Question

Whole enum iteration

foreach (Suit suit in Enum.GetValues(typeof(Suit)))
{
    // ...
}

But how To iterate a bitwise enum Instance?

Suit mySuits = Suit.Hearts | Suit.Diamonds;
// How to now iterate mySuits, which should loop twice instead of four times?

Answer 1

Assuming Suit is a bitwise enum with no overlapping values, then this would be sufficient:

var availableSuits = Enum.GetValues(typeof(Suit)).Cast<Enum>();
foreach (Suit suit in availableSuits.Where(mySuits.HasFlag)) {
    // ...
}

If it needs to be fast, or if it needs to ignore composite values or a zero value, then you should probably instead check successive powers of two in a for loop and identify which values match that way.