In Ruby, as in Java 8 or Scala, an interface (mix-in) can provide method code as well as signatures. (It can’t provide data members; that would be multiple inheritance.) Explain why dynamic typing...

In Ruby, as in Java 8 or Scala, an interface (mix-in) can provide method code as well as signatures. (It can’t provide data members; that would be multiple inheritance.) Explain why dynamic typing makes this feature more powerful than it is in the other languages. Return for a moment to Exercise 3.7. Build a (more complete) C++ version of the singly linked list library of Figure 3.16. Discuss the issue of storage management. Under what circumstances should one delete the elements of a list when deleting the list itself? What should the destructor for list_node do? Should it delete its data member? Should it recursively delete node next?