Re: garbage collection

[tmoran@bix.com]

> If an implementation doesn't provide garbage collection then that
> storage is forever lost, is that correct?

No.  When the access type goes out of scope there is clearly no way
the storage can be on the target end of a pointer, so the
implementation should free that storage.  With the 'Storage_Size
attribute on the access type, "the storage for the pool is reclaimed
when the master containing the declaration of the access type is
left".  If that's not soon enough, you have several options,
including:

1) Ada.Unchecked_Deallocation (the equivalent of "free"), if you are
careful not to deallocate and later refer to the same storage.

2) Use a controlled type so your Finalize routine can recycle storage.

3) Do your own storage management for the relevant types using the
Storage_Pool facility.  See Barnes, section 21.4 for a good
discussion of storage management.

4) The most straightforward way, as has been pointed out, is not to
use "new" unnecessarily.  Since you can declare dynamically sized
things inside a subroutine, and can nest subroutines, storage that
is allocated in a stack-like (first allocated is last deallocated)
style can normally be handled with simple declarations, without the
overhead or dangers of "new".  With tasks, you can even have several
separate stack-like allocations going on at once.