exactlyOne<T> static method
Calculates the number of elements in exactly one of the sets.
This is equivalent to the symmetric difference cardinality.
Example:
final a = CustomSet<int>([1, 2, 3, 4]);
final b = CustomSet<int>([3, 4, 5, 6]);
print(CardinalityUtils.exactlyOne(a, b)); // Output: 4
Implementation
static int exactlyOne<T>(CustomSet<T> a, CustomSet<T> b) =>
symmetricDifferenceCardinality(a, b);