public void With(Action<int> intAction, Action<double> doubleAction)
    {
        switch (_type)
        {
        case Type.Integral:
            intAction(_intValue);
            break;
        case Type.Floating:
            doubleAction(_doubleValue);
            break;
        default:
            throw new Exception();
        }
    }

    public T Match<T>(Func<int, T> intFunc, Func<double, T> doubleFunc)
    {
        switch (_type)
        {
        case Type.Integral:
            return intFunc(_intValue);
        case Type.Floating:
            return doubleFunc(_doubleValue);
        default:
            throw new Exception();
        }
    }
}