HP Integrity NonStop J-Series - Manual (Page 104)

Making a shallow copy and a deep copy of Bag would produce the following results:
You can see that the deep copy copies not only the bag itself, but recursively all objects within it.
The copying approach you choose is important. For example, shallow copies can be useful and fast,
because less copying is done, but you must be careful because two collections now reference the same
object. If you delete all the items in one collection, you will leave the other collection pointing into
nonsense.
You also need to consider the approach when writing an object to disk. If an object includes two or
more pointers or references to the same object, it is important to preserve this morphology when the
object is restored. Classes that inherit from
RWCollectable inherit algorithms that guarantee to preserve
an object's morphology. You'll see more on this in Chapter 14 .
Copying Value-based Collection Classes
Let us now contrast the results of copying the reference-based collection with the value-based
collection. Consider the class:
RWTValOrderedVector < RWCString >