Implicit garbage collection in Ada systems

[dritz@ANTARES.MCS.ANL.GOV]

In a chapter that I am writing for a book, I would like to say that, whereas
Ada permits implicit garbage collection, not a single implementation of Ada
has it.  Is that correct, as far as you know?  (I mean fully general and
complete garbage collection, not just the freeing of the collection associated
with an access type when the scope of the type's declaration is exited.)

Actually, I need to say only that implicit garbage collection is not routinely
implemented, which is certainly true.  Such a statement justifies the strategy
chosen for a problem solution demonstrated in the chapter.  For added effect,
I would like to make a stronger statement.  I could hedge and say that I am not
aware of an Ada system that implements implicit (i.e., automatic) garbage
collection.  Can I do better and accurately say that no Ada system implements
it?  Does anyone know of a counterexample?

Ken Dritz
Argonne National Lab
dritz@mcs.anl.gov