§2.3.4.(c) Actual ambiguity

At runtime actual ambiguity may occur if for the dynamic type of a base to be lifted the conditions of (b) above hold accordingly. Actual ambiguity is only possible in cases reported by the compiler as potential or definite ambiguity.

Example code (Actual Ambiguity):

import org.objectteams.LiftingFailedException;

team class MyTeam {

  public class SuperRole playedBy MyBase {...}

  public class SubRoleA extends SuperRole playedBy SubBase {...}

  public class SubRoleB extends SuperRole playedBy SubBase {...}

  public void useSuperRole(MyBase as SuperRole r) throws LiftingFailedException {...}

}

// plus these calls:

MyTeam mt = new MyTeam();

mt.useSuperRole(new SubBase()); // will throw a LiftingFailedException